anderson accelation

initial filter
draft
2026-01-12 09:18:05 -08:00 · 2026-01-08 23:05:02 -08:00 · 2026-01-06 08:22:41 -08:00 · 2025-12-23 15:44:38 -08:00 · 2025-12-23 09:43:21 -08:00 · 2025-12-22 22:11:27 -08:00
163 changed files with 5110 additions and 13286 deletions
@@ -313,8 +313,6 @@ miniapps/nurbs/nurbs_ex1
 miniapps/nurbs/nurbs_ex1p
 miniapps/nurbs/nurbs_ex3
 miniapps/nurbs/nurbs_ex5
-miniapps/nurbs/nurbs_ex10
-miniapps/nurbs/nurbs_ex10p
 miniapps/nurbs/nurbs_ex11p
 miniapps/nurbs/nurbs_ex24
 miniapps/nurbs/nurbs_solenoidal
@@ -340,14 +338,7 @@ miniapps/nurbs/nurbs_naca_cmesh
 miniapps/nurbs/naca-cmesh.mesh
 miniapps/nurbs/glvis_naca-cmesh.mesh
 miniapps/nurbs/Naca_cmesh
-miniapps/nurbs/nurbs_mesh_info
-miniapps/nurbs/k*_*.dat
 miniapps/nurbs/*-Surface.mesh
-miniapps/nurbs/*.mesh
-miniapps/nurbs/*.sol
-miniapps/nurbs/deformed.*
-miniapps/nurbs/elastic_energy.*
-miniapps/nurbs/velocity.*

 miniapps/performance/ex1
 miniapps/performance/ex1p
@@ -369,7 +360,6 @@ miniapps/shifted/lsf_integral
 miniapps/tools/display-basis
 miniapps/tools/load-dc
 miniapps/tools/convert-dc
-miniapps/tools/compare-dc
 miniapps/tools/gridfunction-bounds
 miniapps/tools/lor-transfer
 miniapps/tools/plor-transfer
@@ -11,22 +11,6 @@
 Version 4.9.1 (development)
 ===========================

-Discretization improvements
---------------------------
- Improved the gridfunction projection routines. Projections work for Scalar,
-  Vector and VectorFE, also NURBS versions. Optionally different types of
-  projections can be selected, default behaviour has not changed.
-
-Meshing improvements
--------------------
- Improved support for 1D NURBS meshes with variable order, including using
-  the patches construct for 1D NURBS meshes.
-
-New and updated examples and miniapps
-------------------------------------
- Electromagnetics/lorentz miniapp has been updated to leverage the ParticleSet
-  capability.
-

 Version 4.9, released on Dec 11, 2025
 =====================================
@@ -111,23 +95,6 @@ Linear and nonlinear solvers
  Filtering (AMGF), providing robust preconditioning for linear systems arising
  in constrained optimization problems such as frictionless contact.

-  Added 'GetResiduals' and 'GetFinalAbsResidualNorm' to 'HyprePCG',
-  'HypreGMRES', and 'HypreFGMRES' to get 'r' and '|r|_p'. Note that the latter
-  computes '|r|_p' from 'r' instead of returning a cached value like the
-  relative 'GetFinalResidualNorm'. These require Hypre >= 2.15.0.
-
-  Changed the default solver parameters for 'HyprePCG' to 'tol=1e-6' and
-  'max_iter=1000'. This matches the default parameters in Hypre 3.0.
-
-  Added various helper functions for querying/modifying Hypre solvers:
-  'HypreSmoother::GetType', 'HypreSmoother::GetSOROptions',
-  'HypreSmoother::GetPolyOptions', 'HypreSmoother::GetWindowParameters',
-  'HypreSmoother::IsOperatorSymmetric', 'HyprePCG::GetTol',
-  'HyprePCG::GetAbsTol', 'HyprePCG::GetMaxIter', 'HyprePCG::SetUseTwoNorm',
-  'HypreGMRES::GetTol', 'HypreGMRES::GetAbsTol', 'HypreGMRES::GetMaxIter',
-  'HypreGMRES::GetKDim', 'HypreFGMRES::GetTol', 'HypreFGMRES::GetMaxIter',
-  'HypreFGMRES::GetKDim', and 'HypreBoomerAMG::GetMaxIter'.
-
 GPU computing
 -------------
 - Added the 'gpu', 'raja-gpu', and 'ceed-gpu' backend aliases/shortcuts which
@@ -723,7 +723,6 @@ set(MFEM_INSTALL_DIR ${CMAKE_INSTALL_PREFIX})

 # Declaring the library
 mfem_add_library(mfem ${SOURCES} ${HEADERS} ${MASTER_HEADERS})
-target_compile_features(mfem PUBLIC cxx_std_${CMAKE_CXX_STANDARD})
 # message(STATUS "TPL_LIBRARIES = ${TPL_LIBRARIES}")
 target_link_libraries(mfem PUBLIC ${TPL_LIBRARIES} ${TPL_TARGETS})
 if (TPL_TARGETS)
@@ -870,12 +869,11 @@ add_dependencies(exec
 #  - https://cmake.org/Bug/view.php?id=8438

 # Add a target to copy the mfem data directory to the build directory
-# Implementable as a single copy_directory_if_different command w/ CMake >= 3.26
-file(GLOB DATA_FILES CONFIGURE_DEPENDS ${PROJECT_SOURCE_DIR}/data/*)
-add_custom_target(copy_data
-  COMMAND ${CMAKE_COMMAND} -E make_directory data
-  COMMAND ${CMAKE_COMMAND} -E copy_if_different ${DATA_FILES} data
-  COMMENT "Syncing the data directory ...")
+add_custom_command(OUTPUT data_is_copied
+  COMMAND ${CMAKE_COMMAND} -E copy_directory ${PROJECT_SOURCE_DIR}/data data
+  COMMAND ${CMAKE_COMMAND} -E touch data_is_copied
+  COMMENT "Copying the data directory ...")
+add_custom_target(copy_data DEPENDS data_is_copied)
 # Add 'copy_data' as a prerequisite for all executables, if the source and the
 # build directories are not the same.
 if (NOT ("${PROJECT_SOURCE_DIR}" STREQUAL "${PROJECT_BINARY_DIR}"))
@@ -1007,10 +1005,6 @@ install(FILES
 install(EXPORT ${PROJECT_NAME_UC}Targets
    DESTINATION ${INSTALL_CMAKE_DIR})

-# Install the data directory if present, i.e. if the copy_data target is built
-install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/data
-  DESTINATION ${MFEM_INSTALL_DIR} OPTIONAL)
-
 #-------------------------------------------------------------------------------
 # Create 'config.mk' from 'config.mk.in' for the build and install locations and
 # define install rules for 'config.mk' and 'test.mk'
@@ -725,9 +725,7 @@ The specific libraries and their options are:
  URL: https://ginkgo-project.github.io
  Options: GINKGO_OPT, GINKGO_LIB, GINKGO_DIR, GINKGO_BUILD_TYPE (Release or
           Debug).
-  Versions: Ginkgo >= 1.9.0. When building Ginkgo with distributed support, a
-            recent version of the "develop" branch is required (1.11 as defined
-            in include/ginkgo/config.hpp).
+  Versions: Ginkgo >= 1.9.0.

 - AmgX (optional), used when MFEM_USE_AMGX = YES.
  URL: https://github.com/NVIDIA/AMGX
@@ -18,7 +18,6 @@
 # Some choices below are based on the OS type:
 NOTMAC := $(subst Darwin,,$(shell uname -s))

-ASTYLE_BIN = astyle
 ETAGS_BIN = $(shell command -v etags 2> /dev/null)
 EGREP_BIN = $(shell command -v egrep 2> /dev/null)

@@ -408,7 +407,7 @@ AMGX_LIB = -L$(AMGX_DIR)/lib -lamgx -lcusparse -lcusolver -lcublas -lnvToolsExt
 # MAGMA library configuration
 MAGMA_DIR = @MFEM_DIR@/../magma
 MAGMA_OPT = -I$(MAGMA_DIR)/include
-MAGMA_LIB = -L$(MAGMA_DIR)/lib -l:libmagma.a $(LAPACK_LIB)
+MAGMA_LIB = -L$(MAGMA_DIR)/lib -l:libmagma.a -lcublas -lcusparse $(LAPACK_LIB)

 # GnuTLS library configuration
 GNUTLS_OPT =
@@ -1,86 +0,0 @@
-MFEM NURBS mesh v1.0
-
-dimension
-1
-
-# Four segments with different NURBS orders, described via patches.
-elements
-4
-1 1 0 1
-2 1 2 3
-3 1 4 5
-4 1 6 7
-
-boundary
-0
-
-edges
-4
-0 0 1
-1 2 3
-2 4 5
-3 6 7
-
-vertices
-8
-
-patches
-
-# Patch 0: linear (order 1, 3 spans)
-knotvectors
-1
-1 4  0 0  .4 .6 1 1
-
-dimension
-2
-
-controlpoints
-0.0  0.0  1.0
-0.6  0.4  1.0
-0.4  0.6  1.0
-1.0  1.0  1.0
-
-# Patch 1: quadratic (order 2, 2 spans)
-knotvectors
-1
-2 4  0 0 0  .5 1 1 1
-
-dimension
-2
-
-controlpoints
-1.0  0.0  1.0
-1.9  0.0  1.21
-2.0  0.9  1.22
-2.0  1.0  1.0
-
-# Patch 2: cubic (order 3, 3 spans)
-knotvectors
-1
-3 6  0 0 0 0 .33 .66 1 1 1 1
-
-dimension
-2
-
-controlpoints
-2.0   0.0  1.0
-2.1   0.2  1.31
-3.5   0.4  1.32
-2.5   0.6  1.33
-2.9   1.0  1.34
-3.0   1.0  1.0
-
-# Patch 3: quartic (order 4, 1 span)
-knotvectors
-1
-4 5  0 0 0 0 0 1 1 1 1 1
-
-dimension
-2
-
-controlpoints
-3.0    0.0  1.0
-3.45   0.5  1.41
-3.50   1.0  1.42
-3.75   0.8  1.43
-4.0    0.0  1.0
@@ -1,79 +0,0 @@
-MFEM NURBS mesh v1.0
-
-#
-# MFEM Geometry Types (see fem/geom.hpp):
-#
-# SEGMENT     = 1
-# SQUARE      = 3
-# CUBE        = 5
-#
-
-dimension
-1
-
-# Three segments with different NURBS orders, described via patches.
-elements
-3
-1 1 0 1
-2 1 2 3
-3 1 4 5
-
-boundary
-6
-1 0 0
-1 0 1
-1 0 2
-1 0 3
-1 0 4
-1 0 5
-
-edges
-3
-0 0 1
-1 2 3
-2 4 5
-
-vertices
-6
-
-patches
-
-# Patch 0: linear (order 1, 2 control points)
-knotvectors
-1
-1 2  0 0  1 1
-
-dimension
-2
-
-controlpoints
-0.0  0.0  1.0
-1.0  1.0  1.0
-
-# Patch 1: quadratic (order 2, 3 control points)
-knotvectors
-1
-2 3  0 0 0  1 1 1
-
-dimension
-2
-
-controlpoints
-1.0  0.0   1.0
-1.02 1.02  1.2
-2.0  1.0   1.0
-
-# Patch 2: cubic (order 3, 4 control points)
-knotvectors
-1
-3 4  0 0 0 0  1 1 1 1
-
-dimension
-2
-
-controlpoints
-2.0   0.0   1.0
-2.03  0.83  1.31
-2.33  1.03  1.32
-3.0   1.0   1.0
-
@@ -1,72 +0,0 @@
-MFEM NURBS mesh v1.0
-
-#
-# MFEM Geometry Types (see fem/geom.hpp):
-#
-# SEGMENT     = 1
-# SQUARE      = 3
-# CUBE        = 5
-#
-
-dimension
-1
-
-elements
-3
-1 1 0 1
-2 1 2 3
-3 1 4 5
-
-boundary
-6
-1 0 0
-1 0 1
-1 0 2
-1 0 3
-1 0 4
-1 0 5
-
-edges
-3
-0 0 1
-1 2 3
-2 4 5
-
-vertices
-6
-
-# Edge 0: linear (order 1, 2 control points)
-# Edge 1: quadratic (order 2, 3 control points)
-# Edge 2: cubic (order 3, 4 control points)
-knotvectors
-3
-1 2  0 0  1 1
-2 3  0 0 0  1 1 1
-3 4  0 0 0 0  1 1 1 1
-
-# One weight per control point, in the same order as the control points; (2 + 3 + 4) = 9 weights total
-weights
-1
-1
-1
-1
-1
-1
-1.2
-1.31
-1.32
-
-FiniteElementSpace
-FiniteElementCollection: NURBS
-VDim: 2
-Ordering: 1
-
-0.0  0.0
-1.0  1.0
-1.0  0.0
-2.0  1.0
-2.0  0.0
-3.0  1.0
-1.02 1.02
-2.03 0.83
-2.33 1.03
@@ -1,79 +0,0 @@
-MFEM NURBS mesh v1.0
-
-#
-# MFEM Geometry Types (see fem/geom.hpp):
-#
-# SEGMENT     = 1
-# SQUARE      = 3
-# CUBE        = 5
-#
-
-dimension
-1
-
-# Three segments with different NURBS orders, described via patches.
-elements
-3
-1 1 0 1
-2 1 2 3
-3 1 4 5
-
-boundary
-6
-1 0 0
-1 0 1
-1 0 2
-1 0 3
-1 0 4
-1 0 5
-
-edges
-3
-0 0 1
-1 2 3
-2 4 5
-
-vertices
-6
-
-patches
-
-# Patch 0: linear (order 1, 2 control points)
-knotvectors
-1
-1 2  0 0  1 1
-
-dimension
-3
-
-controlpoints
-0.0  0.0  0.01 1.0
-1.0  1.0  1.01 1.0
-
-# Patch 1: quadratic (order 2, 3 control points)
-knotvectors
-1
-2 3  0 0 0  1 1 1
-
-dimension
-3
-
-controlpoints
-1.0  0.0   0.02 1.0
-1.02 1.02  0.52 1.2
-2.0  1.0   1.02 1.0
-
-# Patch 2: cubic (order 3, 4 control points)
-knotvectors
-1
-3 4  0 0 0 0  1 1 1 1
-
-dimension
-3
-
-controlpoints
-2.0   0.0   0.03 1.0
-2.03  0.83  0.33 1.31
-2.33  1.03  0.63 1.32
-3.0   1.0   1.03 1.0
-
@@ -1,72 +0,0 @@
-MFEM NURBS mesh v1.0
-
-#
-# MFEM Geometry Types (see fem/geom.hpp):
-#
-# SEGMENT     = 1
-# SQUARE      = 3
-# CUBE        = 5
-#
-
-dimension
-1
-
-elements
-3
-1 1 0 1
-2 1 2 3
-3 1 4 5
-
-boundary
-6
-1 0 0
-1 0 1
-1 0 2
-1 0 3
-1 0 4
-1 0 5
-
-edges
-3
-0 0 1
-1 2 3
-2 4 5
-
-vertices
-6
-
-# Edge 0: linear (order 1, 2 control points)
-# Edge 1: quadratic (order 2, 3 control points)
-# Edge 2: cubic (order 3, 4 control points)
-knotvectors
-3
-1 2  0 0  1 1
-2 3  0 0 0  1 1 1
-3 4  0 0 0 0  1 1 1 1
-
-# One weight per control point, in the same order as the control points; (2 + 3 + 4) = 9 weights total
-weights
-1
-1
-1
-1
-1
-1
-1.2
-1.31
-1.32
-
-FiniteElementSpace
-FiniteElementCollection: NURBS
-VDim: 3
-Ordering: 1
-
-0.0  0.0   0.01
-1.0  1.0   1.01
-1.0  0.0   0.02
-2.0  1.0   1.02
-2.0  0.0   0.03
-3.0  1.0   1.03
-1.02 1.02  0.52
-2.03 0.83  0.33
-2.33 1.03  0.63
@@ -190,8 +190,6 @@ namespace mfem {
 *  <a class="el" href="nurbs__ex1p_8cpp_source.html">1p</a>,
 *  <a class="el" href="nurbs__ex3_8cpp_source.html">3</a>,
 *  <a class="el" href="nurbs__ex5_8cpp_source.html">5</a>,
- *  <a class="el" href="nurbs__ex10_8cpp_source.html">10</a>,
- *  <a class="el" href="nurbs__ex10p_8cpp_source.html">10p</a>,
 *  <a class="el" href="nurbs__ex11p_8cpp_source.html">11p</a>, and
 *  <a class="el" href="nurbs__ex24_8cpp_source.html">24</a>,
 *   demonstrating howto perform NURBS-based Isogeometric Analysis.
@@ -200,7 +198,6 @@ namespace mfem {
 * - <a class="el" href="nurbs__curveint_8cpp_source.html">NURBS Interpolation</a>: NURBS interpolation of given geometry
 * - <a class="el" href="nurbs__naca__cmesh_8cpp_source.html">NURBS NACA Mesher</a>: generate NURBS based mesh around a NACA foil
 * - <a class="el" href="nurbs__printfunc_8cpp_source.html">NURBS Printer</a>: print the NURBS-basis
- * - <a class="el" href="nurbs__mesh_info_8cpp_source.html">NURBS Mesh info</a>: print the info of a NURBS mesh
 *
 * <H3>Miniapps</H3>
 * - <a class="el" href="volta_8cpp_source.html">Volta</a>: simple electrostatics simulation code
@@ -105,7 +105,6 @@ int main(int argc, char *argv[])
   bool visualization = true;
   bool visit = false;
   int vis_steps = 5;
-   bool solve_implicit_state = false;

   int precision = 8;
   cout.precision(precision);
@@ -127,9 +126,6 @@ int main(int argc, char *argv[])
                  "Alpha coefficient.");
   args.AddOption(&kappa, "-k", "--kappa",
                  "Kappa coefficient offset.");
-   args.AddOption(&solve_implicit_state, "-imp-state", "--implicit-state",
-                  "-imp-slope", "--implicit-slope",
-                  "Implicitly solve for stage state or slope.");
   args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
                  "--no-visualization",
                  "Enable or disable GLVis visualization.");
@@ -183,11 +179,6 @@ int main(int argc, char *argv[])

   // 7. Initialize the conduction operator and the visualization.
   ConductionOperator oper(fespace, alpha, kappa, u);
-   using ImplicitVariableType = ConductionOperator::ImplicitVariableType;
-   ImplicitVariableType imp_var = solve_implicit_state ?
-                                  ImplicitVariableType::STATE
-                                  : ImplicitVariableType::SLOPE;
-   oper.SetImplicitVariableType(imp_var);

   u_gf.SetFromTrueDofs(u);
   {
@@ -325,14 +316,11 @@ void ConductionOperator::Mult(const Vector &u, Vector &du_dt) const
 }

 void ConductionOperator::ImplicitSolve(const real_t dt,
-                                       const Vector &u, Vector &k)
+                                       const Vector &u, Vector &du_dt)
 {
   // Solve the equation:
-   //    M*k = -K(u + dt*k) for k = du/dt, if solving for stage-slope
-   // or
-   //    M*k = -dt*K(k) + M*u for k = u_s, if solving for stage-state
-   // where K is linearized by using u from the previous timestep, and
-   // the stage-state and slope relation: du/dt = (u_s - u)/dt.
+   //    du_dt = M^{-1}*[-K(u + dt*du_dt)]
+   // for du_dt, where K is linearized by using u from the previous timestep
   if (!T)
   {
      T = Add(1.0, Mmat, dt, Kmat);
@@ -340,20 +328,9 @@ void ConductionOperator::ImplicitSolve(const real_t dt,
      T_solver.SetOperator(*T);
   }
   MFEM_VERIFY(dt == current_dt, ""); // SDIRK methods use the same dt
-
-   // Construct current right-hand side for stage state vs. slope solve
-   if (ImplicitVarTypeIsState())
-   {
-      // k, on return, is the stage value u_s
-      Mmat.Mult(u, z);
-   }
-   else
-   {
-      // k, on return, is the stage slope du/dt
-      Kmat.Mult(u, z);
-      z.Neg();
-   }
-   T_solver.Mult(z, k);
+   Kmat.Mult(u, z);
+   z.Neg();
+   T_solver.Mult(z, du_dt);
 }

 void ConductionOperator::SetParameters(const Vector &u)
@@ -115,7 +115,6 @@ int main(int argc, char *argv[])
   bool visit = false;
   int vis_steps = 5;
   bool adios2 = false;
-   bool solve_implicit_state = false;

   int precision = 8;
   cout.precision(precision);
@@ -139,9 +138,6 @@ int main(int argc, char *argv[])
                  "Alpha coefficient.");
   args.AddOption(&kappa, "-k", "--kappa",
                  "Kappa coefficient offset.");
-   args.AddOption(&solve_implicit_state, "-imp-state", "--implicit-state",
-                  "-imp-slope", "--implicit-slope",
-                  "Implicitly solve for stage state or slope.");
   args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
                  "--no-visualization",
                  "Enable or disable GLVis visualization.");
@@ -216,11 +212,6 @@ int main(int argc, char *argv[])

   // 9. Initialize the conduction operator and the VisIt visualization.
   ConductionOperator oper(fespace, alpha, kappa, u);
-   using ImplicitVariableType = ConductionOperator::ImplicitVariableType;
-   ImplicitVariableType imp_var = solve_implicit_state ?
-                                  ImplicitVariableType::STATE
-                                  : ImplicitVariableType::SLOPE;
-   oper.SetImplicitVariableType(imp_var);

   u_gf.SetFromTrueDofs(u);
   {
@@ -416,14 +407,11 @@ void ConductionOperator::Mult(const Vector &u, Vector &du_dt) const
 }

 void ConductionOperator::ImplicitSolve(const real_t dt,
-                                       const Vector &u, Vector &k)
+                                       const Vector &u, Vector &du_dt)
 {
   // Solve the equation:
-   //    M*k = -K(u + dt*k) for k = du/dt, if solving for stage-slope
-   // or
-   //    M*k = -dt*K(k) + M*u for k = u_s, if solving for stage-state
-   // where K is linearized by using u from the previous timestep, and
-   // the stage-state and slope relation: du/dt = (u_s - u)/dt.
+   //    du_dt = M^{-1}*[-K(u + dt*du_dt)]
+   // for du_dt, where K is linearized by using u from the previous timestep
   if (!T)
   {
      T = Add(1.0, Mmat, dt, Kmat);
@@ -431,20 +419,9 @@ void ConductionOperator::ImplicitSolve(const real_t dt,
      T_solver.SetOperator(*T);
   }
   MFEM_VERIFY(dt == current_dt, ""); // SDIRK methods use the same dt
-
-   // Construct current right-hand side for stage state vs. slope solve
-   if (ImplicitVarTypeIsState())
-   {
-      // k, on return, is the stage value u
-      Mmat.Mult(u, z);
-   }
-   else
-   {
-      // k, on return, is the stage slope du/dt
-      Kmat.Mult(u, z);
-      z.Neg();
-   }
-   T_solver.Mult(z, k);
+   Kmat.Mult(u, z);
+   z.Neg();
+   T_solver.Mult(z, du_dt);
 }

 void ConductionOperator::SetParameters(const Vector &u)
@@ -119,7 +119,7 @@ int main(int argc, char *argv[])
   }

   LinearForm b(&fespace);
-   b.AddBoundaryIntegrator(new VectorBoundaryLFIntegrator(f));
+   b.AddDomainIntegrator(new VectorBoundaryLFIntegrator(f));

   // 6. Set up the bilinear form a(.,.) on the finite element space
   //    corresponding to the linear elasticity integrator with piece-wise
@@ -140,7 +140,7 @@ int main(int argc, char *argv[])
   }

   ParLinearForm b(&fespace);
-   b.AddBoundaryIntegrator(new VectorBoundaryLFIntegrator(f));
+   b.AddDomainIntegrator(new VectorBoundaryLFIntegrator(f));

   // 6. Set up the bilinear form a(.,.) on the finite element space
   //    corresponding to the linear elasticity integrator with piece-wise
@@ -9,7 +9,6 @@
 //               ex4 -m ../data/beam-hex.mesh -o 2 -pa
 //               ex4 -m ../data/escher.mesh
 //               ex4 -m ../data/fichera.mesh -o 2 -hb
-//               ex4 -m ../data/fichera.mesh -o 2 -hb -ea
 //               ex4 -m ../data/fichera-q2.vtk
 //               ex4 -m ../data/fichera-q3.mesh -o 2 -sc
 //               ex4 -m ../data/square-disc-nurbs.mesh
@@ -19,7 +18,6 @@
 //               ex4 -m ../data/amr-quad.mesh
 //               ex4 -m ../data/amr-hex.mesh
 //               ex4 -m ../data/amr-hex.mesh -o 2 -hb
-//               ex4 -m ../data/amr-hex.mesh -o 2 -hb -ea
 //               ex4 -m ../data/fichera-amr.mesh -o 2 -sc
 //               ex4 -m ../data/ref-prism.mesh -o 1
 //               ex4 -m ../data/octahedron.mesh -o 1
@@ -27,8 +25,6 @@
 //
 // Device sample runs:
 //               ex4 -m ../data/star.mesh -pa -d cuda
-//               ex4 -m ../data/star.mesh -hb -ea -d cuda
-//               ex4 -m ../data/amr-quad.mesh -hb -ea -d cuda
 //               ex4 -m ../data/star.mesh -pa -d raja-cuda
 //               ex4 -m ../data/star.mesh -pa -d raja-omp
 //               ex4 -m ../data/beam-hex.mesh -pa -d cuda
@@ -197,7 +193,7 @@ int main(int argc, char *argv[])
   cout << "Size of linear system: " << A->Height() << endl;

   // 11. Solve the linear system A X = B.
-   if (!pa && (!ea || hybridization))
+   if (!pa)
   {
 #ifndef MFEM_USE_SUITESPARSE
      // Use a simple symmetric Gauss-Seidel preconditioner with PCG.
@@ -9,7 +9,6 @@
 //               mpirun -np 4 ex4p -m ../data/beam-hex.mesh -o 2 -pa
 //               mpirun -np 4 ex4p -m ../data/escher.mesh -o 2 -sc
 //               mpirun -np 4 ex4p -m ../data/fichera.mesh -o 2 -hb
-//               mpirun -np 4 ex4p -m ../data/fichera.mesh -o 2 -hb -ea
 //               mpirun -np 4 ex4p -m ../data/fichera-q2.vtk
 //               mpirun -np 4 ex4p -m ../data/fichera-q3.mesh -o 2 -sc
 //               mpirun -np 4 ex4p -m ../data/square-disc-nurbs.mesh -o 3
@@ -18,18 +17,14 @@
 //               mpirun -np 4 ex4p -m ../data/periodic-cube.mesh -no-bc
 //               mpirun -np 4 ex4p -m ../data/amr-quad.mesh
 //               mpirun -np 3 ex4p -m ../data/amr-quad.mesh -o 2 -hb
-//               mpirun -np 3 ex4p -m ../data/amr-quad.mesh -o 2 -hb -ea
 //               mpirun -np 4 ex4p -m ../data/amr-hex.mesh -o 2 -sc
 //               mpirun -np 4 ex4p -m ../data/amr-hex.mesh -o 2 -hb
-//               mpirun -np 4 ex4p -m ../data/amr-hex.mesh -o 2 -hb -ea
 //               mpirun -np 4 ex4p -m ../data/ref-prism.mesh -o 1
 //               mpirun -np 4 ex4p -m ../data/octahedron.mesh -o 1
 //               mpirun -np 4 ex4p -m ../data/star-surf.mesh -o 3 -hb
 //
 // Device sample runs:
 //               mpirun -np 4 ex4p -m ../data/star.mesh -pa -d cuda
-//               mpirun -np 4 ex4p -m ../data/star.mesh -ea -hb -d cuda
-//               mpirun -np 4 ex4p -m ../data/amr-hex.mesh -ea -hb -d cuda
 //               mpirun -np 4 ex4p -m ../data/star.mesh -pa -d raja-cuda
 //               mpirun -np 4 ex4p -m ../data/star.mesh -pa -d raja-omp
 //               mpirun -np 4 ex4p -m ../data/beam-hex.mesh -pa -d cuda
@@ -235,7 +230,7 @@ int main(int argc, char *argv[])
   pcg->SetMaxIter(2000);
   pcg->SetPrintLevel(1);
   if (hybridization) { prec = new HypreBoomerAMG(*A.As<HypreParMatrix>()); }
-   else if (pa || ea) { prec = new OperatorJacobiSmoother(*a, ess_tdof_list); }
+   else if (pa) { prec = new OperatorJacobiSmoother(*a, ess_tdof_list); }
   else
   {
      ParFiniteElementSpace *prec_fespace =
@@ -160,7 +160,6 @@ int main(int argc, char *argv[])
   bool paraview = false;
   bool binary = false;
   int vis_steps = 5;
-   bool solve_implicit_state = false;

   int precision = 8;
   cout.precision(precision);
@@ -188,9 +187,6 @@ int main(int argc, char *argv[])
                  "Final time; start time is 0.");
   args.AddOption(&dt, "-dt", "--time-step",
                  "Time step.");
-   args.AddOption(&solve_implicit_state, "-imp-state", "--implicit-state",
-                  "-imp-slope", "--implicit-slope",
-                  "Implicitly solve for stage state or slope.");
   args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
                  "--no-visualization",
                  "Enable or disable GLVis visualization.");
@@ -370,11 +366,6 @@ int main(int argc, char *argv[])
   //    right-hand side, and perform time-integration (looping over the time
   //    iterations, ti, with a time-step dt).
   FE_Evolution adv(m, k, b);
-   using ImplicitVariableType = FE_Evolution::ImplicitVariableType;
-   ImplicitVariableType imp_var = solve_implicit_state ?
-                                  ImplicitVariableType::STATE
-                                  : ImplicitVariableType::SLOPE;
-   adv.SetImplicitVariableType(imp_var);

   real_t t = 0.0;
   adv.SetTime(t);
@@ -468,17 +459,7 @@ void FE_Evolution::ImplicitSolve(const real_t dt, const Vector &x, Vector &k)
 {
   MFEM_VERIFY(dg_solver != NULL,
               "Implicit time integration is not supported with partial assembly");
-   // Construct current right-hand side for stage state vs. slope solve
-   if (ImplicitVarTypeIsState())
-   {
-      // k, on return, is the stage value u
-      M.Mult(x, z);
-   }
-   else
-   {
-      // k, on return, is the stage slope du/dt
-      K.Mult(x, z);
-   }
+   K.Mult(x, z);
   z += b;
   dg_solver->SetTimeStep(dt);
   dg_solver->Mult(z, k);
@@ -257,7 +257,6 @@ int main(int argc, char *argv[])
   bool adios2 = false;
   bool binary = false;
   int vis_steps = 5;
-   bool solve_implicit_state = false;
 #if MFEM_HYPRE_VERSION >= 21800
   PrecType prec_type = PrecType::AIR;
 #else
@@ -291,9 +290,6 @@ int main(int argc, char *argv[])
                  "Final time; start time is 0.");
   args.AddOption(&dt, "-dt", "--time-step",
                  "Time step.");
-   args.AddOption(&solve_implicit_state, "-imp-state", "--implicit-state",
-                  "-imp-slope", "--implicit-slope",
-                  "Implicitly solve for stage state or slope.");
   args.AddOption((int *)&prec_type, "-pt", "--prec-type", "Preconditioner for "
                  "implicit solves. 0 for ILU, 1 for pAIR-AMG.");
   args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
@@ -540,11 +536,6 @@ int main(int argc, char *argv[])
   //     right-hand side, and perform time-integration (looping over the time
   //     iterations, ti, with a time-step dt).
   FE_Evolution adv(*m, *k, *B, prec_type);
-   using ImplicitVariableType = FE_Evolution::ImplicitVariableType;
-   ImplicitVariableType imp_var = solve_implicit_state ?
-                                  ImplicitVariableType::STATE
-                                  : ImplicitVariableType::SLOPE;
-   adv.SetImplicitVariableType(imp_var);

   real_t t = 0.0;
   adv.SetTime(t);
@@ -685,17 +676,7 @@ FE_Evolution::FE_Evolution(ParBilinearForm &M_, ParBilinearForm &K_,
 //    (M - dt*K) d = K*u + b
 void FE_Evolution::ImplicitSolve(const real_t dt, const Vector &x, Vector &k)
 {
-   // Construct current right-hand side for stage state vs. slope solve
-   if (ImplicitVarTypeIsState())
-   {
-      // k, on return, is the stage value u
-      M->Mult(x, z);
-   }
-   else
-   {
-      // k, on return, is the stage slope du/dt
-      K->Mult(x, z);
-   }
+   K->Mult(x, z);
   z += b;
   dg_solver->SetTimeStep(dt);
   dg_solver->Mult(z, k);
@@ -14,12 +14,6 @@ list(APPEND GINKGO_EXAMPLES_SRCS
  ex1.cpp
 )

-if (MFEM_USE_MPI AND GINKGO_BUILD_MPI)
-    list(APPEND GINKGO_EXAMPLES_SRCS
-    ex1p.cpp
-)
-endif()
-
 # Include the source directory where mfem.hpp and mfem-performance.hpp are.
 include_directories(BEFORE ${PROJECT_BINARY_DIR})

@@ -207,7 +207,7 @@ int main(int argc, char *argv[])
            Ginkgo::IcPreconditioner ginkgo_precond(exec, "paric", 30);
            Ginkgo::CGSolver ginkgo_solver(exec, ginkgo_precond);
            ginkgo_solver.SetPrintLevel(print_lvl);
-            ginkgo_solver.SetRelTol(sqrt(1e-12));
+            ginkgo_solver.SetRelTol(1e-12);
            ginkgo_solver.SetAbsTol(0.0);
            ginkgo_solver.SetMaxIter(400);
            ginkgo_solver.SetOperator(*(A.Ptr()));
@@ -225,7 +225,7 @@ int main(int argc, char *argv[])
            Ginkgo::MFEMPreconditioner gko_M(exec, M);
            Ginkgo::CGSolver ginkgo_solver(exec, gko_M);
            ginkgo_solver.SetPrintLevel(print_lvl);
-            ginkgo_solver.SetRelTol(sqrt(1e-12));
+            ginkgo_solver.SetRelTol(1e-12);
            ginkgo_solver.SetAbsTol(0.0);
            ginkgo_solver.SetMaxIter(400);
            ginkgo_solver.SetOperator(*(A.Ptr()));
@@ -283,7 +283,7 @@ int main(int argc, char *argv[])
               Ginkgo::MFEMPreconditioner gko_M(exec, M);
               Ginkgo::CGSolver ginkgo_solver(exec, gko_M);
               ginkgo_solver.SetPrintLevel(print_lvl);
-               ginkgo_solver.SetRelTol(sqrt(1e-12));
+               ginkgo_solver.SetRelTol(1e-12);
               ginkgo_solver.SetAbsTol(0.0);
               ginkgo_solver.SetMaxIter(400);
               ginkgo_solver.SetOperator(*(A.Ptr()));
@@ -1,436 +0,0 @@
-//                       MFEM Example 1 - Parallel Version
-//                             GINKGO Modification
-//
-// Compile with: make ex1p
-//
-// Sample runs:  mpirun -np 4 ex1p -m ../data/square-disc.mesh
-//               mpirun -np 4 ex1p -m ../data/star.mesh
-//               mpirun -np 4 ex1p -m ../data/star-mixed.mesh
-//               mpirun -np 4 ex1p -m ../data/escher.mesh
-//               mpirun -np 4 ex1p -m ../data/fichera.mesh
-//               mpirun -np 4 ex1p -m ../data/fichera-mixed.mesh
-//               mpirun -np 4 ex1p -m ../data/toroid-wedge.mesh
-//               mpirun -np 4 ex1p -m ../data/octahedron.mesh -o 1
-//               mpirun -np 4 ex1p -m ../data/periodic-annulus-sector.msh
-//               mpirun -np 4 ex1p -m ../data/periodic-torus-sector.msh
-//               mpirun -np 4 ex1p -m ../data/square-disc-p2.vtk -o 2
-//               mpirun -np 4 ex1p -m ../data/square-disc-p3.mesh -o 3
-//               mpirun -np 4 ex1p -m ../data/square-disc-nurbs.mesh -o -1
-//               mpirun -np 4 ex1p -m ../data/star-mixed-p2.mesh -o 2
-//               mpirun -np 4 ex1p -m ../data/disc-nurbs.mesh -o -1
-//               mpirun -np 4 ex1p -m ../data/pipe-nurbs.mesh -o -1
-//               mpirun -np 4 ex1p -m ../data/ball-nurbs.mesh -o 2
-//               mpirun -np 4 ex1p -m ../data/fichera-mixed-p2.mesh -o 2
-//               mpirun -np 4 ex1p -m ../data/star-surf.mesh
-//               mpirun -np 4 ex1p -m ../data/square-disc-surf.mesh
-//               mpirun -np 4 ex1p -m ../data/inline-segment.mesh
-//               mpirun -np 4 ex1p -m ../data/amr-quad.mesh
-//               mpirun -np 4 ex1p -m ../data/amr-hex.mesh
-//               mpirun -np 4 ex1p -m ../data/mobius-strip.mesh
-//               mpirun -np 4 ex1p -m ../data/mobius-strip.mesh -o -1 -sc
-//
-// Device sample runs:
-//               mpirun -np 4 ex1p -pa -d cuda
-//               mpirun -np 4 ex1p -fa -d cuda
-//               mpirun -np 4 ex1p -pa -d occa-cuda
-//               mpirun -np 4 ex1p -pa -d raja-omp
-//               mpirun -np 4 ex1p -pa -d ceed-cpu
-//               mpirun -np 4 ex1p -pa -d ceed-cpu -o 4 -a
-//               mpirun -np 4 ex1p -pa -d ceed-cpu -m ../data/square-mixed.mesh
-//               mpirun -np 4 ex1p -pa -d ceed-cpu -m ../data/fichera-mixed.mesh
-//             * mpirun -np 4 ex1p -pa -d ceed-cuda
-//             * mpirun -np 4 ex1p -pa -d ceed-hip
-//               mpirun -np 4 ex1p -pa -d ceed-cuda:/gpu/cuda/shared
-//               mpirun -np 4 ex1p -pa -d ceed-cuda:/gpu/cuda/shared -m ../data/square-mixed.mesh
-//               mpirun -np 4 ex1p -pa -d ceed-cuda:/gpu/cuda/shared -m ../data/fichera-mixed.mesh
-//               mpirun -np 4 ex1p -m ../data/beam-tet.mesh -pa -d ceed-cpu
-//
-// Description:  This example code demonstrates the use of MFEM to define a
-//               simple finite element discretization of the Laplace problem
-//               -Delta u = 1 with homogeneous Dirichlet boundary conditions.
-//               Specifically, we discretize using a FE space of the specified
-//               order, or if order < 1 using an isoparametric/isogeometric
-//               space (i.e. quadratic for quadratic curvilinear mesh, NURBS for
-//               NURBS mesh, etc.)
-//
-//               The example highlights the use of mesh refinement, finite
-//               element grid functions, as well as linear and bilinear forms
-//               corresponding to the left-hand side and right-hand side of the
-//               discrete linear system. We also cover the explicit elimination
-//               of essential boundary conditions, static condensation, and the
-//               optional connection to the GLVis tool for visualization.
-
-#include "mfem.hpp"
-#include <fstream>
-#include <iostream>
-
-#ifndef MFEM_USE_GINKGO
-#error This example requires that MFEM is built with MFEM_USE_GINKGO=YES
-#endif
-
-using namespace std;
-using namespace mfem;
-
-int main(int argc, char *argv[])
-{
-   // 1. Initialize MPI and HYPRE.
-   Mpi::Init();
-   int num_procs = Mpi::WorldSize();
-   int myid = Mpi::WorldRank();
-   Hypre::Init();
-
-   // 2. Parse command-line options.
-   const char *mesh_file = "../../data/star.mesh";
-   int order = 1;
-   bool static_cond = false;
-   bool pa = false;
-   bool fa = false;
-   const char *device_config = "cpu";
-   bool visualization = true;
-   int solver_config = 0;
-   int print_lvl = 1;
-
-   OptionsParser args(argc, argv);
-   args.AddOption(&mesh_file, "-m", "--mesh",
-                  "Mesh file to use.");
-   args.AddOption(&order, "-o", "--order",
-                  "Finite element order (polynomial degree) or -1 for"
-                  " isoparametric space.");
-   args.AddOption(&static_cond, "-sc", "--static-condensation", "-no-sc",
-                  "--no-static-condensation", "Enable static condensation.");
-   args.AddOption(&pa, "-pa", "--partial-assembly", "-no-pa",
-                  "--no-partial-assembly", "Enable Partial Assembly.");
-   args.AddOption(&fa, "-fa", "--full-assembly", "-no-fa",
-                  "--no-full-assembly", "Enable Full Assembly.");
-   args.AddOption(&device_config, "-d", "--device",
-                  "Device configuration string, see Device::Configure().");
-   args.AddOption(&visualization, "-vis", "--visualization", "-no-vis",
-                  "--no-visualization",
-                  "Enable or disable GLVis visualization.");
-   args.AddOption(&solver_config, "-s", "--solver-config",
-                  "Solver and preconditioner combination: \n\t"
-                  "   0 - Ginkgo solver and Ginkgo preconditioner, \n\t"
-                  "   1 - Ginkgo solver and MFEM preconditioner, \n\t"
-                  "   2 - MFEM solver and Ginkgo preconditioner, \n\t"
-                  "   3 - MFEM solver and MFEM preconditioner.");
-   args.AddOption(&print_lvl, "-pl", "--print-level",
-                  "Print level for iterative solver (1 prints every iteration).");
-   args.Parse();
-   if (!args.Good())
-   {
-      if (myid == 0)
-      {
-         args.PrintUsage(cout);
-      }
-      return 1;
-   }
-   if (myid == 0)
-   {
-      args.PrintOptions(cout);
-   }
-
-   // 3. Enable hardware devices such as GPUs, and programming models such as
-   //    CUDA, OCCA, RAJA and OpenMP based on command line options.
-   Device device(device_config);
-   device.SetGPUAwareMPI(true);
-   if (myid == 0) { device.Print(); }
-
-   // 4. Read the (serial) mesh from the given mesh file on all processors.  We
-   //    can handle triangular, quadrilateral, tetrahedral, hexahedral, surface
-   //    and volume meshes with the same code.
-   Mesh mesh(mesh_file, 1, 1);
-   int dim = mesh.Dimension();
-
-   // 5. Refine the serial mesh on all processors to increase the resolution. In
-   //    this example we do 'ref_levels' of uniform refinement. We choose
-   //    'ref_levels' to be the largest number that gives a final mesh with no
-   //    more than 10,000 elements.
-   {
-      int ref_levels =
-         (int)floor(log(10000./mesh.GetNE())/log(2.)/dim);
-      for (int l = 0; l < ref_levels; l++)
-      {
-         mesh.UniformRefinement();
-      }
-   }
-
-   // 6. Define a parallel mesh by a partitioning of the serial mesh. Refine
-   //    this mesh further in parallel to increase the resolution. Once the
-   //    parallel mesh is defined, the serial mesh can be deleted.
-   ParMesh pmesh(MPI_COMM_WORLD, mesh);
-   mesh.Clear();
-   {
-      int par_ref_levels = 2;
-      for (int l = 0; l < par_ref_levels; l++)
-      {
-         pmesh.UniformRefinement();
-      }
-   }
-
-   // 7. Define a parallel finite element space on the parallel mesh. Here we
-   //    use continuous Lagrange finite elements of the specified order. If
-   //    order < 1, we instead use an isoparametric/isogeometric space.
-   FiniteElementCollection *fec;
-   bool delete_fec;
-   if (order > 0)
-   {
-      fec = new H1_FECollection(order, dim);
-      delete_fec = true;
-   }
-   else if (pmesh.GetNodes())
-   {
-      fec = pmesh.GetNodes()->OwnFEC();
-      delete_fec = false;
-      if (myid == 0)
-      {
-         cout << "Using isoparametric FEs: " << fec->Name() << endl;
-      }
-   }
-   else
-   {
-      fec = new H1_FECollection(order = 1, dim);
-      delete_fec = true;
-   }
-   ParFiniteElementSpace fespace(&pmesh, fec);
-   HYPRE_BigInt size = fespace.GlobalTrueVSize();
-   if (myid == 0)
-   {
-      cout << "Number of finite element unknowns: " << size << endl;
-   }
-
-   // 8. Determine the list of true (i.e. parallel conforming) essential
-   //    boundary dofs. In this example, the boundary conditions are defined
-   //    by marking all the boundary attributes from the mesh as essential
-   //    (Dirichlet) and converting them to a list of true dofs.
-   Array<int> ess_tdof_list;
-   if (pmesh.bdr_attributes.Size())
-   {
-      Array<int> ess_bdr(pmesh.bdr_attributes.Max());
-      ess_bdr = 1;
-      fespace.GetEssentialTrueDofs(ess_bdr, ess_tdof_list);
-   }
-
-   // 9. Set up the parallel linear form b(.) which corresponds to the
-   //    right-hand side of the FEM linear system, which in this case is
-   //    (1,phi_i) where phi_i are the basis functions in fespace.
-   ParLinearForm b(&fespace);
-   ConstantCoefficient one(1.0);
-   b.AddDomainIntegrator(new DomainLFIntegrator(one));
-   b.Assemble();
-
-   // 10. Define the solution vector x as a parallel finite element grid
-   //     function corresponding to fespace. Initialize x with initial guess of
-   //     zero, which satisfies the boundary conditions.
-   ParGridFunction x(&fespace);
-   x = 0.0;
-
-   // 11. Set up the parallel bilinear form a(.,.) on the finite element space
-   //     corresponding to the Laplacian operator -Delta, by adding the
-   //     Diffusion domain integrator.
-   ParBilinearForm a(&fespace);
-   if (pa) { a.SetAssemblyLevel(AssemblyLevel::PARTIAL); }
-   if (fa)
-   {
-      a.SetAssemblyLevel(AssemblyLevel::FULL);
-      // Sort the matrix column indices when running on GPU or with OpenMP (i.e.
-      // when Device::IsEnabled() returns true). This makes the results
-      // bit-for-bit deterministic at the cost of somewhat longer run time.
-      a.EnableSparseMatrixSorting(Device::IsEnabled());
-   }
-   a.AddDomainIntegrator(new DiffusionIntegrator(one));
-
-   // 12. Assemble the parallel bilinear form and the corresponding linear
-   //     system, applying any necessary transformations such as: parallel
-   //     assembly, eliminating boundary conditions, applying conforming
-   //     constraints for non-conforming AMR, static condensation, etc.
-   if (static_cond) { a.EnableStaticCondensation(); }
-   a.Assemble();
-
-   OperatorPtr A;
-   Vector B, X;
-   a.FormLinearSystem(ess_tdof_list, x, b, A, X, B);
-
-   // 13. Solve the linear system A X = B.
-   if (!pa)
-   {
-      switch (solver_config)
-      {
-         // Solve the linear system with CG + Schwarz (with IC) from Ginkgo
-         case 0:
-         {
-            if (myid == 0) { cout << "Using Ginkgo solver + preconditioner...\n"; }
-            Ginkgo::GinkgoExecutor exec(device);
-            Ginkgo::IcPreconditioner local_solver(exec, "exact");
-            Ginkgo::SchwarzPreconditioner gko_M(exec, MPI_COMM_WORLD, local_solver);
-            Ginkgo::CGSolver ginkgo_solver(exec, MPI_COMM_WORLD, gko_M);
-            ginkgo_solver.SetPrintLevel(print_lvl);
-            ginkgo_solver.SetRelTol(sqrt(1e-12));
-            ginkgo_solver.SetAbsTol(0.0);
-            ginkgo_solver.SetMaxIter(400);
-            ginkgo_solver.SetOperator(*(A.Ptr()));
-            ginkgo_solver.Mult(B, X);
-            break;
-         }
-
-         // Solve the linear system with CG from Ginkgo + MFEM preconditioner
-         case 1:
-         {
-            if (myid == 0) { cout << "Using Ginkgo solver + MFEM preconditioner...\n"; }
-            Ginkgo::GinkgoExecutor exec(device);
-            //Create MFEM preconditioner and wrap it for Ginkgo's use.
-            HypreBoomerAMG M((HypreParMatrix&)(*A));
-            Ginkgo::MFEMPreconditioner gko_M(exec, M, MPI_COMM_WORLD);
-            Ginkgo::CGSolver ginkgo_solver(exec, MPI_COMM_WORLD, gko_M);
-            ginkgo_solver.SetPrintLevel(print_lvl);
-            ginkgo_solver.SetRelTol(sqrt(1e-12));
-            ginkgo_solver.SetAbsTol(0.0);
-            ginkgo_solver.SetMaxIter(400);
-            ginkgo_solver.SetOperator(*(A.Ptr()));
-            ginkgo_solver.Mult(B, X);
-            break;
-         }
-
-         // Ginkgo Schwarz preconditioner (local ParIC) +  MFEM CG solver
-         case 2:
-         {
-            if (myid == 0) { cout << "Using MFEM solver + Ginkgo preconditioner...\n"; }
-            Ginkgo::GinkgoExecutor exec(device);
-            Ginkgo::IcPreconditioner local_M(exec, "exact");
-            Ginkgo::SchwarzPreconditioner M(exec, MPI_COMM_WORLD, local_M);
-            M.SetOperator(*(A.Ptr()));  // Generate the preconditioner for the matrix A.
-            CGSolver cg(MPI_COMM_WORLD);
-            cg.SetRelTol(sqrt(1e-12));
-            cg.SetMaxIter(400);
-            cg.SetPrintLevel(1);
-            cg.SetPreconditioner(M);
-            cg.SetOperator(*A);
-            cg.Mult(B, X);
-            break;
-         }
-
-         // MFEM solver + MFEM preconditioner
-         case 3:
-         {
-            if (myid == 0) { cout << "Using MFEM solver + MFEM preconditioner...\n"; }
-            HypreBoomerAMG M((HypreParMatrix&)(*A));
-            CGSolver cg(MPI_COMM_WORLD);
-            cg.SetRelTol(sqrt(1e-12));
-            cg.SetMaxIter(400);
-            cg.SetPrintLevel(1);
-            cg.SetPreconditioner(M);
-            cg.SetOperator(*A);
-            cg.Mult(B, X);
-            break;
-         }
-      } // End switch on solver_config
-   }
-   // Partial assembly mode.  Cannot use Ginkgo preconditioners, but can use Ginkgo
-   // solvers.
-   else
-   {
-      if (UsesTensorBasis(fespace))
-      {
-         // Use Jacobi preconditioning in partial assembly mode.
-         OperatorJacobiSmoother M(a, ess_tdof_list);
-         switch (solver_config)
-         {
-            case 0:
-            {
-               if (myid == 0) { cout << "Using Ginkgo solver + preconditioner...\n"; }
-               MFEM_ABORT("Cannot use Ginkgo preconditioner in partial assembly mode.\n"
-                          "            Try -s 1 to test Ginkgo solver with an MFEM preconditioner.");
-               break;
-            }
-
-            // Use Ginkgo solver with MFEM preconditioner
-            case 1:
-            {
-               if (myid == 0) { cout << "Using Ginkgo solver + MFEM preconditioner...\n"; }
-               Ginkgo::GinkgoExecutor exec(device);
-               // Wrap MFEM preconditioner for Ginkgo's use.
-               Ginkgo::MFEMPreconditioner gko_M(exec, M, MPI_COMM_WORLD);
-               Ginkgo::CGSolver ginkgo_solver(exec, MPI_COMM_WORLD, gko_M);
-               ginkgo_solver.SetPrintLevel(print_lvl);
-               ginkgo_solver.SetRelTol(sqrt(1e-12));
-               ginkgo_solver.SetAbsTol(0.0);
-               ginkgo_solver.SetMaxIter(400);
-               ginkgo_solver.SetOperator(*(A.Ptr()));
-               ginkgo_solver.Mult(B, X);
-               break;
-            }
-
-            // No Ginkgo preconditioners work with matrix-free; error
-            case 2:
-            {
-               if (myid == 0) { cout << "Using Ginkgo solver + preconditioner...\n"; }
-               MFEM_ABORT("Cannot use Ginkgo preconditioner in partial assembly mode.\n"
-                          "            Try -s 1 to test Ginkgo solver with an MFEM preconditioner.");
-               break;
-            }
-
-            // Use MFEM solver and preconditioner
-            case 3:
-            {
-               if (myid == 0) { cout << "Using MFEM solver + MFEM preconditioner...\n"; }
-               CGSolver cg(MPI_COMM_WORLD);
-               cg.SetRelTol(sqrt(1e-12));
-               cg.SetMaxIter(400);
-               cg.SetPrintLevel(1);
-               cg.SetPreconditioner(M);
-               cg.SetOperator(*A);
-               cg.Mult(B, X);
-               break;
-            }
-         } // End switch on solver_config
-      }
-      else // CG with no preconditioning
-      {
-         if (myid == 0) { cout << "Using MFEM solver + no preconditioner...\n"; }
-         CGSolver cg(MPI_COMM_WORLD);
-         cg.SetRelTol(sqrt(1e-12));
-         cg.SetMaxIter(400);
-         cg.SetPrintLevel(1);
-         cg.SetOperator(*A);
-         cg.Mult(B, X);
-      }
-   }
-
-   // 14. Recover the parallel grid function corresponding to X. This is the
-   //     local finite element solution on each processor.
-   a.RecoverFEMSolution(X, b, x);
-
-   // 15. Save the refined mesh and the solution in parallel. This output can
-   //     be viewed later using GLVis: "glvis -np <np> -m mesh -g sol".
-   {
-      ostringstream mesh_name, sol_name;
-      mesh_name << "mesh." << setfill('0') << setw(6) << myid;
-      sol_name << "sol." << setfill('0') << setw(6) << myid;
-
-      ofstream mesh_ofs(mesh_name.str().c_str());
-      mesh_ofs.precision(8);
-      pmesh.Print(mesh_ofs);
-
-      ofstream sol_ofs(sol_name.str().c_str());
-      sol_ofs.precision(8);
-      x.Save(sol_ofs);
-   }
-
-   // 16. Send the solution by socket to a GLVis server.
-   if (visualization)
-   {
-      char vishost[] = "localhost";
-      int  visport   = 19916;
-      socketstream sol_sock(vishost, visport);
-      sol_sock << "parallel " << num_procs << " " << myid << "\n";
-      sol_sock.precision(8);
-      sol_sock << "solution\n" << pmesh << x << flush;
-   }
-
-   // 17. Free the used memory.
-   if (delete_fec)
-   {
-      delete fec;
-   }
-
-   return 0;
-}
@@ -20,8 +20,9 @@ CONFIG_MK = $(or $(wildcard $(MFEM_BUILD_DIR)/config/config.mk),\
 MFEM_LIB_FILE = mfem_is_not_built
 -include $(CONFIG_MK)

