Changes/Release Notes
On this page we provide a summary of the main API changes, new features and examples for each release of libCEED.
Current main branch
Interface changes
Add
boolfield type forCeedQFunctionContextand related interfaces to useboolfields.CEED_BASIS_COLLOCATEDremoved; users should only useCEED_BASIS_NONE.Remove unneeded pointer for
CeedElemRestrictionGetELayout.Change QFunction source include file handling in JiT compilers
Add
CEED_RUNNING_JIT_PASScompiler definition for wrapping header files that device JiT compilers cannot readUsers should now prefer
#include <ceed/types.h>rather than#include <ceed.h>in QFunction source files
Require use of
Ceed*Destroy()on Ceed objects returned fromCeed*Get*().Rename
CeedCompositeOperatorCreate()toCeedOperatorCreateComposite()for uniformity.Rename
CeedCompositeOperator*()toCeedOperatorComposite*()for uniformity.
New features
Add
CeedOperatorCreateAtPointswhich evaluates theCeedQFunctionat arbitrary locations in each element, for use in Particle in Cell, Material Point Method, and similar methods.Add
CeedElemRestrictionGetLLayoutto provide L-vector layout for stridedCeedElemRestrictioncreated withCEED_BACKEND_STRIDES.Add
CeedVectorReturnCeedand similar when parentCeedcontext for a libCEED object is only needed once in a calling scope.Enable
#pragma oncefor all JiT source; remove duplicate includes in JiT source string before compilation.Allow user to set additional compiler options for CUDA and HIP JiT. Specifically, directories set with
CeedAddJitSourceRoot(ceed, "foo/bar")will be used to set-Ifoo/barand defines set withCeedAddJitDefine(ceed, "foo=bar")will be used to set-Dfoo=bar.Added non-tensor basis support to code generation backends
/gpu/cuda/genand/gpu/hip/gen.Added support to code generation backends
/gpu/cuda/genand/gpu/hip/genfor operators with both tensor and non-tensor bases.Add
CeedGetGitVersion()to access the Git commit and dirty state of the repository at build time.Add
CeedGetBuildConfiguration()to access compilers, flags, and related information about the build environment.Add support for full
CeedOperatorassembly for operators with multiple active fields with different bases for CPU backends and/gpu/cuda/refand/gpu/hip/genbackends.
Examples
Add deal.II example with CEED BP suite.
Maintainability
OCCA backends were retired.
v0.12 (Oct 31, 2023)
Interface changes
Update
CeedOperatorContext*functions toCeedOperator*Context*functions for consistency. For example,CeedOperatorContextGetFieldLabelwas renamed toCeedOperatorGetContextFieldLabel.Removed
CeedBasisSetNumQuadraturePointsas redundant and bug-prone interface.
New features
Added
CeedOperatorGetFieldByName()to access a specificCeedOperatorFieldby its name.Update
/cpu/self/memcheck/*backends to help verifyCeedVectorarray access assumptions andCeedQFunctionuser output assumptions.Update
CeedOperatorLinearAssembleDiagonal()to provide default implementation that supportsCeedOperatorwith multiple active bases.Added Sycl backends
/gpu/sycl/ref,/gpu/sycl/shared, and/gpu/sycl/gen.Added
CeedBasisApplyAtPoints()for evaluation of values and derivatives at arbitrary points inside elements.Added support for non-tensor \(H(\text{curl})\) finite element spaces with
CeedBasisCreateHcurl().Added
CeedElemRestrictionCreateCurlOriented(), similar toCeedElemRestrictionCreateOriented(), for element restrictions requiring more general element transformations such as those for high-order \(H(\text{curl})\) spaces on tetrahedra (see https://dl.acm.org/doi/pdf/10.1145/3524456).Added
CeedOperatorLinearAssemblePointBlockDiagonalSymbolic()to create COO mapping for mapping out ofCeedOperatorLinearAssemblePointBlockDiagonal().Added support for application codes which manage multiple Ceed objects, parallelized across OpenMP threads.
Examples
Add
DMSwarmexample demonstrating interpolation from background mesh to swarm points and projection from swarm points to background mesh.
Bakeoff problems and generalizations
Requires PETSc version 3.19 or later.
v0.11 (Dec 24, 2022)
Interface changes
Added
CeedOperatorSetName()for more readableCeedOperatorView()output.Added
CeedBasisCreateProjection()to facilitate interpolation between nodes for separateCeedBases.Rename and move
CeedCompositeOperatorGetNumSub()andCeedCompositeOperatorGetSubList()to public interface.Renamed
CEED_BASIS_COLLOCATEDtoCEED_BASIS_NONEfor clarity. Some users previously misinterpreted aCeedOperatorfield usingCEED_BASIS_COLLOCATEDas meaning that the entireCeedOperatorused a quadrature space that is collocated with the nodal space of the active bases.