+# Currently there are only serial Ginkgo examples
 SEQ_EXAMPLES = ex1
-PAR_EXAMPLES = ex1p
+PAR_EXAMPLES =
 ifeq ($(MFEM_USE_MPI),NO)
   EXAMPLES = $(SEQ_EXAMPLES)
 else
@@ -825,46 +825,14 @@ void BilinearForm::FormLinearSystem(const Array<int> &ess_tdof_list, Vector &x,
                                    Vector &b, OperatorHandle &A, Vector &X,
                                    Vector &B, int copy_interior)
 {
-   const SparseMatrix *P = fes->GetConformingProlongation();
-   const SparseMatrix *R = fes->GetConformingRestriction();
   if (ext)
   {
      if (hybridization)
      {
         FormSystemMatrix(ess_tdof_list, A);
-
-         std::unique_ptr<ConstrainedOperator> A_constrained([&]()
-         {
-            Operator *op;
-            Operator::FormSystemOperator(ess_tdof_list, op);
-            return dynamic_cast<ConstrainedOperator*>(op);
-         }());
-         MFEM_ASSERT(A_constrained != nullptr, "");
-
-         Vector conf_b, conf_x;
-         if (P)
-         {
-            // Nonconforming
-            conf_b.SetSize(P->Width());
-            conf_x.SetSize(P->Width());
-            P->MultTranspose(b, conf_b);
-            R->Mult(x, conf_x);
-         }
-         else
-         {
-            // Conforming
-            conf_b.MakeRef(b, 0, b.Size());
-            conf_x.MakeRef(x, 0, x.Size());
-         }
-
-         A_constrained->EliminateRHS(conf_x, conf_b);
-
-         if (P)
-         {
-            R->MultTranspose(conf_b, b); // store eliminated rhs in b
-         }
-
-         hybridization->ReduceRHS(conf_b, B);
+         ConstrainedOperator A_constrained(this, ess_tdof_list);
+         A_constrained.EliminateRHS(x, b);
+         hybridization->ReduceRHS(b, B);
         X.SetSize(B.Size());
         X = 0.0;
      }
@@ -874,6 +842,7 @@ void BilinearForm::FormLinearSystem(const Array<int> &ess_tdof_list, Vector &x,
      }
      return;
   }
+   const SparseMatrix *P = fes->GetConformingProlongation();
   FormSystemMatrix(ess_tdof_list, A);

   // Transform the system and perform the elimination in B, based on the
@@ -909,6 +878,7 @@ void BilinearForm::FormLinearSystem(const Array<int> &ess_tdof_list, Vector &x,
      if (hybridization)
      {
         // Reduction to the Lagrange multipliers system
+         const SparseMatrix *R = fes->GetConformingRestriction();
         Vector conf_b(P->Width()), conf_x(P->Width());
         P->MultTranspose(b, conf_b);
         R->Mult(x, conf_x);
@@ -921,6 +891,7 @@ void BilinearForm::FormLinearSystem(const Array<int> &ess_tdof_list, Vector &x,
      else
      {
         // Variational restriction with P
+         const SparseMatrix *R = fes->GetConformingRestriction();
         B.SetSize(P->Width());
         P->MultTranspose(b, B);
         X.SetSize(R->Height());
@@ -1302,73 +1302,6 @@ real_t TraceCoefficient::Eval(ElementTransformation &T,
   return ma.Trace();
 }

-VectorComponentCoefficient::VectorComponentCoefficient(VectorCoefficient &A,
-                                                       int c)
-   : a(&A), va(A.GetVDim())
-{
-   SetComponent(c);
-}
-
-void VectorComponentCoefficient::SetComponent(int c)
-{
-   MFEM_ASSERT(c < a->GetVDim() && c >= 0,
-               "VectorComponentCoefficient:  "
-               "Index not in range.");
-
-   component = c;
-}
-
-void VectorComponentCoefficient::SetTime(real_t t)
-{
-   if (a) { a->SetTime(t); }
-   this->Coefficient::SetTime(t);
-}
-
-real_t VectorComponentCoefficient::Eval(ElementTransformation &T,
-                                        const IntegrationPoint &ip)
-{
-   a->Eval(va, T, ip);
-   return va[component];
-}
-
-MatrixComponentCoefficient::MatrixComponentCoefficient(MatrixCoefficient &A,
-                                                       int ri, int ci)
-   : a(&A), ma(A.GetHeight(), A.GetWidth())
-{
-   SetRowIndex(ri);
-   SetColumnIndex(ci);
-}
-
-void MatrixComponentCoefficient::SetRowIndex(int ri)
-{
-   MFEM_ASSERT(ri < a->GetHeight() && ri >= 0,
-               "MatrixComponentCoefficient:  "
-               "Row index not in range.");
-
-   row_idx = ri;
-}
-
-void MatrixComponentCoefficient::SetColumnIndex(int ci)
-{
-   MFEM_ASSERT(ci < a->GetWidth() && ci >= 0,
-               "MatrixComponentCoefficient:  "
-               "Column index not in range.");
-   col_idx = ci;
-}
-
-void MatrixComponentCoefficient::SetTime(real_t t)
-{
-   if (a) { a->SetTime(t); }
-   this->Coefficient::SetTime(t);
-}
-
-real_t MatrixComponentCoefficient::Eval(ElementTransformation &T,
-                                        const IntegrationPoint &ip)
-{
-   a->Eval(ma, T, ip);
-   return ma(row_idx,col_idx);
-}
-
 VectorSumCoefficient::VectorSumCoefficient(int dim)
   : VectorCoefficient(dim),
     ACoef(NULL), BCoef(NULL),
@@ -114,10 +114,11 @@ public:
   /// Construct the constant coefficient using a vector of constants.
   /** @a c should be a vector defined by attributes, so for region with
       attribute @a i @a c[i-1] is the coefficient in that region */
-   PWConstCoefficient(const Vector &c) { UpdateConstants(c); }
+   PWConstCoefficient(Vector &c)
+   { constants.SetSize(c.Size()); constants=c; }

   /// Update the constants with vector @a c.
-   void UpdateConstants(const Vector &c) { constants = c; }
+   void UpdateConstants(Vector &c) { constants.SetSize(c.Size()); constants=c; }

   /// Return a reference to the i-th constant
   real_t &operator()(int i) { return constants(i-1); }
@@ -1331,8 +1332,8 @@ public:
   /// Get the coefficient located at (i,j) in the matrix.
   Coefficient* GetCoeff (int i, int j) { return Coeff[i*width+j]; }

-   /** @brief Set the coefficient located at (i,j) in the matrix.  By default
-       this will take ownership of the Coefficient passed in, but this
+   /** @brief Set the coefficient located at (i,j) in the matrix.  By default by
+       default this will take ownership of the Coefficient passed in, but this
       can be overridden with the @a own parameter. */
   void Set(int i, int j, Coefficient * c, bool own=true);

@@ -1872,85 +1873,6 @@ public:
               const IntegrationPoint &ip) override;
 };

-/// Scalar coefficient defined as component of a vector coefficient
-class VectorComponentCoefficient : public Coefficient
-{
-private:
-   VectorCoefficient *a = nullptr;
-
-   mutable Vector va;
-   int component;
-
-public:
-   /// Construct with a vector coefficient.
-   VectorComponentCoefficient(VectorCoefficient &A)
-      : a(&A), va(A.GetVDim()), component(0) {};
-
-   VectorComponentCoefficient(VectorCoefficient &A, int c);
-
-   /// Set the time for internally stored coefficients
-   void SetTime(real_t t) override;
-
-   /// Reset the vector coefficient
-   void SetACoef(VectorCoefficient &A) { a = &A; }
-
-   /// Return the vector coefficient
-   VectorCoefficient * GetACoef() const { return a; }
-
-   /// Set the component
-   void SetComponent(int c);
-
-   /// Return the component
-   int GetComponent() const { return component; }
-
-   /// Evaluate the trace coefficient at @a ip.
-   real_t Eval(ElementTransformation &T,
-               const IntegrationPoint &ip) override;
-};
-
-/// Scalar coefficient defined as component of a matrix coefficient
-class MatrixComponentCoefficient : public Coefficient
-{
-private:
-   MatrixCoefficient *a = nullptr;
-
-   mutable DenseMatrix ma;
-   int row_idx,col_idx;
-
-public:
-   MatrixComponentCoefficient(MatrixCoefficient &A)
-      : a(&A), ma(A.GetHeight(), A.GetWidth()), row_idx(0), col_idx(0) {};
-
-   /// Construct with the matrix coefficient.
-   MatrixComponentCoefficient(MatrixCoefficient &A, int ri, int ci);
-
-   /// Set the time for internally stored coefficients
-   void SetTime(real_t t) override;
-
-   /// Reset the matrix coefficient
-   void SetACoef(MatrixCoefficient &A) { a = &A; }
-
-   /// Return the matrix coefficient
-   MatrixCoefficient * GetACoef() const { return a; }
-
-   /// Reset the index
-   void SetRowIndex(int ri);
-
-   /// Return the index
-   int GetRowIndex() const { return row_idx; }
-
-   /// Reset the index
-   void SetColumnIndex(int ci);
-
-   /// Return the index
-   int GetColumnIndex() const { return col_idx; }
-
-
-   /// Evaluate the trace coefficient at @a ip.
-   real_t Eval(ElementTransformation &T,
-               const IntegrationPoint &ip) override;
-};
-
 /// Vector coefficient defined as the linear combination of two vectors
 class VectorSumCoefficient : public VectorCoefficient
 {
@@ -10,7 +10,7 @@
 // CONTRIBUTING.md for details.
 #pragma once

-// This is smith's tuple implementation
+// This is serac's tuple implementation

 #include <ostream>
 #include "../../config/config.hpp"
@@ -12,6 +12,7 @@
 #include "dgmassinv.hpp"
 #include "bilinearform.hpp"
 #include "dgmassinv_kernels.hpp"
+#include "../general/forall.hpp"

 namespace mfem
 {
@@ -118,6 +119,151 @@ void DGMassInverse::Update()

 DGMassInverse::~DGMassInverse() = default;

+template<int DIM, int D1D, int Q1D>
+void DGMassInverse::DGMassCGIteration(const Vector &b_, Vector &u_) const
+{
+   using namespace internal; // host/device kernel functions
+
+   const int NE = fes.GetNE();
+   const int d1d = m->dofs1D;
+   const int q1d = m->quad1D;
+
+   const int ND = static_cast<int>(pow(d1d, DIM));
+
+   const auto B = m->maps->B.Read();
+   const auto Bt = m->maps->Bt.Read();
+   const auto pa_data = m->pa_data.Read();
+   const auto dinv = diag_inv.Read();
+   auto r = r_.Write();
+   auto d = d_.Write();
+   auto z = z_.Write();
+   auto u = u_.ReadWrite();
+
+   const real_t RELTOL = rel_tol;
+   const real_t ABSTOL = abs_tol;
+   const int MAXIT = max_iter;
+   const bool IT_MODE = iterative_mode;
+   const bool CHANGE_BASIS = (d2q != nullptr);
+
+   // b is the right-hand side (if no change of basis, this just points to the
+   // incoming RHS vector, if we have to change basis, this points to the
+   // internal b2 vector where we put the transformed RHS)
+   const real_t *b;
+   // the following are non-null if we have to change basis
+   real_t *b2 = nullptr; // non-const access to b2
+   const real_t *b_orig = nullptr; // RHS vector in "original" basis
+   const real_t *d2q_B = nullptr; // matrix to transform initial guess
+   const real_t *q2d_B = nullptr; // matrix to transform solution
+   const real_t *q2d_Bt = nullptr; // matrix to transform RHS
+   if (CHANGE_BASIS)
+   {
+      d2q_B = d2q->B.Read();
+      q2d_B = B_.Read();
+      q2d_Bt = Bt_.Read();
+
+      b2 = b2_.Write();
+      b_orig = b_.Read();
+      b = b2;
+   }
+   else
+   {
+      b = b_.Read();
+   }
+
+   static constexpr int NB = Q1D ? Q1D : 1; // block size
+
+   mfem::forall_2D(NE, NB, NB, [=] MFEM_HOST_DEVICE (int e)
+   {
+      // Perform change of basis if needed
+      if (CHANGE_BASIS)
+      {
+         // Transform RHS
+         DGMassBasis<DIM,D1D>(e, NE, q2d_Bt, b_orig, b2, d1d);
+         if (IT_MODE)
+         {
+            // Transform initial guess
+            DGMassBasis<DIM,D1D>(e, NE, d2q_B, u, u, d1d);
+         }
+      }
+
+      const int tid = MFEM_THREAD_ID(x) + NB*MFEM_THREAD_ID(y);
+
+      // Compute first residual
+      if (IT_MODE)
+      {
+         DGMassApply<DIM,D1D,Q1D>(e, NE, B, Bt, pa_data, u, r, d1d, q1d);
+         DGMassAxpy(e, NE, ND, 1.0, b, -1.0, r, r); // r = b - r
+      }
+      else
+      {
+         // if not in iterative mode, use zero initial guess
+         const int BX = MFEM_THREAD_SIZE(x);
+         const int BY = MFEM_THREAD_SIZE(y);
+         const int bxy = BX*BY;
+         const auto B = ConstDeviceMatrix(b, ND, NE);
+         auto U = DeviceMatrix(u, ND, NE);
+         auto R = DeviceMatrix(r, ND, NE);
+         for (int i = tid; i < ND; i += bxy)
+         {
+            U(i, e) = 0.0;
+            R(i, e) = B(i, e);
+         }
+         MFEM_SYNC_THREAD;
+      }
+
+      DGMassPreconditioner(e, NE, ND, dinv, r, z);
+      DGMassAxpy(e, NE, ND, 1.0, z, 0.0, z, d); // d = z
+
+      real_t nom = DGMassDot<NB>(e, NE, ND, d, r);
+      if (nom < 0.0) { return; /* Not positive definite */ }
+      real_t r0 = fmax(nom*RELTOL*RELTOL, ABSTOL*ABSTOL);
+      if (nom <= r0) { return; /* Converged */ }
+
+      DGMassApply<DIM,D1D,Q1D>(e, NE, B, Bt, pa_data, d, z, d1d, q1d);
+      real_t den = DGMassDot<NB>(e, NE, ND, z, d);
+      if (den <= 0.0)
+      {
+         DGMassDot<NB>(e, NE, ND, d, d);
+         // d2 > 0 => not positive definite
+         if (den == 0.0) { return; }
+      }
+
+      // start iteration
+      int i = 1;
+      while (true)
+      {
+         const real_t alpha = nom/den;
+         DGMassAxpy(e, NE, ND, 1.0, u, alpha, d, u); // u = u + alpha*d
+         DGMassAxpy(e, NE, ND, 1.0, r, -alpha, z, r); // r = r - alpha*A*d
+
+         DGMassPreconditioner(e, NE, ND, dinv, r, z);
+
+         real_t betanom = DGMassDot<NB>(e, NE, ND, r, z);
+         if (betanom < 0.0) { return; /* Not positive definite */ }
+         if (betanom <= r0) { break; /* Converged */ }
+
+         if (++i > MAXIT) { break; }
+
+         const real_t beta = betanom/nom;
+         DGMassAxpy(e, NE, ND, 1.0, z, beta, d, d); // d = z + beta*d
+         DGMassApply<DIM,D1D,Q1D>(e, NE, B, Bt, pa_data, d, z, d1d, q1d); // z = A d
+         den = DGMassDot<NB>(e, NE, ND, d, z);
+         if (den <= 0.0)
+         {
+            DGMassDot<NB>(e, NE, ND, d, d);
+            // d2 > 0 => not positive definite
+            if (den == 0.0) { break; }
+         }
+         nom = betanom;
+      }
+
+      if (CHANGE_BASIS)
+      {
+         DGMassBasis<DIM,D1D>(e, NE, q2d_B, u, u, d1d);
+      }
+   });
+}
+
 void DGMassInverse::Mult(const Vector &Mu, Vector &u) const
 {
   // Dispatch to templated version based on dim, d1d, and q1d.
@@ -160,4 +306,23 @@ DGMassInvKernels::DGMassInvKernels()
   k::Specialization<3,6,7>::Add();
 }

+/// @cond Suppress_Doxygen_warnings
+
+template <int DIM, int D1D, int Q1D>
+DGMassInverse::CGKernelType DGMassInverse::CGKernels::Kernel()
+{
+   return &DGMassInverse::DGMassCGIteration<DIM,D1D,Q1D>;
+}
+
+DGMassInverse::CGKernelType DGMassInverse::CGKernels::Fallback(
+   int dim, int, int)
+{
+   if (dim == 1) { return &DGMassInverse::DGMassCGIteration<1>; }
+   else if (dim == 2) { return &DGMassInverse::DGMassCGIteration<2>; }
+   else if (dim == 3) { return &DGMassInverse::DGMassCGIteration<3>; }
+   else { MFEM_ABORT("Unsupported dimension."); }
+}
+
+/// @endcond
+
 } // namespace mfem
@@ -15,7 +15,6 @@
 #include "../linalg/kernels.hpp"
 #include "kernels.hpp"
 #include "integ/bilininteg_mass_kernels.hpp"
-#include "dgmassinv.hpp"

 namespace mfem
 {
@@ -334,170 +333,6 @@ void DGMassBasis(const int e,

 } // namespace internal

-template<int DIM, int D1D, int Q1D>
-void DGMassInverse::DGMassCGIteration(const Vector &b_, Vector &u_) const
-{
-   using namespace internal; // host/device kernel functions
-
-   const int NE = fes.GetNE();
-   const int d1d = m->dofs1D;
-   const int q1d = m->quad1D;
-
-   const int ND = static_cast<int>(pow(d1d, DIM));
-
-   const auto B = m->maps->B.Read();
-   const auto Bt = m->maps->Bt.Read();
-   const auto pa_data = m->pa_data.Read();
-   const auto dinv = diag_inv.Read();
-   auto r = r_.Write();
-   auto d = d_.Write();
-   auto z = z_.Write();
-   auto u = u_.ReadWrite();
-
-   const real_t RELTOL = rel_tol;
-   const real_t ABSTOL = abs_tol;
-   const int MAXIT = max_iter;
-   const bool IT_MODE = iterative_mode;
-   const bool CHANGE_BASIS = (d2q != nullptr);
-
-   // b is the right-hand side (if no change of basis, this just points to the
-   // incoming RHS vector, if we have to change basis, this points to the
-   // internal b2 vector where we put the transformed RHS)
-   const real_t *b;
-   // the following are non-null if we have to change basis
-   real_t *b2 = nullptr; // non-const access to b2
-   const real_t *b_orig = nullptr; // RHS vector in "original" basis
-   const real_t *d2q_B = nullptr; // matrix to transform initial guess
-   const real_t *q2d_B = nullptr; // matrix to transform solution
-   const real_t *q2d_Bt = nullptr; // matrix to transform RHS
-   if (CHANGE_BASIS)
-   {
-      d2q_B = d2q->B.Read();
-      q2d_B = B_.Read();
-      q2d_Bt = Bt_.Read();
-
-      b2 = b2_.Write();
-      b_orig = b_.Read();
-      b = b2;
-   }
-   else
-   {
-      b = b_.Read();
-   }
-
-   static constexpr int NB = Q1D ? Q1D : 1; // block size
-
-   mfem::forall_2D<NB*NB>(NE, NB, NB, [=] MFEM_HOST_DEVICE (int e)
-   {
-      // Perform change of basis if needed
-      if (CHANGE_BASIS)
-      {
-         // Transform RHS
-         DGMassBasis<DIM,D1D>(e, NE, q2d_Bt, b_orig, b2, d1d);
-         if (IT_MODE)
-         {
-            // Transform initial guess
-            DGMassBasis<DIM,D1D>(e, NE, d2q_B, u, u, d1d);
-         }
-      }
-
-      const int tid = MFEM_THREAD_ID(x) + NB*MFEM_THREAD_ID(y);
-
-      // Compute first residual
-      if (IT_MODE)
-      {
-         DGMassApply<DIM,D1D,Q1D>(e, NE, B, Bt, pa_data, u, r, d1d, q1d);
-         DGMassAxpy(e, NE, ND, 1.0, b, -1.0, r, r); // r = b - r
-      }
-      else
-      {
-         // if not in iterative mode, use zero initial guess
-         const int BX = MFEM_THREAD_SIZE(x);
-         const int BY = MFEM_THREAD_SIZE(y);
-         const int bxy = BX*BY;
-         const auto B = ConstDeviceMatrix(b, ND, NE);
-         auto U = DeviceMatrix(u, ND, NE);
-         auto R = DeviceMatrix(r, ND, NE);
-         for (int i = tid; i < ND; i += bxy)
-         {
-            U(i, e) = 0.0;
-            R(i, e) = B(i, e);
-         }
-         MFEM_SYNC_THREAD;
-      }
-
-      DGMassPreconditioner(e, NE, ND, dinv, r, z);
-      DGMassAxpy(e, NE, ND, 1.0, z, 0.0, z, d); // d = z
-
-      real_t nom = DGMassDot<NB>(e, NE, ND, d, r);
-      if (nom < 0.0) { return; /* Not positive definite */ }
-      real_t r0 = fmax(nom*RELTOL*RELTOL, ABSTOL*ABSTOL);
-      if (nom <= r0) { return; /* Converged */ }
-
-      DGMassApply<DIM,D1D,Q1D>(e, NE, B, Bt, pa_data, d, z, d1d, q1d);
-      real_t den = DGMassDot<NB>(e, NE, ND, z, d);
-      if (den <= 0.0)
-      {
-         DGMassDot<NB>(e, NE, ND, d, d);
-         // d2 > 0 => not positive definite
-         if (den == 0.0) { return; }
-      }
-
-      // start iteration
-      int i = 1;
-      while (true)
-      {
-         const real_t alpha = nom/den;
-         DGMassAxpy(e, NE, ND, 1.0, u, alpha, d, u); // u = u + alpha*d
-         DGMassAxpy(e, NE, ND, 1.0, r, -alpha, z, r); // r = r - alpha*A*d
-
-         DGMassPreconditioner(e, NE, ND, dinv, r, z);
-
-         real_t betanom = DGMassDot<NB>(e, NE, ND, r, z);
-         if (betanom < 0.0) { return; /* Not positive definite */ }
-         if (betanom <= r0) { break; /* Converged */ }
-
-         if (++i > MAXIT) { break; }
-
-         const real_t beta = betanom/nom;
-         DGMassAxpy(e, NE, ND, 1.0, z, beta, d, d); // d = z + beta*d
-         DGMassApply<DIM,D1D,Q1D>(e, NE, B, Bt, pa_data, d, z, d1d, q1d); // z = A d
-         den = DGMassDot<NB>(e, NE, ND, d, z);
-         if (den <= 0.0)
-         {
-            DGMassDot<NB>(e, NE, ND, d, d);
-            // d2 > 0 => not positive definite
-            if (den == 0.0) { break; }
-         }
-         nom = betanom;
-      }
-
-      if (CHANGE_BASIS)
-      {
-         DGMassBasis<DIM,D1D>(e, NE, q2d_B, u, u, d1d);
-      }
-   });
-}
-
-/// @cond Suppress_Doxygen_warnings
-
-template <int DIM, int D1D, int Q1D>
-inline DGMassInverse::CGKernelType DGMassInverse::CGKernels::Kernel()
-{
-   return &DGMassInverse::DGMassCGIteration<DIM,D1D,Q1D>;
-}
-
-inline DGMassInverse::CGKernelType DGMassInverse::CGKernels::Fallback(
-   int dim, int, int)
-{
-   if (dim == 1) { return &DGMassInverse::DGMassCGIteration<1>; }
-   else if (dim == 2) { return &DGMassInverse::DGMassCGIteration<2>; }
-   else if (dim == 3) { return &DGMassInverse::DGMassCGIteration<3>; }
-   else { MFEM_ABORT("Unsupported dimension."); }
-}
-
-/// @endcond
-
 } // namespace mfem

 #endif
@@ -69,9 +69,9 @@ inline int ToLexOrdering2D(const int face_id, const int size1d, const int i)
 }

 /// @brief Given a face DOF index on a shared face, ordered lexicographically
-/// relative to the element (where the local face is face_id), return the
-/// corresponding face DOF index ordered lexicographically relative to the face
-/// itself.
+/// relative to element the element (where the local face is face_id), and
+/// return the corresponding face DOF index ordered lexicographically relative
+/// to the face itself.
 MFEM_HOST_DEVICE
 inline int PermuteFace2D(const int face_id, const int orientation,
                         const int size1d, const int index)
@@ -231,7 +231,7 @@ void FiniteElement::CalcPhysLaplacian(ElementTransformation &Trans,
   {
      for (int nd = 0; nd < dof; nd++)
      {
-         Laplacian[nd] = hess(nd,0) + hess(nd,3) + hess(nd,5);
+         Laplacian[nd] = hess(nd,0) + hess(nd,4) + hess(nd,5);
      }
   }
   else if (dim == 2)
@@ -268,9 +268,11 @@ void FiniteElement::CalcPhysLinLaplacian(ElementTransformation &Trans,
      scale[0] =   Gij(0,0);
      scale[1] = 2*Gij(0,1);
      scale[2] = 2*Gij(0,2);
-      scale[3] =   Gij(1,1);
-      scale[4] = 2*Gij(1,2);
-      scale[5] =   Gij(2,2);
+
+      scale[3] = 2*Gij(1,2);
+      scale[4] =   Gij(2,2);
+
+      scale[5] =   Gij(1,1);
   }
   else if (dim == 2)
   {
@@ -307,12 +309,12 @@ void  FiniteElement::CalcPhysHessian(ElementTransformation &Trans,
      map[2] = 2;

      map[3] = 1;
-      map[4] = 3;
-      map[5] = 4;
+      map[4] = 5;
+      map[5] = 3;

      map[6] = 2;
-      map[7] = 4;
-      map[8] = 5;
+      map[7] = 3;
+      map[8] = 4;
   }
   else if (dim == 2)
   {
@@ -380,7 +382,11 @@ const DofToQuad &FiniteElement::GetDofToQuad(const IntegrationRule &ir,
   #pragma omp critical (DofToQuad)
 #endif
   {
-      d2q = DofToQuad::SearchArray(dof2quad_array, ir, mode);
+      for (int i = 0; i < dof2quad_array.Size(); i++)
+      {
+         d2q = dof2quad_array[i];
+         if (d2q->IntRule != &ir || d2q->mode != mode) { d2q = nullptr; }
+      }
      if (!d2q)
      {
 #ifdef MFEM_THREAD_SAFE
@@ -655,22 +661,14 @@ void ScalarFiniteElement::ScalarLocalL2Restriction(
 void NodalFiniteElement::CreateLexicographicFullMap(const IntegrationRule &ir)
 const
 {
-   // Get the FULL version of the map. This call contains omp critical region,
-   // so it is done before the critical region below.
-   auto &d2q = GetDofToQuad(ir, DofToQuad::FULL);

 #if defined(MFEM_THREAD_SAFE) && defined(MFEM_USE_OPENMP)
   #pragma omp critical (DofToQuad)
 #endif
   {
-      // If the new Dof2Quad is already present, e.g. added in a previous call
-      // or added by another omp thread, return.
-      if (DofToQuad::SearchArray(dof2quad_array, ir,
-                                 DofToQuad::LEXICOGRAPHIC_FULL))
-      { return; }
-
-      // Undo the native ordering which is what FiniteElement::GetDofToQuad
-      // returns.
+      // Get the FULL version of the map.
+      auto &d2q = GetDofToQuad(ir, DofToQuad::FULL);
+      //Undo the native ordering which is what FiniteElement::GetDofToQuad returns.
      auto *d2q_new = new DofToQuad(d2q);
      d2q_new->mode = DofToQuad::LEXICOGRAPHIC_FULL;
      const int nqpt = ir.GetNPoints();
@@ -726,7 +724,13 @@ const DofToQuad &NodalFiniteElement::GetDofToQuad(const IntegrationRule &ir,
   #pragma omp critical (DofToQuad)
 #endif
   {
-      d2q = DofToQuad::SearchArray(dof2quad_array, ir, mode);
+      //Should make this loop a function of FiniteElement
+      for (int i = 0; i < dof2quad_array.Size(); i++)
+      {
+         d2q = dof2quad_array[i];
+         if (d2q->IntRule == &ir && d2q->mode == mode) { break; }
+         d2q = nullptr;
+      }
   }
   if (d2q) { return *d2q; }
   if (mode != DofToQuad::LEXICOGRAPHIC_FULL)
@@ -2627,7 +2631,15 @@ const DofToQuad &TensorBasisElement::GetTensorDofToQuad(
   #pragma omp critical (DofToQuad)
 #endif
   {
-      d2q = DofToQuad::SearchArray(dof2quad_array, ir, mode);
+      for (int i = 0; i < dof2quad_array.Size(); i++)
+      {
+         auto* d2q_ = dof2quad_array[i];
+         if (d2q_->IntRule == &ir && d2q_->mode == mode)
+         {
+            d2q = d2q_;
+            break;
+         }
+      }
      if (!d2q)
      {
         d2q = new DofToQuad;
@@ -44,7 +44,7 @@ public:
      NumBasisTypes   = 9   /**< Keep track of maximum types to prevent
                                 hard-coding */
   };
-   /** @brief If the input does not represent a valid BasisType, abort with an
+   /** @brief If the input does not represents a valid BasisType, abort with an
       error; otherwise return the input. */
   static int Check(int b_type)
   {
@@ -52,7 +52,7 @@ public:
                  "unknown BasisType: " << b_type);
      return b_type;
   }
-   /** @brief If the input does not represent a valid nodal BasisType, abort
+   /** @brief If the input does not represents a valid nodal BasisType, abort
       with an error; otherwise return the input. */
   static int CheckNodal(int b_type)
   {
@@ -222,12 +222,6 @@ public:

   /// Returns absolute value of the maps
   DofToQuad Abs() const;
-
-   /// Auxiliary function for searching DofToQuad arrays.
-   static inline DofToQuad *SearchArray(
-      const Array<DofToQuad*> &dof2quad_array,
-      const IntegrationRule &ir,
-      DofToQuad::Mode mode);
 };

 /// Describes the function space on each element
@@ -413,7 +407,6 @@ public:
   /** Each row of the result DenseMatrix @a Hessian contains upper triangular
       part of the Hessian of one shape function.
       The order in 2D is {u_xx, u_xy, u_yy}.
-       The order in 3D is {u_xx, u_xy, u_xz, u_yy, u_yz, u_zz}.
       The size (#dof x (#dim (#dim+1)/2) of @a Hessian must be set in advance.*/
   virtual void CalcHessian(const IntegrationPoint &ip,
                            DenseMatrix &Hessian) const;
@@ -1127,7 +1120,7 @@ public:
      return GetPoints(p, btype, on_device);
   }

-   /// Get coordinates of a closed (GaussLobatto) set of points if degree @a p
+   /// Get coordinates of a closed (GaussLegendre) set of points if degree @a p
   const real_t *ClosedPoints(const int p,
                              const int btype = BasisType::GaussLobatto,
                              bool on_device = false)
@@ -1383,21 +1376,6 @@ public:
 void InvertLinearTrans(ElementTransformation &trans,
                       const IntegrationPoint &pt, Vector &x);

-
-// static inline method
-inline DofToQuad *DofToQuad::SearchArray(
-   const Array<DofToQuad*> &dof2quad_array,
-   const IntegrationRule &ir,
-   DofToQuad::Mode mode)
-{
-   for (int i = 0; i < dof2quad_array.Size(); i++)
-   {
-      DofToQuad *d2q = dof2quad_array[i];
-      if (d2q->IntRule == &ir && d2q->mode == mode) { return d2q; }
-   }
-   return nullptr;
-}
-
 } // namespace mfem

 #endif
@@ -60,12 +60,6 @@ void Linear1DFiniteElement::CalcDShape(const IntegrationPoint &ip,
   dshape(1,0) =  1.;
 }

-void Linear1DFiniteElement::CalcHessian(const IntegrationPoint &ip,
-                                        DenseMatrix &h) const
-{
-   h = 0.0;
-}
-
 Linear2DFiniteElement::Linear2DFiniteElement()
   : NodalFiniteElement(2, Geometry::TRIANGLE, 3, 1)
 {
@@ -93,11 +87,6 @@ void Linear2DFiniteElement::CalcDShape(const IntegrationPoint &ip,
   dshape(2,0) =  0.; dshape(2,1) =  1.;
 }

-void Linear2DFiniteElement::CalcHessian(const IntegrationPoint &ip,
-                                        DenseMatrix &h) const
-{
-   h = 0.0;
-}

 BiLinear2DFiniteElement::BiLinear2DFiniteElement()
   : NodalFiniteElement(2, Geometry::SQUARE, 4, 1, FunctionSpace::Qk)
@@ -1267,12 +1256,6 @@ void Linear3DFiniteElement::CalcDShape(const IntegrationPoint &ip,
   }
 }

-void Linear3DFiniteElement::CalcHessian(const IntegrationPoint &ip,
-                                        DenseMatrix &h) const
-{
-   h = 0.0;
-}
-
 void Linear3DFiniteElement::GetFaceDofs (int face, int **dofs, int *ndofs)
 const
 {
@@ -1649,37 +1632,6 @@ void TriLinear3DFiniteElement::CalcDShape(const IntegrationPoint &ip,
   dshape(7,2) =   ox *  y;
 }

-void TriLinear3DFiniteElement::CalcHessian(const IntegrationPoint &ip,
-                                           DenseMatrix &h) const
-{
-   real_t x = ip.x, y = ip.y, z = ip.z;
-   real_t ox = 1.-x, oy = 1.-y, oz = 1.-z;
-
-   h(0,0) = 0.;   h(0,1) =  oz;   h(0,2) = oy;
-   h(0,3) = 0.;   h(0,4) =  ox;   h(0,5) = 0.;
-
-   h(1,0) = 0.;   h(1,1) = -oz;   h(1,2) = -oy;
-   h(1,3) = 0.;   h(1,4) =  x;    h(1,5) = 0.;
-
-   h(2,0) = 0.;   h(2,1) =  oz;   h(2,2) = -y;
-   h(2,3) = 0.;   h(2,4) =  -x;   h(2,5) = 0.;
-
-   h(3,0) = 0.;   h(3,1) = -oz;   h(3,2) = y;
-   h(3,3) = 0.;   h(3,4) = -ox;   h(3,5) = 0.;
-
-   h(4,0) = 0.;   h(4,1) =  z;    h(4,2) = -oy;
-   h(4,3) = 0.;   h(4,4) = -ox;   h(4,5) = 0.;
-
-   h(5,0) = 0.;   h(5,1) = -z;    h(5,2) = oy;
-   h(5,3) = 0.;   h(5,4) = -x;    h(5,5) = 0.;
-
-   h(6,0) = 0.;   h(6,1) =  z;    h(6,2) = y;
-   h(6,3) = 0.;   h(6,4) =  x;    h(6,5) = 0.;
-
-   h(7,0) = 0.;   h(7,1) = -z;    h(7,2) = -y;
-   h(7,3) = 0.;   h(7,4) = ox;    h(7,5) = 0.;
-}
-

 P0SegmentFiniteElement::P0SegmentFiniteElement(int Ord)
   : NodalFiniteElement(1, Geometry::SEGMENT, 1, Ord)   // default Ord = 0
@@ -50,8 +50,6 @@ public:
       contains the derivative of one shape function */
   void CalcDShape(const IntegrationPoint &ip,
                   DenseMatrix &dshape) const override;
-   void CalcHessian(const IntegrationPoint &ip,
-                    DenseMatrix &h) const override;
 };

 /// A 2D linear element on triangle with nodes at the vertices of the triangle
@@ -72,8 +70,6 @@ public:
       so that each row contains the derivatives of one shape function */
   void CalcDShape(const IntegrationPoint &ip,
                   DenseMatrix &dshape) const override;
-   void CalcHessian(const IntegrationPoint &ip,
-                    DenseMatrix &h) const override;
   void ProjectDelta(int vertex, Vector &dofs) const override
   { dofs = 0.0; dofs(vertex) = 1.0; }
 };
@@ -408,9 +404,6 @@ public:
   void CalcDShape(const IntegrationPoint &ip,
                   DenseMatrix &dshape) const override;

-   void CalcHessian(const IntegrationPoint &ip,
-                    DenseMatrix &h) const override;
-
   void ProjectDelta(int vertex, Vector &dofs) const override
   { dofs = 0.0; dofs(vertex) = 1.0; }

@@ -452,8 +445,7 @@ public:
       so that each row contains the derivatives of one shape function */
   void CalcDShape(const IntegrationPoint &ip,
                   DenseMatrix &dshape) const override;
-   void CalcHessian(const IntegrationPoint &ip,
-                    DenseMatrix &h) const override;
+
   void ProjectDelta(int vertex, Vector &dofs) const override
   { dofs = 0.0; dofs(vertex) = 1.0; }
 };
@@ -84,46 +84,6 @@ void NURBS1DFiniteElement::CalcHessian (const IntegrationPoint &ip,
   add(1.0, hess, (-d2sum + 2*dsum*dsum*sum)*sum*sum, shape_x, hess);
 }

-void NURBS1DFiniteElement::Project(Coefficient &coeff,
-                                   ElementTransformation &Trans,
-                                   Vector &dofs) const
-{
-   IntegrationPoint ip;
-
-   for (int i = 0; i <= order; i++)
-   {
-      real_t kx = kv[0]->GetBotella(ijk[0] + i);
-      if (!kv[0]->inSpan(kx, ijk[0]+order)) { continue; }
-      ip.x = kv[0]->GetRefPoint(kx, ijk[0]+order);
-
-      Trans.SetIntPoint(&ip);
-      dofs(i) = coeff.Eval(Trans, ip);
-   }
-}
-
-void NURBS1DFiniteElement::Project(VectorCoefficient &vc,
-                                   ElementTransformation &Trans,
-                                   Vector &dofs) const
-{
-   MFEM_ASSERT(dofs.Size() == vc.GetVDim()*dof, "");
-   Vector x(vc.GetVDim());
-   IntegrationPoint ip;
-
-   for (int i = 0; i <= order; i++)
-   {
-      real_t kx = kv[0]->GetBotella(ijk[0] + i);
-      if (!kv[0]->inSpan(kx, ijk[0]+order)) { continue; }
-      ip.x = kv[0]->GetRefPoint(kx, ijk[0]+order);
-
-      Trans.SetIntPoint(&ip);
-      vc.Eval(x, Trans, ip);
-      for (int j = 0; j < x.Size(); j++)
-      {
-         dofs(dof*j+i) = x(j);
-      }
-   }
-}
-

 void NURBS2DFiniteElement::SetOrder() const
 {
@@ -255,63 +215,6 @@ void NURBS2DFiniteElement::CalcHessian (const IntegrationPoint &ip,
   }
 }

-void NURBS2DFiniteElement::Project(Coefficient &coeff,
-                                   ElementTransformation &Trans,
-                                   Vector &dofs) const
-{
-   IntegrationPoint ip;
-   for (int o = 0, j = 0; j <= orders[1]; j++)
-   {
-      real_t ky = kv[1]->GetBotella(ijk[1] + j);
-      if (!kv[1]->inSpan(ky, ijk[1]+orders[1]))
-      {
-         o += orders[0] + 1;
-         continue;
-      }
-      ip.y = kv[1]->GetRefPoint(ky, ijk[1]+orders[1]);
-      for (int i = 0; i <= orders[0]; i++, o++)
-      {
-         real_t kx = kv[0]->GetBotella(ijk[0] + i);
-         if (!kv[0]->inSpan(kx, ijk[0]+orders[0])) { continue; }
-         ip.x = kv[0]->GetRefPoint(kx, ijk[0]+orders[0]);
-
-         Trans.SetIntPoint(&ip);
-         dofs(o) = coeff.Eval(Trans, ip);
-      }
-   }
-}
-
-void NURBS2DFiniteElement::Project(VectorCoefficient &vc,
-                                   ElementTransformation &Trans,
-                                   Vector &dofs) const
-{
-   MFEM_ASSERT(dofs.Size() == vc.GetVDim()*dof, "");
-   Vector x(vc.GetVDim());
-   IntegrationPoint ip;
-   for (int o = 0, j = 0; j <= orders[1]; j++)
-   {
-      real_t ky = kv[1]->GetBotella(ijk[1] + j);
-      if (!kv[1]->inSpan(ky, ijk[1]+orders[1]))
-      {
-         o += orders[0] + 1;
-         continue;
-      }
-      ip.y = kv[1]->GetRefPoint(ky, ijk[1]+orders[1]);
-      for (int i = 0; i <= orders[0]; i++, o++)
-      {
-         real_t kx = kv[0]->GetBotella(ijk[0] + i);
-         if (!kv[0]->inSpan(kx, ijk[0]+orders[0])) { continue; }
-         ip.x = kv[0]->GetRefPoint(kx, ijk[0]+orders[0]);
-
-         Trans.SetIntPoint(&ip);
-         vc.Eval(x, Trans, ip);
-         for (int v = 0; v < x.Size(); v++)
-         {
-            dofs(dof*v+o) = x(v);
-         }
-      }
-   }
-}

 void NURBS3DFiniteElement::SetOrder() const
 {
@@ -445,10 +348,11 @@ void NURBS3DFiniteElement::CalcHessian (const IntegrationPoint &ip,
            d2sum[0] += ( hessian(o,0) = d2sx*sy*sz*weights(o) );
            d2sum[1] += ( hessian(o,1) = dsx*dsy*sz*weights(o) );
            d2sum[2] += ( hessian(o,2) = dsx*sy*dsz*weights(o) );
-            d2sum[3] += ( hessian(o,3) = sx*d2sy*sz*weights(o) );
-            d2sum[4] += ( hessian(o,4) = sx*dsy*dsz*weights(o) );
-            d2sum[5] += ( hessian(o,5) = sx*sy*d2sz*weights(o) );

+            d2sum[3] += ( hessian(o,3) = sx*dsy*dsz*weights(o) );
+
+            d2sum[4] += ( hessian(o,4) = sx*sy*d2sz*weights(o) );
+            d2sum[5] += ( hessian(o,5) = sx*d2sy*sz*weights(o) );
         }
      }
   }
@@ -497,85 +401,6 @@ void NURBS3DFiniteElement::CalcHessian (const IntegrationPoint &ip,
   }
 }

-void NURBS3DFiniteElement::Project(Coefficient &coeff,
-                                   ElementTransformation &Trans,
-                                   Vector &dofs) const
-{
-   IntegrationPoint ip;
-
-   for (int o = 0, k = 0; k <= orders[2]; k++)
-   {
-      real_t kz = kv[2]->GetBotella(ijk[2] + k);
-      if (!kv[2]->inSpan(kz, ijk[2]+orders[2]))
-      {
-         o += (orders[0] + 1)*(orders[1] + 1);
-         continue;
-      }
-      ip.z = kv[2]->GetRefPoint(kz, ijk[2]+orders[2]);
-      for (int j = 0; j <= orders[1]; j++)
-      {
-         real_t ky = kv[1]->GetBotella(ijk[1] + j);
-         if (!kv[1]->inSpan(ky, ijk[1]+orders[1]))
-         {
-            o += orders[0] + 1;
-            continue;
-         }
-         ip.y = kv[1]->GetRefPoint(ky, ijk[1]+orders[1]);
-         for (int i = 0; i <= orders[0]; i++, o++)
-         {
-            real_t kx = kv[0]->GetBotella(ijk[0] + i);
-            if (!kv[0]->inSpan(kx, ijk[0]+orders[0])) { continue; }
-            ip.x = kv[0]->GetRefPoint(kx, ijk[0]+orders[0]);
-
-            Trans.SetIntPoint(&ip);
-            dofs(o) = coeff.Eval(Trans, ip);
-         }
-      }
-   }
-}
-
-void NURBS3DFiniteElement::Project(VectorCoefficient &vc,
-                                   ElementTransformation &Trans,
-                                   Vector &dofs) const
-{
-   MFEM_ASSERT(dofs.Size() == vc.GetVDim()*dof, "");
-   Vector x(vc.GetVDim());
-   IntegrationPoint ip;
-
-   for (int o = 0, k = 0; k <= orders[2]; k++)
-   {
-      real_t kz = kv[2]->GetBotella(ijk[2] + k);
-      if (!kv[2]->inSpan(kz, ijk[2]+orders[2]))
-      {
-         o += (orders[0] + 1)*(orders[1] + 1);
-         continue;
-      }
-      ip.z = kv[2]->GetRefPoint(kz, ijk[2]+orders[2]);
-      for (int j = 0; j <= orders[1]; j++)
-      {
-         real_t ky = kv[1]->GetBotella(ijk[1] + j);
-         if (!kv[1]->inSpan(ky, ijk[1]+orders[1]))
-         {
-            o += orders[0] + 1;
-            continue;
-         }
-         ip.y = kv[1]->GetRefPoint(ky, ijk[1]+orders[1]);
-         for (int i = 0; i <= orders[0]; i++, o++)
-         {
-            real_t kx = kv[0]->GetBotella(ijk[0] + i);
-            if (!kv[0]->inSpan(kx, ijk[0]+orders[0])) { continue; }
-            ip.x = kv[0]->GetRefPoint(kx, ijk[0]+orders[0]);
-
-            Trans.SetIntPoint(&ip);
-            vc.Eval(x, Trans, ip);
-            for (int v = 0; v < x.Size(); v++)
-            {
-               dofs(dof*v+o) = x(v);
-            }
-         }
-      }
-   }
-}

 void NURBS_HDiv2DFiniteElement::SetOrder() const
 {
@@ -692,63 +517,6 @@ void NURBS_HDiv2DFiniteElement::CalcDivShape(const IntegrationPoint &ip,
   }
 }

-void NURBS_HDiv2DFiniteElement::Project(VectorCoefficient &vc,
-                                        ElementTransformation &Trans,
-                                        Vector &dofs) const
-{
-   MFEM_ASSERT(dofs.Size() == dof, "");
-   MFEM_ASSERT(vc.GetVDim() == 2, "");
-   Vector x(2), mx(2);
-   IntegrationPoint ip;
-   int o = 0;
-
-   for (int j = 0; j <= orders[1]; j++)
-   {
-      real_t ky = kv[1]->GetBotella(ijk[1] + j);
-      if (!kv[1]->inSpan(ky, ijk[1]+orders[1]))
-      {
-         o += orders[0] + 2;
-         continue;
-      }
-      ip.y = kv[1]->GetRefPoint(ky, ijk[1]+orders[1]);
-      for (int i = 0; i <= orders[0]+1; i++, o++)
-      {
-         real_t kx = kv1[0]->GetBotella(ijk[0] + i);
-         if (!kv1[0]->inSpan(kx, ijk[0]+orders[0]+1)) { continue; }
-         ip.x = kv1[0]->GetRefPoint(kx, ijk[0]+orders[0]+1);
-
-         Trans.SetIntPoint(&ip);
-         vc.Eval(x, Trans, ip);
-
-         Trans.AdjugateJacobian().Mult(x,mx);
-         dofs(o) = mx(0);
-      }
-   }
-
-   for (int j = 0; j <= orders[1]+1; j++)
-   {
-      real_t ky = kv1[1]->GetBotella(ijk[1] + j);
-      if (!kv1[1]->inSpan(ky, ijk[1]+orders[1]+1))
-      {
-         o += orders[0] + 1;
-         continue;
-      }
-      ip.y = kv1[1]->GetRefPoint(ky, ijk[1]+orders[1]+1);
-      for (int i = 0; i <= orders[0]; i++, o++)
-      {
-         real_t kx = kv[0]->GetBotella(ijk[0] + i);
-         if (!kv[0]->inSpan(kx, ijk[0]+orders[0])) { continue; }
-         ip.x = kv[0]->GetRefPoint(kx, ijk[0]+orders[0]);
-
-         Trans.SetIntPoint(&ip);
-         vc.Eval(x, Trans, ip);
-
-         Trans.AdjugateJacobian().Mult(x,mx);
-         dofs(o) = mx(1);
-      }
-   }
-}
-
 NURBS_HDiv2DFiniteElement::~NURBS_HDiv2DFiniteElement()
 {
   if (kv1[0]) { delete kv1[0]; }
@@ -928,120 +696,6 @@ void NURBS_HDiv3DFiniteElement::CalcDivShape(const IntegrationPoint &ip,
   }
 }

-
-void NURBS_HDiv3DFiniteElement::Project(VectorCoefficient &vc,
-                                        ElementTransformation &Trans,
-                                        Vector &dofs) const
-{
-   MFEM_ASSERT(dofs.Size() == dof, "");
-   MFEM_ASSERT(vc.GetVDim() == 3, "");
-   Vector x(2), mx(3);
-   IntegrationPoint ip;
-
-   int o = 0;
-
-   for (int k = 0; k <= orders[2]; k++)
-   {
-      real_t kz = kv[2]->GetBotella(ijk[2] + k);
-      if (!kv[2]->inSpan(kz, ijk[2]+orders[2]))
-      {
-         o += (orders[0] + 2)*(orders[1] + 1);
-         continue;
-      }
-      ip.z = kv[2]->GetRefPoint(kz, ijk[2]+orders[2]);
-      for (int j = 0; j <= orders[1]; j++)
-      {
-         real_t ky = kv[1]->GetBotella(ijk[1] + j);
-         if (!kv[1]->inSpan(ky, ijk[1]+orders[1]))
-         {
-            o += orders[0] + 2;
-            continue;
-         }
-         ip.y = kv[1]->GetRefPoint(ky, ijk[1]+orders[1]);
-         for (int i = 0; i <= orders[0]+1; i++, o++)
-         {
-            real_t kx = kv1[0]->GetBotella(ijk[0] + i);
-            if (!kv1[0]->inSpan(kx, ijk[0]+orders[0]+1)) { continue; }
-            ip.x = kv1[0]->GetRefPoint(kx, ijk[0]+orders[0]+1);
-
-            Trans.SetIntPoint(&ip);
-            vc.Eval(x, Trans, ip);
-
-            Trans.AdjugateJacobian().Mult(x,mx);
-            dofs(o) = mx(0);
-         }
-      }
-   }
-
-   for (int k = 0; k <= orders[2]; k++)
-   {
-      real_t kz = kv[2]->GetBotella(ijk[2] + k);
-      if (!kv[2]->inSpan(kz, ijk[2]+orders[2]))
-      {
-         o += (orders[0] + 1)*(orders[1] + 2);
-         continue;
-      }
-      ip.z = kv[2]->GetRefPoint(kz, ijk[2]+orders[2]);
-      for (int j = 0; j <= orders[1]+1; j++)
-      {
-         real_t ky = kv1[1]->GetBotella(ijk[1] + j);
-         if (!kv1[1]->inSpan(ky, ijk[1]+orders[1]+1))
-         {
-            o += orders[0] + 1;
-            continue;
-         }
-         ip.y = kv1[1]->GetRefPoint(ky, ijk[1]+orders[1]+1);
-         for (int i = 0; i <= orders[0]; i++, o++)
-         {
-            real_t kx = kv[0]->GetBotella(ijk[0] + i);
-            if (!kv[0]->inSpan(kx, ijk[0]+orders[0])) { continue; }
-            ip.x = kv[0]->GetRefPoint(kx, ijk[0]+orders[0]);
-
-            Trans.SetIntPoint(&ip);
-            vc.Eval(x, Trans, ip);
-
-            Trans.AdjugateJacobian().Mult(x,mx);
-            dofs(o) = mx(1);
-         }
-      }
-   }
-
-   for (int k = 0; k <= orders[2]+1; k++)
-   {
-      real_t kz = kv1[2]->GetBotella(ijk[2] + k);
-      if (!kv1[2]->inSpan(kz, ijk[2]+orders[2]+1))
-      {
-         o += (orders[0] + 1)*(orders[1] + 1);
-         continue;
-      }
-      ip.z = kv1[2]->GetRefPoint(kz, ijk[2]+orders[2]+1);
-      for (int j = 0; j <= orders[1]; j++)
-      {
-         real_t ky = kv[1]->GetBotella(ijk[1] + j);
-         if (!kv[1]->inSpan(ky, ijk[1]+orders[1]))
-         {
-            o += orders[0] + 1;
-            continue;
-         }
-         ip.y = kv[1]->GetRefPoint(ky, ijk[1]+orders[1]);
-         for (int i = 0; i <= orders[0]; i++, o++)
-         {
-            real_t kx = kv[0]->GetBotella(ijk[0] + i);
-            if (!kv[0]->inSpan(kx, ijk[0]+orders[0])) { continue; }
-            ip.x = kv[0]->GetRefPoint(kx, ijk[0]+orders[0]);
-
-            Trans.SetIntPoint(&ip);
-            vc.Eval(x, Trans, ip);
-
-            Trans.AdjugateJacobian().Mult(x,mx);
-            dofs(o) = mx(2);
-         }
-      }
-   }
-
-}
-
-
 NURBS_HDiv3DFiniteElement::~NURBS_HDiv3DFiniteElement()
 {
   if (kv1[0]) { delete kv1[0]; }
@@ -1163,68 +817,13 @@ void NURBS_HCurl2DFiniteElement::CalcCurlShape(const IntegrationPoint &ip,
   }
 }

-void NURBS_HCurl2DFiniteElement::Project(VectorCoefficient &vc,
-                                         ElementTransformation &Trans,
-                                         Vector &dofs) const
-{
-   MFEM_ASSERT(dofs.Size() == dof, "");
-   MFEM_ASSERT(vc.GetVDim() == 2, "");
-   Vector x(2), xm(2);
-   IntegrationPoint ip;
-   int i, j, o;
-   for (o = 0, j = 0; j <= orders[1]+1; j++)
-   {
-      real_t ky = kv1[1]->GetBotella(ijk[1] + j);
-      if (!kv1[1]->inSpan(ky, ijk[1]+orders[1]+1))
-      {
-         o += orders[0] + 1;
-         continue;
-      }
-      ip.y = kv1[1]->GetRefPoint(ky, ijk[1]+orders[1]+1);
-      for (i = 0; i <= orders[0]; i++, o++)
-      {
-         real_t kx = kv[0]->GetBotella(ijk[0] + i);
-         if (!kv[0]->inSpan(kx, ijk[0]+orders[0])) { continue; }
-         ip.x = kv[0]->GetRefPoint(kx, ijk[0]+orders[0]);
-
-         Trans.SetIntPoint(&ip);
-         vc.Eval(x, Trans, ip);
-
-         Trans.Jacobian().MultTranspose(x,xm);
-         dofs(o) = xm(0);
-      }
-   }
-
-   for (j = 0; j <= orders[1]; j++)
-   {
-      real_t ky = kv[1]->GetBotella(ijk[1] + j);
-      if (!kv[1]->inSpan(ky, ijk[1]+orders[1]))
-      {
-         o += orders[0] + 2;
-         continue;
-      }
-      ip.y = kv[1]->GetRefPoint(ky, ijk[1]+orders[1]);
-      for (i = 0; i <= orders[0]+1; i++, o++)
-      {
-         real_t kx = kv1[0]->GetBotella(ijk[0] + i);
-         if (!kv1[0]->inSpan(kx, ijk[0]+orders[0]+1)) { continue; }
-         ip.x = kv1[0]->GetRefPoint(kx, ijk[0]+orders[0]+1);
-
-         Trans.SetIntPoint(&ip);
-         vc.Eval(x, Trans, ip);
-
-         Trans.Jacobian().MultTranspose(x,xm);
-         dofs(o) = xm(1);
-      }
-   }
-}
-
 NURBS_HCurl2DFiniteElement::~NURBS_HCurl2DFiniteElement()
 {
   if (kv1[0]) { delete kv1[0]; }
   if (kv1[1]) { delete kv1[1]; }
 }

+
 void NURBS_HCurl3DFiniteElement::SetOrder() const
 {
   orders[0] = kv[0]->GetOrder();
@@ -1404,124 +1003,11 @@ void NURBS_HCurl3DFiniteElement::CalcCurlShape(const IntegrationPoint &ip,
            curl_shape(o,0) = shape1_x(i)*dsy1_sz;
            curl_shape(o,1) = -dshape1_x(i)*sy1_sz;
            curl_shape(o,2) = 0.0;
-
         }
      }
   }
 }

-void NURBS_HCurl3DFiniteElement::Project(VectorCoefficient &vc,
-                                         ElementTransformation &Trans,
-                                         Vector &dofs) const
-{
-   MFEM_ASSERT(dofs.Size() == dof, "");
-   MFEM_ASSERT(vc.GetVDim() == 3, "");
-   Vector x(3), xm(3);
-   IntegrationPoint ip;
-
-   int o = 0;
-   for (int k = 0; k <= orders[2]+1; k++)
-   {
-      real_t kz = kv1[2]->GetBotella(ijk[2] + k);
-      if (!kv1[2]->inSpan(kz, ijk[2]+orders[2]+1))
-      {
-         o += (orders[0] + 1)*(orders[1] + 2);
-         continue;
-      }
-      ip.z = kv1[2]->GetRefPoint(kz, ijk[2]+orders[2]+1);
-      for (int j = 0; j <= orders[1]+1; j++)
-      {
-         real_t ky = kv1[1]->GetBotella(ijk[1] + j);
-         if (!kv1[1]->inSpan(ky, ijk[1]+orders[1]+1))
-         {
-            o += orders[0] + 1;
-            continue;
-         }
-         ip.y = kv1[1]->GetRefPoint(ky, ijk[1]+orders[1]+1);
-         for (int i = 0; i <= orders[0]; i++, o++)
-         {
-            real_t kx = kv[0]->GetBotella(ijk[0] + i);
-            if (!kv[0]->inSpan(kx, ijk[0]+orders[0])) { continue; }
-            ip.x = kv[0]->GetRefPoint(kx, ijk[0]+orders[0]);
-
-            Trans.SetIntPoint(&ip);
-            vc.Eval(x, Trans, ip);
-
-            Trans.Jacobian().MultTranspose(x,xm);
-            dofs(o) = xm(0);
-         }
-      }
-   }
-
-   for (int k = 0; k <= orders[2]+1; k++)
-   {
-      real_t kz = kv1[2]->GetBotella(ijk[2] + k);
-      if (!kv1[2]->inSpan(kz, ijk[2]+orders[2]+1))
-      {
-         o += (orders[0] + 2)*(orders[1] + 1);
-         continue;
-      }
-      ip.z = kv1[2]->GetRefPoint(kz, ijk[2]+orders[2]+1);
-      for (int j = 0; j <= orders[1]; j++)
-      {
-         real_t ky = kv[1]->GetBotella(ijk[1] + j);
-         if (!kv[1]->inSpan(ky, ijk[1]+orders[1]))
-         {
-            o += orders[0] + 2;
-            continue;
-         }
-         ip.y = kv[1]->GetRefPoint(ky, ijk[1]+orders[1]);
-         for (int i = 0; i <= orders[0]+1; i++, o++)
-         {
-            real_t kx = kv1[0]->GetBotella(ijk[0] + i);
-            if (!kv1[0]->inSpan(kx, ijk[0]+orders[0]+1)) { continue; }
-            ip.x = kv1[0]->GetRefPoint(kx, ijk[0]+orders[0]+1);
-
-            Trans.SetIntPoint(&ip);
-            vc.Eval(x, Trans, ip);
-
-            Trans.Jacobian().MultTranspose(x,xm);
-            dofs(o) = xm(1);
-         }
-      }
-   }
-
-   for (int k = 0; k <= orders[2]; k++)
-   {
-      real_t kz = kv[2]->GetBotella(ijk[2] + k);
-      if (!kv[2]->inSpan(kz, ijk[2]+orders[2]))
-      {
-         o += (orders[0] + 2)*(orders[1] + 2);
-         continue;
-      }
-      ip.z = kv[2]->GetRefPoint(kz, ijk[2]+orders[2]);
-      for (int j = 0; j <= orders[1]+1; j++)
-      {
-         real_t ky = kv1[1]->GetBotella(ijk[1] + j);
-         if (!kv1[1]->inSpan(ky, ijk[1]+orders[1]+1))
-         {
-            o += orders[0] + 2;
-            continue;
-         }
-         ip.y = kv1[1]->GetRefPoint(ky, ijk[1]+orders[1]+1);
-         for (int i = 0; i <= orders[0]+1; i++, o++)
-         {
-            real_t kx = kv1[0]->GetBotella(ijk[0] + i);
-            if (!kv1[0]->inSpan(kx, ijk[0]+orders[0]+1)) { continue; }
-            ip.x = kv1[0]->GetRefPoint(kx, ijk[0]+orders[0]+1);
-
-            Trans.SetIntPoint(&ip);
-            vc.Eval(x, Trans, ip);
-
-            Trans.Jacobian().MultTranspose(x,xm);
-            dofs(o) = xm(2);
-         }
-      }
-   }
-
-}
-
-
 NURBS_HCurl3DFiniteElement::~NURBS_HCurl3DFiniteElement()
 {
   if (kv1[0]) { delete kv1[0]; }
@@ -86,18 +86,6 @@ public:
                   DenseMatrix &dshape) const override;
   void CalcHessian (const IntegrationPoint &ip,
                     DenseMatrix &hessian) const override;
-
-   using FiniteElement::Project;
-
-   /** Evaluate the dofs that are defined on this element.
-       Dofs that can not be evaluated will remain unmodified. */
-   void Project(Coefficient &coeff,
-                ElementTransformation &Trans, Vector &dofs) const override;
-
-   /** Evaluate the dofs that are defined on this element.
-       Dofs that can not be evaluated will remain unmodified. */
-   void Project(VectorCoefficient &vcoeff,
-                ElementTransformation &Trans, Vector &dofs) const override;
 };

 /// An arbitrary order 2D NURBS element on a square
@@ -133,18 +121,6 @@ public:
                   DenseMatrix &dshape) const override;
   void CalcHessian (const IntegrationPoint &ip,
                     DenseMatrix &hessian) const override;
-
-   using FiniteElement::Project;
-
-   /** Evaluate the dofs that are defined on this element.
-       Dofs that can not be evaluated will remain unmodified. */
-   void Project(Coefficient &coeff,
-                ElementTransformation &Trans, Vector &dofs) const override;
-
-   /** Evaluate the dofs that are defined on this element.
-       Dofs that can not be evaluated will remain unmodified. */
-   void Project(VectorCoefficient &vcoeff,
-                ElementTransformation &Trans, Vector &dofs) const override;
 };

 /// An arbitrary order 3D NURBS element on a cube
@@ -185,18 +161,6 @@ public:
                   DenseMatrix &dshape) const override;
   void CalcHessian (const IntegrationPoint &ip,
                     DenseMatrix &hessian) const override;
-
-   using FiniteElement::Project;
-
-   /** Evaluate the dofs that are defined on this element.
-       Dofs that can not be evaluated will remain unmodified. */
-   void Project(Coefficient &coeff,
-                ElementTransformation &Trans, Vector &dofs) const override;
-
-   /** Evaluate the dofs that are defined on this element.
-       Dofs that can not be evaluated will remain unmodified. */
-   void Project(VectorCoefficient &vcoeff,
-                ElementTransformation &Trans, Vector &dofs) const override;
 };


@@ -278,13 +242,6 @@ public:
   void CalcDivShape(const IntegrationPoint &ip,
                     Vector &divshape) const override;

-   using FiniteElement::Project;
-
-   /** Evaluate the dofs that are defined on this element.
-       Dofs that can not be evaluated will remain unmodified. */
-   void Project(VectorCoefficient &vcoeff,
-                ElementTransformation &Trans, Vector &dofs) const override;
-
   ~NURBS_HDiv2DFiniteElement();
 };

@@ -379,13 +336,6 @@ public:
   void CalcDivShape(const IntegrationPoint &ip,
                     Vector &divshape) const override;

-   using FiniteElement::Project;
-
-   /** Evaluate the dofs that are defined on this element.
-       Dofs that can not be evaluated will remain unmodified. */
-   void Project(VectorCoefficient &vcoeff,
-                ElementTransformation &Trans, Vector &dofs) const override;
-
   ~NURBS_HDiv3DFiniteElement();
 };

@@ -465,13 +415,6 @@ public:
   void CalcCurlShape(const IntegrationPoint &ip,
                      DenseMatrix &curl_shape) const override;

-   using FiniteElement::Project;
-
-   /** Evaluate the dofs that are defined on this element.
-       Dofs that can not be evaluated will remain unmodified. */
-   void Project(VectorCoefficient &vcoeff,
-                ElementTransformation &Trans, Vector &dofs) const override;
-
   ~NURBS_HCurl2DFiniteElement();
 };

@@ -563,13 +506,6 @@ public:
   void CalcCurlShape(const IntegrationPoint &ip,
                      DenseMatrix &curl_shape) const override;

-   using FiniteElement::Project;
-
-   /** Evaluate the dofs that are defined on this element.
-       Dofs that can not be evaluated will remain unmodified. */
-   void Project(VectorCoefficient &vcoeff,
-                ElementTransformation &Trans, Vector &dofs) const override;
-
   ~NURBS_HCurl3DFiniteElement();
 };

@@ -111,36 +111,36 @@ public:
   | :------: | :---: | :---: | :-------: | :-----: | :---: |
   | H1_[DIM]_[ORDER] | H1 | * | 1 | VALUE | H1 nodal elements |
   | H1@[BTYPE]_[DIM]_[ORDER] | H1 | * | * | VALUE | H1 nodal elements |
-   | H1Pos_[DIM]_[ORDER] | H1 | * | 2 | VALUE | H1 nodal elements |
+   | H1Pos_[DIM]_[ORDER] | H1 | * | 1 | VALUE | H1 nodal elements |
   | H1Pos_Trace_[DIM]_[ORDER] | H^{1/2} | * | 2 | VALUE | H^{1/2}-conforming trace elements for H1 defined on the interface between mesh elements (faces,edges,vertices) |
   | H1_Trace_[DIM]_[ORDER] | H^{1/2} | * | 1 | VALUE | H^{1/2}-conforming trace elements for H1 defined on the interface between mesh elements (faces,edges,vertices) |
-   | H1_Trace@[BTYPE]_[DIM]_[ORDER] | H^{1/2} | * | * | VALUE | H^{1/2}-conforming trace elements for H1 defined on the interface between mesh elements (faces,edges,vertices) |
+   | H1_Trace@[BTYPE]_[DIM]_[ORDER] | H^{1/2} | * | 1 | VALUE | H^{1/2}-conforming trace elements for H1 defined on the interface between mesh elements (faces,edges,vertices) |
   | ND_[DIM]_[ORDER] | H(curl) | * | 1 / 0 | H_CURL | Nedelec vector elements |
   | ND@[CBTYPE][OBTYPE]_[DIM]_[ORDER] | H(curl) | * | * / * | H_CURL | Nedelec vector elements |
-   | ND_Trace_[DIM]_[ORDER] | H^{1/2} | * | 1 / 0  | H_CURL | H^{1/2}-conforming trace elements for H(curl) defined on the interface between mesh elements (faces,edges) |
-   | ND_Trace@[CBTYPE][OBTYPE]_[DIM]_[ORDER] | H^{1/2} | * | * / * | H_CURL | H^{1/2}-conforming trace elements for H(curl) defined on the interface between mesh elements (faces,edges) |
+   | ND_Trace_[DIM]_[ORDER] | H^{1/2} | * | 1 / 0  | H_CURL | H^{1/2}-conforming trace elements for H(curl) defined on the interface between mesh elements (faces) |
+   | ND_Trace@[CBTYPE][OBTYPE]_[DIM]_[ORDER] | H^{1/2} | * | 1 / 0 | H_CURL | H^{1/2}-conforming trace elements for H(curl) defined on the interface between mesh elements (faces) |
   | ND_R1D_[DIM]_[ORDER] | H(curl) | * | 1 / 0 | H_CURL | 3D H(curl)-conforming Nedelec vector elements in 1D. |
   | ND_R1D@[CBTYPE][OBTYPE]_[DIM]_[ORDER] | H(curl) | * | * / * | H_CURL | 3D H(curl)-conforming Nedelec vector elements in 1D. |
   | ND_R2D_[DIM]_[ORDER] | H(curl) | * | 1 / 0 | H_CURL | 3D H(curl)-conforming Nedelec vector elements in 2D. |
   | ND_R2D@[CBTYPE][OBTYPE]_[DIM]_[ORDER] | H(curl) | * | * / * | H_CURL | 3D H(curl)-conforming Nedelec vector elements in 2D. |
   | RT_[DIM]_[ORDER] | H(div) | * | 1 / 0 | H_DIV | Raviart-Thomas vector elements |
   | RT@[CBTYPE][OBTYPE]_[DIM]_[ORDER] | H(div) | * | * / * | H_DIV | Raviart-Thomas vector elements |
-   | RT_Trace_[DIM]_[ORDER] | H^{1/2} | * | 0 | INTEGRAL | H^{1/2}-conforming trace elements for H(div) defined on the interface between mesh elements (faces) |
-   | RT_ValTrace_[DIM]_[ORDER] | H^{1/2} | * | 0 | VALUE | H^{1/2}-conforming trace elements for H(div) defined on the interface between mesh elements (faces) |
-   | RT_Trace@[BTYPE]_[DIM]_[ORDER] | H^{1/2} | * | * | INTEGRAL | H^{1/2}-conforming trace elements for H(div) defined on the interface between mesh elements (faces) |
-   | RT_ValTrace@[BTYPE]_[DIM]_[ORDER] |  H^{1/2} | * | * | VALUE | H^{1/2}-conforming trace elements for H(div) defined on the interface between mesh elements (faces) |
+   | RT_Trace_[DIM]_[ORDER] | H^{1/2} | * | 1 / 0 | INTEGRAL | H^{1/2}-conforming trace elements for H(div) defined on the interface between mesh elements (faces) |
+   | RT_ValTrace_[DIM]_[ORDER] | H^{1/2} | * | 1 / 0 | VALUE | H^{1/2}-conforming trace elements for H(div) defined on the interface between mesh elements (faces) |
+   | RT_Trace@[BTYPE]_[DIM]_[ORDER] | H^{1/2} | * | 1 / 0 | INTEGRAL | H^{1/2}-conforming trace elements for H(div) defined on the interface between mesh elements (faces) |
+   | RT_ValTrace@[BTYPE]_[DIM]_[ORDER] |  H^{1/2} | * | 1 / 0 | VALUE | H^{1/2}-conforming trace elements for H(div) defined on the interface between mesh elements (faces) |
   | RT_R1D_[DIM]_[ORDER] | H(div) | * | 1 / 0 | H_DIV | 3D H(div)-conforming Raviart-Thomas vector elements in 1D. |
   | RT_R1D@[CBTYPE][OBTYPE]_[DIM]_[ORDER] | H(div) | * | * / * | H_DIV | 3D H(div)-conforming Raviart-Thomas vector elements in 1D. |
   | RT_R2D_[DIM]_[ORDER] | H(div) | * | 1 / 0 | H_DIV | 3D H(div)-conforming Raviart-Thomas vector elements in 2D. |
   | RT_R2D@[CBTYPE][OBTYPE]_[DIM]_[ORDER] | H(div) | * | * / * | H_DIV | 3D H(div)-conforming Raviart-Thomas vector elements in 2D. |
   | L2_[DIM]_[ORDER] | L2 | * | 0 | VALUE | Discontinuous L2 elements |
-   | L2_T[BTYPE]_[DIM]_[ORDER] | L2 | * | * | VALUE | Discontinuous L2 elements |
+   | L2_T[BTYPE]_[DIM]_[ORDER] | L2 | * | 0 | VALUE | Discontinuous L2 elements |
   | L2Int_[DIM]_[ORDER] | L2 | * | 0 | INTEGRAL | Discontinuous L2 elements |
-   | L2Int_T[BTYPE]_[DIM]_[ORDER] | L2 | * | * | INTEGRAL | Discontinuous L2 elements |
+   | L2Int_T[BTYPE]_[DIM]_[ORDER] | L2 | * | 0 | INTEGRAL | Discontinuous L2 elements |
   | DG_Iface_[DIM]_[ORDER] | - | * | 0 | VALUE | Discontinuous elements on the interface between mesh elements (faces) |
-   | DG_Iface@[BTYPE]_[DIM]_[ORDER] | - | * | * | VALUE | Discontinuous elements on the interface between mesh elements (faces) |
+   | DG_Iface@[BTYPE]_[DIM]_[ORDER] | - | * | 0 | VALUE | Discontinuous elements on the interface between mesh elements (faces) |
   | DG_IntIface_[DIM]_[ORDER] | - | * | 0 | INTEGRAL | Discontinuous elements on the interface between mesh elements (faces) |
-   | DG_IntIface@[BTYPE]_[DIM]_[ORDER] | - | * | * | INTEGRAL | Discontinuous elements on the interface between mesh elements (faces) |
+   | DG_IntIface@[BTYPE]_[DIM]_[ORDER] | - | * | 0 | INTEGRAL | Discontinuous elements on the interface between mesh elements (faces) |
   | NURBS[ORDER] | - | * | - | VALUE | Non-Uniform Rational B-Splines (NURBS) elements |
   | LinearNonConf3D | - | 1 | 1 | VALUE | Piecewise-linear nonconforming finite elements in 3D |
   | CrouzeixRaviart | - | - | - | - | Crouzeix-Raviart nonconforming elements in 2D |
@@ -172,7 +172,7 @@ public:
   | :------: | :--------: |
   | [DIM]    | Dimension of the elements (1D, 2D, 3D) |
   | [ORDER]  | Approximation order of the elements (P0, P1, P2, ...) |
-   | [BTYPE]  | BasisType of the element (0-GaussLegendre, 1-GaussLobatto, 2-Bernstein, 3-OpenUniform, 4-CloseUniform, 5-OpenHalfUniform 6-Serendipity 7-ClosedGL 8-IntegratedGLL) |
+   | [BTYPE]  | BasisType of the element (0-GaussLegendre, 1 - GaussLobatto, 2-Bernstein, 3-OpenUniform, 4-CloseUniform, 5-OpenHalfUniform) |
   | [OBTYPE] | Open BasisType of the element for elements which have both types |
   | [CBTYPE] | Closed BasisType of the element for elements which have both types |

@@ -1516,76 +1516,36 @@ const FaceRestriction *FiniteElementSpace::GetFaceRestriction(
   const bool is_dg_space = IsDGSpace();
   const L2FaceValues m = (is_dg_space && mul==L2FaceValues::DoubleValued) ?
                          L2FaceValues::DoubleValued : L2FaceValues::SingleValued;
-   auto key = std::make_tuple(is_dg_space, f_ordering, type, m);
+   key_face key = std::make_tuple(is_dg_space, f_ordering, type, m);
   auto itr = L2F.find(key);
   if (itr != L2F.end())
   {
-      return itr->second.get();
+      return itr->second;
   }
   else
   {
-      std::unique_ptr<FaceRestriction> res;
+      FaceRestriction *res;
      if (is_dg_space)
      {
         if (Conforming())
         {
-            res.reset(new L2FaceRestriction(*this, f_ordering, type, m));
+            res = new L2FaceRestriction(*this, f_ordering, type, m);
         }
         else
         {
-            res.reset(new NCL2FaceRestriction(*this, f_ordering, type, m));
+            res = new NCL2FaceRestriction(*this, f_ordering, type, m);
         }
      }
      else if (dynamic_cast<const DG_Interface_FECollection*>(fec))
      {
-         res.reset(new L2InterfaceFaceRestriction(*this, f_ordering, type));
+         res = new L2InterfaceFaceRestriction(*this, f_ordering, type);
      }
      else
      {
-         res.reset(new ConformingFaceRestriction(*this, f_ordering, type));
+         res = new ConformingFaceRestriction(*this, f_ordering, type);
      }
-      return L2F.emplace(key, std::move(res)).first->second.get();
-   }
-}
-
-const InterpolationManager &FiniteElementSpace::GetInterpolationManager(
-   ElementDofOrdering f_ordering, FaceType type) const
-{
-   const auto key = make_tuple(f_ordering, type);
-
-   auto it = interpolations.find(key);
-   if (it != interpolations.end())
-   {
-      return *it->second;
-   }
-   else
-   {
-      auto interp = make_unique<InterpolationManager>(*this, f_ordering, type);
-
-      int face_idx = 0;
-      for (int f = 0; f < mesh->GetNumFacesWithGhost(); ++f)
-      {
-         Mesh::FaceInformation face = mesh->GetFaceInformation(f);
-         if (!face.IsOfFaceType(type) || face.IsNonconformingCoarse())
-         {
-            continue;
-         }
-         if (face.IsConforming() || face.IsBoundary())
-         {
-            interp->RegisterFaceConformingInterpolation(face, face_idx);
-         }
-         else
-         {
-            interp->RegisterFaceCoarseToFineInterpolation(face, face_idx);
-         }
-         ++face_idx;
-      }
-
-      // Transform the interpolation matrix map into contiguous memory.
-      interp->LinearizeInterpolatorMapIntoVector();
-      interp->InitializeNCInterpConfig();
-
-      return *interpolations.emplace(key, std::move(interp)).first->second;
+      L2F[key] = res;
+      return res;
   }
 }

@@ -4009,8 +3969,11 @@ void FiniteElementSpace::Destroy()
      delete E2Q_array[i];
   }
   E2Q_array.SetSize(0);
+   for (auto &x : L2F)
+   {
+      delete x.second;
+   }
   L2F.clear();
-   interpolations.clear();
   for (int i = 0; i < E2IFQ_array.Size(); i++)
   {
      delete E2IFQ_array[i];
@@ -13,7 +13,6 @@
 #define MFEM_FESPACE

 #include "../config/config.hpp"
-#include "../general/hash_util.hpp"
 #include "../linalg/ordering.hpp"
 #include "../linalg/sparsemat.hpp"
 #include "../mesh/mesh.hpp"
@@ -321,11 +320,18 @@ protected:
   mutable OperatorHandle L2E_nat, L2E_lex;
   /// The face restriction operators, see GetFaceRestriction().
   using key_face = std::tuple<bool, ElementDofOrdering, FaceType, L2FaceValues>;
-   mutable std::unordered_map<key_face,std::unique_ptr<FaceRestriction>,
-           TupleHasher> L2F;
-
-   mutable std::unordered_map<std::tuple<ElementDofOrdering,FaceType>,
-           std::unique_ptr<InterpolationManager>, TupleHasher> interpolations;
+   struct key_hash
+   {
+      std::size_t operator()(const key_face& k) const
+      {
+         return std::get<0>(k)
+                + 2 * (int)std::get<1>(k)
+                + 4 * (int)std::get<2>(k)
+                + 8 * (int)std::get<3>(k);
+      }
+   };
+   using map_L2F = std::unordered_map<const key_face,FaceRestriction*,key_hash>;
+   mutable map_L2F L2F;

   mutable Array<QuadratureInterpolator*> E2Q_array;
   mutable Array<FaceQuadratureInterpolator*> E2IFQ_array;
@@ -745,9 +751,6 @@ public:
      ElementDofOrdering f_ordering, FaceType,
      L2FaceValues mul = L2FaceValues::DoubleValued) const;

-   const InterpolationManager &GetInterpolationManager(
-      ElementDofOrdering f_ordering, FaceType type) const;
-
   /** @brief Return a QuadratureInterpolator that interpolates E-vectors to
       quadrature point values and/or derivatives (Q-vectors). */
   /** An E-vector represents the element-wise discontinuous version of the FE
@@ -2352,83 +2352,52 @@ void GridFunction::ProjectDeltaCoefficient(DeltaCoefficient &delta_coeff,
   }
 }

-void GridFunction::ProjectCoefficient(Coefficient &coeff, ProjectType type)
+void GridFunction::ProjectCoefficient(Coefficient &coeff)
 {
   DeltaCoefficient *delta_c = dynamic_cast<DeltaCoefficient *>(&coeff);
   DofTransformation doftrans;
-   Array<int> vdofs;
-   Vector vals;

   if (delta_c == NULL)
   {
      if (fes->GetNURBSext() == NULL)
      {
-         switch (type)
+         Array<int> vdofs;
+         Vector vals;
+
+         for (int i = 0; i < fes->GetNE(); i++)
         {
-            case ProjectType::ELEMENT_L2:
-               ProjectCoefficientElementL2(coeff);
-               return;
-            case ProjectType::GLOBAL_L2:
-               ProjectCoefficientGlobalL2(coeff);
-               return;
-            default:
-               for (int i = 0; i < fes->GetNE(); i++)
-               {
-                  fes->GetElementVDofs(i, vdofs, doftrans);
-                  vals.SetSize(vdofs.Size());
-                  fes->GetFE(i)->Project(coeff, *fes->GetElementTransformation(i), vals);
-                  doftrans.TransformPrimal(vals);
-                  SetSubVector(vdofs, vals);
-               }
+            fes->GetElementVDofs(i, vdofs, doftrans);
+            vals.SetSize(vdofs.Size());
+            fes->GetFE(i)->Project(coeff, *fes->GetElementTransformation(i), vals);
+            doftrans.TransformPrimal(vals);
+            SetSubVector(vdofs, vals);
         }
      }
      else
      {
-         switch (type)
-         {
-            case ProjectType::DEFAULT:
-            case ProjectType::ELEMENT_L2:
-               ProjectCoefficientElementL2(coeff);
-               return;
-            case ProjectType::GLOBAL_L2:
-               ProjectCoefficientGlobalL2(coeff);
-               return;
-            case ProjectType::ELEMENT:
-               constexpr real_t signal = std::numeric_limits<real_t>::min();
+         // Define and assemble linear form
+         LinearForm b(fes);
+         b.AddDomainIntegrator(new DomainLFIntegrator(coeff));
+         b.Assemble();

-               for (int i = 0; i < fes->GetNE(); i++)
-               {
-                  fes->GetElementVDofs(i, vdofs, doftrans);
-                  vals.SetSize(vdofs.Size());
-                  vals = signal;
+         // Define and assemble bilinear form
+         BilinearForm a(fes);
+         a.AddDomainIntegrator(new MassIntegrator());
+         a.Assemble();

-                  fes->GetFE(i)->Project(coeff,
-                                         *fes->GetElementTransformation(i),
-                                         vals);
-                  doftrans.TransformPrimal(vals);
+         // Set solver and preconditioner
+         SparseMatrix A(a.SpMat());
+         GSSmoother  prec(A);
+         CGSolver cg;
+         cg.SetOperator(A);
+         cg.SetPreconditioner(prec);
+         cg.SetRelTol(1e-12);
+         cg.SetMaxIter(1000);
+         cg.SetPrintLevel(0);

-                  // Remove undefined dofs
-                  // The knot location (either Botella, Demko or Greville point)
-                  // where the NURBS dof are evaluated might fall outside of the
-                  // domain of the element. In that case the value is not set, and
-                  // the value remains the signal value.
-                  int s = 0;
-                  for (int ii = 0; ii < vals.Size(); ii++)
-                  {
-                     if (vals[ii] != signal)
-                     {
-                        vdofs[s] = vdofs[ii];
-                        vals(s) = vals(ii);
-                        s++;
-                     }
-                  }
-                  vdofs.SetSize(s);
-                  vals.SetSize(s);
-
-                  // Add reduced dofs to global vector
-                  SetSubVector(vdofs, vals);
-               }
-         }
+         // Solve and get solution
+         *this = 0.0;
+         cg.Mult(b,*this);
      }
   }
   else
@@ -2441,167 +2410,6 @@ void GridFunction::ProjectCoefficient(Coefficient &coeff, ProjectType type)
   }
 }