New features
Update
/cpu/self/memcheck/*backends to help verifyCeedQFunctionContextdata sizes provided by user.Improved support for \(H(\text{div})\) bases.
Added
CeedInt_FMTto support potential future use of larger integer sizes.Added
CEED_QFUNCTION_ATTRfor setting compiler attributes/pragmas toCEED_QFUNCTION_HELPERandCEED_QFUNCTION.OCCA backend updated to latest OCCA release; DPC++ and OMP OCCA modes enabled. Due to a limitation of the OCCA parser, typedefs are required to use pointers to arrays in QFunctions with the OCCA backend. This issue will be fixed in a future OCCA release.
Bugfix
Fix bug in setting device id for GPU backends.
Fix storing of indices for
CeedElemRestrictionon the host with GPU backends.Fix
CeedElemRestrictionsizing forCeedOperatorAssemblePointBlockDiagonal().Fix bugs in CPU implementation of
CeedOperatorLinearAssemble()when there are different number of active input modes and active output modes.
Examples
Compressible Navier-Stokes mini-app
Various performance enhancements, analytic matrix-free and assembled Jacobian, and PETSc solver configurations for GPUs.
Refactored to improve code reuse and modularity.
Support for primitive variables for more accurate boundary layers and all-speed flow.
Added \(YZ\beta\) shock capturing scheme and Shock Tube example.
Added Channel example, with comparison to analytic solutions.
Added Flat Plate with boundary layer mesh and compressible Blasius inflow condition based on Chebyshev collocation solution of the Blasius equations.
Added strong and weak synthetic turbulence generation (STG) inflow boundary conditions.
Added “freestream” boundary conditions based on HLLC Riemann solver.
Automated stabilization coefficients for different basis degree.
Bakeoff problems and generalizations
Support for convergence studies.
Maintainability
Refactored
/gpu/cuda/sharedand/gpu/cuda/genas well as/gpu/hip/sharedand/gpu/hip/genbackend to improve maintainablity and reduce duplicated code.Enabled support for
p > 8for/gpu/*/sharedbackends.Switch to
clang-formatoverastylefor automatic formatting; Makefile command changed tomake formatfrommake style.Improved test harness.
v0.10.1 (Apr 11, 2022)
Interface changes
Added
CeedQFunctionSetUserFlopsEstimate()andCeedOperatorGetFlopsEstimate()to facilitate estimating FLOPs in operator application.
New features
Switched MAGMA backends to use runtime compilation for tensor basis kernels (and element restriction kernels, in non-deterministic
/gpu/*/magmabackends). This reduces time to compile the library and increases the range of parameters for which the MAGMA tensor basis kernels will work.
Bugfix
Install JiT source files in install directory to fix GPU functionality for installed libCEED.
v0.10 (Mar 21, 2022)
Interface changes
Update
CeedQFunctionGetFields()andCeedOperatorGetFields()to include number of fields.Promote to the public API: QFunction and Operator field objects,
CeedQFunctionFieldandCeedOperatorField, and associated getters,CeedQFunctionGetFields();CeedQFunctionFieldGetName();CeedQFunctionFieldGetSize();CeedQFunctionFieldGetEvalMode();CeedOperatorGetFields();CeedOperatorFieldGetElemRestriction();CeedOperatorFieldGetBasis(); andCeedOperatorFieldGetVector().Clarify and document conditions where
CeedQFunctionandCeedOperatorbecome immutable and no further fields or suboperators can be added.Add
CeedOperatorLinearAssembleQFunctionBuildOrUpdate()to reduce object creation overhead in assembly of CeedOperator preconditioning ingredients.Promote
CeedOperatorCheckReady()to the public API to facilitate interactive interfaces.Warning added when compiling OCCA backend to alert users that this backend is experimental.