-void GridFunction::ProjectCoefficientGlobalL2(Coefficient &coeff, real_t rtol,
-                                              int iter)
-{
-   // Define and assemble linear form
-   LinearForm b(fes);
-   b.AddDomainIntegrator(new DomainLFIntegrator(coeff));
-   b.Assemble();
-
-   // Define and assemble bilinear form
-   BilinearForm a(fes);
-   a.AddDomainIntegrator(new MassIntegrator());
-   a.Assemble();
-
-   // Set solver and preconditioner
-   SparseMatrix A(a.SpMat());
-   GSSmoother  prec(A);
-   CGSolver cg;
-   cg.SetOperator(A);
-   cg.SetPreconditioner(prec);
-   cg.SetRelTol(rtol);
-   cg.SetMaxIter(iter);
-   cg.SetPrintLevel(0);
-
-   // Solve and get solution
-   *this = 0.0;
-   cg.Mult(b,*this);
-}
-
-void GridFunction::ProjectCoefficientElementL2(Coefficient &coeff)
-{
-   Vector Va;
-   ProjectCoefficientElementL2_(coeff, *this, Va);
-   (*this) /= Va;
-}
-
-void GridFunction::ProjectCoefficientElementL2_(Coefficient &coeff,
-                                                Vector &x, Vector &Va)
-{
-   DofTransformation doftrans;
-   Array<int> vdofs;
-   Vector shape,shape2, elvect, elwght;
-   DenseMatrix elmat;
-   Va.SetSize(fes->GetNDofs() );
-   x.SetSize(fes->GetNDofs() );
-   Va = 0.0;
-   x = 0.0;
-
-   if (fes->GetNURBSext() == NULL)
-   {
-      for (int e = 0; e < fes->GetNE(); e++)
-      {
-         fes->GetElementDofs (e, vdofs, doftrans);
-         ElementTransformation &tr = *fes -> GetElementTransformation (e);
-         const FiniteElement &el = *fes->GetFE(e);
-         int dof = el.GetDof();
-         shape.SetSize(dof);
-         elvect.SetSize(dof);
-         elwght.SetSize(dof);
-         elmat.SetSize(dof,dof);
-         elvect = 0.0;
-         elwght = 0.0;
-         elmat = 0.0;
-
-         const IntegrationRule &ir = IntRules.Get(el.GetGeomType(),
-                                                  2 * el.GetOrder() + 1);
-
-         // Element vector & weight
-         for (int i = 0; i < ir.GetNPoints(); i++)
-         {
-            const IntegrationPoint &ip = ir.IntPoint(i);
-
-            tr.SetIntPoint (&ip);
-            real_t wght = ip.weight*tr.Weight();
-            real_t val = coeff.Eval(tr, ip);
-
-            el.CalcPhysShape(tr, shape);
-
-            elvect.Add(wght * val, shape);
-            elwght.Add(wght, shape);
-            AddMult_a_VVt(wght, shape, elmat);
-         }
-
-         // Solve
-         if (!LinearSolve(elmat, elvect.GetData(),1e-12))
-         {
-            MFEM_WARNING("Error in inverting element local matrix");
-         }
-
-         // Scale
-         elvect *= elwght;
-
-         // Add reduced dofs to global vector
-         x.AddElementVector(vdofs, elvect);
-         Va.AddElementVector(vdofs, elwght);
-      }
-   }
-   else
-   {
-      for (int e = 0; e < fes->GetNE(); e++)
-      {
-         fes->GetElementDofs (e, vdofs, doftrans);
-         ElementTransformation &tr = *fes -> GetElementTransformation (e);
-         const FiniteElement &el = *fes->GetFE(e);
-         int dof = el.GetDof();
-         int dim = el.GetDim();
-         int p = el.GetOrder();
-         L2_FECollection fe_coll(p,  dim);
-         //H1_FECollection fe_coll(p,  dim, BasisType::Positive);
-         const FiniteElement &el2 = *fe_coll.FiniteElementForGeometry(el.GetGeomType());
-         MFEM_ASSERT(el2.GetDof() == dof, "Element dofs do not match.");
-
-         shape.SetSize(dof);
-         shape2.SetSize(dof);
-         elvect.SetSize(dof);
-         elwght.SetSize(dof);
-         elmat.SetSize(dof,dof);
-         elvect = 0.0;
-         elwght = 0.0;
-         elmat = 0.0;
-
-         const IntegrationRule &ir = IntRules.Get(el.GetGeomType(),
-                                                  2 * el.GetOrder() + 1);
-
-         // Element vector & weight
-         for (int i = 0; i < ir.GetNPoints(); i++)
-         {
-            const IntegrationPoint &ip = ir.IntPoint(i);
-
-            tr.SetIntPoint (&ip);
-            real_t wght = ip.weight*tr.Weight();
-            real_t val = coeff.Eval(tr, ip);
-            el.CalcPhysShape(tr, shape);
-            el2.CalcPhysShape(tr, shape2);
-
-            elvect.Add(wght * val, shape2);
-            elwght.Add(wght, shape);
-            AddMult_a_VVt(wght, shape2, elmat);
-         }
-         // Solve
-         if (!LinearSolve(elmat, elvect.GetData(),1e-12))
-         {
-            MFEM_WARNING("Error in inverting element local matrix 2");
-         }
-         // Map to NURBS
-         DenseMatrix I;
-         el2.Project(el,tr,I);
-         if (!LinearSolve(I, elvect.GetData(),1e-32))
-         {
-            MFEM_WARNING("Error in inverting element local matrix 3");
-         }
-
-         // Scale
-         elvect *= elwght;
-
-         // Add reduced dofs to global vector
-         x.AddElementVector(vdofs, elvect);
-         Va.AddElementVector(vdofs, elwght);
-      }
-   }
-}
-
 void GridFunction::ProjectCoefficient(
   Coefficient &coeff, Array<int> &dofs, int vd)
 {
@@ -2626,318 +2434,49 @@ void GridFunction::ProjectCoefficient(
   }
 }

-void GridFunction::ProjectCoefficient(VectorCoefficient &vcoeff,
-                                      ProjectType type)
+void GridFunction::ProjectCoefficient(VectorCoefficient &vcoeff)
 {
-   Array<int> vdofs;
-   Vector vals;
   DofTransformation doftrans;
-
   if (fes->GetNURBSext() == NULL)
   {
-      switch (type)
+      int i;
+      Array<int> vdofs;
+      Vector vals;
+
+      for (i = 0; i < fes->GetNE(); i++)
      {
-         case ProjectType::ELEMENT_L2:
-            ProjectCoefficientElementL2(vcoeff);
-            return;
-         case ProjectType::GLOBAL_L2:
-            ProjectCoefficientGlobalL2(vcoeff);
-            return;
-         default:
-            for (int i = 0; i < fes->GetNE(); i++)
-            {
-               fes->GetElementVDofs(i, vdofs, doftrans);
-               vals.SetSize(vdofs.Size());
-               fes->GetFE(i)->Project(vcoeff, *fes->GetElementTransformation(i), vals);
-               doftrans.TransformPrimal(vals);
-               SetSubVector(vdofs, vals);
-            }
+         fes->GetElementVDofs(i, vdofs, doftrans);
+         vals.SetSize(vdofs.Size());
+         fes->GetFE(i)->Project(vcoeff, *fes->GetElementTransformation(i), vals);
+         doftrans.TransformPrimal(vals);
+         SetSubVector(vdofs, vals);
      }
   }
   else
   {
-      switch (type)
-      {
-         case ProjectType::DEFAULT:
-         case ProjectType::ELEMENT_L2:
-            ProjectCoefficientElementL2(vcoeff);
-            return;
-         case ProjectType::GLOBAL_L2:
-            ProjectCoefficientGlobalL2(vcoeff);
-            return;
-         case ProjectType::ELEMENT:
-            constexpr real_t signal = std::numeric_limits<real_t>::min();
-            for (int i = 0; i < fes->GetNE(); i++)
-            {
-               fes->GetElementVDofs(i, vdofs, doftrans);
-               vals.SetSize(vdofs.Size());
-               vals = signal;
-               fes->GetFE(i)->Project(vcoeff, *fes->GetElementTransformation(i), vals);
-               doftrans.TransformPrimal(vals);
-               // Remove undefined dofs
-               // The knot location (either Botella, Demko or Greville point)
-               // where the NURBS dof are evaluated might fall outside of the
-               // domain of the element. In that case the value is not set, and
-               // the value remains the signal value.
-               int s = 0;
-               for (int ii = 0; ii < vals.Size(); ii++)
-               {
-                  if (vals[ii] != signal)
-                  {
-                     vdofs[s] = vdofs[ii];
-                     vals(s) = vals(ii);
-                     s++;
-                  }
-               }
-               vdofs.SetSize(s);
-               vals.SetSize(s);
-
-               // Add reduced dofs to global vector
-               SetSubVector(vdofs, vals);
-            }
-      }
-   }
-}
-
-void GridFunction::ProjectCoefficientGlobalL2(VectorCoefficient &vcoeff,
-                                              real_t rtol, int iter)
-{
-   // Define and assemble linear form
-   LinearForm b(fes);
-   BilinearForm a(fes);
-
-   if (fes->GetTypicalFE()->GetRangeType() == mfem::FiniteElement::VECTOR)
-   {
+      // Define and assemble linear form
+      LinearForm b(fes);
      b.AddDomainIntegrator(new VectorFEDomainLFIntegrator(vcoeff));
+      b.Assemble();
+
+      // Define and assemble bilinear form
+      BilinearForm a(fes);
      a.AddDomainIntegrator(new VectorFEMassIntegrator());
-   }
-   else
-   {
-      b.AddDomainIntegrator(new VectorDomainLFIntegrator(vcoeff));
-      a.AddDomainIntegrator(new VectorMassIntegrator());
-   }
-   a.Assemble();
-   b.Assemble();
+      a.Assemble();

-   // Set solver and preconditioner
-   SparseMatrix A(a.SpMat());
-   GSSmoother  prec(A);
-   CGSolver cg;
-   cg.SetOperator(A);
-   cg.SetPreconditioner(prec);
-   cg.SetRelTol(rtol);
-   cg.SetMaxIter(iter);
-   cg.SetPrintLevel(0);
+      // Set solver and preconditioner
+      SparseMatrix A(a.SpMat());
+      GSSmoother  prec(A);
+      CGSolver cg;
+      cg.SetOperator(A);
+      cg.SetPreconditioner(prec);
+      cg.SetRelTol(1e-12);
+      cg.SetMaxIter(1000);
+      cg.SetPrintLevel(0);

-   // Solve and get solution
-   *this = 0.0;
-   cg.Mult(b,*this);
-}
-
-void GridFunction::ProjectCoefficientElementL2_(VectorCoefficient &vcoeff,
-                                                Vector &x, Vector &Va)
-{
-   DofTransformation doftrans;
-   Array<int> vdofs;
-   Vector shapel2, elvect, elwght, val;
-   DenseMatrix  shape, elmat;
-   Va.SetSize(Size());
-   x.SetSize(Size());
-   Va = 0.0;
-   x = 0.0;
-
-   if (fes->GetNURBSext() == NULL)
-   {
-      for (int e = 0; e < fes->GetNE(); e++)
-      {
-         fes->GetElementVDofs (e, vdofs, doftrans);
-         ElementTransformation &tr = *fes -> GetElementTransformation (e);
-         const FiniteElement &el = *fes->GetFE(e);
-         int dof = el.GetDof();
-         int dim = el.GetRangeDim();
-         shape.SetSize(dof,dim);
-         shapel2.SetSize(dof);
-         elvect.SetSize(dof);
-         elwght.SetSize(dof);
-         elmat.SetSize(dof,dof);
-         elvect = 0.0;
-         elwght = 0.0;
-         elmat = 0.0;
-
-         const IntegrationRule &ir = IntRules.Get(el.GetGeomType(),
-                                                  2 * el.GetOrder() + 1);
-
-         // Element vector & weight
-         for (int i = 0; i < ir.GetNPoints(); i++)
-         {
-            const IntegrationPoint &ip = ir.IntPoint(i);
-
-            tr.SetIntPoint (&ip);
-            real_t wght = ip.weight*tr.Weight();
-            vcoeff.Eval(val, tr, ip);
-            val *= wght;
-
-            el.CalcPhysVShape(tr, shape);
-
-            shape.AddMult (val, elvect);
-            AddMult_a_AAt(wght, shape, elmat);
-
-            shape.GetRowl2(shapel2);
-            elwght.Add(wght, shapel2);
-         }
-
-         // Solve
-         if (!LinearSolve(elmat, elvect.GetData(),1e-12))
-         {
-            MFEM_WARNING("Error in inverting element local matrix");
-         }
-
-         // Scale
-         elvect *= elwght;
-
-         // Add to global vector
-         x.AddElementVector(vdofs, elvect);
-
-         // Add to weight vector -- no need for an orientation
-         for (int i = 0; i < vdofs.Size(); i++)
-         {
-            vdofs[i] = FiniteElementSpace::DecodeDof(vdofs[i]);
-         }
-         Va.AddElementVector(vdofs, elwght);
-      }
-   }
-   else
-   {
-      DenseMatrix partelmat;
-      Vector shape2;
-
-      if (fes->GetTypicalFE()->GetOrder() >= 6 )
-      {
-         MFEM_WARNING("This project is not stable for"
-                      "NURBS VectorFE with order >= 5");
-      }
-      for (int e = 0; e < fes->GetNE(); e++)
-      {
-         fes->GetElementVDofs (e, vdofs, doftrans);
-         ElementTransformation &tr = *fes -> GetElementTransformation (e);
-         const FiniteElement &el = *fes->GetFE(e);
-         int dof = el.GetDof();
-         int dim = el.GetRangeDim();
-         int p = el.GetOrder();
-         L2_FECollection fe_coll(p,  dim);
-         const FiniteElement &el2 = *fe_coll.FiniteElementForGeometry(el.GetGeomType());
-         int dof2 = el2.GetDof();
-         MFEM_ASSERT(dof2*dim >= dof, "Element dofs do not match.");
-         shape2.SetSize(dof2);
-         shape.SetSize(dof,dim);
-         shapel2.SetSize(dof);
-         elvect.SetSize(dof2*dim);
-         elwght.SetSize(dof);
-         elmat.SetSize(dof2*dim,dof2*dim);
-         partelmat.SetSize(dof2,dof2);
-         elvect = 0.0;
-         elwght = 0.0;
-         elmat = 0.0;
-
-         const IntegrationRule &ir = IntRules.Get(el.GetGeomType(),
-                                                  2 * el.GetOrder() + 1);
-
-         // Element vector & weight
-         for (int i = 0; i < ir.GetNPoints(); i++)
-         {
-            const IntegrationPoint &ip = ir.IntPoint(i);
-
-            tr.SetIntPoint (&ip);
-            real_t wght = ip.weight*tr.Weight();
-            vcoeff.Eval(val, tr, ip);
-            val *= wght;
-
-            el2.CalcPhysShape(tr, shape2);
-            el.CalcPhysVShape(tr, shape);
-
-            for (int k = 0; k < dim; k++)
-            {
-               for (int s = 0; s < dof2; s++)
-               {
-                  elvect(dof2*k+s) += val(k) * shape2(s);
-               }
-            }
-
-            MultVVt(shape2, partelmat);
-            partelmat *= wght;
-            for (int k = 0; k < dim; k++)
-            {
-               elmat.AddMatrix(partelmat, dof2*k, dof2*k);
-            }
-
-            shape.GetRowl2(shapel2);
-            elwght.Add(wght, shapel2);
-         }
-
-         // Solve
-         if (!LinearSolve(elmat, elvect.GetData()))
-         {
-            MFEM_WARNING("Error in inverting element local matrix");
-         }
-
-         // Map to NURBS
-         DenseMatrix I;
-         el2.Project(el,tr,I);
-
-         // LSQ solve
-         // For higher order NURBS solving this non-square matrix causes issues.
-         // For Order <=4 the routine seems to work fine.
-         Vector vec(dof);
-         DenseMatrix mat(dof, dof);
-         I.Transpose();
-         I.Mult(elvect, vec);
-         MultAAt(I, mat);
-         if (!LinearSolve(mat, vec.GetData(), 1e-24))
-         {
-            mat.TestInversion();
-            MFEM_WARNING("Error in inverting element local matrix");
-         }
-         elvect = vec;
-
-         // Scale
-         elvect *= elwght;
-
-         // Add to global vector
-         x.AddElementVector(vdofs, elvect);
-
-         // Add to weight vector -- no need for an orientation
-         for (int i = 0; i < vdofs.Size(); i++)
-         {
-            vdofs[i] = FiniteElementSpace::DecodeDof(vdofs[i]);
-         }
-         Va.AddElementVector(vdofs, elwght);
-      }
-   }
-}
-
-void GridFunction::ProjectCoefficientElementL2(VectorCoefficient &vcoeff)
-{
-   if (fes->GetTypicalFE()->GetRangeType() == mfem::FiniteElement::VECTOR)
-   {
-      Vector Va;
-      ProjectCoefficientElementL2_(vcoeff, *this, Va);
-      (*this) /= Va;
-   }
-   else
-   {
-      Array<int> vdofs(fes->GetNDofs());
-      Vector x, Va;
-      VectorComponentCoefficient coeff(vcoeff,
-                                       0);  // 0  to ensure we have a valid object
-
-      for (int v = 0; v < VectorDim(); v++)
-      {
-         coeff.SetComponent(v);
-         ProjectCoefficientElementL2_(coeff, x, Va);
-         x /= Va;
-         fes->GetVDofs(v, vdofs);
-         SetSubVector(vdofs, x);
-      }
+      // Solve and get solution
+      *this = 0.0;
+      cg.Mult(b,*this);
   }
 }

@@ -27,24 +27,6 @@
 namespace mfem
 {

-/** This enumerated type describes the three main projection types:
-    - ELEMENT, assigns the degree of freedom per element, as specified in the
-      specific element
-    - GLOBAL_L2, solves a global L2 projection
-    - ELEMENT_L2, solves a element level L2 projection. Inter element
-      connectivity is dealt with similar as in:
-      Bezier-Projection : A unified approach for local projection and
-      quadrature-free refinement and coarsening of NURBS and T-splines with
-      particular application to isogeometric design and analysis
-      [CMAME (284) 2015 pg 55-105]
-    - DEFAULT, for NURBS spaces this is ELEMENT_L2, while for all other spaces
-      this ELEMENT.
-   Note 1: ELEMENT_L2 also works for non NURBS elements
-   Note 2: For NURBS elements the ELEMENT projection gives results without
-   over and undershoots. However, the gradient near the boundary does not
-   converge.*/
-enum class ProjectType { DEFAULT, ELEMENT, GLOBAL_L2, ELEMENT_L2 };
-
 /// Class for grid function - Vector with associated FE space.
 class GridFunction : public Vector
 {
@@ -84,17 +66,13 @@ protected:
       degree of freedom. */
   void ProjectDiscCoefficient(VectorCoefficient &coeff, Array<int> &dof_attr);

-   /** Helper function for ProjectCoefficientElementL2 */
-   void ProjectCoefficientElementL2_(Coefficient &coeff, Vector &sol, Vector &Va);
-   void ProjectCoefficientElementL2_(VectorCoefficient &vcoeff, Vector &sol,
-                                     Vector &Va);
-
   /// Loading helper.
   void LegacyNCReorder();

   void Destroy();

 public:
+
   GridFunction() { fes = NULL; fec_owned = NULL; fes_sequence = 0; UseDevice(true); }

   /// Copy constructor. The internal true-dof vector #t_vec is not copied.
@@ -106,10 +84,6 @@ public:
   GridFunction(FiniteElementSpace *f) : Vector(f->GetVSize())
   { fes = f; fec_owned = NULL; fes_sequence = f->GetSequence(); UseDevice(true); }

-   /// Same as above but specify the memory type
-   GridFunction(FiniteElementSpace *f, MemoryType mt) : Vector(f->GetVSize(), mt)
-   { fes = f; fec_owned = NULL; fes_sequence = f->GetSequence(); UseDevice(true); }
-
   /// Construct a GridFunction using previously allocated array @a data.
   /** The GridFunction does not assume ownership of @a data which is assumed to
       be of size at least `f->GetVSize()`. Similar to the Vector constructor
@@ -446,30 +420,9 @@ public:
   /** @brief Project @a coeff Coefficient to @a this GridFunction. The
       projection computation depends on the choice of the FiniteElementSpace
       #fes. Note that this is usually interpolation at the degrees of freedom
-       in each element (not L2 projection). For elements without a projection
-       member function one could use ProjectCoefficientGlobalL2 instead.
-       NOTE: For parallel simulations with NURBS elements some dofs might
-       not be defined, if the evaluation point does not reside on this rank.
-       If that is the case it is defined on another rank, and the issue is
-       rectified with the appropriate communication, see in ParGridFunction.
-       */
-   virtual void ProjectCoefficient(Coefficient &coeff,
-                                   ProjectType type = ProjectType::DEFAULT);
-
-   /** @brief Project @a coeff Coefficient to @a this GridFunction. The
-       projection is a global L2 projection. This routine can be used a
-       fallback for elements without a projection member function.*/
-   virtual void ProjectCoefficientGlobalL2(Coefficient &coeff,
-                                           real_t rtol = 1e-12,
-                                           int iter = 1000);
-
-   /** @brief Project @a coeff Coefficient to @a this GridFunction. The
-       projection is an element local L2 projection, with an appropriate
-       weighting for Dofs that are shared between elements. Inspired on
-       Bezier-Projection [CMAME (284) 2015 pg 55-105]
-       This routine can be used a fallback for elements without a projection
-       member function.*/
-   virtual void ProjectCoefficientElementL2(Coefficient &coeff);
+       in each element (not L2 projection). For NURBS spaces these degrees of
+       freedom are not available and L2 projection is resorted to as fallback. */
+   virtual void ProjectCoefficient(Coefficient &coeff);

   /** @brief Project @a coeff Coefficient to @a this GridFunction, using one
       element for each degree of freedom in @a dofs and nodal interpolation on
@@ -479,26 +432,9 @@ public:
   /** @brief Project @a vcoeff VectorCoefficient to @a this GridFunction. The
       projection computation depends on the choice of the FiniteElementSpace
       #fes. Note that this is usually interpolation at the degrees of freedom
-       in each element (not L2 projection). For elements without a projection
-       member function one could use ProjectCoefficientGlobalL2 instead.
-       NOTE: For parallel simulations with NURBS elements some dofs might
-       not be defined, if the evaluation point does not reside on this rank.
-       If that is the case it is defined on another rank, and the issue is
-       rectified with the appropriate communication, see in ParGridFunction.*/
-   virtual void ProjectCoefficient(VectorCoefficient &vcoeff,
-                                   ProjectType type = ProjectType::DEFAULT);
-
-   /** @brief Project @a coeff Coefficient to @a this GridFunction. The
-       projection is a global L2 projection. This routine can be used a
-       fallback for elements without a projection member function.*/
-   virtual void ProjectCoefficientGlobalL2(VectorCoefficient &vcoeff,
-                                           real_t rtol = 1e-12,
-                                           int iter = 1000);
-
-   /** @brief Project @a coeff Coefficient to @a this GridFunction. The
-       projection is a global L2 projection. This routine can be used a
-       fallback for elements without a projection member function.*/
-   virtual void ProjectCoefficientElementL2(VectorCoefficient &vcoeff);
+       in each element (not L2 projection). For NURBS spaces these degrees of
+       freedom are not available and L2 projection is resorted to as fallback. */
+   void ProjectCoefficient(VectorCoefficient &vcoeff);

   /** @brief Project @a vcoeff VectorCoefficient to @a this GridFunction, using
       one element for each degree of freedom in @a dofs and nodal interpolation
@@ -234,7 +234,7 @@ void FindPointsGSLIB::Setup(Mesh &m, const double bb_t, const double newt_tol,
 }

 void FindPointsGSLIB::FindPoints(const Vector &point_pos,
-                                 const int point_pos_ordering)
+                                 int point_pos_ordering)
 {
   MFEM_VERIFY(setupflag, "Use FindPointsGSLIB::Setup before finding points.");
   bool dev_mode = (point_pos.UseDevice() && Device::IsEnabled());
@@ -482,7 +482,7 @@ void FindPointsGSLIB::SetupDevice()
 }

 void FindPointsGSLIB::FindPointsOnDevice(const Vector &point_pos,
-                                         const int point_pos_ordering)
+                                         int point_pos_ordering)
 {
   if (!DEV.setup_device)
   {
@@ -505,13 +505,13 @@ void FindPointsGSLIB::FindPointsOnDevice(const Vector &point_pos,

   if (dim == 2)
   {
-      FindPointsLocal2(point_pos, point_pos_ordering, gsl_code, gsl_elem,
-                       gsl_ref, gsl_dist, points_cnt);
+      FindPointsLocal2(point_pos, point_pos_ordering, gsl_code, gsl_elem, gsl_ref,
+                       gsl_dist, points_cnt);
   }
   else
   {
-      FindPointsLocal3(point_pos, point_pos_ordering, gsl_code, gsl_elem,
-                       gsl_ref, gsl_dist, points_cnt);
+      FindPointsLocal3(point_pos, point_pos_ordering, gsl_code, gsl_elem, gsl_ref,
+                       gsl_dist, points_cnt);
   }

   // Sync from device to host
@@ -1085,7 +1085,7 @@ void FindPointsGSLIB::InterpolateOnDevice(const Vector &field_in_evec,
 #else
 void FindPointsGSLIB::SetupDevice() {};
 void FindPointsGSLIB::FindPointsOnDevice(const Vector &point_pos,
-                                         const int point_pos_ordering) {};
+                                         int point_pos_ordering) {};
 void FindPointsGSLIB::InterpolateOnDevice(const Vector &field_in_evec,
                                          Vector &field_out,
                                          const int nel, const int ncomp,
@@ -1094,8 +1094,7 @@ void FindPointsGSLIB::InterpolateOnDevice(const Vector &field_in_evec,
 #endif

 void FindPointsGSLIB::FindPoints(Mesh &m, const Vector &point_pos,
-                                 const int point_pos_ordering,
-                                 const double bb_t,
+                                 int point_pos_ordering, const double bb_t,
                                 const double newt_tol, const int npt_max)
 {
   if (!setupflag || (mesh != &m) )
@@ -1106,28 +1105,16 @@ void FindPointsGSLIB::FindPoints(Mesh &m, const Vector &point_pos,
 }

 void FindPointsGSLIB::Interpolate(const Vector &point_pos,
-                                  const GridFunction &field_in,
-                                  Vector &field_out,
-                                  const int point_pos_ordering)
+                                  const GridFunction &field_in, Vector &field_out,
+                                  int point_pos_ordering)
 {
   FindPoints(point_pos, point_pos_ordering);
   Interpolate(field_in, field_out);
 }

-void FindPointsGSLIB::Interpolate(const Vector &point_pos,
-                                  const GridFunction &field_in,
-                                  Vector &field_out,
-                                  const int point_pos_ordering,
-                                  const int field_out_ordering)
-{
-   FindPoints(point_pos, point_pos_ordering);
-   Interpolate(field_in, field_out, field_out_ordering);
-}
-
 void FindPointsGSLIB::Interpolate(Mesh &m, const Vector &point_pos,
-                                  const GridFunction &field_in,
-                                  Vector &field_out,
-                                  const int point_pos_ordering)
+                                  const GridFunction &field_in, Vector &field_out,
+                                  int point_pos_ordering)
 {
   FindPoints(m, point_pos, point_pos_ordering);
   Interpolate(field_in, field_out);
@@ -1483,7 +1470,7 @@ void FindPointsGSLIB::SetupSplitMeshesAndIntegrationRules(const int order)
 }

 void FindPointsGSLIB::GetNodalValues(const GridFunction *gf_in,
-                                     Vector &node_vals) const
+                                     Vector &node_vals)
 {
   const GridFunction *nodes     = gf_in;
   const FiniteElementSpace *fes = nodes->FESpace();
@@ -1771,13 +1758,6 @@ void FindPointsGSLIB::MapRefPosAndElemIndices()

 void FindPointsGSLIB::Interpolate(const GridFunction &field_in,
                                  Vector &field_out)
-{
-   Interpolate(field_in, field_out, field_in.FESpace()->GetOrdering());
-}
-
-void FindPointsGSLIB::Interpolate(const GridFunction &field_in,
-                                  Vector &field_out,
-                                  const int field_out_ordering)
 {
   const int  gf_order   = field_in.FESpace()->GetMaxElementOrder(),
              mesh_order = mesh->GetNodalFESpace()->GetMaxElementOrder();
@@ -1820,7 +1800,7 @@ void FindPointsGSLIB::Interpolate(const GridFunction &field_in,
      const int maxOrder = field_in.FESpace()->GetMaxElementOrder();

      InterpolateOnDevice(node_vals, field_out, NE_split_total, ncomp,
-                          maxOrder+1, field_out_ordering);
+                          maxOrder+1, field_in.FESpace()->GetOrdering());
      return;
 #endif
   }
@@ -1832,13 +1812,12 @@ void FindPointsGSLIB::Interpolate(const GridFunction &field_in,
       field_in.FESpace()->IsVariableOrder() ==
       mesh->GetNodalFESpace()->IsVariableOrder())
   {
-      InterpolateH1(field_in, field_out, field_out_ordering);
+      InterpolateH1(field_in, field_out);
      return;
   }
   else
   {
-      InterpolateGeneral(field_in, field_out,
-                         field_out_ordering);
+      InterpolateGeneral(field_in, field_out);
      if (!fec_l2 || avgtype == AvgType::NONE) { return; }
   }

@@ -1882,11 +1861,11 @@ void FindPointsGSLIB::Interpolate(const GridFunction &field_in,

      if (gf_order_h1 == mesh_order) // basis is GaussLobatto by default
      {
-         InterpolateH1(field_in_h1, field_out_l2, field_out_ordering);
+         InterpolateH1(field_in_h1, field_out_l2);
      }
      else
      {
-         InterpolateGeneral(field_in_h1, field_out_l2, field_out_ordering);
+         InterpolateGeneral(field_in_h1, field_out_l2);
      }

      // Copy interpolated values for the points on element border
@@ -1894,7 +1873,7 @@ void FindPointsGSLIB::Interpolate(const GridFunction &field_in,
      {
         for (int i = 0; i < indl2.Size(); i++)
         {
-            int idx = field_out_ordering == Ordering::byNODES?
+            int idx = field_in_h1.FESpace()->GetOrdering() == Ordering::byNODES?
                      indl2[i] + j*points_cnt:
                      indl2[i]*ncomp + j;
            field_out(idx) = field_out_l2(idx);
@@ -1904,8 +1883,7 @@ void FindPointsGSLIB::Interpolate(const GridFunction &field_in,
 }

 void FindPointsGSLIB::InterpolateH1(const GridFunction &field_in,
-                                    Vector &field_out,
-                                    const int field_out_ordering)
+                                    Vector &field_out)
 {
   FiniteElementSpace ind_fes(mesh, field_in.FESpace()->FEColl());
   if (field_in.FESpace()->IsVariableOrder())
@@ -1935,8 +1913,7 @@ void FindPointsGSLIB::InterpolateH1(const GridFunction &field_in,
                dataptrout = i*points_cnt;
      if (field_in.FESpace()->GetOrdering() == Ordering::byNODES)
      {
-         field_in_scalar.NewDataAndSize(field_in.GetData()+dataptrin,
-                                        points_fld);
+         field_in_scalar.NewDataAndSize(field_in.GetData()+dataptrin, points_fld);
      }
      else
      {
@@ -1968,7 +1945,7 @@ void FindPointsGSLIB::InterpolateH1(const GridFunction &field_in,
                        (gslib::findpts_data_3 *)this->fdataD);
      }
   }
-   if (field_out_ordering == Ordering::byVDIM)
+   if (field_in.FESpace()->GetOrdering() == Ordering::byVDIM)
   {
      Vector field_out_temp = field_out;
      for (int i = 0; i < ncomp; i++)
@@ -1982,8 +1959,7 @@ void FindPointsGSLIB::InterpolateH1(const GridFunction &field_in,
 }

 void FindPointsGSLIB::InterpolateGeneral(const GridFunction &field_in,
-                                         Vector &field_out,
-                                         const int field_out_ordering)
+                                         Vector &field_out)
 {
   int ncomp   = field_in.VectorDim(),
       nptorig = points_cnt,
@@ -2003,7 +1979,7 @@ void FindPointsGSLIB::InterpolateGeneral(const GridFunction &field_in,
         if (dim == 3) { ip.z = gsl_mfem_ref(index*dim + 2); }
         Vector localval(ncomp);
         field_in.GetVectorValue(gsl_mfem_elem[index], ip, localval);
-         if (field_out_ordering == Ordering::byNODES)
+         if (field_in.FESpace()->GetOrdering() == Ordering::byNODES)
         {
            for (int i = 0; i < ncomp; i++)
            {
@@ -2038,10 +2014,7 @@ void FindPointsGSLIB::InterpolateGeneral(const GridFunction &field_in,
      for (int index = 0; index < npt; index++)
      {
         if (gsl_code[index] == 2) { continue; }
-         for (int d = 0; d < dim; ++d)
-         {
-            pt->r[d]= gsl_mfem_ref(index*dim + d);
-         }
+         for (int d = 0; d < dim; ++d) { pt->r[d]= gsl_mfem_ref(index*dim + d); }
         pt->index = index;
         pt->proc  = gsl_proc[index];
         pt->el    = gsl_mfem_elem[index];
@@ -2131,7 +2104,7 @@ void FindPointsGSLIB::InterpolateGeneral(const GridFunction &field_in,
            sdpt = (struct send_pt *)sendpt->ptr;
            for (int index = 0; index < static_cast<int>(sendpt->n); index++)
            {
-               int idx = field_out_ordering == Ordering::byNODES ?
+               int idx = field_in.FESpace()->GetOrdering() == Ordering::byNODES ?
                         sdpt->index + j*nptorig :
                         sdpt->index*ncomp + j;
               field_out(idx) = sdpt->ival;
@@ -2273,7 +2246,7 @@ void FindPointsGSLIB::DistributeInterpolatedValues(const Vector &int_vals,
   }
 }

-void FindPointsGSLIB::GetAxisAlignedBoundingBoxes(Vector &aabb) const
+void FindPointsGSLIB::GetAxisAlignedBoundingBoxes(Vector &aabb)
 {
   MFEM_VERIFY(setupflag, "Call FindPointsGSLIB::Setup method first");
   auto *findptsData3 = (gslib::findpts_data_3 *)this->fdataD;
@@ -2344,7 +2317,7 @@ void FindPointsGSLIB::GetAxisAlignedBoundingBoxes(Vector &aabb) const
 }

 void FindPointsGSLIB::GetOrientedBoundingBoxes(DenseTensor &obbA, Vector &obbC,
-                                               Vector &obbV) const
+                                               Vector &obbV)
 {
   MFEM_VERIFY(setupflag, "Call FindPointsGSLIB::Setup method first");
   auto *findptsData3 = (gslib::findpts_data_3 *)this->fdataD;
@@ -2529,8 +2502,8 @@ void OversetFindPointsGSLIB::Setup(Mesh &m, const int meshid,
 }

 void OversetFindPointsGSLIB::FindPoints(const Vector &point_pos,
-                                        const Array<unsigned int> &point_id,
-                                        const int point_pos_ordering)
+                                        Array<unsigned int> &point_id,
+                                        int point_pos_ordering)
 {
   MFEM_VERIFY(setupflag, "Use OversetFindPointsGSLIB::Setup before "
               "finding points.");
@@ -2609,10 +2582,10 @@ void OversetFindPointsGSLIB::FindPoints(const Vector &point_pos,
 }

 void OversetFindPointsGSLIB::Interpolate(const Vector &point_pos,
-                                         const Array<unsigned int> &point_id,
+                                         Array<unsigned int> &point_id,
                                         const GridFunction &field_in,
                                         Vector &field_out,
-                                         const int point_pos_ordering)
+                                         int point_pos_ordering)
 {
   FindPoints(point_pos, point_id, point_pos_ordering);
   Interpolate(field_in, field_out);
@@ -119,13 +119,11 @@ protected:
   } DEV;

   /// Use GSLIB for communication and interpolation
-   virtual void InterpolateH1(const GridFunction &field_in, Vector &field_out,
-                              const int field_out_ordering);
+   virtual void InterpolateH1(const GridFunction &field_in, Vector &field_out);
   /// Uses GSLIB Crystal Router for communication followed by MFEM's
   /// interpolation functions
   virtual void InterpolateGeneral(const GridFunction &field_in,
-                                   Vector &field_out,
-                                   const int field_out_ordering);
+                                   Vector &field_out);

   /// Since GSLIB is designed to work with quads/hexes, we split every
   /// triangle/tet/prism/pyramid element into quads/hexes.
@@ -142,7 +140,7 @@ protected:
   virtual void SetupSplitMeshesAndIntegrationRules(const int order);

   /// Get GridFunction value at the points expected by GSLIB.
-   virtual void GetNodalValues(const GridFunction *gf_in, Vector &node_vals) const;
+   virtual void GetNodalValues(const GridFunction *gf_in, Vector &node_vals);

   /// Map {r,s,t} coordinates from [-1,1] to [0,1] for MFEM. For simplices,
   /// find the original element number (that was split into micro quads/hexes)
@@ -184,7 +182,7 @@ protected:
       These positions can be ordered byNodes: (XXX...,YYY...,ZZZ) or
       byVDim: (XYZ,XYZ,....XYZ) specified by @a point_pos_ordering. */
   void FindPointsOnDevice(const Vector &point_pos,
-                           const int point_pos_ordering = Ordering::byNODES);
+                           int point_pos_ordering = Ordering::byNODES);

   /** Interpolation of field values at prescribed reference space positions.
       @param[in] field_in_evec E-vector of grid function to be interpolated.
@@ -255,15 +253,10 @@ public:
       #gsl_dist        Distance between the sought and the found point
                        in physical space. */
   void FindPoints(const Vector &point_pos,
-                   const int point_pos_ordering = Ordering::byNODES);
-   /// Convenience function when point positions are in a ParticleVector
-   void FindPoints(const ParticleVector &point_pos)
-   {
-      FindPoints(point_pos, point_pos.GetOrdering());
-   }
+                   int point_pos_ordering = Ordering::byNODES);
   /// Setup FindPoints and search positions
   void FindPoints(Mesh &m, const Vector &point_pos,
-                   const int point_pos_ordering = Ordering::byNODES,
+                   int point_pos_ordering = Ordering::byNODES,
                   const double bb_t = 0.1, const double newt_tol = 1.0e-12,
                   const int npt_max = 256);

@@ -273,28 +266,20 @@ public:
                              \p field_in is in H1 and in the same space as the
                              mesh that was given to Setup().
       @param[out] field_out  Interpolated values. For points that are not found
-                              the value is set to #default_interp_value.
-                              The output ordering is determined from field_in.*/
+                              the value is set to #default_interp_value. */
   virtual void Interpolate(const GridFunction &field_in, Vector &field_out);
-   /// Interpolation of field values, with output ordering specification.
-   virtual void Interpolate(const GridFunction &field_in, Vector &field_out,
-                            const int field_out_ordering);
   /** Search positions and interpolate. The ordering (byNODES or byVDIM) of
       the output values in \p field_out corresponds to the ordering used
       in the input GridFunction \p field_in. */
   void Interpolate(const Vector &point_pos, const GridFunction &field_in,
                    Vector &field_out,
-                    const int point_pos_ordering = Ordering::byNODES);
-   /// Search positions and interpolate with given point and output ordering.
-   void Interpolate(const Vector &point_pos, const GridFunction &field_in,
-                    Vector &field_out, const int point_pos_ordering,
-                    const int field_out_ordering);
+                    int point_pos_ordering = Ordering::byNODES);
   /** Setup FindPoints, search positions and interpolate. The ordering (byNODES
       or byVDIM) of the output values in \p field_out corresponds to the
       ordering used in the input GridFunction \p field_in. */
   void Interpolate(Mesh &m, const Vector &point_pos,
                    const GridFunction &field_in, Vector &field_out,
-                    const int point_pos_ordering = Ordering::byNODES);
+                    int point_pos_ordering = Ordering::byNODES);

   /// Average type to be used for L2 functions in-case a point is located at
   /// an element boundary where the function might be multi-valued.
@@ -391,7 +376,7 @@ public:
   /// The size of the returned vector is (nel x nverts x dim), where nel is the
   /// number of elements (after splitting for simplcies), nverts is number of
   /// vertices (4 in 2D, 8 in 3D), and dim is the spatial dimension.
-   void GetAxisAlignedBoundingBoxes(Vector &aabb) const;
+   void GetAxisAlignedBoundingBoxes(Vector &aabb);

   /// Return the oriented bounding boxes (OBB) computed during \ref Setup.
   /// Each OBB is represented using the inverse transformation (A^{-1}) and
@@ -401,8 +386,7 @@ public:
   /// size (dim x dim x nel), and the OBB centers are returned in \p obbC,
   /// a vector of size (nel x dim). The vertices of the OBBs are returned in
   /// \p obbV, a vector of size (nel x nverts x dim) .
-   void GetOrientedBoundingBoxes(DenseTensor &obbA, Vector &obbC,
-                                 Vector &obbV) const;
+   void GetOrientedBoundingBoxes(DenseTensor &obbA, Vector &obbC, Vector &obbV);
 };

 /** \brief OversetFindPointsGSLIB enables use of findpts for arbitrary number of
@@ -462,14 +446,13 @@ public:
                                       byNodes: (XXX...,YYY...,ZZZ) or
                                       byVDim: (XYZ,XYZ,....XYZ) */
   void FindPoints(const Vector &point_pos,
-                   const Array<unsigned int> &point_id,
-                   const int point_pos_ordering = Ordering::byNODES);
+                   Array<unsigned int> &point_id,
+                   int point_pos_ordering = Ordering::byNODES);

   /** Search positions and interpolate */
-   void Interpolate(const Vector &point_pos,
-                    const Array<unsigned int> &point_id,
+   void Interpolate(const Vector &point_pos, Array<unsigned int> &point_id,
                    const GridFunction &field_in, Vector &field_out,
-                    const int point_pos_ordering = Ordering::byNODES);
+                    int point_pos_ordering = Ordering::byNODES);
   using FindPointsGSLIB::Interpolate;
 };

@@ -789,6 +789,7 @@ void Hybridization::ComputeH()
   }
   else
   {
+      // TODO: add ones on the diagonal of zero rows
      V->Finalize();
      Array<HYPRE_BigInt> V_J(V->NumNonZeroElems());
      MFEM_ASSERT(c_pfes, "");
@@ -822,13 +823,6 @@ void Hybridization::ComputeH()
      MFEM_VERIFY(pH.Type() != Operator::PETSC_MATIS, "To be implemented");
      pH.MakePtAP(plpH, pP);
      delete lpH;
-
-      HypreParMatrix *hH = pH.As<HypreParMatrix>();
-      MFEM_ASSERT(hH, "");
-
-      SparseMatrix H_diag;
-      hH->GetDiag(H_diag);
-      H_diag.SetDiagIdentity();
   }
 #endif
 }
@@ -14,11 +14,8 @@

 #include "../config/config.hpp"
 #include "../general/array.hpp"
-#include "../linalg/operator.hpp"
 #include "../linalg/vector.hpp"

-#include <memory>
-
 namespace mfem
 {

@@ -48,30 +45,15 @@ protected:
   Array<int> hat_dof_gather_map;
   Array<DofType> hat_dof_marker;

-   Array<int> el_to_face; ///< Element to face connectivity.
-   Array<int> el_face_offsets; ///< Per-element offsets into @a el_to_face.
-   Array<int> face_to_el; ///< Face-to-element connectivity.
-   Array<int> face_face_offsets; ///< Face-to-face offsets.
-
-   int n_el_face; ///< Total number of element-to-face connections.
-   int n_face_face; ///< Total number of face-to-face connections.
-
+   Array<int> el_to_face;
+   Array<int> face_to_el;
   Vector Ct_mat; ///< Constraint matrix (transposed) stored element-wise.

-   /// @name For parallel non-conforming meshes
-   ///@{
-   std::unique_ptr<Operator> P_pc; ///< Partially conforming prolongation.
-   std::unique_ptr<Operator> P_nbr; ///< Face-neighbor prolongation.
-   ///@}
-
   Array<int> idofs, bdofs;

   Vector Ahat, Ahat_ii, Ahat_ib, Ahat_bi, Ahat_bb;
   Array<int> Ahat_ii_piv, Ahat_bb_piv;

-   /// Return the (partially) conforming prolongation on the constraint space.
-   const Operator &GetProlongation() const;
-
 public:
   /// Construct the constraint matrix.
   void ConstructC();
@@ -1004,16 +1004,13 @@ inline void SmemPADiffusionApply3D(const int NE,
   const int max_d1d = T_D1D ? T_D1D : DeviceDofQuadLimits::Get().MAX_D1D;
   MFEM_VERIFY(D1D <= max_d1d, "");
   MFEM_VERIFY(Q1D <= max_q1d, "");
-   const auto b = Reshape(b_.Read(), Q1D, D1D);
-   const auto g = Reshape(g_.Read(), Q1D, D1D);
-   const auto d = Reshape(d_.Read(), Q1D, Q1D, Q1D, symmetric ? 6 : 9, NE);
-   const auto x = Reshape(x_.Read(), D1D, D1D, D1D, NE);
+   auto b = Reshape(b_.Read(), Q1D, D1D);
+   auto g = Reshape(g_.Read(), Q1D, D1D);
+   auto d = Reshape(d_.Read(), Q1D, Q1D, Q1D, symmetric ? 6 : 9, NE);
+   auto x = Reshape(x_.Read(), D1D, D1D, D1D, NE);
   auto y = Reshape(y_.ReadWrite(), D1D, D1D, D1D, NE);
   MFEM_VERIFY(D1D <= Q1D, "THREAD_DIRECT requires D1D <= Q1D");
-
-   mfem::forall_3D<T_Q1D*T_Q1D*T_Q1D>(NE,
-                                      Q1D, Q1D, Q1D,
-                                      [=] MFEM_HOST_DEVICE (int e)
+   mfem::forall_3D(NE, Q1D, Q1D, Q1D, [=] MFEM_HOST_DEVICE (int e)
   {
      const int D1D = T_D1D ? T_D1D : d1d;
      const int Q1D = T_Q1D ? T_Q1D : q1d;
@@ -1133,11 +1133,11 @@ inline void SmemPAMassApply3D(const int NE,
   const int max_d1d = T_D1D ? T_D1D : DeviceDofQuadLimits::Get().MAX_D1D;
   MFEM_VERIFY(D1D <= max_d1d, "");
   MFEM_VERIFY(Q1D <= max_q1d, "");
-   const auto b = b_.Read();
-   const auto d = d_.Read();
-   const auto x = x_.Read();
+   auto b = b_.Read();
+   auto d = d_.Read();
+   auto x = x_.Read();
   auto y = y_.ReadWrite();
-   mfem::forall_2D<T_Q1D*T_Q1D>(NE, Q1D, Q1D, [=] MFEM_HOST_DEVICE (int e)
+   mfem::forall_2D(NE, Q1D, Q1D, [=] MFEM_HOST_DEVICE (int e)
   {
      internal::SmemPAMassApply3D_Element<T_D1D,T_Q1D>(e, NE, b, d, x, y, d1d, q1d);
   });
@@ -1156,8 +1156,8 @@ inline void EAMassAssemble1D(const int NE,
   const int Q1D = T_Q1D ? T_Q1D : q1d;
   MFEM_VERIFY(D1D <= DeviceDofQuadLimits::Get().MAX_D1D, "");
   MFEM_VERIFY(Q1D <= DeviceDofQuadLimits::Get().MAX_Q1D, "");
-   const auto B = Reshape(basis.Read(), Q1D, D1D);
-   const auto D = Reshape(padata.Read(), Q1D, NE);
+   auto B = Reshape(basis.Read(), Q1D, D1D);
+   auto D = Reshape(padata.Read(), Q1D, NE);
   auto M = Reshape(add ? eadata.ReadWrite() : eadata.Write(), D1D, D1D, NE);
   mfem::forall_2D(NE, D1D, D1D, [=] MFEM_HOST_DEVICE (int e)
   {
@@ -28,7 +28,7 @@ void NormalTraceJumpIntegrator::AssembleEAInteriorFaces(
   const FaceType ftype = FaceType::Interior;
   const int nf = mesh.GetNFbyType(ftype);

-   const Geometry::Type geom = mesh.GetTypicalFaceGeometry();
+   const Geometry::Type geom = mesh.GetFaceGeometry(0);
   const int trial_order = trial_fes.GetMaxElementOrder();
   const int test_order = test_fes.GetMaxElementOrder();
   const int qorder = test_order + trial_order - 1;
@@ -47,7 +47,7 @@ void NormalTraceJumpIntegrator::AssembleEAInteriorFaces(
      });
   }

-   const FiniteElement &trial_face_el = *trial_fes.GetTypicalTraceElement();
+   const FiniteElement &trial_face_el = *trial_fes.GetFaceElement(0);
   const auto maps = &trial_face_el.GetDofToQuad(ir, DofToQuad::TENSOR);
   const int ndof_face = trial_face_el.GetDof();

@@ -72,7 +72,7 @@ void NormalTraceJumpIntegrator::AssembleEAInteriorFaces(
      MFEM_ABORT("Unknown kernel.");
   }

-   const FiniteElement &test_el = *test_fes.GetTypicalFE();
+   const FiniteElement &test_el = *test_fes.GetFE(0);
   const int n_faces_per_el = 2*dim; // assuming tensor product
   // Get all the local face maps (mapping from lexicographic face index to
   // lexicographic volume index, depending on the local face index).
@@ -90,10 +90,10 @@ void NormalTraceJumpIntegrator::AssembleEAInteriorFaces(
   Array<int> face_info(nf * 4);
   {
      int fidx = 0;
-      for (int f = 0; f < mesh.GetNumFacesWithGhost(); ++f)
+      for (int f = 0; f < mesh.GetNumFaces(); ++f)
      {
         Mesh::FaceInformation finfo = mesh.GetFaceInformation(f);
-         if (!finfo.IsInterior() || finfo.IsNonconformingCoarse()) { continue; }
+         if (!finfo.IsInterior()) { continue; }
         face_info[0 + fidx*4] = finfo.element[0].local_face_id;
         face_info[1 + fidx*4] = finfo.element[0].orientation;
         face_info[2 + fidx*4] = finfo.element[1].local_face_id;
@@ -114,7 +114,7 @@ void NormalTraceJumpIntegrator::AssembleEAInteriorFaces(
   else
   {
      d_emat = emat.Write();
-      emat = 0.0; // Will execute on device, since Write() sets the device flag
+      mfem::forall(emat.Size(), [=] MFEM_HOST_DEVICE (int i) { d_emat[i] = 0.0; });
   }

   const auto face_mats = Reshape(mass_emat.Read(), ndof_face, ndof_face, nf);
@@ -133,104 +133,26 @@ void NormalTraceJumpIntegrator::AssembleEAInteriorFaces(
      }
   };

-   auto permute_face_2 = [=] MFEM_HOST_DEVICE(int local_face_1, int local_face_2,
-                                              int orient, int size1d, int index)
+   mfem::forall_3D(nf, ndof_face, ndof_face, 2, [=] MFEM_HOST_DEVICE (int f)
   {
-      if (dim == 2)
+      MFEM_FOREACH_THREAD(el_i, z, 2)
      {
-         return internal::PermuteFace2D(local_face_1, local_face_2, orient,
-                                        size1d, index);
-      }
-      else // dim == 3
-      {
-         return internal::PermuteFace3D(local_face_1, local_face_2, orient,
-                                        size1d, index);
-      }
-   };
-
-   if (mesh.Conforming())
-   {
-      mfem::forall_3D(nf, ndof_face, ndof_face, 2, [=] MFEM_HOST_DEVICE (int f)
-      {
-         MFEM_FOREACH_THREAD(el_i, z, 2)
+         const int lf_i = d_face_info(0, el_i, f);
+         const int orient = d_face_info(1, el_i, f);
+         // Loop over face indices in "native ordering"
+         MFEM_FOREACH_THREAD(i_lex, x, ndof_face)
         {
-            const int lf_i = d_face_info(0, el_i, f);
-            const int orient = d_face_info(1, el_i, f);
-            // Loop over face indices in "native ordering"
-            MFEM_FOREACH_THREAD(i_lex, x, ndof_face)
+            // Convert to lexicographic relative to the face itself
+            const int i_face = permute_face(lf_i, orient, d1d, i_lex);
+            // Convert from lexicographic face DOF to volume DOF
+            const int i = d_face_maps(i_lex, lf_i);
+            MFEM_FOREACH_THREAD(j, y, ndof_face)
            {
-               // Convert to lexicographic relative to the face itself
-               const int i_face = permute_face(lf_i, orient, d1d, i_lex);
-               // Convert from lexicographic face DOF to volume DOF
-               const int i = d_face_maps(i_lex, lf_i);
-               MFEM_FOREACH_THREAD(j, y, ndof_face)
-               {
-                  el_mats(i, j, el_i, f) += face_mats(i_face, j, f);
-               }
+               el_mats(i, j, el_i, f) += face_mats(i_face, j, f);
            }
         }
-      });
-   }
-   else
-   {
-      const InterpolationManager &interp =
-         test_fes.GetInterpolationManager(ElementDofOrdering::LEXICOGRAPHIC, ftype);
-
-      auto interp_configs = interp.GetFaceInterpConfig().Read();
-      const int nc_size = interp.GetNumInterpolators();
-      auto d_interp = Reshape(interp.GetInterpolators().Read(),
-                              ndof_face, ndof_face, nc_size);
-
-      mfem::forall(nf, [=] MFEM_HOST_DEVICE (int f)
-      {
-         const InterpConfig conf = interp_configs[f];
-         const int master_side = conf.master_side;
-         const int interp_index = conf.index;
-
-         const int lf_0 = d_face_info(0, 0, f);
-
-         for (int el_i = 0; el_i < 2; ++el_i)
-         {
-            const int lf_i = d_face_info(0, el_i, f);
-            const int orient = d_face_info(1, el_i, f);
-
-            for (int j = 0; j < ndof_face; j++)
-            {
-               for (int i_lex = 0; i_lex < ndof_face; i_lex++)
-               {
-                  real_t val = 0.0;
-                  if (conf.is_non_conforming && el_i == master_side)
-                  {
-                     // Interpolate from el_i (coarse element) to the fine face.
-                     // The mapping is given by d_interp, which uses indices
-                     // relative to element 0.
-
-                     // i0 is lexicographic relative to element 0
-                     const int i0 = permute_face_2(lf_i, lf_0, orient, d1d, i_lex);
-
-                     // k0 is lexicographic relative to element 0
-                     for (int k0 = 0; k0 < ndof_face; k0++)
-                     {
-                        // k is relative to the face itself
-                        const int k = permute_face(lf_0, orient, d1d, k0);
-                        val += d_interp(k0, i0, interp_index)
-                               * face_mats(k, j, f);
-                     }
-                  }
-                  else
-                  {
-                     // Convert to lexicographic relative to the face itself
-                     const int i_face = permute_face(lf_i, orient, d1d, i_lex);
-                     val = face_mats(i_face, j, f);
-                  }
-                  // Convert from lexicographic face DOF to volume DOF
-                  const int i = d_face_maps(i_lex, lf_i);
-                  el_mats(i, j, el_i, f) += val;
-               }
-            }
-         }
-      });
-   }
+      }
+   });
 }

 }
@@ -54,7 +54,7 @@ void SmemPAVectorDiffusionApply2D(const int NE,
   const auto XE = Reshape(x.Read(), D1D, D1D, SDIM, NE);
   auto YE = Reshape(y.ReadWrite(), D1D, D1D, SDIM, NE);

-   mfem::forall_2D<T_Q1D*T_Q1D>(NE, Q1D, Q1D, [=] MFEM_HOST_DEVICE(int e)
+   mfem::forall_2D(NE, Q1D, Q1D, [=] MFEM_HOST_DEVICE(int e)
   {
      constexpr int MD1 = T_D1D > 0 ? SetMaxOf(T_D1D) : DofQuadLimits::MAX_T1D;
      constexpr int MQ1 = T_Q1D > 0 ? SetMaxOf(T_Q1D) : DofQuadLimits::MAX_T1D;
@@ -120,7 +120,7 @@ void SmemPAVectorDiffusionApply3D(const int NE,
   const auto XE = Reshape(x.Read(), D1D, D1D, D1D, SDIM, NE);
   auto YE = Reshape(y.ReadWrite(), D1D, D1D, D1D, SDIM, NE);

-   mfem::forall_2D<T_Q1D*T_Q1D>(NE, Q1D, Q1D, [=] MFEM_HOST_DEVICE(int e)
+   mfem::forall_2D(NE, Q1D, Q1D, [=] MFEM_HOST_DEVICE(int e)
   {
      constexpr int MD1 = T_D1D > 0 ? SetMaxOf(T_D1D) : DofQuadLimits::MAX_T1D;
      constexpr int MQ1 = T_Q1D > 0 ? SetMaxOf(T_Q1D) : DofQuadLimits::MAX_T1D;
@@ -51,7 +51,7 @@ void SmemPAVectorMassApply2D(const int NE,
   const auto X = Reshape(x.Read(), D1D, D1D, VDIM, NE);
   auto Y = Reshape(y.ReadWrite(), D1D, D1D, VDIM, NE);

-   mfem::forall_2D<T_Q1D*T_Q1D>(NE, Q1D, Q1D, [=] MFEM_HOST_DEVICE(int e)
+   mfem::forall_2D(NE, Q1D, Q1D, [=] MFEM_HOST_DEVICE(int e)
   {
      constexpr int MD1 = T_D1D > 0 ? SetMaxOf(T_D1D) : DofQuadLimits::MAX_T1D;
      constexpr int MQ1 = T_Q1D > 0 ? SetMaxOf(T_Q1D) : DofQuadLimits::MAX_T1D;
@@ -119,7 +119,7 @@ void SmemPAVectorMassApply3D(const int NE,
   const auto X = Reshape(x.Read(), D1D, D1D, D1D, VDIM, NE);
   auto Y = Reshape(y.ReadWrite(), D1D, D1D, D1D, VDIM, NE);

-   mfem::forall_2D<T_Q1D*T_Q1D>(NE, Q1D, Q1D, [=] MFEM_HOST_DEVICE(int e)
+   mfem::forall_2D(NE, Q1D, Q1D, [=] MFEM_HOST_DEVICE(int e)
   {
      constexpr int MD1 = T_D1D > 0 ? SetMaxOf(T_D1D) : DofQuadLimits::MAX_T1D;
      constexpr int MQ1 = T_Q1D > 0 ? SetMaxOf(T_Q1D) : DofQuadLimits::MAX_T1D;
@@ -14,7 +14,6 @@

 #include "../config/config.hpp"
 #include "kernel_reporter.hpp"
-#include "../general/hash_util.hpp"
 #include <unordered_map>
 #include <tuple>
 #include <type_traits>
@@ -87,6 +86,35 @@ namespace mfem
    }                                                                          \
  }

+/// @brief Hashes variadic packs for which each type contained in the variadic
+/// pack has a specialization of `std::hash` available.
+///
+/// For example, packs containing int, bool, enum values, etc.
+template<typename ...KernelParameters>
+struct KernelDispatchKeyHash
+{
+private:
+   template<int N>
+   size_t operator()(std::tuple<KernelParameters...> value) const { return 0; }
+
+   // The hashing formula here is taken directly from the Boost library, with
+   // the magic number 0x9e3779b9 chosen to minimize hashing collisions.
+   template<std::size_t N, typename THead, typename... TTail>
+   size_t operator()(std::tuple<KernelParameters...> value) const
+   {
+      constexpr int Index = N - sizeof...(TTail) - 1;
+      auto lhs_hash = std::hash<THead>()(std::get<Index>(value));
+      auto rhs_hash = operator()<N, TTail...>(value);
+      return lhs_hash^(rhs_hash + 0x9e3779b9 + (lhs_hash<<6) + (lhs_hash>>2));
+   }
+public:
+   /// Returns the hash of the given @a value.
+   size_t operator()(std::tuple<KernelParameters...> value) const
+   {
+      return operator()<sizeof...(KernelParameters),KernelParameters...>(value);
+   }
+};
+
 namespace internal { template<typename... Types> struct KernelTypeList { }; }

 template<typename... T> class KernelDispatchTable { };
@@ -100,8 +128,8 @@ class KernelDispatchTable<Kernels,
         internal::KernelTypeList<Params...>,
         internal::KernelTypeList<OptParams...>>
 {
-   using TableType =
-      std::unordered_map<std::tuple<Params...>, Signature, TupleHasher>;
+   using TableType = std::unordered_map<std::tuple<Params...>,
+         Signature, KernelDispatchKeyHash<Params...>>;
   TableType table;

   /// @brief Call function @a f with arguments @a args (perfect forwaring).
@@ -23,8 +23,6 @@ class BatchedLOR_DG : BatchedLORKernel
 {
   IntegrationRule ir_face; ///< Collocated Gauss-Lobatto face quadrature rule.
   real_t kappa; ///< DG penalty parameter.
-   bool has_bdr_integ; ///< Is there a boundary integrator?
-   const Array<int> *bdr_markers; ///< Boundary integrator markers.
 public:
   template <int ORDER, int SDIM> void Assemble2D();
   template <int ORDER> void Assemble3D();
@@ -40,7 +38,8 @@ public:
      ProjectLORCoefficient<MassIntegrator>(a, c1);
      ProjectLORCoefficient<DiffusionIntegrator>(a, c2);

-      if (auto *integ = GetInteriorFaceIntegrator<DGDiffusionIntegrator>(a))
+      auto *integ = GetInteriorFaceIntegrator<DGDiffusionIntegrator>(a);
+      if (integ)
      {
         kappa = integ->GetPenaltyParameter();
      }
@@ -48,19 +47,6 @@ public:
      {
         kappa = 0.0;
      }
-
-      has_bdr_integ = false;
-      auto *bdr_face_integs = a.GetBFBFI();
-      for (int i = 0; i < bdr_face_integs->Size(); ++i)
-      {
-         if (auto *integ = dynamic_cast<DGDiffusionIntegrator*>((*bdr_face_integs)[i]))
-         {
-            kappa = integ->GetPenaltyParameter();
-            bdr_markers = (*a.GetBFBFI_Marker())[i];
-            has_bdr_integ = true;
-            break;
-         }
-      }
   }

   /// @brief Compute and return the face info array.
@@ -22,13 +22,9 @@ namespace mfem
 Array<int> BatchedLOR_DG::GetFaceInfo() const
 {
   Mesh &mesh = *fes_ho.GetMesh();
-   const Array<int> &bdr_face_attrs = mesh.GetBdrFaceAttributes();
   const int nf = mesh.GetNumFaces();
   Array<int> face_info(nf * 6); // (e0, f0, o0, e1, f1, o1)
   auto h_face_info = Reshape(face_info.HostWrite(), 6, nf);
-
-   int bdr_face_counter = 0;
-
   for (int f = 0; f < nf; ++f)
   {
      auto finfo = mesh.GetFaceInformation(f);
@@ -47,19 +43,6 @@ Array<int> BatchedLOR_DG::GetFaceInfo() const
         h_face_info(4, f) = -1;
         h_face_info(5, f) = -1;
      }
-
-      if (finfo.IsBoundary())
-      {
-         // Check if Neumann boundary; skip these when adding boundary penalties
-         const int bdr_attr = bdr_face_attrs[bdr_face_counter];
-         if (!has_bdr_integ || (bdr_markers && !(*bdr_markers)[bdr_attr - 1]))
-         {
-            h_face_info(0, f) = -1;
-            h_face_info(1, f) = -1;
-            h_face_info(2, f) = -1;
-         }
-         bdr_face_counter += 1;
-      }
   }
   return face_info;
 }
@@ -161,7 +144,6 @@ void BatchedLOR_DG::AssembleFaceTerms()
   {
      const int f_0 = d_face_info(1, f);
      const int f_1 = d_face_info(4, f);
-      if (f_0 < 0) { return; } // Skip Neumann boundary faces
      const int nsides = (f_1 >= 0) ? 2 : 1;
      for (int el_i = 0; el_i < nsides; ++el_i)
      {
@@ -78,7 +78,10 @@ template <int Dim>
 void BuildBoxes(const Mesh &mesh,
                std::vector<::moonolith::AABB<Dim, double>> &element_boxes)
 {
-   MFEM_ASSERT(mesh.Dimension() == Dim, "Mesh and box dimensions mismatched");
+#ifndef NDEBUG
+   const int dim = mesh.Dimension();
+   assert(dim == Dim);
+#endif
   element_boxes.resize(mesh.GetNE());

   DenseMatrix pts;
@@ -488,16 +488,10 @@ void ParBilinearForm::FormLinearSystem(
         R.Mult(x, true_X);

         FormSystemMatrix(ess_tdof_list, A);
-
-         std::unique_ptr<ConstrainedOperator> A_constrained([&]()
-         {
-            Operator *op;
-            Operator::FormSystemOperator(ess_tdof_list, op);
-            return dynamic_cast<ConstrainedOperator*>(op);
-         }());
-         MFEM_ASSERT(A_constrained != nullptr, "");
-
+         ConstrainedOperator *A_constrained;
+         Operator::FormConstrainedSystemOperator(ess_tdof_list, A_constrained);
         A_constrained->EliminateRHS(true_X, true_B);
+         delete A_constrained;
         R.MultTranspose(true_B, b);
         hybridization->ReduceRHS(true_B, B);
         X.SetSize(B.Size());
@@ -646,38 +646,39 @@ const FaceRestriction *ParFiniteElementSpace::GetFaceRestriction(
   auto itr = L2F.find(key);
   if (itr != L2F.end())
   {
-      return itr->second.get();
+      return itr->second;
   }
   else
   {
-      std::unique_ptr<FaceRestriction> res;
+      FaceRestriction *res;
      if (is_dg_space)
      {
         if (Conforming())
         {
-            res.reset(new ParL2FaceRestriction(*this, f_ordering, type, m));
+            res = new ParL2FaceRestriction(*this, f_ordering, type, m);
         }
         else
         {
-            res.reset(new ParNCL2FaceRestriction(*this, f_ordering, type, m));
+            res = new ParNCL2FaceRestriction(*this, f_ordering, type, m);
         }
      }
      else if (dynamic_cast<const DG_Interface_FECollection*>(fec))
      {
-         res.reset(new L2InterfaceFaceRestriction(*this, f_ordering, type));
+         res = new L2InterfaceFaceRestriction(*this, f_ordering, type);
      }
      else
      {
         if (Conforming())
         {
-            res.reset(new ConformingFaceRestriction(*this, f_ordering, type));
+            res = new ConformingFaceRestriction(*this, f_ordering, type);
         }
         else
         {
-            res.reset(new ParNCH1FaceRestriction(*this, f_ordering, type));
+            res = new ParNCH1FaceRestriction(*this, f_ordering, type);
         }
      }
-      return L2F.emplace(key, std::move(res)).first->second.get();
+      L2F[key] = res;
+      return res;
   }
 }

@@ -483,8 +483,6 @@ public:
   const FiniteElement *GetFaceNbrFaceFE(int i) const;
   const Array<HYPRE_BigInt> &GetFaceNbrGlobalDofMapArray() { return face_nbr_glob_dof_map; }
   const HYPRE_BigInt *GetFaceNbrGlobalDofMap() { return face_nbr_glob_dof_map; }
-   const Array<HYPRE_BigInt> &GetFaceNbrGlobalDofMapArray() const
-   { return face_nbr_glob_dof_map; }
   ElementTransformation *GetFaceNbrElementTransformation(int i) const
   { return pmesh->GetFaceNbrElementTransformation(i); }

@@ -543,22 +543,13 @@ void ParGridFunction::GetElementDofValues(int el, Vector &dof_vals) const
   }
 }

-void ParGridFunction::ProjectCoefficient(Coefficient &coeff, ProjectType type)
+void ParGridFunction::ProjectCoefficient(Coefficient &coeff)
 {
   DeltaCoefficient *delta_c = dynamic_cast<DeltaCoefficient *>(&coeff);

   if (delta_c == NULL)
   {
-      (*this) = std::numeric_limits<real_t>::min();
-      GridFunction::ProjectCoefficient(coeff,type);
-
-      // Accumulate for all vdofs.
-      if (pfes->GetNURBSext())
-      {
-         GroupCommunicator &gcomm = pfes->GroupComm();
-         gcomm.Reduce<real_t>(data, GroupCommunicator::Max);
-         gcomm.Bcast<real_t>(data);
-      }
+      GridFunction::ProjectCoefficient(coeff);
   }
   else
   {
@@ -574,147 +565,6 @@ void ParGridFunction::ProjectCoefficient(Coefficient &coeff, ProjectType type)
   }
 }

-void ParGridFunction::ProjectCoefficient(VectorCoefficient &vcoeff,
-                                         ProjectType type)
-{
-   GridFunction::ProjectCoefficient(vcoeff, type);
-
-   // Accumulate for all vdofs.
-   if (pfes->GetNURBSext())
-   {
-      GroupCommunicator &gcomm = pfes->GroupComm();
-      gcomm.Reduce<real_t>(data, GroupCommunicator::Max);
-      gcomm.Bcast<real_t>(data);
-   }
-}
-
-void ParGridFunction::ProjectCoefficientGlobalL2(Coefficient &coeff,
-                                                 real_t rtol,
-                                                 int iter)
-{
-   // Define and assemble linear form
-   ParLinearForm b(pfes);
-   b.AddDomainIntegrator(new DomainLFIntegrator(coeff));
-   b.Assemble();
-
-   // Define and assemble bilinear form
-   ParBilinearForm a(pfes);
-   a.AddDomainIntegrator(new MassIntegrator());
-   a.Assemble();
-
-   // Configure solver
-   OperatorPtr A;
-   Vector B, X, x(*this);
-   Array<int> ess_tdof_list;
-   a.FormLinearSystem(ess_tdof_list, x, b, A, X, B);
-   Solver *prec = new HypreBoomerAMG;
-   CGSolver cg(MPI_COMM_WORLD);
-   cg.SetRelTol(rtol);
-   cg.SetMaxIter(iter);
-   cg.SetPrintLevel(0);
-   cg.SetPreconditioner(*prec);
-   cg.SetOperator(*A);
-   cg.Mult(B, X);
-   a.RecoverFEMSolution(X, b, x);
-   delete prec;
-}
-
-void ParGridFunction::ProjectCoefficientElementL2(Coefficient &coeff)
-{
-   Vector Va;
-   ProjectCoefficientElementL2_(coeff, *this, Va);
-
-   GroupCommunicator &gcomm = pfes->GroupComm();
-   gcomm.Reduce<real_t>(GetData(), GroupCommunicator::Sum);
-   gcomm.Bcast<real_t>(GetData());
-
-   gcomm.Reduce<real_t>(Va.GetData(), GroupCommunicator::Sum);
-   gcomm.Bcast<real_t>(Va.GetData());
-   (*this)/=Va;
-}
-
-void ParGridFunction::ProjectCoefficientGlobalL2(VectorCoefficient &vcoeff,
-                                                 real_t rtol, int iter)
-{
-   // Define and assemble linear form
-   ParLinearForm b(pfes);
-   ParBilinearForm a(pfes);
-
-   // Dimension argument to GetRangeType is arbitrary to be 3, could also be 2.
-   if (fes->FEColl()->GetRangeType(3)  == mfem::FiniteElement::VECTOR)
-   {
-      b.AddDomainIntegrator(new VectorFEDomainLFIntegrator(vcoeff));
-      a.AddDomainIntegrator(new VectorFEMassIntegrator());
-   }
-   else
-   {
-      b.AddDomainIntegrator(new VectorDomainLFIntegrator(vcoeff));
-      a.AddDomainIntegrator(new VectorMassIntegrator());
-   }
-   b.Assemble();
-   a.Assemble();
-
-   // Configure solver
-   OperatorPtr A;
-   Vector B, X, x(*this);
-   x = 0.0;
-   Array<int> ess_tdof_list;
-   a.FormLinearSystem(ess_tdof_list, x, b, A, X, B);
-   Solver *prec = new HypreBoomerAMG;
-   CGSolver cg(MPI_COMM_WORLD);
-   cg.SetRelTol(rtol);
-   cg.SetMaxIter(iter);
-   cg.SetPrintLevel(0);
-   cg.SetPreconditioner(*prec);
-   cg.SetOperator(*A);
-   cg.Mult(B, X);
-   a.RecoverFEMSolution(X, b, x);
-   x.Print();
-   delete prec;
-}
-
-void ParGridFunction::ProjectCoefficientElementL2(VectorCoefficient &vcoeff)
-{
-   if (fes->GetTypicalFE()->GetRangeType() == mfem::FiniteElement::VECTOR)
-   {
-      Vector Va;
-      ProjectCoefficientElementL2_(vcoeff, *this, Va);
-
-      GroupCommunicator &gcomm = pfes->GroupComm();
-      gcomm.Reduce<real_t>(GetData(), GroupCommunicator::Sum);
-      gcomm.Bcast<real_t>(GetData());
-
-      gcomm.Reduce<real_t>(Va.GetData(), GroupCommunicator::Sum);
-      gcomm.Bcast<real_t>(Va.GetData());
-      (*this)/=Va;
-   }
-   else
-   {
-      Array<int> vdofs(fes->GetNDofs());
-      Vector x, Va, gVa(Size());
-      VectorComponentCoefficient coeff(vcoeff,0);
-      *this = 0.0;
-      gVa = 0.0;
-      for (int v = 0; v < VectorDim(); v++)
-      {
-         coeff.SetComponent(v);
-         ProjectCoefficientElementL2_(coeff, x, Va);
-         fes->GetVDofs(v, vdofs);
-         SetSubVector(vdofs, x);
-         gVa.SetSubVector(vdofs, Va);
-      }
-
-      GroupCommunicator &gcomm = pfes->GroupComm();
-      gcomm.Reduce<real_t>(GetData(), GroupCommunicator::Sum);
-      gcomm.Bcast<real_t>(GetData());
-
-      gcomm.Reduce<real_t>(gVa.GetData(), GroupCommunicator::Sum);
-      gcomm.Bcast<real_t>(gVa.GetData());
-      *this /= gVa;
-   }
-}
-
-
 void ParGridFunction::ProjectDiscCoefficient(VectorCoefficient &coeff)
 {
   // local maximal element attribute for each dof
@@ -72,10 +72,6 @@ public:

   ParGridFunction(ParFiniteElementSpace *pf) : GridFunction(pf), pfes(pf) { }

-   /// Same as above but specify the device memory type
-   ParGridFunction(ParFiniteElementSpace *pf, MemoryType mt) :
-      GridFunction(pf, mt), pfes(pf) { }
-
   /// Construct a ParGridFunction using previously allocated array @a data.
   /** The ParGridFunction does not assume ownership of @a data which is assumed
       to be of size at least `pf->GetVSize()`. Similar to the GridFunction and
@@ -261,11 +257,7 @@ public:
   void GetElementDofValues(int el, Vector &dof_vals) const override;

   using GridFunction::ProjectCoefficient;
-   void ProjectCoefficient(Coefficient &coeff,
-                           ProjectType type = ProjectType::DEFAULT) override;
-
-   void ProjectCoefficient(VectorCoefficient &vcoeff,
-                           ProjectType type = ProjectType::DEFAULT) override;
+   void ProjectCoefficient(Coefficient &coeff) override;

   using GridFunction::ProjectDiscCoefficient;
   /** @brief Project a discontinuous vector coefficient as a grid function on
@@ -290,18 +282,6 @@ public:
   void ProjectBdrCoefficientTangent(VectorCoefficient &vcoeff,
                                     const Array<int> &bdr_attr) override;

-   void ProjectCoefficientGlobalL2(Coefficient &coeff,
-                                   real_t rtol = 1e-12,
-                                   int iter = 1000) override;
-
-   void ProjectCoefficientElementL2(Coefficient &coeff) override;
-
-   void ProjectCoefficientGlobalL2(VectorCoefficient &vcoeff,
-                                   real_t rtol = 1e-12,
-                                   int iter = 1000) override;
-
-   void ProjectCoefficientElementL2(VectorCoefficient &vcoeff) override;
-
   /// @brief Returns ||u_ex - u_h||_L1 in parallel for H1 or L2 elements
   ///
   /// @see GridFunction::ComputeL1Error(Coefficient *exsol[],
@@ -994,6 +994,7 @@ void ParNCL2FaceRestriction::ComputeScatterIndicesAndOffsets()
      {
         if ( face.IsConforming() )
         {
+            interpolations.RegisterFaceConformingInterpolation(face,f_ind);
            SetFaceDofsScatterIndices1(face,f_ind);
            if ( m==L2FaceValues::DoubleValued )
            {
@@ -1009,6 +1010,7 @@ void ParNCL2FaceRestriction::ComputeScatterIndicesAndOffsets()
         }
         else // Non-conforming face
         {
+            interpolations.RegisterFaceCoarseToFineInterpolation(face,f_ind);
            SetFaceDofsScatterIndices1(face,f_ind);
            if ( m==L2FaceValues::DoubleValued )
            {
@@ -1026,6 +1028,7 @@ void ParNCL2FaceRestriction::ComputeScatterIndicesAndOffsets()
      }
      else if (type==FaceType::Boundary && face.IsBoundary())
      {
+         interpolations.RegisterFaceConformingInterpolation(face,f_ind);
         SetFaceDofsScatterIndices1(face,f_ind);
         if ( m==L2FaceValues::DoubleValued )
         {
@@ -1043,6 +1046,10 @@ void ParNCL2FaceRestriction::ComputeScatterIndicesAndOffsets()
   {
      gather_offsets[i] += gather_offsets[i - 1];
   }
+
+   // Transform the interpolation matrix map into a contiguous memory structure.
+   interpolations.LinearizeInterpolatorMapIntoVector();
+   interpolations.InitializeNCInterpConfig();
 }

 void ParNCL2FaceRestriction::ComputeGatherIndices()
@@ -326,7 +326,9 @@ public:
       @param[in] keep_nbr_block When set to true the SparseMatrix will
                                 include the rows (in addition to the columns)
                                 corresponding to face-neighbor dofs. The
-                                 default behavior is to disregard those rows. */
+                                 default behavior is to disregard those rows.
+
+       @warning This method is not implemented yet. */
   void FillI(SparseMatrix &mat,
              const bool keep_nbr_block = false) const override;

@@ -362,7 +364,9 @@ public:
       @param[in] keep_nbr_block When set to true the SparseMatrix will
                                 include the rows (in addition to the columns)
                                 corresponding to face-neighbor dofs. The
-                                 default behavior is to disregard those rows. */
+                                 default behavior is to disregard those rows.
+
+       @warning This method is not implemented yet. */
   void FillJAndData(const Vector &fea_data,
                     SparseMatrix &mat,
                     const bool keep_nbr_block = false) const override;
@@ -50,13 +50,7 @@ QuadratureInterpolator::DetKernelType
 QuadratureInterpolator::DetKernels::Fallback(
   int DIM, int SDIM, int D1D, int Q1D)
 {
-   if (DIM == 1)
-   {
-      if (SDIM == 1) { return internal::quadrature_interpolator::Det1D; }
-      else if (SDIM == 2) { return internal::quadrature_interpolator::Det1DSurface<0,0,2>; }
-      else if (SDIM == 3) { return internal::quadrature_interpolator::Det1DSurface<0,0,3>; }
-      else { MFEM_ABORT(""); }
-   }
+   if (DIM == 1) { return internal::quadrature_interpolator::Det1D; }
   else if (DIM == 2 && SDIM == 2) { return internal::quadrature_interpolator::Det2D; }
   else if (DIM == 2 && SDIM == 3) { return internal::quadrature_interpolator::Det2DSurface; }
   else if (DIM == 3)
@@ -56,50 +56,6 @@ inline void Det1D(const int NE,
   });
 }

-template<int T_D1D = 0, int T_Q1D = 0, int T_SDIM = 3>
-inline void Det1DSurface(const int NE,
-                         const real_t *b,
-                         const real_t *g,
-                         const real_t *x,
-                         real_t *y,
-                         const int d1d = 0,
-                         const int q1d = 0,
-                         Vector *d_buff = nullptr)
-{
-   MFEM_CONTRACT_VAR(b);
-   MFEM_CONTRACT_VAR(d_buff);
-
-   const int D1D = T_D1D ? T_D1D : d1d;
-   const int Q1D = T_Q1D ? T_Q1D : q1d;
-
-   const auto G = Reshape(g, Q1D, D1D);
-   const auto X = Reshape(x, D1D, T_SDIM, NE);
-   auto Y = Reshape(y, Q1D, NE);
-
-   mfem::forall(NE, [=] MFEM_HOST_DEVICE (int e)
-   {
-      for (int q = 0; q < Q1D; q++)
-      {
-         real_t grad[T_SDIM];
-         for (int s = 0; s < T_SDIM; s++) { grad[s] = 0.0; }
-         for (int d = 0; d < D1D; d++)
-         {
-            const real_t gval = G(q, d);
-            for (int s = 0; s < T_SDIM; s++)
-            {
-               grad[s] += gval * X(d, s, e);
-            }
-         }
-         real_t norm2 = 0.0;
-         for (int s = 0; s < T_SDIM; s++)
-         {
-            norm2 += grad[s] * grad[s];
-         }
-         Y(q, e) = std::sqrt(norm2);
-      }
-   });
-}
-
 template<int T_D1D = 0, int T_Q1D = 0>
 inline void Det2D(const int NE,
                  const real_t *b,
@@ -334,13 +290,7 @@ template<int DIM, int SDIM, int D1D, int Q1D>
 QuadratureInterpolator::DetKernelType
 QuadratureInterpolator::DetKernels::Kernel()
 {
-   if (DIM == 1)
-   {
-      if (SDIM == 1) { return internal::quadrature_interpolator::Det1D; }
-      else if (SDIM == 2) { return internal::quadrature_interpolator::Det1DSurface<D1D, Q1D, 2>; }
-      else if (SDIM == 3) { return internal::quadrature_interpolator::Det1DSurface<D1D, Q1D, 3>; }
-      else { MFEM_ABORT(""); }
-   }
+   if (DIM == 1) { return internal::quadrature_interpolator::Det1D; }
   else if (DIM == 2 && SDIM == 2) { return internal::quadrature_interpolator::Det2D<D1D, Q1D>; }
   else if (DIM == 2 && SDIM == 3) { return internal::quadrature_interpolator::Det2DSurface<D1D, Q1D>; }
   else if (DIM == 3) { return internal::quadrature_interpolator::Det3D<D1D, Q1D>; }
@@ -542,8 +542,7 @@ void QuadratureInterpolator::Mult(const Vector &e_vec,
   }

   MFEM_ASSERT(!(eval_flags & DETERMINANTS) || dim == vdim ||
-               (dim == 2 && vdim == 3) || (dim == 1 && vdim == 2) ||
-               (dim == 1 && vdim == 3), "Invalid dimensions for determinants.");
+               (dim == 2 && vdim == 3), "Invalid dimensions for determinants.");
   MFEM_ASSERT(fespace->GetMesh()->GetNumGeometries(
                  fespace->GetMesh()->Dimension()) == 1,
               "mixed meshes are not supported");
@@ -1506,12 +1506,12 @@ void L2FaceRestriction::EnsureNormalDerivativeRestriction() const
   }
 }

-InterpolationManager::InterpolationManager(const FiniteElementSpace &fes_,
-                                           ElementDofOrdering ordering_,
+InterpolationManager::InterpolationManager(const FiniteElementSpace &fes,
+                                           ElementDofOrdering ordering,
                                           FaceType type)
-   : fes(fes_),
-     ordering(ordering_),
-     interp_config(fes.GetNFbyType(type)),
+   : fes(fes),
+     ordering(ordering),
+     interp_config( fes.GetNFbyType(type) ),
     nc_cpt(0)
 { }

@@ -1536,8 +1536,7 @@ void InterpolationManager::RegisterFaceCoarseToFineInterpolation(
                        face.element[0].local_face_id +
                        6*face.element[1].local_face_id +
                        36*face.element[1].orientation ;
-   // Unfortunately we can't trust uniqueness of the ptMat to identify the
-   // transformation.
+   // Unfortunately we can't trust unicity of the ptMat to identify the transformation.
   Key key(ptMat, face_key);
   auto itr = interp_map.find(key);
   if ( itr == interp_map.end() )
@@ -1584,27 +1583,17 @@ const DenseMatrix* InterpolationManager::GetCoarseToFineInterpolation(
   IsoparametricTransformation isotr;
   isotr.SetIdentityTransformation(trace_fe->GetGeomType());
   isotr.SetPointMat(*ptMat);
+   DenseMatrix& trans_pt_mat = isotr.GetPointMat();
+   // PointMatrix needs to be flipped in 2D
+   if ( trace_fe->GetGeomType()==Geometry::SEGMENT && !is_ghost_slave )
+   {
+      std::swap(trans_pt_mat(0,0),trans_pt_mat(0,1));
+   }
   DenseMatrix native_interpolator(face_dofs,face_dofs);
   trace_fe->GetLocalInterpolation(isotr, native_interpolator);
-
-   if (trace_fe->GetMapType() == FiniteElement::INTEGRAL)
-   {
-      // Handle potentially inverted Jacobian matrix
-      isotr.SetIntPoint(&Geometries.GetCenter(trace_fe->GetGeomType()));
-      native_interpolator *= (isotr.Weight() >= 0) ? 1.0 : -1.0;
-   }
-
   const int dim = trace_fe->GetDim()+1;
   const int dof1d = trace_fe->GetOrder()+1;
-   int orientation_i = face.element[1].orientation;
-   const int orientation_j = face.element[1].orientation;
-
-   // In 2D, need to flip orientation of the segments`
-   if (trace_fe->GetGeomType() == Geometry::SEGMENT && !is_ghost_slave)
-   {
-      orientation_i = 1;
-   }
-
+   const int orientation = face.element[1].orientation;
   for (int i = 0; i < face_dofs; i++)
   {
      const int ni = (dof_map.Size()==0) ? i : dof_map[i];
@@ -1613,7 +1602,7 @@ const DenseMatrix* InterpolationManager::GetCoarseToFineInterpolation(
      {
         // master side is elem 2, so we permute to order dofs as elem 1.
         li = PermuteFaceL2(dim, face_id2, face_id1,
-                            orientation_i, dof1d, li);
+                            orientation, dof1d, li);
      }
      for (int j = 0; j < face_dofs; j++)
      {
@@ -1622,7 +1611,7 @@ const DenseMatrix* InterpolationManager::GetCoarseToFineInterpolation(
         {
            // master side is elem 2, so we permute to order dofs as elem 1.
            lj = PermuteFaceL2(dim, face_id2, face_id1,
-                               orientation_j, dof1d, lj);
+                               orientation, dof1d, lj);
         }
         const int nj = (dof_map.Size()==0) ? j : dof_map[j];
         (*interpolator)(li,lj) = native_interpolator(ni,nj);
@@ -1687,7 +1676,7 @@ NCL2FaceRestriction::NCL2FaceRestriction(const FiniteElementSpace &fes,
                                         const L2FaceValues m,
                                         bool build)
   : L2FaceRestriction(fes, f_ordering, type, m, false),
-     interpolations(fes.GetInterpolationManager(ordering, type))
+     interpolations(fes, f_ordering, type)
 {
   if (!build) { return; }
   x_interp.UseDevice(true);
@@ -2213,6 +2202,14 @@ void NCL2FaceRestriction::ComputeScatterIndicesAndOffsets()
         {
            PermuteAndSetFaceDofsScatterIndices2(face,f_ind);
         }
+         if ( face.IsConforming() )
+         {
+            interpolations.RegisterFaceConformingInterpolation(face,f_ind);
+         }
+         else // Non-conforming face
+         {
+            interpolations.RegisterFaceCoarseToFineInterpolation(face,f_ind);
+         }
         f_ind++;
      }
      else if ( type==FaceType::Boundary && face.IsBoundary() )
@@ -2222,6 +2219,7 @@ void NCL2FaceRestriction::ComputeScatterIndicesAndOffsets()
         {
            SetBoundaryDofsScatterIndices2(face,f_ind);
         }
+         interpolations.RegisterFaceConformingInterpolation(face,f_ind);
         f_ind++;
      }
   }
@@ -2234,6 +2232,10 @@ void NCL2FaceRestriction::ComputeScatterIndicesAndOffsets()
   {
      gather_offsets[i] += gather_offsets[i - 1];
   }
+
+   // Transform the interpolation matrix map into a contiguous memory structure.
+   interpolations.LinearizeInterpolatorMapIntoVector();
+   interpolations.InitializeNCInterpConfig();
 }

 void NCL2FaceRestriction::ComputeGatherIndices()
@@ -2276,18 +2278,6 @@ void NCL2FaceRestriction::ComputeGatherIndices()
   gather_offsets[0] = 0;
 }

-static int GetSharedVSize(const FiniteElementSpace &fes)
-{
-#ifdef MFEM_USE_MPI
-   if (auto pfes = dynamic_cast<const ParFiniteElementSpace*>(&fes))
-   {
-      const_cast<ParFiniteElementSpace*>(pfes)->ExchangeFaceNbrData();
-      return pfes->GetFaceNbrVSize();
-   }
-#endif
-   return 0;
-}
-
 L2InterfaceFaceRestriction::L2InterfaceFaceRestriction(
   const FiniteElementSpace& fes_,
   const ElementDofOrdering ordering_,
@@ -2298,54 +2288,25 @@ L2InterfaceFaceRestriction::L2InterfaceFaceRestriction(
     nfaces(fes.GetNFbyType(type)),
     vdim(fes.GetVDim()),
     byvdim(fes.GetOrdering() == Ordering::byVDIM),
-     face_dofs(fes.GetTypicalTraceElement()->GetDof()),
+     face_dofs(nfaces > 0 ? fes.GetFaceElement(0)->GetDof() : 0),
     nfdofs(face_dofs*nfaces),
-     ndofs(fes.GetNDofs()),
-     nsdofs(GetSharedVSize(fes))
+     ndofs(fes.GetNDofs())
 {
   height = nfdofs;
   width = ndofs;

-#ifdef MFEM_USE_MPI
-   auto pfes = dynamic_cast<const ParFiniteElementSpace*>(&fes);
-#endif
-
   const Table &face2dof = fes.GetFaceToDofTable();

   const Mesh &mesh = *fes.GetMesh();
   int face_idx = 0;
-   scatter_map.SetSize(nfdofs);
-   gather_map.SetSize(ndofs + nsdofs);
-   gather_map = -1;
-
-   Array<int> dofs;
-   for (int f = 0; f < mesh.GetNumFacesWithGhost(); ++f)
+   gather_map.SetSize(nfdofs);
+   for (int f = 0; f < mesh.GetNumFaces(); ++f)
   {
      Mesh::FaceInformation face = mesh.GetFaceInformation(f);
-      if (!face.IsOfFaceType(type) || face.IsNonconformingCoarse()) { continue; }
-
-      if (f < mesh.GetNumFaces())
+      if (!face.IsOfFaceType(type)) { continue; }
+      for (int i = 0; i < face_dofs; ++i)
      {
-         // Local face
-         face2dof.GetRow(f, dofs);
-         for (int i = 0; i < face_dofs; ++i)
-         {
-            scatter_map[i + face_idx*face_dofs] = dofs[i];
-            gather_map[dofs[i]] = i + face_idx*face_dofs;
-         }
-      }
-      else
-      {
-         // Shared (non-conforming) ghost face
-#ifdef MFEM_USE_MPI
-         MFEM_ASSERT(pfes != nullptr, "");
-         pfes->GetFaceNbrFaceVDofs(f, dofs);
-         for (int i = 0; i < face_dofs; ++i)
-         {
-            scatter_map[i + face_idx*face_dofs] = ndofs + dofs[i];
-            gather_map[ndofs + dofs[i]] = i + face_idx*face_dofs;
-         }
-#endif
+         gather_map[i + face_idx*face_dofs] = face2dof.GetJ()[i + f*face_dofs];
      }
      ++face_idx;
   }
@@ -2353,19 +2314,13 @@ L2InterfaceFaceRestriction::L2InterfaceFaceRestriction(

 void L2InterfaceFaceRestriction::Mult(const Vector &x, Vector &y) const
 {
-   const int NDOFS = ndofs;
   const int nd = face_dofs;
   const int nf = nfaces;
   const int vd = vdim;
   const bool t = byvdim;
-   const int *map = scatter_map.Read();
-
-   Vector face_nbr_data = GetLVectorFaceNbrData(fes, x, type);
-   MFEM_ASSERT(face_nbr_data.Size() / vd == nsdofs, "");
+   const int *map = gather_map.Read();

   const auto d_x = Reshape(x.Read(), t?vd:ndofs, t?ndofs:vd);
-   const auto d_x_shared = Reshape(face_nbr_data.Read(),
-                                   t?vd:nsdofs, t?nsdofs:vd);
   auto d_y = Reshape(y.Write(), nd, vd, nf);

   mfem::forall(nd*nf, [=] MFEM_HOST_DEVICE (int i)
@@ -2373,8 +2328,7 @@ void L2InterfaceFaceRestriction::Mult(const Vector &x, Vector &y) const
      const int j = map[i];
      for (int c = 0; c < vd; ++c)
      {
-         if (j < NDOFS) { d_y(i % nd, c, i / nd) = d_x(t?c:j, t?j:c); }
-         else { d_y(i % nd, c, i / nd) = d_x_shared(t?c:(j-NDOFS), t?(j-NDOFS):c); }
+         d_y(i % nd, c, i / nd) = d_x(t?c:j, t?j:c);
      }
   });
 }
@@ -2389,39 +2343,15 @@ void L2InterfaceFaceRestriction::AddMultTranspose(
   const int *map = gather_map.Read();

   const auto d_x = Reshape(x.Read(), nd, vd, nf);
-   auto d_y = Reshape(y.ReadWrite(), t?vd:ndofs, t?ndofs:vd);
+   auto d_y = Reshape(y.Write(), t?vd:ndofs, t?ndofs:vd);

-   mfem::forall(ndofs, [=] MFEM_HOST_DEVICE (int i)
+   mfem::forall(ndofs, [=] MFEM_HOST_DEVICE (int i) { d_y[i] = 0.0; });
+   mfem::forall(nd*nf, [=] MFEM_HOST_DEVICE (int i)
   {
      const int j = map[i];
-      if (j < 0) { return; }
      for (int c = 0; c < vd; ++c)
      {
-         d_y(t?c:i, t?i:c) += a*d_x(j % nd, c, j / nd);
-      }
-   });
-}
-
-void L2InterfaceFaceRestriction::MultTransposeShared(
-   const Vector &x, Vector &y) const
-{
-   const int nd = face_dofs;
-   const int nf = nfaces;
-   const int vd = vdim;
-   const bool t = byvdim;
-   const int *map = gather_map.Read();
-
-   const auto d_x = Reshape(x.Read(), nd, vd, nf);
-   auto d_y = Reshape(y.Write(), t?vd:(ndofs+nsdofs), t?(ndofs+nsdofs):vd);
-   y = 0.0;
-
-   mfem::forall(ndofs + nsdofs, [=] MFEM_HOST_DEVICE (int i)
-   {
-      const int j = map[i];
-      if (j < 0) { return; }
-      for (int c = 0; c < vd; ++c)
-      {
-         d_y(t?c:i, t?i:c) = d_x(j % nd, c, j / nd);
+         d_y(t?c:j, t?j:c) = d_x(i % nd, c, i / nd);
      }
   });
 }
@@ -2431,11 +2361,6 @@ const Array<int> &L2InterfaceFaceRestriction::GatherMap() const
   return gather_map;
 }

-const Array<int> &L2InterfaceFaceRestriction::ScatterMap() const
-{
-   return scatter_map;
-}
-
 Vector GetLVectorFaceNbrData(
   const FiniteElementSpace &fes, const Vector &x, FaceType ftype)
 {
@@ -2457,7 +2382,6 @@ Vector GetLVectorFaceNbrData(
         {
            ParGridFunction gf(pfes, const_cast<Vector&>(x));
            gf.ExchangeFaceNbrData();
-            x.SyncMemory(gf);
            return std::move(gf.FaceNbrData());
         }
      }
@@ -812,12 +812,13 @@ protected:
       PointMatrix and a local face identifier. */
   using Key = std::pair<const DenseMatrix*,int>;
   /// The temporary map used to store the different interpolators.
-   using Map =
-      std::unordered_map<Key, std::pair<int,const DenseMatrix*>, PairHasher>;
+   using Map = std::map<Key, std::pair<int,const DenseMatrix*>>;
   Map interp_map; // The temporary map that stores the interpolators.

 public:
-   /** @brief Constructor.
+   InterpolationManager() = delete;
+
+   /** @brief main constructor.

       @param[in] fes      The FiniteElementSpace on which this operates
       @param[in] ordering Request a specific element ordering.
@@ -908,7 +909,7 @@ private:
 class NCL2FaceRestriction : virtual public L2FaceRestriction
 {
 protected:
-   const InterpolationManager &interpolations;
+   InterpolationManager interpolations;
   mutable Vector x_interp;

   /** @brief Constructs an NCL2FaceRestriction, this is a specialization of a
@@ -995,7 +996,9 @@ public:
       @param[in] keep_nbr_block When set to true the SparseMatrix will
                                 include the rows (in addition to the columns)
                                 corresponding to face-neighbor dofs. The
-                                 default behavior is to disregard those rows. */
+                                 default behavior is to disregard those rows.
+
+       @warning This method is not implemented yet. */
   void FillI(SparseMatrix &mat,
              const bool keep_nbr_block = false) const override;

@@ -1013,7 +1016,9 @@ public:
       @param[in] keep_nbr_block When set to true the SparseMatrix will
                                 include the rows (in addition to the columns)
                                 corresponding to face-neighbor dofs. The
-                                 default behavior is to disregard those rows. */
+                                 default behavior is to disregard those rows.
+
+       @warning This method is not implemented yet. */
   void FillJAndData(const Vector &fea_data,
                     SparseMatrix &mat,
                     const bool keep_nbr_block = false) const override;
@@ -1031,7 +1036,9 @@ public:
                              added the face contributions.
                              The format is: dofs x dofs x ne, where dofs is the
                              number of dofs per element and ne the number of
-                              elements. */
+                              elements.
+
+       @warning This method is not implemented yet. */
   void AddFaceMatricesToElementMatrices(const Vector &fea_data,
                                         Vector &ea_data) const override;

@@ -1123,9 +1130,7 @@ protected:
   const int face_dofs; ///< Number of dofs on each face
   const int nfdofs; ///< Total number of dofs on the faces (E-vector size)
   const int ndofs; ///< Number of dofs in the space (L-vector size)
-   const int nsdofs; ///< Number of shared face neighbor (ghost) dofs
   Array<int> gather_map; ///< Gather map
-   Array<int> scatter_map; ///< Scatter map

 public:
   /** @brief Constructs an L2InterfaceFaceRestriction.
@@ -1163,24 +1168,7 @@ public:
   void AddMultTranspose(const Vector &x, Vector &y,
                         const real_t a = 1.0) const override;

-   /// @brief Gather degrees of freedom, from face E-vector to L-vector and
-   /// shared (ghost) DOFs.
-   ///
-   /// @param[in]     x The face E-Vector degrees of freedom with size
-   ///                  (face_dofs, vdim, nf), where nf is the number of
-   ///                  interior or boundary faces requested by @a type in the
-   ///                  constructor. The face_dofs should be ordered according
-   ///                  to the given ElementDofOrdering
-   /// @param[out]    y Vector of length vsize + face neighbor vsize
-   void MultTransposeShared(const Vector &x, Vector &y) const;
-
   const Array<int> &GatherMap() const override;
-
-   /// @brief Return the low-level mapping from L-dofs to E-dofs.
-   ///
-   /// L-dofs that do not correspond to an E-dof (e.g. that lie on a face of a
-   /// different type) are given index -1.
-   const Array<int> &ScatterMap() const;
 };

 /** @brief Convert a dof face index from Native ordering to lexicographic
@@ -333,12 +333,6 @@ void L2ProjectionGridTransfer::L2Projection::MixedMassEA(
   int nel_ho = mesh_ho->GetNE();
   int nel_lor = mesh_lor->GetNE();

-   if (nel_ho == 0)
-   {
-      M_LH.SetSize(0);
-      return;
-   }
-
   const CoarseFineTransformations& cf_tr = mesh_lor->GetRefinementTransforms();

   int nref_max = 0;
@@ -837,17 +831,11 @@ void L2ProjectionGridTransfer::L2ProjectionL2Space::Mult(
 void L2ProjectionGridTransfer::L2ProjectionL2Space::EAMult(
   const Vector &x, Vector &y) const
 {
-   const int nel_ho = fes_ho.GetMesh()->GetNE();
-
-   if (nel_ho == 0)
-   {
-      return;
-   }
-
   const int iho = 0;
   const int nref = ho2lor.RowSize(iho);
   const int ndof_ho = fes_ho.GetFE(iho)->GetDof();
   const int ndof_lor = fes_lor.GetFE(ho2lor.GetRow(iho)[0])->GetDof();
+   const int nel_ho = fes_ho.GetMesh()->GetNE();

   DenseTensor R_dt;
   R_dt.NewMemoryAndSize(R.GetMemory(), ndof_lor*nref, ndof_ho, nel_ho, false);
@@ -899,17 +887,11 @@ void L2ProjectionGridTransfer::L2ProjectionL2Space::MultTranspose(
 void L2ProjectionGridTransfer::L2ProjectionL2Space::EAMultTranspose(
   const Vector &x, Vector &y) const
 {
-   const int nel_ho = fes_ho.GetMesh()->GetNE();
-
-   if (nel_ho == 0)
-   {
-      return;
-   }
-
   const int iho = 0;
   const int nref = ho2lor.RowSize(iho);
   const int ndof_ho = fes_ho.GetFE(iho)->GetDof();
   const int ndof_lor = fes_lor.GetFE(ho2lor.GetRow(iho)[0])->GetDof();
+   const int nel_ho = fes_ho.GetMesh()->GetNE();

   DenseTensor R_dt;
   R_dt.NewMemoryAndSize(R.GetMemory(), ndof_lor*nref, ndof_ho, nel_ho, false);
@@ -919,6 +901,7 @@ void L2ProjectionGridTransfer::L2ProjectionL2Space::EAMultTranspose(
 void L2ProjectionGridTransfer::L2ProjectionL2Space::Prolongate(
   const Vector &x, Vector &y) const
 {
+
   if (fes_ho.GetNE() == 0) { return; }

   if (use_ea)
@@ -977,13 +960,14 @@ void L2ProjectionGridTransfer::L2ProjectionL2Space::EAProlongate(
 void L2ProjectionGridTransfer::L2ProjectionL2Space::ProlongateTranspose(
   const Vector &x, Vector &y) const
 {
-   if (fes_ho.GetNE() == 0) { return; }

   if (use_ea)
   {
      return EAProlongateTranspose(x,y);
   }

+
+   if (fes_ho.GetNE() == 0) { return; }
   MFEM_VERIFY(P.Size() > 0, "Prolongation not supported for these spaces.")
   int vdim = fes_ho.GetVDim();
   Array<int> vdofs;
@@ -1260,6 +1244,13 @@ void L2ProjectionGridTransfer::L2ProjectionH1Space::EAL2ProjectionH1Space
   int ndof_ho = pfes_ho.GetNDofs();
   int ndof_lor = pfes_lor.GetNDofs();

+
+   // If the local mesh is empty, skip all computations
+   if (nel_ho == 0)
+   {
+      return;
+   }
+
   const CoarseFineTransformations& cf_tr = mesh_lor->GetRefinementTransforms();

   int nref_max = 0;
@@ -1869,11 +1860,6 @@ L2ProjectionGridTransfer::H1SpaceMixedMassOperator::H1SpaceMixedMassOperator(
 void L2ProjectionGridTransfer::H1SpaceMixedMassOperator::Mult(const Vector &x,
                                                              Vector &y) const
 {
-   if (fes_ho->GetNE() == 0)
-   {
-      return;
-   }
-
   const Operator* elem_restrict_ho = fes_ho->GetElementRestriction(
                                         ElementDofOrdering::NATIVE);
   const Operator* elem_restrict_lor = fes_lor->GetElementRestriction(
@@ -1920,11 +1906,6 @@ void L2ProjectionGridTransfer::H1SpaceMixedMassOperator::Mult(const Vector &x,
 void L2ProjectionGridTransfer::H1SpaceMixedMassOperator::MultTranspose(
   const Vector &x, Vector &y) const
 {
-   if (fes_ho->GetNE() == 0)
-   {
-      return;
-   }
-
   const Operator* elem_restrict_ho = fes_ho->GetElementRestriction(
                                         ElementDofOrdering::NATIVE);
   const Operator* elem_restrict_lor = fes_lor->GetElementRestriction(
@@ -18,7 +18,6 @@ list(APPEND SRCS
  gecko.cpp
  globals.cpp
  hash.cpp
-  hash_util.cpp
  isockstream.cpp
  mem_manager.cpp
  occa.cpp
@@ -47,7 +46,6 @@ list(APPEND HDRS
  globals.hpp
  zstr.hpp
  hash.hpp
-  hash_util.hpp
  isockstream.hpp
  kdtree.hpp
  mem_alloc.hpp
@@ -44,7 +44,6 @@
 #endif

 #if !defined(MFEM_USE_CUDA_OR_HIP)
-constexpr bool mfem_use_gpu = false;
 #define MFEM_DEVICE
 #define MFEM_HOST
 #define MFEM_LAMBDA
@@ -53,7 +52,6 @@ constexpr bool mfem_use_gpu = false;
 #define MFEM_DEVICE_SYNC
 // MFEM_STREAM_SYNC is used for UVM and MPI GPU-Aware kernels
 #define MFEM_STREAM_SYNC
-#define MFEM_LAUNCH_BOUNDS(...)
 #endif

 #if !((defined(MFEM_USE_CUDA) && defined(__CUDA_ARCH__)) || \
@@ -20,11 +20,9 @@

 #if defined(MFEM_USE_CUDA) && defined(__CUDACC__)
 #define MFEM_USE_CUDA_OR_HIP
-constexpr bool mfem_use_gpu = true;
 #define MFEM_DEVICE __device__
 #define MFEM_HOST __host__
 #define MFEM_LAMBDA __host__
-#define MFEM_LAUNCH_BOUNDS __launch_bounds__
 // #define MFEM_HOST_DEVICE __host__ __device__ // defined in config/config.hpp
 #define MFEM_DEVICE_SYNC MFEM_GPU_CHECK(cudaDeviceSynchronize())
 #define MFEM_STREAM_SYNC MFEM_GPU_CHECK(cudaStreamSynchronize(0))
@@ -22,8 +22,6 @@

 #include <unordered_map>
 #include <map>
-#include <sstream>
-#include <iomanip>

 namespace mfem
 {
@@ -718,29 +716,6 @@ void Device::DeviceMem(size_t *free, size_t *total)
 #endif
 }

-std::string Device::GetUUID(const int device_id)
-{
-   std::stringstream res;
-#if defined(MFEM_USE_CUDA)
-   cudaDeviceProp prop;
-   MFEM_GPU_CHECK(cudaGetDeviceProperties(&prop, device_id));
-   for (int i = 0; i < 16; ++i)
-   {
-      res << std::setfill('0') << std::setw(2) << std::hex
-          << static_cast<unsigned>(prop.uuid.bytes[i]);
-   }
-#elif defined(MFEM_USE_HIP)
-   hipUUID uuid;
-   MFEM_GPU_CHECK(hipDeviceGetUuid(&uuid, device_id));
-   for (int i = 0; i < 16; ++i)
-   {
-      res << std::setfill('0') << std::setw(2) << std::hex
-          << static_cast<unsigned>(uuid.bytes[i]);
-   }
-#endif
-   return res.str();
-}
-
 int Device::NumMultiprocessors(int dev)
 {
 #if defined(MFEM_USE_CUDA)
@@ -255,10 +255,6 @@ public:
   /// Get the number of available devices (may be called before configuration).
   static int GetDeviceCount();

-   /// Gets a string representation of the GPU UUID.
-   /// 0 <= @a device_id < GetDeviceCount()
-   static std::string GetUUID(const int device_id = 0);
-
   /** @brief Return true if any of the backends in the backend mask, @a b_mask,
       are allowed. */
   /** This method can be used with any of the Backend::Id constants, the
@@ -295,12 +295,11 @@ using hip_threads_z =
 #endif

 #if defined(MFEM_USE_RAJA) && defined(RAJA_ENABLE_CUDA) && defined(__CUDACC__)
-template <typename DBODY>
+template <const int BLOCKS = MFEM_CUDA_BLOCKS, typename DBODY>
 void RajaCuWrap1D(const int N, DBODY &&d_body)
 {
   //true denotes asynchronous kernel
-   RAJA::forall<RAJA::cuda_exec<MFEM_CUDA_BLOCKS,true>>(RAJA::RangeSegment(0,N),
-                                                        d_body);
+   RAJA::forall<RAJA::cuda_exec<BLOCKS,true>>(RAJA::RangeSegment(0,N),d_body);
 }

 template <typename DBODY>
@@ -363,18 +362,18 @@ struct RajaCuWrap;
 template <>
 struct RajaCuWrap<1>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
-      RajaCuWrap1D(N, d_body);
+      RajaCuWrap1D<BLCK>(N, d_body);
   }
 };

 template <>
 struct RajaCuWrap<2>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
@@ -385,7 +384,7 @@ struct RajaCuWrap<2>
 template <>
 struct RajaCuWrap<3>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
@@ -396,12 +395,11 @@ struct RajaCuWrap<3>
 #endif

 #if defined(MFEM_USE_RAJA) && defined(RAJA_ENABLE_HIP) && defined(__HIP__)
-template <typename DBODY>
+template <const int BLOCKS = MFEM_HIP_BLOCKS, typename DBODY>
 void RajaHipWrap1D(const int N, DBODY &&d_body)
 {
   //true denotes asynchronous kernel
-   RAJA::forall<RAJA::hip_exec<MFEM_HIP_BLOCKS,true>>(RAJA::RangeSegment(0,N),
-                                                      d_body);
+   RAJA::forall<RAJA::hip_exec<BLOCKS,true>>(RAJA::RangeSegment(0,N),d_body);
 }

 template <typename DBODY>
@@ -464,18 +462,18 @@ struct RajaHipWrap;
 template <>
 struct RajaHipWrap<1>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
-      RajaHipWrap1D(N, d_body);
+      RajaHipWrap1D<BLCK>(N, d_body);
   }
 };

 template <>
 struct RajaHipWrap<2>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
@@ -486,7 +484,7 @@ struct RajaHipWrap<2>
 template <>
 struct RajaHipWrap<3>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
@@ -586,31 +584,12 @@ void CuKernel2D(const int N, BODY body)
   body(k);
 }

-// __launch_bounds__ second argument is omitted to get the default behavior
-template <int MAX_THREADS_PER_BLOCK, typename BODY>
-__global__
-MFEM_LAUNCH_BOUNDS(MAX_THREADS_PER_BLOCK)
-static void CuKernel2DLaunchBounds(const int N, BODY body)
-{
-   const int k = blockIdx.x*blockDim.z + threadIdx.z;
-   if (k >= N) { return; }
-   body(k);
-}
-
 template <typename BODY> __global__ static
 void CuKernel3D(const int N, BODY body)
 {
   for (int k = blockIdx.x; k < N; k += gridDim.x) { body(k); }
 }

-template <int MAX_THREADS_PER_BLOCK, typename BODY>
-__global__
-MFEM_LAUNCH_BOUNDS(MAX_THREADS_PER_BLOCK)
-static void CuKernel3DLaunchBounds(const int N, BODY body)
-{
-   for (int k = blockIdx.x; k < N; k += gridDim.x) { body(k); }
-}
-
 template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
 void CuWrap1D(const int N, DBODY &&d_body)
 {
@@ -625,8 +604,6 @@ void CuWrap2D(const int N, DBODY &&d_body,
              const int X, const int Y, const int BZ)
 {
   if (N==0) { return; }
-   // required for optimized GCC/NVCC builds to prevent runtime
-   // ODR/linkage violations of inlined templated kernel helpers
   MFEM_VERIFY(BZ>0, "");
   const int GRID = (N+BZ-1)/BZ;
   const dim3 BLCK(X,Y,BZ);
@@ -634,19 +611,6 @@ void CuWrap2D(const int N, DBODY &&d_body,
   MFEM_GPU_CHECK(cudaGetLastError());
 }

-template <int MAX_THREADS_PER_BLOCK, typename DBODY>
-void CuWrap2DLaunchBounds(const int N, DBODY &&d_body,
-                          const int X, const int Y, const int BZ)
-{
-   if (N==0) { return; }
-   MFEM_VERIFY(BZ>0, "");
-   const int GRID = (N+BZ-1)/BZ;
-   const dim3 BLCK(X,Y,BZ);
-   static_assert(MAX_THREADS_PER_BLOCK > 0);
-   CuKernel2DLaunchBounds<MAX_THREADS_PER_BLOCK><<<GRID,BLCK>>>(N, d_body);
-   MFEM_GPU_CHECK(cudaGetLastError());
-}
-
 template <typename DBODY>
 void CuWrap3D(const int N, DBODY &&d_body,
              const int X, const int Y, const int Z, const int G)
@@ -658,35 +622,24 @@ void CuWrap3D(const int N, DBODY &&d_body,
   MFEM_GPU_CHECK(cudaGetLastError());
 }

-template <int MAX_THREADS_PER_BLOCK, typename DBODY>
-void CuWrap3DLaunchBounds(const int N, DBODY &&d_body,
-                          const int X, const int Y, const int Z, const int G)
-{
-   if (N==0) { return; }
-   const int GRID = G == 0 ? N : G;
-   const dim3 BLCK(X,Y,Z);
-   static_assert(MAX_THREADS_PER_BLOCK > 0);
-   CuKernel3DLaunchBounds<MAX_THREADS_PER_BLOCK><<<GRID, BLCK>>>(N, d_body);
-   MFEM_GPU_CHECK(cudaGetLastError());
-}
+template <int Dim>
+struct CuWrap;

-template <int Dim, int MAX_THREADS_PER_BLOCK> struct CuWrap;
-
-template <int MAX_THREADS_PER_BLOCK>
-struct CuWrap<1, MAX_THREADS_PER_BLOCK>
+template <>
+struct CuWrap<1>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
-      CuWrap1D<MFEM_CUDA_BLOCKS>(N, d_body);
+      CuWrap1D<BLCK>(N, d_body);
   }
 };

 template <>
-struct CuWrap<2, 0>
+struct CuWrap<2>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
@@ -694,22 +647,10 @@ struct CuWrap<2, 0>
   }
 };

-template <int MAX_THREADS_PER_BLOCK>
-struct CuWrap<2, MAX_THREADS_PER_BLOCK>
-{
-   template <typename DBODY>
-   static void run(const int N, DBODY &&d_body,
-                   const int X, const int Y, const int Z, const int G)
-   {
-      static_assert(MAX_THREADS_PER_BLOCK > 0);
-      CuWrap2DLaunchBounds<MAX_THREADS_PER_BLOCK>(N, d_body, X, Y, Z);
-   }
-};
-
 template <>
-struct CuWrap<3, 0>
+struct CuWrap<3>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
@@ -717,17 +658,6 @@ struct CuWrap<3, 0>
   }
 };

-template <int MAX_THREADS_PER_BLOCK>
-struct CuWrap<3, MAX_THREADS_PER_BLOCK>
-{
-   template <typename DBODY>
-   static void run(const int N, DBODY &&d_body,
-                   const int X, const int Y, const int Z, const int G)
-   {
-      CuWrap3DLaunchBounds<MAX_THREADS_PER_BLOCK>(N, d_body, X, Y, Z, G);
-   }
-};
-
 #endif // defined(MFEM_USE_CUDA) && defined(__CUDACC__)


@@ -750,31 +680,13 @@ void HipKernel2D(const int N, BODY body)
   body(k);
 }

-template <int MAX_THREADS_PER_BLOCK, typename BODY>
-__global__
-MFEM_LAUNCH_BOUNDS(MAX_THREADS_PER_BLOCK)
-static void HipKernel2DLaunchBounds(const int N, BODY body)
-{
-   const int k = hipBlockIdx_x*hipBlockDim_z + hipThreadIdx_z;
-   if (k >= N) { return; }
-   body(k);
-}
-
 template <typename BODY> __global__ static
 void HipKernel3D(const int N, BODY body)
 {
   for (int k = hipBlockIdx_x; k < N; k += hipGridDim_x) { body(k); }
 }

-template <int MAX_THREADS_PER_BLOCK, typename BODY>
-__global__
-MFEM_LAUNCH_BOUNDS(MAX_THREADS_PER_BLOCK)
-static void HipKernel3DLaunchBounds(const int N, BODY body)
-{
-   for (int k = hipBlockIdx_x; k < N; k += hipGridDim_x) { body(k); }
-}
-
-template <int BLCK = MFEM_HIP_BLOCKS, typename DBODY>
+template <const int BLCK = MFEM_HIP_BLOCKS, typename DBODY>
 void HipWrap1D(const int N, DBODY &&d_body)
 {
   if (N==0) { return; }
@@ -788,27 +700,12 @@ void HipWrap2D(const int N, DBODY &&d_body,
               const int X, const int Y, const int BZ)
 {
   if (N==0) { return; }
-   MFEM_VERIFY(BZ>0, "");
   const int GRID = (N+BZ-1)/BZ;
   const dim3 BLCK(X,Y,BZ);
   hipLaunchKernelGGL(HipKernel2D,GRID,BLCK,0,nullptr,N,d_body);
   MFEM_GPU_CHECK(hipGetLastError());
 }

-template <int MAX_THREADS_PER_BLOCK, typename DBODY>
-void HipWrap2DLaunchBounds(const int N, DBODY &&d_body,
-                           const int X, const int Y, const int BZ)
-{
-   if (N==0) { return; }
-   MFEM_VERIFY(BZ>0, "");
-   const int GRID = (N+BZ-1)/BZ;
-   const dim3 BLCK(X,Y,BZ);
-   static_assert(MAX_THREADS_PER_BLOCK > 0);
-   HipKernel2DLaunchBounds<MAX_THREADS_PER_BLOCK><<<dim3(GRID), dim3(BLCK), 0, 0>>>
-   (N, d_body);
-   MFEM_GPU_CHECK(hipGetLastError());
-}
-
 template <typename DBODY>
 void HipWrap3D(const int N, DBODY &&d_body,
               const int X, const int Y, const int Z, const int G)
@@ -820,36 +717,24 @@ void HipWrap3D(const int N, DBODY &&d_body,
   MFEM_GPU_CHECK(hipGetLastError());
 }

-template <int MAX_THREADS_PER_BLOCK, typename DBODY>
-void HipWrap3DLaunchBounds(const int N, DBODY &&d_body,
-                           const int X, const int Y, const int Z, const int G)
-{
-   if (N==0) { return; }
-   const int GRID = G == 0 ? N : G;
-   const dim3 BLCK(X,Y,Z);
-   static_assert(MAX_THREADS_PER_BLOCK > 0);
-   HipKernel3DLaunchBounds<MAX_THREADS_PER_BLOCK><<<dim3(GRID), dim3(BLCK), 0, 0>>>
-   (N, d_body);
-   MFEM_GPU_CHECK(hipGetLastError());
-}
+template <int Dim>
+struct HipWrap;

-template <int Dim, int MAX_THREADS_PER_BLOCK> struct HipWrap;
-
-template <int MAX_THREADS_PER_BLOCK>
-struct HipWrap<1, MAX_THREADS_PER_BLOCK>
+template <>
+struct HipWrap<1>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
-      HipWrap1D<MFEM_HIP_BLOCKS>(N, d_body);
+      HipWrap1D<BLCK>(N, d_body);
   }
 };

 template <>
-struct HipWrap<2, 0>
+struct HipWrap<2>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
@@ -857,21 +742,10 @@ struct HipWrap<2, 0>
   }
 };

-template <int MAX_THREADS_PER_BLOCK>
-struct HipWrap<2, MAX_THREADS_PER_BLOCK>
-{
-   template <typename DBODY>
-   static void run(const int N, DBODY &&d_body,
-                   const int X, const int Y, const int Z, const int G)
-   {
-      HipWrap2DLaunchBounds<MAX_THREADS_PER_BLOCK>(N, d_body, X, Y, Z);
-   }
-};
-
 template <>
-struct HipWrap<3, 0>
+struct HipWrap<3>
 {
-   template <typename DBODY>
+   template <const int BLCK = MFEM_CUDA_BLOCKS, typename DBODY>
   static void run(const int N, DBODY &&d_body,
                   const int X, const int Y, const int Z, const int G)
   {
@@ -879,24 +753,11 @@ struct HipWrap<3, 0>
   }
 };

-template <int MAX_THREADS_PER_BLOCK>
-struct HipWrap<3, MAX_THREADS_PER_BLOCK>
-{
-   template <typename DBODY>
-   static void run(const int N, DBODY &&d_body,
-                   const int X, const int Y, const int Z, const int G)
-   {
-      HipWrap3DLaunchBounds<MAX_THREADS_PER_BLOCK>(N, d_body, X, Y, Z, G);
-   }
-};
-
 #endif // defined(MFEM_USE_HIP) && defined(__HIP__)


-///////////////////////////////////////////////////////////////////////////////
-/// Forall host & device kernel dispatch
-template <int DIM, int MAX_THREADS_PER_BLOCK = 0,
-          typename d_lambda, typename h_lambda>
+/// The forall kernel body wrapper
+template <const int DIM, typename d_lambda, typename h_lambda>
 inline void ForallWrap(const bool use_dev, const int N,
                       d_lambda &&d_body, h_lambda &&h_body,
                       const int X=0, const int Y=0, const int Z=0,
@@ -929,7 +790,7 @@ inline void ForallWrap(const bool use_dev, const int N,
   // If Backend::CUDA is allowed, use it
   if (Device::Allows(Backend::CUDA))
   {
-      return CuWrap<DIM, MAX_THREADS_PER_BLOCK>::run(N, d_body, X, Y, Z, G);
+      return CuWrap<DIM>::run(N, d_body, X, Y, Z, G);
   }
 #endif

@@ -937,7 +798,7 @@ inline void ForallWrap(const bool use_dev, const int N,
   // If Backend::HIP is allowed, use it
   if (Device::Allows(Backend::HIP))
   {
-      return HipWrap<DIM, MAX_THREADS_PER_BLOCK>::run(N, d_body, X, Y, Z, G);
+      return HipWrap<DIM>::run(N, d_body, X, Y, Z, G);
   }
 #endif

@@ -966,9 +827,7 @@ backend_cpu:
   for (int k = 0; k < N; k++) { h_body(k); }
 }

-///////////////////////////////////////////////////////////////////////////////
-/// Forall host & device kernel wrappers
-template <int DIM, typename lambda>
+template <const int DIM, typename lambda>
 inline void ForallWrap(const bool use_dev, const int N, lambda &&body,
                       const int X=0, const int Y=0, const int Z=0,
                       const int G=0)
@@ -976,16 +835,6 @@ inline void ForallWrap(const bool use_dev, const int N, lambda &&body,
   ForallWrap<DIM>(use_dev, N, body, body, X, Y, Z, G);
 }

-template <int DIM, int MAX_THREADS_PER_BLOCK, typename lambda>
-inline void ForallWrap(const bool use_dev, const int N, lambda &&body,
-                       const int X=0, const int Y=0, const int Z=0,
-                       const int G=0)
-{
-   ForallWrap<DIM, MAX_THREADS_PER_BLOCK>(use_dev, N, body, body, X, Y, Z, G);
-}
-
-///////////////////////////////////////////////////////////////////////////////
-// forall interfaces
 template<typename lambda>
 inline void forall(int N, lambda &&body) { ForallWrap<1>(true, N, body); }

@@ -994,7 +843,7 @@ inline void forall(int Nx, int Ny, lambda &&body)
 {
   if (Device::Allows(Backend::DEVICE_MASK))
   {
-      mfem::forall(Nx * Ny, [=] MFEM_HOST_DEVICE(int idx)
+      forall(Nx * Ny, [=] MFEM_HOST_DEVICE(int idx)
      {
         int j = idx / Nx;
         int i = idx % Nx;
@@ -1030,7 +879,7 @@ inline void forall(int Nx, int Ny, int Nz, lambda &&body)
 {
   if (Device::Allows(Backend::DEVICE_MASK))
   {
-      mfem::forall(Nx * Ny * Nz, [=] MFEM_HOST_DEVICE(int idx)
+      forall(Nx * Ny * Nz, [=] MFEM_HOST_DEVICE(int idx)
      {
         int i = idx % Nx;
         int j = idx / Nx;
@@ -1078,12 +927,6 @@ inline void forall_2D(int N, int X, int Y, lambda &&body)
   ForallWrap<2>(true, N, body, X, Y, 1);
 }

-template<int MAX_THREADS_PER_BLOCK, typename lambda>
-inline void forall_2D(int N, int X, int Y, lambda &&body)
-{
-   ForallWrap<2, MAX_THREADS_PER_BLOCK>(true, N, body, X, Y, 1);
-}
-
 template<typename lambda>
 inline void forall_2D_batch(int N, int X, int Y, int BZ, lambda &&body)
 {
@@ -1096,12 +939,6 @@ inline void forall_3D(int N, int X, int Y, int Z, lambda &&body)
   ForallWrap<3>(true, N, body, X, Y, Z, 0);
 }

-template<int MAX_THREADS_PER_BLOCK, typename lambda>
-inline void forall_3D(int N, int X, int Y, int Z, lambda &&body)
-{
-   ForallWrap<3, MAX_THREADS_PER_BLOCK>(true, N, body, X, Y, Z, 0);
-}
-
 template<typename lambda>
 inline void forall_3D_grid(int N, int X, int Y, int Z, int G, lambda &&body)
 {
@@ -80,4 +80,159 @@ std::string HashFunction::GetHash() const
   return hash;
 }

+constexpr static uint64_t rotl64(uint64_t x, int r)
+{
+   return (x << r) | (x >> (64 - r));
+}
+
+void Hasher::init(uint64_t seed)
+{
+   data[0] = seed;
+   data[1] = seed;
+   nbytes = 0;
+}
+
+void Hasher::add_block(uint64_t k1, uint64_t k2)
+{
+   constexpr uint64_t c1 = 0x87c37b91114253d5ull;
+   constexpr uint64_t c2 = 0x4cf5ad432745937full;
+
+   k1 *= c1;
+   k1 = rotl64(k1, 31);
+   k1 *= c2;
+   data[0] ^= k1;
+
+   data[0] = rotl64(data[0], 27);
+   data[0] += data[1];
+   data[0] = data[0] * 5 + 0x52dce729ull;
+
+   k2 *= c2;
+   k2 = rotl64(k2, 33);
+   k2 *= c1;
+   data[1] ^= k2;
+
+   data[1] = rotl64(data[1], 31);
+   data[1] += data[0];
+   data[1] = data[1] * 5 + 0x38495ab5ull;
+}
+
+static uint64_t fmix64(uint64_t k)
+{
+   // http://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html
+   // mix13
+   k ^= k >> 30;
+   k *= 0xbf58476d1ce4e5b9ull;
+   k ^= k >> 27;
+   k *= 0x94d049bb133111ebull;
+   k ^= k >> 31;
+   return k;
+}
+
+void Hasher::append(const uint8_t *vs, uint64_t bytes)
+{
+   if (bytes == 0)
+   {
+      return;
+   }
+   auto rem = nbytes % 16;
+   nbytes += bytes;
+   uint8_t *tmp = reinterpret_cast<uint8_t *>(buf_);
+   while (true)
+   {
+      if (bytes + rem >= 16)
+      {
+         std::copy(vs, vs + 16 - rem, tmp + rem);
+         add_block(buf_[0], buf_[1]);
+         vs += (16 - rem);
+         bytes -= (16 - rem);
+         rem = 0;
+      }
+      else
+      {
+         std::copy(vs, vs + bytes, tmp + rem);
+         return;
+      }
+   }
+}
+
+void Hasher::finalize()
+{
+   auto rem = nbytes % 16;
+   if (rem > 0)
+   {
+      nbytes -= rem;
+      if (rem <= 8)
+      {
+         finalize(buf_[0], rem);
+      }
+      else
+      {
+         finalize(buf_[0], buf_[1], rem);
+      }
+      return;
+   }
+   data[0] ^= nbytes;
+   data[1] ^= nbytes;
+
+   data[0] += data[1];
+   data[1] += data[0];
+
+   data[0] = fmix64(data[0]);
+   data[1] = fmix64(data[1]);
+
+   data[0] += data[1];
+   data[1] += data[0];
+}
+
+void Hasher::finalize(uint64_t k1, int num)
+{
+   constexpr uint64_t c1 = 0x87c37b91114253d5ull;
+   constexpr uint64_t c2 = 0x4cf5ad432745937full;
+   nbytes += num;
+   k1 *= c1;
+   k1 = rotl64(k1, 31);
+   k1 *= c2;
+   data[0] ^= k1;
+
+   data[0] ^= nbytes;
+   data[1] ^= nbytes;
+
+   data[0] += data[1];
+   data[1] += data[0];
+
+   data[0] = fmix64(data[0]);
+   data[1] = fmix64(data[1]);
+
+   data[0] += data[1];
+   data[1] += data[0];
+}
+
+void Hasher::finalize(uint64_t k1, uint64_t k2, int num)
+{
+   constexpr uint64_t c1 = 0x87c37b91114253d5ull;
+   constexpr uint64_t c2 = 0x4cf5ad432745937full;
+   nbytes += num;
+   k2 *= c2;
+   k2 = rotl64(k2, 33);
+   k2 *= c1;
+   data[1] ^= k2;
+
+   k1 *= c1;
+   k1 = rotl64(k1, 31);
+   k1 *= c2;
+   data[0] ^= k1;
+
+   data[0] ^= nbytes;
+   data[1] ^= nbytes;
+
+   data[0] += data[1];
+   data[1] += data[0];
+
+   data[0] = fmix64(data[0]);
+   data[1] = fmix64(data[1]);
+
+   data[0] += data[1];
+   data[1] += data[0];
+}
+
 } // namespace mfem
@@ -15,8 +15,8 @@
 #include "../config/config.hpp"
 #include "array.hpp"
 #include "globals.hpp"
-#include "hash_util.hpp"

+#include <array>
 #include <cstdint>
 #include <type_traits>
 #include <utility>
@@ -457,6 +457,75 @@ protected:
   int BinSize(int idx) const;
 };

+///
+/// @brief streaming implementation for murmurhash3 128 (x64).
+/// Constructs the hash in 3 stages: init, append, finalize.
+///
+struct Hasher
+{
+   /// where the final hash result is stored after finalize. Use data[1] when
+   /// only 64 bits are required.
+   uint64_t data[2] = {0, 0};
+
+private:
+   uint64_t nbytes = 0;
+
+   uint64_t buf_[2] = {0, 0};
+
+public:
+
+   /// resets this hasher back to an initial seed
+   void init(uint64_t seed = 0);
+   void append(const uint8_t *vs, uint64_t bytes);
+
+   void finalize();
+
+private:
+   // add 16 bytes
+   void add_block(uint64_t k1, uint64_t k2);
+
+   // add [1-8] more bytes, then finalize
+   void finalize(uint64_t k1, int num);
+
+   // add [1-15] more bytes, then finalize
+   // 0 < num < 16
+   void finalize(uint64_t k1, uint64_t k2, int num);
+};
+
+/// Helper class for hashing std::pair. Usable in place of std::hash<std::pair<T,U>>
+struct PairHasher
+{
+   template <class T, class V>
+   size_t operator()(const std::pair<T, V> &v) const noexcept
+   {
+      Hasher hash;
+      // chosen randomly with a 2^64-sided dice
+      hash.init(0xfebd1fe69813c14full);
+      hash.append(reinterpret_cast<const uint8_t *>(&v.first), sizeof(T));
+      hash.append(reinterpret_cast<const uint8_t *>(&v.second), sizeof(V));
+      hash.finalize();
+      return hash.data[1];
+   }
+};
+
+/// Helper class for hashing std::array. Usable in place of std::hash<std::array<T,N>>
+struct ArrayHasher
+{
+   template <class T, size_t N>
+   size_t operator()(const std::array<T, N> &v) const noexcept
+   {
+      Hasher hash;
+      // chosen randomly with a 2^64-sided dice
+      hash.init(0xfebd1fe69813c14full);
+      for (size_t i = 0; i < N; ++i)
+      {
+         hash.append(reinterpret_cast<const uint8_t *>(&v[i]), sizeof(T));
+      }
+      hash.finalize();
+      return hash.data[1];
+   }
+};
+
 /// Hash function for data sequences.
 /** Depends on GnuTLS for SHA-256 hashing. */
 class HashFunction
@@ -1,172 +0,0 @@
-// Copyright (c) 2010-2025, Lawrence Livermore National Security, LLC. Produced
-// at the Lawrence Livermore National Laboratory. All Rights reserved. See files
-// LICENSE and NOTICE for details. LLNL-CODE-806117.
-//
-// This file is part of the MFEM library. For more information and source code
-// availability visit https://mfem.org.
-//
-// MFEM is free software; you can redistribute it and/or modify it under the
-// terms of the BSD-3 license. We welcome feedback and contributions, see file
-// CONTRIBUTING.md for details.
-
-#include "hash_util.hpp"
-
-namespace mfem
-{
-
-constexpr static uint64_t rotl64(uint64_t x, int r)
-{
-   return (x << r) | (x >> (64 - r));
-}
-
-void Hasher::init(uint64_t seed)
-{
-   data[0] = seed;
-   data[1] = seed;
-   nbytes = 0;
-}
-
-void Hasher::add_block(uint64_t k1, uint64_t k2)
-{
-   constexpr uint64_t c1 = 0x87c37b91114253d5ull;
-   constexpr uint64_t c2 = 0x4cf5ad432745937full;
-
-   k1 *= c1;
-   k1 = rotl64(k1, 31);
-   k1 *= c2;
-   data[0] ^= k1;
-
-   data[0] = rotl64(data[0], 27);
-   data[0] += data[1];
-   data[0] = data[0] * 5 + 0x52dce729ull;
-
-   k2 *= c2;
-   k2 = rotl64(k2, 33);
-   k2 *= c1;
-   data[1] ^= k2;
-
-   data[1] = rotl64(data[1], 31);
-   data[1] += data[0];
-   data[1] = data[1] * 5 + 0x38495ab5ull;
-}
-
-static uint64_t fmix64(uint64_t k)
-{
-   // http://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html
-   // mix13
-   k ^= k >> 30;
-   k *= 0xbf58476d1ce4e5b9ull;
-   k ^= k >> 27;
-   k *= 0x94d049bb133111ebull;
-   k ^= k >> 31;
-   return k;
-}
-
-void Hasher::append(const std::byte *vs, uint64_t bytes)
-{
-   if (bytes == 0)
-   {
-      return;
-   }
-   auto rem = nbytes % 16;
-   nbytes += bytes;
-   std::byte *tmp = reinterpret_cast<std::byte *>(buf_);
-   while (true)
-   {
-      if (bytes + rem >= 16)
-      {
-         std::copy(vs, vs + 16 - rem, tmp + rem);
-         add_block(buf_[0], buf_[1]);
-         vs += (16 - rem);
-         bytes -= (16 - rem);
-         rem = 0;
-      }
-      else
-      {
-         std::copy(vs, vs + bytes, tmp + rem);
-         return;
-      }
-   }
-}
-
-void Hasher::finalize()
-{
-   auto rem = nbytes % 16;
-   if (rem > 0)
-   {
-      nbytes -= rem;
-      if (rem <= 8)
-      {
-         finalize(buf_[0], rem);
-      }
-      else
-      {
-         finalize(buf_[0], buf_[1], rem);
-      }
-      return;
-   }
-   data[0] ^= nbytes;
-   data[1] ^= nbytes;
-
-   data[0] += data[1];
-   data[1] += data[0];
-
-   data[0] = fmix64(data[0]);
-   data[1] = fmix64(data[1]);
-
-   data[0] += data[1];
-   data[1] += data[0];
-}
-
-void Hasher::finalize(uint64_t k1, int num)
-{
-   constexpr uint64_t c1 = 0x87c37b91114253d5ull;
-   constexpr uint64_t c2 = 0x4cf5ad432745937full;
-   nbytes += num;
-   k1 *= c1;
-   k1 = rotl64(k1, 31);
-   k1 *= c2;
-   data[0] ^= k1;
-
-   data[0] ^= nbytes;
-   data[1] ^= nbytes;
-
-   data[0] += data[1];
-   data[1] += data[0];
-
-   data[0] = fmix64(data[0]);
-   data[1] = fmix64(data[1]);
-
-   data[0] += data[1];
-   data[1] += data[0];
-}
-
-void Hasher::finalize(uint64_t k1, uint64_t k2, int num)
-{
-   constexpr uint64_t c1 = 0x87c37b91114253d5ull;
-   constexpr uint64_t c2 = 0x4cf5ad432745937full;
-   nbytes += num;
-   k2 *= c2;
-   k2 = rotl64(k2, 33);
-   k2 *= c1;
-   data[1] ^= k2;
-
-   k1 *= c1;
-   k1 = rotl64(k1, 31);
-   k1 *= c2;
-   data[0] ^= k1;
-
-   data[0] ^= nbytes;
-   data[1] ^= nbytes;
-
-   data[0] += data[1];
-   data[1] += data[0];
-
-   data[0] = fmix64(data[0]);
-   data[1] = fmix64(data[1]);
-
-   data[0] += data[1];
-   data[1] += data[0];
-}
-
-}
@@ -1,172 +0,0 @@
-// Copyright (c) 2010-2025, Lawrence Livermore National Security, LLC. Produced
-// at the Lawrence Livermore National Laboratory. All Rights reserved. See files
-// LICENSE and NOTICE for details. LLNL-CODE-806117.
-//
-// This file is part of the MFEM library. For more information and source code
-// availability visit https://mfem.org.
-//
-// MFEM is free software; you can redistribute it and/or modify it under the
-// terms of the BSD-3 license. We welcome feedback and contributions, see file
-// CONTRIBUTING.md for details.
-
-#ifndef MFEM_HASH_UTIL_HPP
-#define MFEM_HASH_UTIL_HPP
-
-#include <array>
-#include <cstddef>
-#include <tuple>
-#include <functional>
-#include <utility>
-#include <cstdint>
-
-namespace mfem
-{
-
-/// @brief streaming implementation for murmurhash3 128 (x64).
-///
-/// Constructs the hash in 3 stages: init, append, finalize.
-struct Hasher
-{
-   /// @brief Storage for the final hash result after finalize() is called.
-   ///
-   /// Use data[1] when only 64 bits are required.
-   uint64_t data[2] = {0, 0};
-
-private:
-   uint64_t nbytes = 0;
-   uint64_t buf_[2] = {0, 0};
-
-public:
-
-   /// Resets the Hasher back to an initial seed
-   void init(uint64_t seed = 0);
-
-   /// Append data @a vs of size @a bytes.
-   void append(const std::byte *vs, uint64_t bytes);
-
-   void finalize();
-
-private:
-   /// Add a block of 16 bytes.
-   void add_block(uint64_t k1, uint64_t k2);
-
-   /// @brief Add [1-8] more bytes, then finalize.
-   ///
-   /// @a num must satisfy 0 < num < 9.
-   void finalize(uint64_t k1, int num);
-
-   /// @brief Add [1-15] more bytes, then finalize.
-   ///
-   /// @a num must satisfy 0 < num < 16.
-   void finalize(uint64_t k1, uint64_t k2, int num);
-};
-
-template <class T> struct ChainedHasher
-{
-   static void Append(Hasher &hasher, const T &value)
-   {
-      if constexpr (std::is_fundamental_v<T> || std::is_pointer_v<T>)
-      {
-         hasher.append(reinterpret_cast<const std::byte *>(&value), sizeof(T));
-      }
-      else
-      {
-         std::hash<T> h;
-         auto v = h(value);
-         hasher.append(reinterpret_cast<std::byte *>(&v), sizeof(v));
-      }
-   }
-};
-
-template <class T, class V> struct ChainedHasher<std::pair<T, V>>
-{
-   static void Append(Hasher &hasher, const std::pair<T, V> &value)
-   {
-      ChainedHasher<T>::Append(hasher, value.first);
-      ChainedHasher<V>::Append(hasher, value.second);
-   }
-};
-
-template <class T, size_t N> struct ChainedHasher<std::array<T, N>>
-{
-   static void Append(Hasher &hasher, const std::array<T, N> &value)
-   {
-      for (size_t i = 0; i < N; ++i)
-      {
-         ChainedHasher<T>::Append(hasher, value[i]);
-      }
-   }
-};
-
-template<class... Ts> struct ChainedHasher<std::tuple<Ts...>>
-{
-private:
-   template <size_t N>
-   static void AppendImpl(Hasher &hasher, const std::tuple<Ts...> &value)
-   {
-      ChainedHasher<std::decay_t<decltype(std::get<N>(value))>>::Append(
-                                                                hasher, std::get<N>(value));
-      if constexpr (N + 1 < sizeof...(Ts))
-      {
-         AppendImpl<N + 1>(hasher, value);
-      }
-   }
-
-public:
-   static void Append(Hasher &hasher, const std::tuple<Ts...> &value)
-   {
-      if constexpr (sizeof...(Ts))
-      {
-         AppendImpl<0>(hasher, value);
-      }
-   }
-};
-
-/// Helper class for hashing std::pair of hashable types.
-struct PairHasher
-{
-   template <class T, class V>
-   size_t operator()(const std::pair<T, V> &v) const noexcept
-   {
-      Hasher hash;
-      // chosen randomly with a 2^64-sided dice
-      hash.init(0xfebd1fe69813c14full);
-      ChainedHasher<std::pair<T, V>>::Append(hash, v);
-      hash.finalize();
-      return hash.data[1];
-   }
-};
-
-/// Helper class for hashing std::array of a hashable type.
-struct ArrayHasher
-{
-   template <class T, size_t N>
-   size_t operator()(const std::array<T, N> &v) const noexcept
-   {
-      Hasher hash;
-      // chosen randomly with a 2^64-sided dice
-      hash.init(0xfebd1fe69813c14full);
-      ChainedHasher<std::array<T, N>>::Append(hash, v);
-      hash.finalize();
-      return hash.data[1];
-   }
-};
-
-/// Helper class for hashing std::tuple of hashable types.
-struct TupleHasher
-{
-   template <class T>
-   size_t operator()(const T &v) const noexcept
-   {
-      Hasher hash;
-      // chosen randomly with a 2^64-sided dice
-      hash.init(0xfebd1fe69813c14full);
-      ChainedHasher<T>::Append(hash, v);
-      hash.finalize();
-      return hash.data[1];
-   }
-};
-
-} // namespace mfem
-
-#endif
@@ -20,11 +20,9 @@

 #if defined(MFEM_USE_HIP) && defined(__HIP__)
 #define MFEM_USE_CUDA_OR_HIP
-constexpr bool mfem_use_gpu = true;
 #define MFEM_DEVICE __device__
 #define MFEM_HOST __host__
 #define MFEM_LAMBDA __host__ __device__
-#define MFEM_LAUNCH_BOUNDS __launch_bounds__
 // #define MFEM_HOST_DEVICE __host__ __device__ // defined in config/config.hpp
 #define MFEM_DEVICE_SYNC MFEM_GPU_CHECK(hipDeviceSynchronize())
 #define MFEM_STREAM_SYNC MFEM_GPU_CHECK(hipStreamSynchronize(0))
@@ -146,7 +146,7 @@ public:
   int *ReadWriteJ(bool on_dev = true) { return J.ReadWrite(on_dev); }
   const int *HostReadJ() const { return J.HostRead(); }
   int *HostWriteJ() { return J.HostWrite(); }
-   int *HostReadWriteJ() { return J.HostReadWrite(); }
+   int *ReadWriteJ() { return J.HostReadWrite(); }

   /// Sort the column (TYPE II) indices in each row.
   void SortRows();
@@ -55,7 +55,6 @@ list(APPEND HDRS
  dinvariants.hpp
  dtensor.hpp
  dual.hpp
-  eigensolver.hpp
  filteredsolver.hpp
  handle.hpp
  invariants.hpp
@@ -1370,35 +1370,6 @@ void DenseMatrix::Getl1Diag(Vector &l) const
      }
 }

-void DenseMatrix::GetRowl1(Vector &l) const
-{
-   l.SetSize(height);
-   l = 0.0;
-
-   for (int j = 0; j < width; ++j)
-      for (int i = 0; i < height; ++i)
-      {
-         l(i) += fabs((*this)(i,j));
-      }
-}
-
-void DenseMatrix::GetRowl2(Vector &l) const
-{
-   l.SetSize(height);
-   l = 0.0;
-
-   for (int j = 0; j < width; ++j)
-      for (int i = 0; i < height; ++i)
-      {
-         l[i] += operator()(i,j)*operator()(i,j);
-      }
-
-   for (int i = 0; i < height; ++i)
-   {
-      l[i] = sqrt(l[i]);
-   }
-}
-
 void DenseMatrix::GetRowSums(Vector &l) const
 {
   l.SetSize(height);
@@ -346,12 +346,8 @@ public:
   /// Returns the diagonal of the matrix
   void GetDiag(Vector &d) const;
   /// Returns the l1 norm of the rows of the matrix v_i = sum_j |a_ij|
-   MFEM_DEPRECATED void Getl1Diag(Vector &l) const;
-   /// Returns the l1 norm of the rows of the matrix v_i = sum_j |a_ij|
-   void GetRowl1(Vector &l) const;
-   /// Returns the l2norm of the rows of the DenseMatrix
-   void GetRowl2(Vector &l) const;
-   /// Returns the row sums of the DenseMatrix
+   void Getl1Diag(Vector &l) const;
+   /// Compute the row sums of the DenseMatrix
   void GetRowSums(Vector &l) const;

   /// Creates n x n diagonal matrix with diagonal elements c
@@ -1,203 +0,0 @@
-// Copyright (c) 2010-2025, Lawrence Livermore National Security, LLC. Produced
-// at the Lawrence Livermore National Laboratory. All Rights reserved. See files
-// LICENSE and NOTICE for details. LLNL-CODE-806117.
-//
-// This file is part of the MFEM library. For more information and source code
-// availability visit https://mfem.org.
-//
-// MFEM is free software; you can redistribute it and/or modify it under the
-// terms of the BSD-3 license. We welcome feedback and contributions, see file
-// CONTRIBUTING.md for details.
-
-/**
- * @file eigensolver.hpp
- *
- * @brief This file contains a common interface for all eigensolver classes
- */
-
-#ifndef MFEM_EIGENSOLVER
-#define MFEM_EIGENSOLVER
-
-#ifdef MFEM_HYPRE
-#include "hypre.hpp"
-#endif
-
-#ifdef MFEM_SLEPC
-#include "slepc.hpp"
-#endif
-
-namespace mfem
-{
-
-enum class EigenSolverType
-{
-   HYPRE,
-   SLEPC,
-   INVALID_TYPE
-};
-
-/// Provides base class for MFEM Eigensolvers
-class EigenSolverBase
-{
-public:
-   EigenSolverBase() {}
-
-   /// Destructor
-   virtual ~EigenSolverBase() = default;
-
-   /// Solves the eigenvalue problem
-   virtual void Solve() = 0;
-
-   /// Set the required number of modes
-   virtual void SetNumModes(int num_Modes)
-   {
-      numModes=num_Modes;
-   }
-
-   /// @brief  Set the operator to the eigenvalue problem
-   /// @param A - operator
-   virtual void SetOperator(Operator& A) = 0;
-
-   /// @brief Sets operators for the generalized eigenvalue problem
-   /// @param A - operator
-   /// @param M - mass matrix
-   virtual void SetOperator(Operator& A, Operator& M)
-   {
-      MFEM_ABORT("Generalized eigensolver is not supported!");
-   }
-
-   /// Optional method - sets preconditioner for the
-   /// eigenvalue solver.
-   virtual void SetPreconditioner(Solver& precond)
-   {
-      MFEM_ABORT("Preconditioner is not supported!");
-   }
-
-   /// Returns the converged eigenvalues
-   virtual void GetEigenvalues(Array<real_t>& eigen_vals) = 0;
-
-   /// Returns the vec_index eigenvector.
-   virtual void GetEigenvector(int vec_index, Vector& vector) = 0;
-
-   /// Returns the eigensolver type.
-   EigenSolverType GetSolverType() { return eigSolverType; }
-
-protected:
-   int numModes = 0;
-   EigenSolverType eigSolverType = EigenSolverType::INVALID_TYPE;
-};
-
-#ifdef MFEM_HYPRE
-class EigenSolverHypreLOBPCG : public EigenSolverBase
-{
-public:
-   EigenSolverHypreLOBPCG(MPI_Comm comm)
-   {
-      eigenSolver = std::make_unique<HypreLOBPCG>(comm);
-      eigSolverType = EigenSolverType::HYPRE;
-   }
-
-   ~EigenSolverHypreLOBPCG() {}
-
-   void Solve() override { eigenSolver->Solve(); }
-   void SetNumModes(int num_Modes) override
-   {
-      eigenSolver->SetNumModes(num_Modes);
-      numModes = num_Modes;
-   }
-
-   void SetOperator(Operator& A) override { eigenSolver->SetOperator(A); }
-
-   void SetOperator(Operator& A, Operator& M) override
-   {
-      eigenSolver->SetOperator(A);
-      eigenSolver->SetMassMatrix(M);
-   }
-
-   void SetPreconditioner(Solver& precond) override { eigenSolver->SetPreconditioner(precond); }
-   void GetEigenvalues(Array<real_t>& eigen_vals) override { eigenSolver->GetEigenvalues(eigen_vals); }
-   void GetEigenvector(int vec_index, Vector& vector) override
-   {
-      const HypreParVector& eigenvec = eigenSolver->GetEigenvector(vec_index);
-      vector = eigenvec;
-   }
-
-   void SetTol(real_t tol) { eigenSolver->SetTol(tol); }
-   void SetRelTol(real_t rel_tol) { eigenSolver->SetRelTol(rel_tol); }
-   void SetMaxIter(int max_iter) { eigenSolver->SetMaxIter(max_iter); }
-   void SetPrintLevel(int logging) { eigenSolver->SetPrintLevel(logging); }
-   void SetRandomSeed(int seed) { eigenSolver->SetRandomSeed(seed); }
-   void SetPrecondUsageMode(int usage_mode) { eigenSolver->SetPrecondUsageMode(usage_mode); }
-
-private:
-   std::unique_ptr<HypreLOBPCG> eigenSolver = nullptr;
-};
-#endif
-
-#ifdef MFEM_SLEPC
-class EigenSolverSlepc : public EigenSolverBase
-{
-public:
-   EigenSolverSlepc(MPI_Comm comm)
-   {
-      eigSolverType = EigenSolverType::SLEPC;
-      eigenSolver = std::make_unique<SlepcEigenSolver>(comm);
-
-      eigenSolver->SetWhichEigenpairs(SlepcEigenSolver::TARGET_REAL);
-      eigenSolver->SetTarget(0.0);
-      eigenSolver->SetSpectralTransformation(SlepcEigenSolver::SHIFT_INVERT);
-   }
-
-   ~EigenSolverSlepc() {}
-
-   void Solve() override { eigenSolver->Solve(); }
-   void SetNumModes(int num_Modes) override
-   {
-      eigenSolver->SetNumModes(num_Modes);
-      numModes = num_Modes;
-   }
-   /// @brief  Set the operator to the slepc eigenvalue problem. This method deep copies data to create a PetscParMatrix
-   /// @param A - operator, must be of type HypreParMatrix.
-   void SetOperator(Operator& A) override
-   {
-      petscMatA = std::make_unique<PetscParMatrix>
-                  (dynamic_cast<HypreParMatrix*>(&A));
-      eigenSolver->SetOperator(*petscMatA);
-   }
-   /// @brief  Set the operators to the slepc eigenvalue problem. This method deep copies data to create a PetscParMatrix
-   /// @param A - operator, must be of type HypreParMatrix.
-   /// @param M - operator, must be of type HypreParMatrix.
-   void SetOperator(Operator& A, Operator& M) override
-   {
-      petscMatA = std::make_unique<PetscParMatrix>
-                  (dynamic_cast<const HypreParMatrix*>(&A));
-      petscMatM = std::make_unique<PetscParMatrix>
-                  (dynamic_cast<const HypreParMatrix*>(&M));
-
-      eigenSolver->SetOperators(*petscMatA, *petscMatM);
-   }
-   void SetPreconditioner([[maybe_unused]] Solver& precond) override {}
-   void GetEigenvalues(Array<real_t>& eigen_vals) override
-   {
-      eigen_vals.SetSize(numModes);
-      for (int ik = 0; ik < numModes; ik++)
-      {
-         eigenSolver->GetEigenvalue(static_cast<unsigned int>(ik), eigen_vals[ik]);
-      }
-   }
-   void GetEigenvector( int vec_index, Vector& vector) override
-   { eigenSolver->GetEigenvector(vec_index, vector); }
-
-   void SetTol(real_t tol) { eigenSolver->SetTol(tol); }
-   void SetMaxIter(int max_iter) { eigenSolver->SetMaxIter(max_iter); }
-
-private:
-   std::unique_ptr<SlepcEigenSolver> eigenSolver = nullptr;
-   std::unique_ptr<PetscParMatrix> petscMatA = nullptr;
-   std::unique_ptr<PetscParMatrix> petscMatM = nullptr;
-};
-#endif
-
-}  // namespace mfem
-
-#endif
@@ -1681,13 +1681,6 @@ void HypreParMatrix::GetOffd(SparseMatrix &offd, HYPRE_BigInt* &cmap) const
   cmap = A->col_map_offd;
 }

-void HypreParMatrix::GetOffdColMap(HYPRE_BigInt* &cmap,
-                                   HYPRE_Int &num_cols) const
-{
-   cmap = A->col_map_offd;
-   num_cols = hypre_CSRMatrixNumCols(A->offd);
-}
-
 void HypreParMatrix::MergeDiagAndOffd(SparseMatrix &merged)
 {
   HostRead();
@@ -3634,25 +3627,12 @@ void HypreSmoother::SetType(HypreSmoother::Type type_, int relax_times_)
   relax_times = relax_times_;
 }

-void HypreSmoother::GetType(HypreSmoother::Type &type_, int &relax_times_) const
-{
-   type_ = static_cast<HypreSmoother::Type>(type);
-   relax_times_ = relax_times;
-}
-
 void HypreSmoother::SetSOROptions(real_t relax_weight_, real_t omega_)
 {
   relax_weight = relax_weight_;
   omega = omega_;
 }

-void HypreSmoother::GetSOROptions(real_t &relax_weight_, real_t &omega_) const
-{
-   // TODO: are these used for all smoother types?
-   relax_weight_ = relax_weight;
-   omega_ = omega;
-}
-
 void HypreSmoother::SetPolyOptions(int poly_order_, real_t poly_fraction_,
                                   int eig_est_cg_iter_)
 {
@@ -3661,15 +3641,6 @@ void HypreSmoother::SetPolyOptions(int poly_order_, real_t poly_fraction_,
   eig_est_cg_iter = eig_est_cg_iter_;
 }

-void HypreSmoother::GetPolyOptions(int &poly_order_, real_t &poly_fraction_,
-                                   int &eig_est_cg_iter_) const
-{
-   // TODO: are these used for all smoother types?
-   poly_order_ = poly_order;
-   poly_fraction_ = poly_fraction;
-   eig_est_cg_iter_ = eig_est_cg_iter;
-}
-
 void HypreSmoother::SetTaubinOptions(real_t lambda_, real_t mu_,
                                     int taubin_iter_)
 {
@@ -3678,14 +3649,6 @@ void HypreSmoother::SetTaubinOptions(real_t lambda_, real_t mu_,
   taubin_iter = taubin_iter_;
 }

-void HypreSmoother::GetTaubinOptions(real_t &lambda_, real_t &mu_,
-                                     int &taubin_iter_) const
-{
-   lambda_ = lambda;
-   mu_ = mu;
-   taubin_iter_ = taubin_iter;
-}
-
 void HypreSmoother::SetWindowByName(const char* name)
 {
   real_t a = -1, b, c;
@@ -3708,13 +3671,6 @@ void HypreSmoother::SetWindowParameters(real_t a, real_t b, real_t c)
   window_params[2] = c;
 }

-void HypreSmoother::GetWindowParameters(real_t &a, real_t &b, real_t &c) const
-{
-   a = window_params[0];
-   b = window_params[1];
-   c = window_params[2];
-}
-
 void HypreSmoother::SetOperator(const Operator &op)
 {
   A = const_cast<HypreParMatrix *>(dynamic_cast<const HypreParMatrix *>(&op));
@@ -4210,20 +4166,12 @@ HypreSolver::~HypreSolver()
   auxX.Delete();
 }

-void HyprePCG::SetDefaultOptions()
-{
-   // Explicitly set just in case past/future versions of hypre change the
-   // defaults
-   SetTol(1e-6);
-   SetMaxIter(1000);
-}

 HyprePCG::HyprePCG(MPI_Comm comm) : precond(NULL)
 {
   iterative_mode = true;

   HYPRE_ParCSRPCGCreate(comm, &pcg_solver);
-   SetDefaultOptions();
 }

 HyprePCG::HyprePCG(const HypreParMatrix &A_) : HypreSolver(&A_), precond(NULL)
@@ -4235,7 +4183,6 @@ HyprePCG::HyprePCG(const HypreParMatrix &A_) : HypreSolver(&A_), precond(NULL)
   HYPRE_ParCSRMatrixGetComm(*A, &comm);

   HYPRE_ParCSRPCGCreate(comm, &pcg_solver);
-   SetDefaultOptions();
 }

 void HyprePCG::SetOperator(const Operator &op)
@@ -4260,54 +4207,21 @@ void HyprePCG::SetOperator(const Operator &op)
   auxX.Delete(); auxX.Reset();
 }

-void HyprePCG::SetUseTwoNorm(bool val)
-{
-   HYPRE_PCGSetTwoNorm(pcg_solver, val);
-}
-
-bool HyprePCG::GetUseTwoNorm() const
-{
-   HYPRE_Int val;
-   HYPRE_PCGGetTwoNorm(pcg_solver, &val);
-   return val != 0;
-}
-
 void HyprePCG::SetTol(real_t tol)
 {
   HYPRE_PCGSetTol(pcg_solver, tol);
 }

-real_t HyprePCG::GetTol() const
-{
-   HYPRE_Real tol;
-   HYPRE_PCGGetTol(pcg_solver, &tol);
-   return tol;
-}
-
 void HyprePCG::SetAbsTol(real_t atol)
 {
   HYPRE_PCGSetAbsoluteTol(pcg_solver, atol);
 }

-real_t HyprePCG::GetAbsTol() const
-{
-   HYPRE_Real atol;
-   hypre_PCGGetAbsoluteTol(pcg_solver, &atol);
-   return atol;
-}
-
 void HyprePCG::SetMaxIter(int max_iter)
 {
   HYPRE_PCGSetMaxIter(pcg_solver, max_iter);
 }

-int HyprePCG::GetMaxIter() const
-{
-   HYPRE_Int max_iter;
-   HYPRE_PCGGetMaxIter(pcg_solver, &max_iter);
-   return max_iter;
-}
-
 void HyprePCG::SetLogging(int logging)
 {
   HYPRE_PCGSetLogging(pcg_solver, logging);
@@ -4423,20 +4337,6 @@ HyprePCG::~HyprePCG()
   HYPRE_ParCSRPCGDestroy(pcg_solver);
 }

-#if MFEM_HYPRE_VERSION >= 21500
-HypreParVector HyprePCG::GetResiduals() const
-{
-   HYPRE_ParVector r;
-   HYPRE_ParCSRPCGGetResidual(pcg_solver, &r);
-   return HypreParVector(r);
-}
-
-void HyprePCG::GetFinalAbsResidualNorm(real_t &final_res_norm, real_t p) const
-{
-   auto r = GetResiduals();
-   ParNormlp(r, p, r.GetComm());
-}
-#endif

 HypreGMRES::HypreGMRES(MPI_Comm comm) : precond(NULL)
 {
@@ -4492,69 +4392,26 @@ void HypreGMRES::SetOperator(const Operator &op)
   auxX.Delete(); auxX.Reset();
 }

-#if MFEM_HYPRE_VERSION >= 21500
-HypreParVector HypreGMRES::GetResiduals() const
-{
-   HYPRE_ParVector r;
-   HYPRE_ParCSRGMRESGetResidual(gmres_solver, &r);
-   return HypreParVector(r);
-}
-
-void HypreGMRES::GetFinalAbsResidualNorm(real_t &final_res_norm, real_t p) const
-{
-   auto r = GetResiduals();
-   ParNormlp(r, p, r.GetComm());
-}
-#endif
-
 void HypreGMRES::SetTol(real_t tol)
 {
   HYPRE_GMRESSetTol(gmres_solver, tol);
 }

-real_t HypreGMRES::GetTol()const
-{
-   HYPRE_Real tol;
-   HYPRE_GMRESGetTol(gmres_solver, &tol);
-   return tol;
-}
-
 void HypreGMRES::SetAbsTol(real_t tol)
 {
   HYPRE_GMRESSetAbsoluteTol(gmres_solver, tol);
 }

-real_t HypreGMRES::GetAbsTol() const
-{
-   HYPRE_Real atol;
-   HYPRE_GMRESGetAbsoluteTol(gmres_solver, &atol);
-   return atol;
-}
-
 void HypreGMRES::SetMaxIter(int max_iter)
 {
   HYPRE_GMRESSetMaxIter(gmres_solver, max_iter);
 }

-int HypreGMRES::GetMaxIter() const
-{
-   HYPRE_Int max_iter;
-   HYPRE_GMRESGetMaxIter(gmres_solver, &max_iter);
-   return max_iter;
-}
-
 void HypreGMRES::SetKDim(int k_dim)
 {
   HYPRE_GMRESSetKDim(gmres_solver, k_dim);
 }

-int HypreGMRES::GetKDim() const
-{
-   HYPRE_Int k_dim;
-   HYPRE_GMRESGetKDim(gmres_solver, &k_dim);
-   return k_dim;
-}
-
 void HypreGMRES::SetLogging(int logging)
 {
   HYPRE_GMRESSetLogging(gmres_solver, logging);
@@ -4712,37 +4569,16 @@ void HypreFGMRES::SetTol(real_t tol)
   HYPRE_ParCSRFlexGMRESSetTol(fgmres_solver, tol);
 }

-real_t HypreFGMRES::GetTol() const
-{
-   HYPRE_Real tol;
-   HYPRE_FlexGMRESGetTol(fgmres_solver, &tol);
-   return tol;
-}
-
 void HypreFGMRES::SetMaxIter(int max_iter)
 {
   HYPRE_ParCSRFlexGMRESSetMaxIter(fgmres_solver, max_iter);
 }

-int HypreFGMRES::GetMaxIter() const
-{
-   HYPRE_Int max_iter;
-   HYPRE_FlexGMRESGetMaxIter(fgmres_solver, &max_iter);
-   return max_iter;
-}
-
 void HypreFGMRES::SetKDim(int k_dim)
 {
   HYPRE_ParCSRFlexGMRESSetKDim(fgmres_solver, k_dim);
 }

-int HypreFGMRES::GetKDim() const
-{
-   HYPRE_Int k_dim;
-   HYPRE_FlexGMRESGetKDim(fgmres_solver, &k_dim);
-   return k_dim;
-}
-
 void HypreFGMRES::SetLogging(int logging)
 {
   HYPRE_ParCSRFlexGMRESSetLogging(fgmres_solver, logging);
@@ -4839,21 +4675,6 @@ HypreFGMRES::~HypreFGMRES()
   HYPRE_ParCSRFlexGMRESDestroy(fgmres_solver);
 }

-#if MFEM_HYPRE_VERSION >= 21500
-HypreParVector HypreFGMRES::GetResiduals() const
-{
-   HYPRE_ParVector r;
-   HYPRE_ParCSRFlexGMRESGetResidual(fgmres_solver, &r);
-   return HypreParVector(r);
-}
-
-void HypreFGMRES::GetFinalAbsResidualNorm(real_t &final_res_norm,
-                                          real_t p) const
-{
-   auto r = GetResiduals();
-   ParNormlp(r, p, r.GetComm());
-}
-#endif

 void HypreDiagScale::SetOperator(const Operator &op)
 {
@@ -5342,13 +5163,6 @@ void HypreBoomerAMG::ResetAMGPrecond()
   }
 }

-int HypreBoomerAMG::GetMaxIter() const
-{
-   HYPRE_Int max_iter;
-   HYPRE_BoomerAMGGetMaxIter(amg_precond, &max_iter);
-   return max_iter;
-}
-
 void HypreBoomerAMG::SetOperator(const Operator &op)
 {
   const HypreParMatrix *new_A = dynamic_cast<const HypreParMatrix *>(&op);
@@ -665,8 +665,6 @@ public:
   void GetDiag(SparseMatrix &diag) const;
   /// Get the local off-diagonal block. NOTE: 'offd' will not own any data.
   void GetOffd(SparseMatrix &offd, HYPRE_BigInt* &cmap) const;
-   /// Get the global column mapping for the local off-diagonal block.
-   void GetOffdColMap(HYPRE_BigInt* &cmap, HYPRE_Int &num_cols) const;
   /** @brief Get a single SparseMatrix containing all rows from this processor,
       merged from the diagonal and off-diagonal blocks stored by the
       HypreParMatrix. */
@@ -961,14 +959,6 @@ public:
   const Memory<HYPRE_Int> &GetDiagMemoryJ() const { return mem_diag.J; }
   const Memory<real_t> &GetDiagMemoryData() const { return mem_diag.data; }

-   Memory<HYPRE_Int> &GetOffdMemoryI() { return mem_offd.I; }
-   Memory<HYPRE_Int> &GetOffdMemoryJ() { return mem_offd.J; }
-   Memory<real_t> &GetOffdMemoryData() { return mem_offd.data; }
-
-   const Memory<HYPRE_Int> &GetOffdMemoryI() const { return mem_offd.I; }
-   const Memory<HYPRE_Int> &GetOffdMemoryJ() const { return mem_offd.J; }
-   const Memory<real_t> &GetOffdMemoryData() const { return mem_offd.data; }
-
   /// @brief Prints the locally owned rows in parallel. The resulting files can
   /// be read with Read_IJMatrix().
   void Print(const std::string &fname, HYPRE_Int offi = 0,
@@ -1160,15 +1150,6 @@ public:
      return HypreUsingGPU() ? l1Jacobi : l1GS;
   }

-   /// Default solver settings:
-   /// type = DefaultType()
-   /// relax_times = 1
-   /// omega = 1.0
-   /// poly_order = 2
-   /// poly_fraction = 0.3
-   /// lambda = 0.5
-   /// mu = -0.5
-   /// taubin_iter = 40
   HypreSmoother();

   HypreSmoother(const HypreParMatrix &A_, int type = DefaultType(),
@@ -1178,28 +1159,20 @@ public:

   /// Set the relaxation type and number of sweeps
   void SetType(HypreSmoother::Type type, int relax_times = 1);
-   using Operator::GetType;
-   void GetType(HypreSmoother::Type &type, int &relax_times) const;
   /// Set SOR-related parameters
   void SetSOROptions(real_t relax_weight, real_t omega);
-   void GetSOROptions(real_t &relax_weight, real_t &omega) const;
-
   /// Set parameters for polynomial smoothing
   /** By default, 10 iterations of CG are used to estimate the eigenvalues.
       Setting eig_est_cg_iter = 0 uses hypre's hypre_ParCSRMaxEigEstimate() instead. */
   void SetPolyOptions(int poly_order, real_t poly_fraction,
                       int eig_est_cg_iter = 10);
-   void GetPolyOptions(int &poly_order, real_t &poly_fraction,
-                       int &eig_est_cg_iter) const;
   /// Set parameters for Taubin's lambda-mu method
   void SetTaubinOptions(real_t lambda, real_t mu, int iter);
-   void GetTaubinOptions(real_t &lambda, real_t &mu, int &iter) const;

   /// Convenience function for setting canonical windowing parameters
   void SetWindowByName(const char* window_name);
   /// Set parameters for windowing function for FIR smoother.
   void SetWindowParameters(real_t a, real_t b, real_t c);
-   void GetWindowParameters(real_t &a, real_t &b, real_t &c) const;
   /// Compute window and Chebyshev coefficients for given polynomial order.
   void SetFIRCoefficients(real_t max_eig);

@@ -1207,15 +1180,12 @@ public:
   /** By default, the l1-norms take their sign from the corresponding diagonal
       entries in the associated matrix. */
   void SetPositiveDiagonal(bool pos = true) { pos_l1_norms = pos; }
-   bool IsPositiveDiagonal() const { return pos_l1_norms; };

   /** Explicitly indicate whether the linear system matrix A is symmetric. If A
       is symmetric, the smoother will also be symmetric. In this case, calling
       MultTranspose will be redirected to Mult. (This is also done if the
       smoother is diagonal.) By default, A is assumed to be nonsymmetric. */
   void SetOperatorSymmetry(bool is_sym) { A_is_symmetric = is_sym; }
-   /// @return true if the smoother assumes A is symmetric, false otherwise
-   bool IsOperatorSymmetric() const { return A_is_symmetric; }

   /** Set/update the associated operator. Must be called after setting the
       HypreSmoother type and options. */
@@ -1347,7 +1317,6 @@ public:
 #endif

 /// PCG solver in hypre
-/// Defaults to (relative) tol=1e-6, atol=0, max_iter=1000
 class HyprePCG : public HypreSolver
 {
 private:
@@ -1355,9 +1324,6 @@ private:

   HypreSolver * precond;

-   /// Default PCG options
-   void SetDefaultOptions();
-
 public:
   HyprePCG(MPI_Comm comm);

@@ -1366,11 +1332,8 @@ public:
   void SetOperator(const Operator &op) override;

   void SetTol(real_t tol);
-   real_t GetTol() const;
   void SetAbsTol(real_t atol);
-   real_t GetAbsTol() const;
   void SetMaxIter(int max_iter);
-   int GetMaxIter() const;
   void SetLogging(int logging);
   void SetPrintLevel(int print_lvl);

@@ -1395,32 +1358,12 @@ public:
      num_iterations = internal::to_int(num_it);
   }

-   /// Gets the relative residual norm
   void GetFinalResidualNorm(real_t &final_res_norm) const
   {
      HYPRE_ParCSRPCGGetFinalRelativeResidualNorm(pcg_solver,
                                                  &final_res_norm);
   }

-   /// @param[in] use
-   ///   Convergence criterion:
-   ///   - when true: (r, r) < max(r_tol^2 (b, b), a_tol^2)
-   ///   - when false: (r, A r) < max(r_tol^2 (b, A b), a_tol^2)
-   /// @sa HYPRE_PCGSetTwoNorm
-   void SetUseTwoNorm(bool use);
-
-   /// @sa HYPRE_PCGGetTwoNorm
-   bool GetUseTwoNorm() const;
-
-#if MFEM_HYPRE_VERSION >= 21500
-   /// Gets the internal Hypre solver residual vector.
-   /// @sa HYPRE_ParCSRPCGGetResidual
-   HypreParVector GetResiduals() const;
-
-   /// Computes the absolute residual p-norm.
-   void GetFinalAbsResidualNorm(real_t &final_res_norm, real_t p = 2) const;
-#endif
-
   /// The typecast to HYPRE_Solver returns the internal pcg_solver
   operator HYPRE_Solver() const override { return pcg_solver; }

@@ -1438,8 +1381,7 @@ public:
   virtual ~HyprePCG();
 };

-/// GMRES solver in hypre.
-/// Defaults to k=50, (relative) tol=1e-6, atol=0, max_iter=100.
+/// GMRES solver in hypre
 class HypreGMRES : public HypreSolver
 {
 private:
@@ -1458,13 +1400,9 @@ public:
   void SetOperator(const Operator &op) override;

   void SetTol(real_t tol);
-   real_t GetTol() const;
   void SetAbsTol(real_t tol);
-   real_t GetAbsTol() const;
   void SetMaxIter(int max_iter);
-   int GetMaxIter() const;
   void SetKDim(int dim);
-   int GetKDim() const;
   void SetLogging(int logging);
   void SetPrintLevel(int print_lvl);

@@ -1484,22 +1422,12 @@ public:
      num_iterations = internal::to_int(num_it);
   }

-   /// Gets the relative residual norm
   void GetFinalResidualNorm(real_t &final_res_norm) const
   {
      HYPRE_ParCSRGMRESGetFinalRelativeResidualNorm(gmres_solver,
                                                    &final_res_norm);
   }

-#if MFEM_HYPRE_VERSION >= 21500
-   /// Gets the internal Hypre solver residual vector.
-   /// @sa HYPRE_ParCSRGMRESGetResidual
-   HypreParVector GetResiduals() const;
-
-   /// Computes the absolute residual p-norm.
-   void GetFinalAbsResidualNorm(real_t &final_res_norm, real_t p = 2) const;
-#endif
-
   /// The typecast to HYPRE_Solver returns the internal gmres_solver
   operator HYPRE_Solver() const override { return gmres_solver; }

@@ -1517,8 +1445,7 @@ public:
   virtual ~HypreGMRES();
 };

-/// Flexible GMRES solver in hypre.
-/// Defaults to k=50, (relative) tol=1e-6, max_iter=100.
+/// Flexible GMRES solver in hypre
 class HypreFGMRES : public HypreSolver
 {
 private:
@@ -1537,11 +1464,8 @@ public:
   void SetOperator(const Operator &op) override;

   void SetTol(real_t tol);
-   real_t GetTol() const;
   void SetMaxIter(int max_iter);
-   int GetMaxIter() const;
   void SetKDim(int dim);
-   int GetKDim() const;
   void SetLogging(int logging);
   void SetPrintLevel(int print_lvl);

@@ -1561,22 +1485,12 @@ public:
      num_iterations = internal::to_int(num_it);
   }

-   /// Gets the relative residual norm
   void GetFinalResidualNorm(real_t &final_res_norm) const
   {
      HYPRE_ParCSRFlexGMRESGetFinalRelativeResidualNorm(fgmres_solver,
                                                        &final_res_norm);
   }

-#if MFEM_HYPRE_VERSION >= 21500
-   /// Gets the internal Hypre solver residual vector.
-   /// @sa HYPRE_ParCSRFlexGMRESGetResidual
-   HypreParVector GetResiduals() const;
-
-   /// Computes the absolute residual p-norm.
-   void GetFinalAbsResidualNorm(real_t &final_res_norm, real_t p = 2) const;
-#endif
-
   /// The typecast to HYPRE_Solver returns the internal fgmres_solver
   operator HYPRE_Solver() const override { return fgmres_solver; }

@@ -1632,8 +1546,7 @@ public:
   virtual ~HypreDiagScale() { }
 };

-/// The ParaSails preconditioner in hypre.
-/// See SetDefaultOptions() for default solver options.
+/// The ParaSails preconditioner in hypre
 class HypreParaSails : public HypreSolver
 {
 private:
@@ -1762,14 +1675,10 @@ public:
 /**
@brief Wrapper for Hypre's native parallel ILU preconditioner.

-Default parameters: ILU(k) factorization type, tol=0.0 (for use as a
-preconditioner), fill level = 1 (for ILU(k)), reverse Cuthill-McKee (RCM)
-re-ordering.
-
-If you need to change this, or any other option, you can use the HYPRE_Solver
-method to cast the object for use with Hypre's native functions. For example, if
-want to use natural ordering rather than RCM reordering, you can use the
-following approach:
+The default ILU factorization type is ILU(k).  If you need to change this, or
+any other option, you can use the HYPRE_Solver method to cast the object for use
+with Hypre's native functions. For example, if want to use natural ordering
+rather than RCM reordering, you can use the following approach:

@code
 mfem::HypreILU ilu();
@@ -1910,7 +1819,6 @@ public:

   void SetMaxIter(int max_iter)
   { HYPRE_BoomerAMGSetMaxIter(amg_precond, max_iter); }
-   int GetMaxIter() const;

   /// Expert option - consult hypre documentation/team
   void SetMaxLevels(int max_levels)
@@ -1935,8 +1843,6 @@ public:
   /// Expert option - consult hypre documentation/team
   void SetRelaxType(int relax_type)
   { HYPRE_BoomerAMGSetRelaxType(amg_precond, relax_type); }
-   // not implemented in hypre
-   // int GetRelaxType() const;

   /// Expert option - consult hypre documentation/team
   void SetCycleType(int cycle_type)
@@ -2237,14 +2143,8 @@ public:
   ~HypreLOBPCG();

   void SetTol(real_t tol);
-   // not implemented in HYPRE
-   // real_t GetTol() const;
   void SetRelTol(real_t rel_tol);
-   // not implemented in HYPRE
-   // real_t GetRelTol() const;
   void SetMaxIter(int max_iter);
-   // not implemented in HYPRE
-   // int GetMaxIter() const;
   void SetPrintLevel(int logging);
   void SetNumModes(int num_eigs) { nev = num_eigs; }
   void SetPrecondUsageMode(int pcg_mode);
@@ -10,7 +10,6 @@
 // CONTRIBUTING.md for details.

 #include "../general/communication.hpp"
-#include "../general/forall.hpp"
 #include "operator.hpp"
 #include "ode.hpp"

@@ -185,23 +184,6 @@ void ODESolver::Init(TimeDependentOperator &f_)
   mem_type = GetMemoryType(f_.GetMemoryClass());
 }

-void ODESolver::ComputeSlopeFromState(const real_t dt, const Vector &u,
-                                      Vector &k)
-{
-   // k currently holds state u(t+dt),
-   // convert to slope k = du/dt ~= (u(t+dt)-u(t))/dt
-   const int usz = u.Size();
-   real_t fac = 1.0/dt;
-   auto d_u = u.Read();
-   auto d_k = k.ReadWrite();
-
-   mfem::forall(usz, [=] MFEM_HOST_DEVICE (int i)
-   {
-      d_k[i] -= d_u[i];
-      d_k[i] *= fac;
-   });
-}
-
 void ForwardEulerSolver::Init(TimeDependentOperator &f_)
 {
   ODESolver::Init(f_);
@@ -647,10 +629,6 @@ void AdamsMoultonSolver::Step(Vector &x, real_t &t, real_t &dt)
      }
      state.ShiftStages();
      f->ImplicitSolve(a[0]*dt, x, state[0]);
-      if (f->ImplicitVarTypeIsState())
-      {
-         ComputeSlopeFromState(a[0]*dt, x, state[0]);
-      }
      x.Add(a[0]*dt, state[0]);
      t += dt;
   }
@@ -683,15 +661,7 @@ void BackwardEulerSolver::Step(Vector &x, real_t &t, real_t &dt)
 {
   f->SetTime(t + dt);
   f->ImplicitSolve(dt, x, k); // solve for k: k = f(x + dt*k, t + dt)
-   if (f->ImplicitVarTypeIsState())
-   {
-      x = k; // x = u_{i+1}
-   }
-   else
-   {
-      x.Add(dt, k);
-   }
-
+   x.Add(dt, k);
   t += dt;
 }

@@ -706,16 +676,7 @@ void ImplicitMidpointSolver::Step(Vector &x, real_t &t, real_t &dt)
 {
   f->SetTime(t + dt/2);
   f->ImplicitSolve(dt/2, x, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      x.Neg();
-      x.Add(2.0, k);
-   }
-   else
-   {
-      x.Add(dt, k);
-   }
-
+   x.Add(dt, k);
   t += dt;
 }

@@ -757,19 +718,11 @@ void SDIRK23Solver::Step(Vector &x, real_t &t, real_t &dt)
   // note: with gamma_opt=3, both solve are outside [t,t+dt] since a>1
   f->SetTime(t + gamma*dt);
   f->ImplicitSolve(gamma*dt, x, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(gamma*dt, x, k);
-   }
   add(x, (1.-2.*gamma)*dt, k, y); // y = x + (1-2*gamma)*dt*k
   x.Add(dt/2, k);

   f->SetTime(t + (1.-gamma)*dt);
   f->ImplicitSolve(gamma*dt, y, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(gamma*dt, y, k);
-   }
   x.Add(dt/2, k);
   t += dt;
 }
@@ -796,29 +749,17 @@ void SDIRK34Solver::Step(Vector &x, real_t &t, real_t &dt)

   f->SetTime(t + a*dt);
   f->ImplicitSolve(a*dt, x, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(a*dt, x, k);
-   }
   add(x, (0.5-a)*dt, k, y);
   add(x,  (2.*a)*dt, k, z);
   x.Add(b*dt, k);

   f->SetTime(t + dt/2);
   f->ImplicitSolve(a*dt, y, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(a*dt, y, k);
-   }
   z.Add((1.-4.*a)*dt, k);
   x.Add((1.-2.*b)*dt, k);

   f->SetTime(t + (1.-a)*dt);
   f->ImplicitSolve(a*dt, z, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(a*dt, z, k);
-   }
   x.Add(b*dt, k);
   t += dt;
 }
@@ -844,27 +785,15 @@ void SDIRK33Solver::Step(Vector &x, real_t &t, real_t &dt)

   f->SetTime(t + a*dt);
   f->ImplicitSolve(a*dt, x, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(a*dt, x, k);
-   }
   add(x, (c-a)*dt, k, y);
   x.Add(b*dt, k);

   f->SetTime(t + c*dt);
   f->ImplicitSolve(a*dt, y, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(a*dt, y, k);
-   }
   x.Add((1.0-a-b)*dt, k);

   f->SetTime(t + dt);
   f->ImplicitSolve(a*dt, x, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(a*dt, x, k);
-   }
   x.Add(a*dt, k);
   t += dt;
 }
@@ -889,10 +818,6 @@ void TrapezoidalRuleSolver::Step(Vector &x, real_t &t, real_t &dt)

   f->SetTime(t + dt);
   f->ImplicitSolve(dt/2.0, y, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(0.5*dt, y, k);
-   }
   x.Add(dt/2.0, k);
   t += dt;
 }
@@ -923,19 +848,11 @@ void ESDIRK32Solver::Step(Vector &x, real_t &t, real_t &dt)

   f->SetTime(t + (2.0*a)*dt);
   f->ImplicitSolve(a*dt, y, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(a*dt, y, k);
-   }
   z.Add(b*dt, k);
   x.Add(b*dt, k);

   f->SetTime(t + dt);
   f->ImplicitSolve(a*dt, z, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(a*dt, z, k);
-   }
   x.Add(a*dt, k);
   t += dt;
 }
@@ -968,19 +885,11 @@ void ESDIRK33Solver::Step(Vector &x, real_t &t, real_t &dt)

   f->SetTime(t + (2.0*a)*dt);
   f->ImplicitSolve(a*dt, y, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(a*dt, y, k);
-   }
   z.Add(b*dt, k);
   x.Add(b_2*dt, k);

   f->SetTime(t + dt);
   f->ImplicitSolve(a*dt, z, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(a*dt, z, k);
-   }
   x.Add(b_3*dt, k);
   t += dt;
 }
@@ -1046,10 +955,6 @@ void GeneralizedAlphaSolver::Step(Vector &x, real_t &t, real_t &dt)
   real_t dt_eff = (gamma*alpha_f/alpha_m)*dt;
   f->SetTime(t + alpha_f*dt);
   f->ImplicitSolve(dt_eff, y, k);
-   if (f->ImplicitVarTypeIsState())
-   {
-      ComputeSlopeFromState(dt_eff, y, k);
-   }

   // Update x and xdot
   x.Add((1.0 - (gamma/alpha_m))*dt, state[0]);
@@ -1211,8 +1116,8 @@ void SecondOrderODESolver::EulerStep(Vector &x, Vector &dxdt, real_t &t,
   f->SetTime(t + dt);
   f->ImplicitSolve(0.5*dt*dt, dt, x, dxdt, state[0]);

-   x.Add(0.5*dt*dt, state[0]);
-   dxdt.Add(dt, state[0]);
+   x   .Add(0.5*dt*dt, state[0]);
+   dxdt.Add(dt,    state[0]);
   t += dt;
 }

@@ -1298,8 +1203,8 @@ void NewmarkSolver::Step(Vector &x, Vector &dxdt, real_t &t, real_t &dt)
   f->SetTime(t + dt);
   f->ImplicitSolve(fac3*dt*dt, fac4*dt, x, dxdt, state[0]);

-   x.Add(fac3*dt*dt, state[0]);
-   dxdt.Add(fac4*dt, state[0]);
+   x   .Add(fac3*dt*dt, state[0]);
+   dxdt.Add(fac4*dt,    state[0]);
   t += dt;
 }

@@ -120,7 +120,6 @@ public:
 class ODESolver
 {
 protected:
-   using ImplicitVariableType = TimeDependentOperator::ImplicitVariableType;
   /// Pointer to the associated TimeDependentOperator.
   TimeDependentOperator *f;  // f(.,t) : R^n --> R^n
   MemoryType mem_type;
@@ -193,22 +192,6 @@ public:
   /// Returns how many State vectors the ODE requires
   virtual int GetStateSize() { return 0; };

-   ///@brief Returns @a true if the ODESolver supports the given
-   /// #ImplicitVariableType, @a var, and returns @a false otherwise.
-   ///@note Should be overriden in ODESolver that calls TimeDependentOperator::ImplicitSolve().
-   virtual bool SupportsImplicitVariableType(ImplicitVariableType var) const
-   { return false; };
-
-   /** @brief Compute the finite-difference slope, @a $\frac{du}{dt} \approx \frac{u(t+dt)-u(t)}{dt}$,
-    * and store it in @a k.
-    * @param [in] dt Finite difference step size.
-    * @param [in] u  state vector, @a u(t).
-    * @param [in,out] k   On input, @a k contains the state vector, @a u( @a t+ @a dt).
-    * On output, @a k contains the computed slope, @a du/dt.
-    * */
-   virtual void ComputeSlopeFromState(const real_t dt, const Vector &u,
-                                      Vector &k);
-
   // Help info for ODESolver options
   static MFEM_EXPORT std::string ExplicitTypes;
   static MFEM_EXPORT std::string ImplicitTypes;
@@ -378,12 +361,6 @@ public:
   void Init(TimeDependentOperator &f_) override;

   void Step(Vector &x, real_t &t, real_t &dt) override;
-
-   bool SupportsImplicitVariableType(ImplicitVariableType var) const override
-   {
-      return (var == ImplicitVariableType::STATE ||
-              var == ImplicitVariableType::SLOPE);
-   }
 };


@@ -397,12 +374,6 @@ public:
   void Init(TimeDependentOperator &f_) override;

   void Step(Vector &x, real_t &t, real_t &dt) override;
-
-   bool SupportsImplicitVariableType(ImplicitVariableType var) const override
-   {
-      return (var == ImplicitVariableType::STATE ||
-              var == ImplicitVariableType::SLOPE);
-   }
 };


@@ -424,12 +395,6 @@ public:
   void Init(TimeDependentOperator &f_) override;

   void Step(Vector &x, real_t &t, real_t &dt) override;
-
-   bool SupportsImplicitVariableType(ImplicitVariableType var) const override
-   {
-      return (var == ImplicitVariableType::STATE ||
-              var == ImplicitVariableType::SLOPE);
-   }
 };


@@ -444,12 +409,6 @@ public:
   void Init(TimeDependentOperator &f_) override;

   void Step(Vector &x, real_t &t, real_t &dt) override;
-
-   bool SupportsImplicitVariableType(ImplicitVariableType var) const override
-   {
-      return (var == ImplicitVariableType::STATE ||
-              var == ImplicitVariableType::SLOPE);
-   }
 };


@@ -464,12 +423,6 @@ public:
   void Init(TimeDependentOperator &f_) override;

   void Step(Vector &x, real_t &t, real_t &dt) override;
-
-   bool SupportsImplicitVariableType(ImplicitVariableType var) const override
-   {
-      return (var == ImplicitVariableType::STATE ||
-              var == ImplicitVariableType::SLOPE);
-   }
 };


@@ -484,12 +437,6 @@ public:
   void Init(TimeDependentOperator &f_) override;

   void Step(Vector &x, real_t &t, real_t &dt) override;
-
-   bool SupportsImplicitVariableType(ImplicitVariableType var) const override
-   {
-      return (var == ImplicitVariableType::STATE ||
-              var == ImplicitVariableType::SLOPE);
-   }
 };


@@ -504,12 +451,6 @@ public:
   void Init(TimeDependentOperator &f_) override;

   void Step(Vector &x, real_t &t, real_t &dt) override;
-
-   bool SupportsImplicitVariableType(ImplicitVariableType var) const override
-   {
-      return (var == ImplicitVariableType::STATE ||
-              var == ImplicitVariableType::SLOPE);
-   }
 };


@@ -524,12 +465,6 @@ public:
   void Init(TimeDependentOperator &f_) override;

   void Step(Vector &x, real_t &t, real_t &dt) override;
-
-   bool SupportsImplicitVariableType(ImplicitVariableType var) const override
-   {
-      return (var == ImplicitVariableType::STATE ||
-              var == ImplicitVariableType::SLOPE);
-   }
 };


@@ -555,12 +490,6 @@ public:

   ODEStateData& GetState() override { return state; }
   const ODEStateData& GetState() const override { return state; }
-
-   bool SupportsImplicitVariableType(ImplicitVariableType var) const override
-   {
-      return (var == ImplicitVariableType::STATE ||
-              var == ImplicitVariableType::SLOPE);
-   }
 };


@@ -677,11 +606,6 @@ public:

   ODEStateData& GetState() override { return state; }
   const ODEStateData& GetState() const override { return state; }
-   bool SupportsImplicitVariableType(ImplicitVariableType var) const override
-   {
-      return (var == ImplicitVariableType::STATE ||
-              var == ImplicitVariableType::SLOPE);
-   }
 };

 /** A 1-stage, 2nd order AM method. */
@@ -381,24 +381,11 @@ public:
      ADDITIVE_TERM_2
   };

-   /** Used to specify the variable being returned by ImplicitSolve(). This can
-    * be queried by ODESolver to identify the variable being solved for.
-    * @warning Not all ODESolver may support all options. See ODESolver::SupportsImplicitVariableType() */
-   enum ImplicitVariableType
-   {
-      SLOPE, ///< stage slope, $k = \frac{du}{dt}$.
-      STATE  ///< stage state, $k = u$.
-   };
-
 protected:
   real_t t;  ///< Current time.
   Type type; /**< @brief Describes the form of the TimeDependentOperator, see
                   the documentation of #Type. */
   EvalMode eval_mode; ///< Current evaluation mode.
-   ImplicitVariableType implicit_variable_type =
-      ImplicitVariableType::SLOPE; /**< @brief
-                                                        Return variable for
-                                                        ImplicitSolve()*/

 public:
   /** @brief Construct a "square" TimeDependentOperator (u,t) -> k(u,t), where
@@ -442,24 +429,6 @@ public:
   virtual void SetEvalMode(const EvalMode new_eval_mode)
   { eval_mode = new_eval_mode; }

-   /** @brief Sets the #ImplicitVariableType for ImplicitSolve()*/
-   virtual void SetImplicitVariableType(const ImplicitVariableType variable_type)
-   { implicit_variable_type = variable_type; }
-
-   /** @brief Returns the #ImplicitVariableType for ImplicitSolve(). */
-   virtual ImplicitVariableType GetImplicitVariableType() const
-   { return implicit_variable_type; }
-
-   /** @brief Returns @a true if implicit variable is #STATE and @a false otherwise.
-    * Used by ODESolver to identify the stage variable returned by ImplicitSolve() */
-   virtual bool ImplicitVarTypeIsState() const
-   { return (implicit_variable_type == ImplicitVariableType::STATE); }
-
-   /** @brief Returns @a true if implicit variable is #SLOPE and @a false otherwise.
-    * Used by ODESolver to identify the stage variable returned by ImplicitSolve() */
-   virtual bool ImplicitVarTypeIsSlope() const
-   { return (implicit_variable_type == ImplicitVariableType::SLOPE); }
-
   /** @brief Perform the action of the explicit part of the operator, G:
       @a v = G(@a u, t) where t is the current time.

@@ -493,8 +462,7 @@ public:

   /** @brief Solve for the unknown @a k, at the current time t, the following
       equation:
-        1. $F( u + \gamma k, k, t) = G( u +  \gamma k, t)$, if solving for stage-slope (default)
-        2. $F( u , \frac{k-u}{\gamma}, t) = G(k, t)$, if solving for stage-state
+       F(@a u + @a gamma @a k, @a k, t) = G(@a u + @a gamma @a k, t).

       For solving an ordinary differential equation of the form
       $ M \frac{dy}{dt} = g(y,t) $, recall that F and G can be defined in
@@ -504,9 +472,8 @@ public:
         2. F(u,k,t) = M k and G(u,t) = g(u,t)
         3. F(u,k,t) = M k - g(u,t) and G(u,t) = 0

-        Regardless of the choice of F and G, this function should solve for @a k:
-        - $~Mk = g( u + \gamma k, t)~$, if solving for stage-slope.
-        - $~Mk  = \gamma g(k, t) + Mu~$, if solving for stage-state
+       Regardless of the choice of F and G, this function should solve for @a k
+       in M @a k = g(@a u + @a gamma @a k, t).

       To see how @a k can be useful, consider the backward Euler method defined
       by $ y(t + \Delta t) = y(t) + \Delta t k_0 $ where
@@ -524,7 +491,6 @@ public:
       $ y(t) + \Delta t \sum_{j=1}^{i-1} a_{ij} k_j $ and @a gamma set to
       $ a_{ii} \Delta t $, for $ k_i $. For example, see class SDIRK33Solver.

-       See SetImplicitVariableType() to switch between different variable modes.
       If not re-implemented, this method simply generates an error. */
   virtual void ImplicitSolve(const real_t gamma, const Vector &u, Vector &k);

@@ -3639,20 +3639,12 @@ void PetscBDDCSolver::BDDCSolverConstructor(const PetscBDDCSolverParams &opts)
      // make sure ess/nat_dof have been collectively set
      PetscBool lpr = PETSC_FALSE,pr;
      if (opts.ess_dof) { lpr = PETSC_TRUE; }
-#if PETSC_VERSION_LT(3,24,0)
      mpiierr = MPI_Allreduce(&lpr,&pr,1,MPIU_BOOL,MPI_LOR,comm);
-#else
-      mpiierr = MPI_Allreduce(&lpr,&pr,1,MPI_C_BOOL,MPI_LOR,comm);
-#endif
      CCHKERRQ(comm,mpiierr);
      MFEM_VERIFY(lpr == pr,"ess_dof should be collectively set");
      lpr = PETSC_FALSE;
      if (opts.nat_dof) { lpr = PETSC_TRUE; }
-#if PETSC_VERSION_LT(3,24,0)
      mpiierr = MPI_Allreduce(&lpr,&pr,1,MPIU_BOOL,MPI_LOR,comm);
-#else
-      mpiierr = MPI_Allreduce(&lpr,&pr,1,MPI_C_BOOL,MPI_LOR,comm);
-#endif
      CCHKERRQ(comm,mpiierr);
      MFEM_VERIFY(lpr == pr,"nat_dof should be collectively set");
      // make sure fields have been collectively set
@@ -4066,13 +4058,8 @@ void PetscNonlinearSolver::SetOperator(const Operator &op)
      ls = (PetscBool)(height == op.Height() && width  == op.Width() &&
                       (void*)&op == fctx &&
                       (void*)&op == jctx);
-#if PETSC_VERSION_LT(3,24,0)
      mpiierr = MPI_Allreduce(&ls,&gs,1,MPIU_BOOL,MPI_LAND,
                              PetscObjectComm((PetscObject)snes));
-#else
-      mpiierr = MPI_Allreduce(&ls,&gs,1,MPI_C_BOOL,MPI_LAND,
-                              PetscObjectComm((PetscObject)snes));
-#endif
      CCHKERRQ(PetscObjectComm((PetscObject)snes),mpiierr);
      if (!gs)
      {
@@ -1066,11 +1066,6 @@ void SparseMatrix::BooleanMultTranspose(const Array<int> &x,
   y.SetSize(Width());
   y = 0;

-   HostReadI();
-   HostReadJ();
-   x.HostRead();
-   y.HostReadWrite();
-
   for (int i = 0; i < Height(); i++)
   {
      if (x[i])
@@ -23,31 +23,15 @@ namespace mfem
 void SparseSmoother::SetOperator(const Operator &a)
 {
   oper = dynamic_cast<const SparseMatrix*>(&a);
-   MFEM_VERIFY(oper != nullptr, "Operator must be a SparseMatrix");
+   if (oper == NULL)
+   {
+      mfem_error("SparseSmoother::SetOperator : not a SparseMatrix!");
+   }
   height = oper->Height();
   width = oper->Width();
-
-   At.reset();
-   oper_T = nullptr;
-}
-
-void SparseSmoother::EnsureTranspose() const
-{
-   if (oper_T) { return; }
-
-   const real_t tol = 1e-14;
-   if (oper->IsSymmetric() > tol * oper->MaxNorm())
-   {
-      At.reset(Transpose(*oper));
-      oper_T = At.get();
-   }
-   else
-   {
-      At.reset();
-      oper_T = oper;
-   }
 }

+/// Matrix vector multiplication with GS Smoother.
 void GSSmoother::Mult(const Vector &x, Vector &y) const
 {
   if (!iterative_mode)
@@ -67,33 +51,21 @@ void GSSmoother::Mult(const Vector &x, Vector &y) const
   }
 }

-void GSSmoother::MultTranspose(const Vector &x, Vector &y) const
+/// Create the Jacobi smoother.
+DSmoother::DSmoother(const SparseMatrix &a, int t, real_t s, int it)
+   : SparseSmoother(a)
 {
-   EnsureTranspose();
-
-   if (!iterative_mode)
-   {
-      y = 0.0;
-   }
-
-   for (int i = 0; i < iterations; i++)
-   {
-      if (type != 1)
-      {
-         oper_T->Gauss_Seidel_forw(x, y);
-      }
-      if (type != 2)
-      {
-         oper_T->Gauss_Seidel_back(x, y);
-      }
-   }
+   type = t;
+   scale = s;
+   iterations = it;
 }

-void DSmoother::Mult_(const SparseMatrix &A, const Vector &x, Vector &y) const
+/// Matrix vector multiplication with Jacobi smoother.
+void DSmoother::Mult(const Vector &x, Vector &y) const
 {
   if (!iterative_mode && type == 0 && iterations == 1)
   {
-      A.DiagScale(x, y, scale, use_abs_diag);
+      oper->DiagScale(x, y, scale, use_abs_diag);
      return;
   }

@@ -118,41 +90,22 @@ void DSmoother::Mult_(const SparseMatrix &A, const Vector &x, Vector &y) const
   {
      if (type == 0)
      {
-         A.Jacobi(x, *p, *r, scale, use_abs_diag);
+         oper->Jacobi(x, *p, *r, scale, use_abs_diag);
      }
      else if (type == 1)
      {
-         A.Jacobi2(x, *p, *r, scale);
+         oper->Jacobi2(x, *p, *r, scale);
      }
      else if (type == 2)
      {
-         A.Jacobi3(x, *p, *r, scale);
+         oper->Jacobi3(x, *p, *r, scale);
      }
      else
      {
-         MFEM_ABORT("Invalid type.");
+         mfem_error("DSmoother::Mult wrong type");
      }
      Swap<Vector*>(r, p);
   }
 }

-void DSmoother::Mult(const Vector &x, Vector &y) const
-{
-   Mult_(*oper, x, y);
-}
-
-void DSmoother::MultTranspose(const Vector &x, Vector &y) const
-{
-   if (iterations == 1 && !iterative_mode)
-   {
-      Mult_(*oper, x, y);
-      return;
-   }
-
-   EnsureTranspose();
-   MFEM_VERIFY(type == 0 || !At, "l1 or lumped Jacobi transpose not implemented"
-               " for non-symmetric matrices");
-   Mult_(*oper_T, x, y);
-}
-
 }
@@ -15,159 +15,67 @@
 #include "../config/config.hpp"
 #include "sparsemat.hpp"

-#include <memory>
-
 namespace mfem
 {

-/// Abstract base class for smoothers created from a SparseMatrix.
 class SparseSmoother : public MatrixInverse
 {
 protected:
-   const SparseMatrix *oper = nullptr; ///< The underlying matrix.
-
-   /// Pointer to the transpose of the underlying matrix. If the matrix is
-   /// symmetric, this will be the same as @a oper. If the matrix is not
-   /// symmetric, the transpose will be formed and stored in @a At. The
-   /// transpose will only be formed if MultTranspose() is called.
-   mutable const SparseMatrix *oper_T = nullptr;
-
-   mutable std::unique_ptr<SparseMatrix> At; ///< Transpose of A, if needed.
-
-   void EnsureTranspose() const; ///< Ensure that the transpose is set.
+   const SparseMatrix *oper;

 public:
-   SparseSmoother() = default;
+   SparseSmoother() { oper = NULL; }

-   SparseSmoother(const SparseMatrix &a) { SetOperator(a); }
+   SparseSmoother(const SparseMatrix &a)
+      : MatrixInverse(a) { oper = &a; }

-   /// Sets the underlying matrix. @a a must be a SparseMatrix.
   void SetOperator(const Operator &a) override;
 };

-/// Gauss-Seidel smoother of a sparse matrix.
+/// Data type for Gauss-Seidel smoother of sparse matrix
 class GSSmoother : public SparseSmoother
 {
-public:
-   enum GSType
-   {
-      SYMMETRIC, ///< Forward Gauss-Seidel, then backward.
-      FORWARD, ///< Forward Gauss-Seidel ($L^{-1}$).
-      BACKWARD ///< Backward Gauss-Seidel ($U^{-1}$).
-   };
 protected:
-   GSType type; ///< Type of Gauss-Seidel, see GSSmoother::GSType.
-   int iterations; ///< Number of stationary iterations.
+   int type; // 0, 1, 2 - symmetric, forward, backward
+   int iterations;

 public:
-   /// @brief Create a Gauss-Seidel smoother. SetOperator() will need to be
-   /// called with a SparseMatrix before first use.
-   ///
-   /// @param[in]  t        Type of GS smoother (see GSSmoother::GSType)
-   /// @param[in]  it       Number of stationary iterations to perform
-   GSSmoother(GSType t = SYMMETRIC, int it = 1) { type = t; iterations = it; }
+   /// Create GSSmoother.
+   GSSmoother(int t = 0, int it = 1) { type = t; iterations = it; }

-   /// @brief Create a Jacobi smoother using the SparseMatrix @a a.
-   ///
-   /// @param[in]  a        The underlying SparseMatrix
-   /// @param[in]  t        Type of GS smoother (see GSSmoother::GSType)
-   /// @param[in]  it       Number of stationary iterations to perform
-   GSSmoother(const SparseMatrix &a, GSType t = SYMMETRIC, int it = 1)
-      : GSSmoother(t, it) { SetOperator(a); }
+   /// Create GSSmoother.
+   GSSmoother(const SparseMatrix &a, int t = 0, int it = 1)
+      : SparseSmoother(a) { type = t; iterations = it; }

-   /// Same as GSSmoother(GSType,int), for backwards compatibility.
-   GSSmoother(int t, int it = 1) : GSSmoother(GSType(t), it) { }
-
-   /// @brief Same as GSSmoother(const SparseMatrix&,GSType,int), for
-   /// backwards compatibility.
-   GSSmoother(const SparseMatrix &a, int t, int it = 1)
-      : GSSmoother(a, GSType(t), it) { }
-
-   /// @brief Application of the Gauss-Seidel smoother.
-   ///
-   /// Applies a stationary Gauss-Seidel iteration. If Solver::iterative_mode is
-   /// true, then @a y is used as the initial guess, and Gauss-Seidel is applied
-   /// to the residual $x - Ay$.
+   /// Matrix vector multiplication with GS Smoother.
   void Mult(const Vector &x, Vector &y) const override;
-
-   /// Application of the transpose of the Gauss-Seidel smoother.
-   void MultTranspose(const Vector &x, Vector &y) const override;
 };

-/// Jacobi-type diagonal smoother of a sparse matrix.
+/// Data type for scaled Jacobi-type smoother of sparse matrix
 class DSmoother : public SparseSmoother
 {
-public:
-   enum JacobiType
-   {
-      JACOBI,       ///< Scale by the diagonal of the matrix.
-      L1_JACOBI,    ///< Scale by the l1-norm of the rows.
-      LUMPED_JACOBI ///< Scale by the sum of the rows.
-   };
 protected:
-   JacobiType type; ///< Type of diagonal scaling, see DSmoother::JacobiType.
-   real_t scale; ///< Scaling (damping) factor.
-   int iterations; ///< Number of stationary iterations to perform.
-
-   /// @brief Uses abs values of the diagonal entries. Relevant only with type
-   /// JacobiType::JACOBI.
+   int type; // 0, 1, 2 - scaled Jacobi, scaled l1-Jacobi, scaled lumped-Jacobi
+   real_t scale;
+   int iterations;
+   /// Uses abs values of the diagonal entries. Relevant only when type = 0.
   bool use_abs_diag = false;

-   mutable Vector z; ///< Temporary work vector.
-
-   /// Apply the Jacobi smoother (used internally by Mult() and MultTranspose())
-   void Mult_(const SparseMatrix &A, const Vector &x, Vector &y) const;
+   mutable Vector z;

 public:
-   /// @brief Create a Jacobi smoother. SetOperator() will need to be called
-   /// with a SparseMatrix before first use.
-   ///
-   /// @param[in]  t        Type of Jacobi smoother (see DSmoother::JacobiType)
-   /// @param[in]  s        Scaling factor
-   /// @param[in]  it       Number of stationary iterations to perform
-   DSmoother(JacobiType t = JACOBI, real_t s = 1., int it = 1)
+   /// Create Jacobi smoother.
+   DSmoother(int t = 0, real_t s = 1., int it = 1)
   { type = t; scale = s; iterations = it; }

-   /// @brief Create a Jacobi smoother using the SparseMatrix @a a.
-   ///
-   /// @param[in]  a        The underlying SparseMatrix
-   /// @param[in]  t        Type of Jacobi smoother (see DSmoother::JacobiType)
-   /// @param[in]  s        Scaling factor
-   /// @param[in]  it       Number of stationary iterations to perform
-   DSmoother(const SparseMatrix &a, JacobiType t = JACOBI, real_t s = 1.,
-             int it = 1) : DSmoother(t, s, it) { SetOperator(a); }
+   /// Create Jacobi smoother.
+   DSmoother(const SparseMatrix &a, int t = 0, real_t s = 1., int it = 1);

-   /// @brief Same as DSmoother(JacobiType,real_t,int), for backwards compatbility.
-   DSmoother(int t, real_t s = 1., int it = 1)
-      : DSmoother(JacobiType(t), s, it) { }
-
-   /// @brief Same as DSmoother(const SparseMatrix&,JacobiType,real_t,int), for
-   /// backwards compatbility.
-   DSmoother(const SparseMatrix &a, int t, real_t s = 1., int it = 1)
-      : DSmoother(a, JacobiType(t), s, it) { }
-
-   /// @brief Replace diagonal entries with their absolute values. Relevant only
-   /// with JacobiType::JACOBI.
+   /// Replace diag entries with their abs values. Relevant only when type = 0.
   void SetPositiveDiagonal(bool pos_diag = true) { use_abs_diag = pos_diag; }

-   /// @brief Apply the Jacobi smoother.
-   ///
-   /// Applies a stationary iteration with diagonal scaling. If
-   /// Solver::iterative_mode is true, then @a y is used as the initial guess
-   /// (and the diagonal scaling is applied to the residual $x - Ay$, giving
-   /// $D^{-1}(x - Ay)$).
-   ///
-   /// By default, Solver::iterative_mode is false and only one iteration is
-   /// performed, corresponding to $y = D^{-1}x$.
+   /// Matrix vector multiplication with Jacobi smoother.
   void Mult(const Vector &x, Vector &y) const override;
-
-   /// @brief Apply the transpose of the Jacobi smoother.
-   ///
-   /// If the underlying matrix is symmetric, or if only one iteration is
-   /// performed with zero initial guess (Solver::iterative_mode is false), then
-   /// this is the same as Mult(). For non-symmetric matrices with iteration
-   /// count greater than one, only JacobiType::JACOBI is supported.
-   void MultTranspose(const Vector &x, Vector &y) const override;
 };

 }
@@ -363,19 +363,14 @@ void SuperLUSolver::Init(MPI_Comm comm)
   // Set default options:
   //    options.Fact = DOFACT;
   //    options.Equil = YES;
-   //    options.ParSymbFact = NO;
   //    options.ColPerm = METIS_AT_PLUS_A;
   //    options.RowPerm = LargeDiag_MC64;
   //    options.ReplaceTinyPivot = NO;
-   //    options.IterRefine = SLU_DOUBLE;
   //    options.Trans = NOTRANS;
+   //    options.IterRefine = SLU_DOUBLE;
   //    options.SolveInitialized = NO;
   //    options.RefineInitialized = NO;
   //    options.PrintStat = YES;
-   //    options.lookahead_etree = NO;
-   //    options.num_lookaheads = 10;
-   //    options.superlu_acc_offload = 1;
-   //    options.SymPattern = NO;
   superlu_dist_options_t *options = (superlu_dist_options_t *)optionsPtr_;
   set_default_options_dist(options);
 #if SUPERLU_DIST_MAJOR_VERSION > 7 || \
@@ -477,12 +472,6 @@ void SuperLUSolver::SetFact(superlu::Fact fact)
   options->Fact = opt;
 }

-void SuperLUSolver::SetDeviceOffload(bool offload)
-{
-   superlu_dist_options_t *options = (superlu_dist_options_t *)optionsPtr_;
-   options->superlu_acc_offload = offload;
-}
-
 void SuperLUSolver::SetOperator(const Operator &op)
 {
   // Verify that we have a compatible operator
@@ -250,8 +250,7 @@ public:
       work (default false) */
   void SetSymmetricPattern(bool sym);

-   /** @brief Specify whether to perform parallel symbolic factorization
-       (default false)
+   /** @brief Specify whether to perform parallel symbolic factorization.
       @note If true SuperLU will use superlu::PARMETIS for the Column
       Permutation regardless of the setting */
   void SetParSymbFact(bool par);
@@ -264,10 +263,6 @@ public:
       superlu::FACTORED*/
   void SetFact(superlu::Fact fact);

-   /** @brief Specify whether to offload numerical factorization onto the device
-       (default true if SuperLU_DIST has been compiled with GPU support) */
-   void SetDeviceOffload(bool offload);
-
   // Processor grid for SuperLU_DIST.
   const int nprow_, npcol_, npdep_;

@@ -794,6 +794,7 @@ status info:
 	$(info MFEM_MPI_NP            = $(MFEM_MPI_NP))
 	@true

+ASTYLE_BIN = astyle
 ASTYLE = $(ASTYLE_BIN) --options=$(SRC)config/mfem.astylerc
 ASTYLE_VER = "Artistic Style Version 3.1"
 FORMAT_FILES = $(foreach dir,$(DIRS) $(EM_DIRS) config,$(dir)/*.?pp)
@@ -113,13 +113,13 @@ AttributeSets::GetAttributeSetMarker(const std::string & set_name) const

 Array<int> AttributeSets::AttrToMarker(int max_attr, const Array<int> &attrs)
 {
-   MFEM_VERIFY(attrs.Min() >= 1, "Found attribute less than one")
-   MFEM_ASSERT(attrs.Max() <= max_attr, "Found attribute greater than max_attr")
+   MFEM_ASSERT(attrs.Max() <= max_attr, "Invalid attribute number present.");

   Array<int> marker(max_attr);
   marker = 0;
   for (auto const &attr : attrs)
   {
+      MFEM_VERIFY(attr > 0, "Attribute number less than one!");
      marker[attr-1] = 1;
   }
   return marker;
@@ -36,7 +36,6 @@
 #include <numeric>
 #include <unordered_map>
 #include <unordered_set>
-#include <list>

 // Include the METIS header, if using version 5. If using METIS 4, the needed
 // declarations are inlined below, i.e. no header is needed.
@@ -4773,12 +4772,12 @@ Mesh::Mesh(real_t *vertices_, int num_vertices,
   FinalizeTopology();
 }

-Mesh::Mesh(const NURBSExtension& ext)
+Mesh::Mesh( const NURBSExtension& ext )
   : attribute_sets(attributes), bdr_attribute_sets(bdr_attributes)
 {
   SetEmpty();
   /// make an internal copy of the NURBSExtension
-   NURBSext = new NURBSExtension(ext);
+   NURBSext = new NURBSExtension( ext );

   Dim              = NURBSext->Dimension();
   NumOfVertices    = NURBSext->GetNV();
@@ -4792,12 +4791,11 @@ Mesh::Mesh(const NURBSExtension& ext)
   if (NURBSext->HavePatches())
   {
      NURBSFECollection  *fec = new NURBSFECollection(NURBSext->GetOrder());
-      const int vdim = NURBSext->GetPatchSpaceDimension();
-      FiniteElementSpace *fes = new FiniteElementSpace(this, fec, vdim,
+      FiniteElementSpace *fes = new FiniteElementSpace(this, fec, Dim,
                                                       Ordering::byVDIM);
      Nodes = new GridFunction(fes);
      Nodes->MakeOwner(fec);
-      NURBSext->SetCoordsFromPatches(*Nodes, vdim);
+      NURBSext->SetCoordsFromPatches(*Nodes);
      own_nodes = 1;
      spaceDim = Nodes->VectorDim();
      for (int i = 0; i < spaceDim; i++)
@@ -6411,7 +6409,7 @@ void Mesh::UpdateNURBS()
   NURBSext->SetKnotsFromPatches();

   Dim = NURBSext->Dimension();
-   spaceDim = Nodes->FESpace()->GetVDim();
+   spaceDim = Dim;

   if (NumOfElements != NURBSext->GetNE())
   {
@@ -6436,8 +6434,7 @@ void Mesh::UpdateNURBS()
   Nodes->FESpace()->Update();
   Nodes->Update();
   NodesUpdated();
-   const int vdim = Nodes->FESpace()->GetVDim();
-   NURBSext->SetCoordsFromPatches(*Nodes, vdim);
+   NURBSext->SetCoordsFromPatches(*Nodes);

   if (NumOfVertices != NURBSext->GetNV())
   {
@@ -6540,8 +6537,6 @@ void Mesh::LoadPatchTopo(std::istream &input, Array<int> &edge_to_ukv)
      Array<int> ukv_to_rpkv;
      GetEdgeToUniqueKnotvector(edge_to_ukv, ukv_to_rpkv);
   }
-
-   CorrectPatchTopoOrientations(edge_to_ukv);
 }

 void Mesh::GetEdgeToUniqueKnotvector(Array<int> &edge_to_ukv,
@@ -6552,9 +6547,9 @@ void Mesh::GetEdgeToUniqueKnotvector(Array<int> &edge_to_ukv,
   const int NPKV = NP * dim;    // number of patch knotvectors
   constexpr int notset = -9999999;
   // Sign convention
-   auto flipSign = [](int i) { return -1 - i; };
-   auto unSign = [](int i) { return (i < 0) ? -1 - i : i; };
-   // Local edge index -> dimension convention
+   auto sign = [](int i) { return -1 - i; };
+   auto unsign = [](int i) { return (i < 0) ? -1 - i : i; };
+   // Edge index -> dimension convention
   auto edge_to_dim = [](int i) { return (i < 8) ? ((i & 1) ? 1 : 0) : 2; };

   Array<int> v(2); // vertices of an edge
@@ -6569,7 +6564,7 @@ void Mesh::GetEdgeToUniqueKnotvector(Array<int> &edge_to_ukv,
      {
         GetElementVertices(i, v);
         // Sign is based on the edge's vertex indices
-         edge_to_ukv[i] = (v[1] > v[0]) ? i : flipSign(i);
+         edge_to_ukv[i] = (v[1] > v[0]) ? i : sign(i);
         ukv_to_rpkv[i] = i;
      }
      return;
@@ -6619,14 +6614,14 @@ void Mesh::GetEdgeToUniqueKnotvector(Array<int> &edge_to_ukv,
         // We've set this edge already - link this index to it
         if (edge_to_pkv[edge] != notset)
         {
-            const int pkv_other = unSign(edge_to_pkv[edge]);
+            const int pkv_other = unsign(edge_to_pkv[edge]);
            unite(pkv, pkv_other);
         }
         else
         {
            GetEdgeVertices(edge, v);
            // Sign is based on the edge's vertex indices
-            edge_to_pkv[edge] = (v[1] > v[0]) ? pkv : flipSign(pkv);
+            edge_to_pkv[edge] = (v[1] > v[0]) ? pkv : sign(pkv);
         }
      }
   }
@@ -6653,255 +6648,11 @@ void Mesh::GetEdgeToUniqueKnotvector(Array<int> &edge_to_ukv,
   edge_to_ukv.SetSize(NumOfEdges);
   for (int i = 0; i < NumOfEdges; i++)
   {
-      const int pkv = unSign(edge_to_pkv[i]);
+      const int pkv = unsign(edge_to_pkv[i]);
      const int rpkv = pkv_to_rpkv[pkv];
      const int ukv = rpkv_to_ukv[rpkv];
-      edge_to_ukv[i] = (edge_to_pkv[i] < 0) ? flipSign(ukv) : ukv;
+      edge_to_ukv[i] = (edge_to_pkv[i] < 0) ? sign(ukv) : ukv;
   }
-
-   CorrectPatchTopoOrientations(edge_to_ukv);
-}
-
-void Mesh::CorrectPatchTopoOrientations(Array<int> &edge_to_ukv) const
-{
-   const int dim = Dimension(); // Topological (not physical) dimension
-   if (dim == 1) { return; }
-
-   // Sign convention
-   auto flipSign = [](int i) { return -1 - i; };
-
-   const Table *face2elem = GetFaceToElementTable();
-   Array<int> pfaces, orient;
-   Array<int> fe, feo;
-
-   // Finds elements sharing a face containing knotvector kv.
-   auto faceNeighbors = [&](int p, int kv, std::unordered_set<int> &nghb)
-   {
-      if (dim == 2) { GetElementEdges(p, pfaces, orient); }
-      else { GetElementFaces(p, pfaces, orient); }
-
-      for (auto face : pfaces)
-      {
-         // Check whether this face contains kv.
-         GetFaceEdges(face, fe, feo);
-         bool hasKV = false;
-         for (auto e : fe)
-         {
-            const int skv = edge_to_ukv[e];
-            if (skv == kv || flipSign(skv) == kv) { hasKV = true; }
-         }
-         if (hasKV)
-         {
-            Array<int> row;
-            face2elem->GetRow(face, row);
-            for (auto elem : row) { nghb.insert(elem); }
-         }
-      }
-   };
-
-   std::vector<std::vector<int>> dir_edges;
-   if (dim == 2)
-   {
-      dir_edges =
-      {
-         {0,2},
-         {1,3}
-      };
-   }
-   else
-   {
-      dir_edges =
-      {
-         {0,2,4,6},
-         {1,3,5,7},
-         {8,9,10,11}
-      };
-   }
-
-   Array<int> ukvs((dim==2) ? 4 : 12);
-   Array<int> pe, oe;
-   bool initKV = false;
-
-   auto setPatchDirections = [&](int p, int kv, Array<bool> &edgeSet,
-                                 std::unordered_set<int> &visited)
-   {
-      // Edges and orientations for this patch
-      GetElementEdges(p, pe, oe);
-
-      // Get the signed unique knot vector indices
-      for (int i = 0; i < pe.Size(); i++)
-      {
-         ukvs[i] = edge_to_ukv[pe[i]];
-         ukvs[i] = (oe[i] < 0) ? flipSign(ukvs[i]) : ukvs[i];
-      }
-
-      // Find the direction with this kv.
-      int thisDir = -1;
-      for (int d=0; d<dim; ++d) // Loop over directions.
-      {
-         const int skv = edge_to_ukv[pe[dir_edges[d][0]]];
-         if (skv == kv || flipSign(skv) == kv)
-         {
-            thisDir = d;
-         }
-      }
-      MFEM_VERIFY(thisDir >= 0, "");
-
-      // For this direction, find any edge already set. If no edge is set, we
-      // arbitrarily take the first.
-      int ref_edge0 = dir_edges[thisDir][0];
-      for (auto ref_edge : dir_edges[thisDir])
-      {
-         const int edge = pe[ref_edge];
-         if (edgeSet[edge])
-         {
-            ref_edge0 = ref_edge;
-         }
-      }
-
-      if (initKV && !edgeSet[pe[ref_edge0]])
-      {
-         visited.erase(p);
-         return false; // There is no set edge in this direction on this patch.
-      }
-
-      initKV = true;
-
-      // Use ref_edge0 to set other edges in this direction.
-      edgeSet[pe[ref_edge0]] = true;
-      for (auto i : dir_edges[thisDir])
-      {
-         if (i == ref_edge0)
-         {
-            continue;
-         }
-
-         const int edge = pe[i];
-         if ((dim == 2 && ukvs[i] != flipSign(ukvs[ref_edge0])) ||
-             (dim == 3 && ukvs[i] == flipSign(ukvs[ref_edge0])))
-         {
-            // Flip the sign of this edge
-            MFEM_VERIFY(!edgeSet[edge], "");
-            edge_to_ukv[edge] = flipSign(edge_to_ukv[edge]);
-         }
-
-         edgeSet[edge] = true;
-      }
-
-      return true;
-   };
-
-   Array<bool> edgeSet(NumOfEdges); // Whether edge has orientation set
-   edgeSet = false;
-
-   std::unordered_set<int> unset; // Patches with an unset edge
-   for (int i=0; i<NumOfElements; ++i) { unset.insert(i); }
-
-   const int max_iter = 3 * NumOfElements;
-   for (int iter=0; iter<max_iter; ++iter)
-   {
-      // Iteratively choose an unset patch (meaning not all edges have
-      // orientation set), choose a knotvector index for which the corresponding
-      // edges on this patch are not set, and sweep over all patches containing
-      // this knotvector. The patch sweep is ordered, by maintaining an ordered
-      // list `nextPatches` set by finding face-neighbor patches of visited
-      // patches, where the common face contains the knotvector. When each patch
-      // is visited, the edge orientations are set consistently. This iteration
-      // terminates when all edges have been set on all patches.
-
-      std::list<int> nextPatches; // Next patches to visit, ordered
-      std::unordered_set<int> nextSet; // nextPatches as a set
-      std::unordered_set<int> visited; // Visit each patch only once
-
-      if (unset.size() == 0)
-      {
-         break;
-      }
-
-      const int p0 = *unset.begin();
-      nextPatches.push_back(p0); // Start from arbitrary unset patch
-      nextSet.insert(p0);
-
-      // Choose an arbitrary unset direction for the first patch.
-      GetElementEdges(p0, pe, oe);
-      int unsetDim = -1;
-      for (int d=0; d<dim; ++d) // Loop over dimensions.
-      {
-         if (!edgeSet[pe[dir_edges[d][0]]])
-         {
-            unsetDim = d;
-         }
-      }
-
-      if (unsetDim == -1)
-      {
-         unset.erase(p0);
-         continue;
-      }
-
-      const int kv_signed = edge_to_ukv[pe[dir_edges[unsetDim][0]]];
-      const int kv = kv_signed < 0 ? flipSign(kv_signed) : kv_signed;
-      MFEM_VERIFY(!edgeSet[pe[dir_edges[unsetDim][0]]], "");
-
-      initKV = false;
-
-      while (nextPatches.size() > 0)
-      {
-         const int p = nextPatches.front();
-         nextPatches.pop_front();
-         nextSet.erase(p);
-         visited.insert(p);
-
-         const bool somethingSet = setPatchDirections(p, kv, edgeSet, visited);
-         if (!somethingSet)
-         {
-            continue;
-         }
-
-         // Find neighbors of patch p sharing a conforming face, via face2elem.
-         std::unordered_set<int> neighbors;
-         faceNeighbors(p, kv, neighbors);
-
-         bool allSet = true;
-         GetElementEdges(p, pe, oe);
-         for (auto edge : pe)
-         {
-            if (!edgeSet[edge])
-            {
-               allSet = false;
-            }
-         }
-         if (allSet)
-         {
-            unset.erase(p);
-         }
-
-         // Add neighbors not done to nextPatches.
-         for (auto n : neighbors)
-         {
-            if (n != p && visited.count(n) == 0 && unset.count(n) > 0)
-            {
-               if (nextSet.count(n) == 0)
-               {
-                  nextPatches.push_back(n);
-                  nextSet.insert(n);
-               }
-            }
-         }
-      }
-   }
-
-   bool allSet = true;
-   for (auto eset : edgeSet)
-   {
-      if (!eset)
-      {
-         allSet = false;
-      }
-   }
-   MFEM_VERIFY(allSet && unset.size() == 0, "Some edge is not set");
-
-   delete face2elem;
 }

 void Mesh::LoadNonconformingPatchTopo(std::istream &input,
@@ -7836,17 +7587,6 @@ bool Mesh::IsMixedMesh() const

 void Mesh::GetElementEdges(int i, Array<int> &edges, Array<int> &cor) const
 {
-   if (Dim == 1)
-   {
-      // In 1D, elements are segments and can be treated as edges.
-      edges.SetSize(1);
-      cor.SetSize(1);
-      edges[0] = i;
-      const int *v = elements[i]->GetVertices();
-      cor[0] = (v[0] < v[1]) ? (1) : (-1);
-      return;
-   }
-
   if (el_to_edge)
   {
      el_to_edge->GetRow(i, edges);
@@ -9823,8 +9563,6 @@ void Mesh::GetVertices(Vector &vert_coord) const

 void Mesh::SetVertices(const Vector &vert_coord)
 {
-   MFEM_VERIFY(vert_coord.Size() == spaceDim * NumOfVertices, "");
-   vertices.SetSize(NumOfVertices);
   for (int i = 0, nv = vertices.Size(); i < nv; i++)
      for (int j = 0; j < spaceDim; j++)
      {
@@ -12402,38 +12140,6 @@ void Mesh::PrintTopoEdges(std::ostream &os, const Array<int> &e_to_k,
 {
   Array<int> vert;

-   // In 1D patch-topology NURBS meshes, knotvector orientation is stored in the
-   // file's `edges` section, but the topological 1D mesh has NumOfEdges == 0
-   // (its "faces" are vertices). When a valid edge->knotvector map is provided,
-   // print a pseudo-edge list derived from the 1D elements so external tools
-   // (e.g. VisIt) can consume the mapping.
-   if (Dim == 1 && NumOfEdges == 0 && e_to_k.Size() == NumOfElements)
-   {
-      const int ne = NumOfElements;
-      os << "\nedges\n" << ne << '\n';
-      for (int i = 0; i < ne; i++)
-      {
-         const int *v = elements[i]->GetVertices();
-         int v0 = v[0], v1 = v[1];
-
-         int ki = e_to_k[i];
-         const bool flip = (ki < 0); // desired output vertex order: descending
-         if (flip) { ki = -1 - ki; } // print the unsigned knotvector index
-
-         // Encode the sign of e_to_k in the vertex ordering, consistent with
-         // Mesh::LoadPatchTopo(): v0 > v1 => negative sign.
-         if ((v0 > v1) != flip) { std::swap(v0, v1); }
-
-         os << ki << ' ' << v0 << ' ' << v1 << '\n';
-      }
-
-      if (!vmap)
-      {
-         os << "\nvertices\n" << NumOfVertices << '\n';
-      }
-      return;
-   }
-
   os << "\nedges\n" << NumOfEdges << '\n';
   for (int i = 0; i < NumOfEdges; i++)
   {
@@ -15746,128 +15452,6 @@ Mesh *Extrude2D(Mesh *mesh, const int nz, const real_t sz)
   return mesh3d;
 }

-Mesh PartitionMPI(int dim, int mpi_cnt, int elem_per_mpi, bool print,
-                  int &par_ref, Array<int> &partitioning)
-{
-   MFEM_VERIFY(dim > 1, "Not implemented for 1D meshes.");
-
-   auto factor = [&](int N)
-   {
-      for (int i = static_cast<int>(sqrt(N)); i > 0; i--)
-      { if (N % i == 0) { return i; } }
-      return 1;
-   };
-
-   par_ref = 0;
-   const int ref_factor = (dim == 2) ? 4 : 8;
-
-   // Elements per task before performing parallel refinements.
-   // This will be used to form the serial mesh.
-   int el0 = elem_per_mpi;
-   while (el0 % ref_factor == 0)
-   {
-      el0 /= ref_factor;
-      par_ref++;
-   }
-
-   // In the serial mesh we have:
-   // The number of MPI blocks is mpi_cnt = mp_x.mpy_y.mpy_z.
-   // The size of each MPI block is el0 = el0_x.el0_y.el0_z.
-   int mpi_x, mpi_y, mpi_z;
-   int el0_x, el0_y, el0_z;
-   if (dim == 2)
-   {
-      mpi_x = factor(mpi_cnt);
-      mpi_y = mpi_cnt / mpi_x;
-
-      // Switch order for better balance.
-      el0_y = factor(el0);
-      el0_x = el0 / el0_y;
-   }
-   else
-   {
-      mpi_x = factor(mpi_cnt);
-      mpi_y = factor(mpi_cnt / mpi_x);
-      mpi_z = mpi_cnt / mpi_x / mpi_y;
-
-      // Switch order for better balance.
-      el0_z = factor(el0);
-      el0_y = factor(el0 / el0_z);
-      el0_x = el0 / el0_y / el0_z;
-   }
-
-   if (print && dim == 2)
-   {
-      int elem_par_x = mpi_x * el0_x * pow(2, par_ref),
-          elem_par_y = mpi_y * el0_y * pow(2, par_ref);
-
-      mfem::out << "--- Mesh generation: \n";
-      mfem::out << "Par mesh:    " << elem_par_x << " x " << elem_par_y
-                << " (" << elem_par_x * elem_par_y << " elements)\n"
-                << "Elem / task: "
-                << el0_x * pow(2, par_ref) << " x "
-                << el0_y * pow(2, par_ref)
-                << " (" << el0_x * pow(2, 2*par_ref) * el0_y << " elements)\n"
-                << "MPI blocks:  " << mpi_x << " x " << mpi_y
-                << " (" << mpi_x * mpi_y << " mpi tasks)\n" << "-\n"
-                << "Serial mesh: "
-                << mpi_x * el0_x << " x " << mpi_y * el0_y
-                << " (" << mpi_x * el0_x * mpi_y * el0_y << " elements)\n"
-                << "Elem / task: " << el0_x << " x " << el0_y << std::endl
-                << "Par refine:  " << par_ref << std::endl;
-      mfem::out << "--- \n";
-   }
-
-   if (print && dim == 3)
-   {
-      int elem_par_x = mpi_x * el0_x * pow(2, par_ref),
-          elem_par_y = mpi_y * el0_y * pow(2, par_ref),
-          elem_par_z = mpi_z * el0_z * pow(2, par_ref);
-
-      mfem::out << "--- Mesh generation: \n";
-      mfem::out << "Par mesh:    "
-                << elem_par_x << " x " << elem_par_y << " x " << elem_par_z
-                << " (" << elem_par_x*elem_par_y*elem_par_z << " elements)\n"
-                << "Elem / task: "
-                << el0_x * pow(2, par_ref) << " x "
-                << el0_y * pow(2, par_ref) << " x "
-                << el0_z * pow(2, par_ref)
-                << " (" << el0_x*pow(2, 3*par_ref)*el0_y*el0_z << " elements)\n"
-                << "MPI blocks:  " << mpi_x << " x " << mpi_y << " x " << mpi_z
-                << " (" << mpi_x * mpi_y * mpi_z << " mpi tasks)\n" << "-\n"
-                << "Serial mesh: "
-                << mpi_x*el0_x << " x " << mpi_y*el0_y << " x " << mpi_z*el0_z
-                << " (" << mpi_x*el0_x*mpi_y*el0_y*mpi_z*el0_z << " elements)\n"
-                << "Elem / task: "
-                << el0_x << " x " << el0_y << " x " << el0_z  << std::endl
-                << "Par refine:  " << par_ref << std::endl;
-      mfem::out << "--- \n";
-   }
-
-   Mesh mesh;
-   int nxyz[3];
-   if (dim == 2)
-   {
-      mesh = Mesh::MakeCartesian2D(mpi_x * el0_x,
-                                   mpi_y * el0_y, Element::QUADRILATERAL, true);
-      nxyz[0] = mpi_x; nxyz[1] = mpi_y;
-   }
-   else
-   {
-      mesh = Mesh::MakeCartesian3D(mpi_x * el0_x,
-                                   mpi_y * el0_y,
-                                   mpi_z * el0_z, Element::HEXAHEDRON, true);
-      nxyz[0] = mpi_x; nxyz[1] = mpi_y; nxyz[2] = mpi_z;
-   }
-
-   const int NE = mesh.GetNE();
-   partitioning.SetSize(NE);
-   std::unique_ptr<int[]> p_raw(mesh.CartesianPartitioning(nxyz));
-   std::copy(p_raw.get(), p_raw.get() + NE, partitioning.GetData());
-
-   return mesh;
-}
-
 bool Mesh::Conforming() const
 {
   if (NURBSext)
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
blaz	390a9d1d36	anderson accelation	2026-01-12 09:18:05 -08:00
blaz	97ef765a8c	initial filter	2026-01-08 23:05:02 -08:00
blaz	64d85b1413	draft	2026-01-06 08:22:41 -08:00
bslazarov	349ae2dd25	forward filter	2025-12-23 15:44:38 -08:00
blaz	727cdd8034	more code	2025-12-23 09:43:21 -08:00
blaz	100ceb28c0	Merge branch 'master' into mtop_filter	2025-12-22 22:11:27 -08:00
blaz	d6daac45b9	modifications	2025-12-22 22:09:32 -08:00
blaz	c3b2f36cbd	mtop-solvers filter	2025-12-11 11:20:43 -08:00
blaz	4b576c12c5	update on the pde filter	2025-12-10 09:15:19 -08:00
blaz	78770a9673	fist version of the filters	2025-12-09 10:03:13 -08:00