ceed-backend.h,ceed-hash.h, andceed-khash.hremoved. Users should useceed/backend.h,ceed/hash.h, andceed/khash.h.Added
CeedQFunctionGetKernelName(); refactoredCeedQFunctionGetSourcePath()to exclude function kernel name.Clarify documentation for
CeedVectorTakeArray(); this function will error ifCeedVectorSetArray()withcopy_mode == CEED_USE_POINTERwas not previously called for the correspondingCeedMemType.Added
CeedVectorGetArrayWrite()that allows access to uninitialized arrays; require initialized data forCeedVectorGetArray().Added
CeedQFunctionContextRegisterDouble()andCeedQFunctionContextRegisterInt32()withCeedQFunctionContextSetDouble()andCeedQFunctionContextSetInt32()to facilitate easy updating ofCeedQFunctionContextdata by user defined field names.Added
CeedQFunctionContextGetFieldDescriptions()to retrieve user defined descriptions of fields that are registered withCeedQFunctionContextRegister*.Renamed
CeedElemTopologyentries for clearer namespacing between libCEED enums.Added type
CeedSizeequivalent toptrdiff_tfor array sizes inCeedVectorCreate(),CeedVectorGetLength(),CeedElemRestrictionCreate*,CeedElemRestrictionGetLVectorSize(), andCeedOperatorLinearAssembleSymbolic(). This is a breaking change.Added
CeedOperatorSetQFunctionUpdated()to facilitate QFunction data re-use between operators sharing the same quadrature space, such as in a multigrid hierarchy.Added
CeedOperatorGetActiveVectorLengths()to get shape of CeedOperator.
New features
CeedScalarcan now be set asfloatordoubleat compile time.Added JiT utilities in
ceed/jit-tools.hto reduce duplicated code in GPU backends.Added support for JiT of QFunctions with
#include "relative/path/local-file.h"statements for additional local files. Note that files included with""are searched relative to the current file first, then by compiler paths (as with<>includes). To use this feature, one should adhere to relative paths only, not compiler flags like-I, which the JiT will not be aware of.Remove need to guard library headers in QFunction source for code generation backends.
CeedDebugEnv()macro created to provide debugging outputs when Ceed context is not present.Added
CeedStringAllocCopy()to reduce repeated code for copying strings internally.Added
CeedPathConcatenate()to facilitate loading kernel source files with a path relative to the current file.Added support for non-tensor \(H(\text{div})\) elements, to include CPU backend implementations and
CeedBasisCreateHdiv()convenience constructor.Added
CeedQFunctionSetContextWritable()and read-only access toCeedQFunctionContextdata as an optional feature to improve GPU performance. By default, calling theCeedQFunctionUserduringCeedQFunctionApply()is assumed to write into theCeedQFunctionContextdata, consistent with the previous behavior. Note that if a user asserts that theirCeedQFunctionUserdoes not write into theCeedQFunctionContextdata, they are responsible for the validity of this assertion.Added support for element matrix assembly in GPU backends.
Maintainability
Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage.
Include-what-you-usemakefile target added asmake iwyu.Create backend constant
CEED_FIELD_MAXto reduce magic numbers in codebase.Put GPU JiTed kernel source code into separate files.
Dropped legacy version support in PETSc based examples to better utilize PETSc DMPlex and Mat updates to support libCEED; current minimum PETSc version for the examples is v3.17.
v0.9 (Jul 6, 2021)
Interface changes
Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact.
New features
Add
CeedVectorAXPY()andCeedVectorPointwiseMult()as a convenience for stand-alone testing and internal use.Add
CEED_QFUNCTION_HELPERmacro to properly annotate QFunction helper functions for code generation backends.Add
CeedPragmaOptimizeOffmacro for code that is sensitive to floating point errors from fast math optimizations.Rust support: split
libceed-syscrate out oflibceedand publish both on crates.io.
Performance improvements
Examples
Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations.
Fluid mechanics example adds GPU support and improves modularity.
Deprecated backends
The
/cpu/self/tmpland/cpu/self/tmpl/subbackends have been removed. These backends were intially added to test the backend inheritance mechanism, but this mechanism is now widely used and tested in multiple backends.
v0.8 (Mar 31, 2021)
Interface changes
Error handling improved to include enumerated error codes for C interface return values.
Installed headers that will follow semantic versioning were moved to
include/ceeddirectory. These headers have been renamed fromceed-*.htoceed/*.h. Placeholder headers with the old naming schema are currently provided, but these headers will be removed in the libCEED v0.9 release.
New features
Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features.
Static libraries can be built with
make STATIC=1and the pkg-config file is installed accordingly.Add
CeedOperatorLinearAssembleSymbolic()andCeedOperatorLinearAssemble()to support full assembly of libCEED operators.
Performance improvements
New HIP MAGMA backends for hipMAGMA library users:
/gpu/hip/magmaand/gpu/hip/magma/det.New HIP backends for improved tensor basis performance:
/gpu/hip/sharedand/gpu/hip/gen.
Examples
Solid mechanics mini-app example updated with traction boundary conditions and improved Dirichlet boundary conditions.
Solid mechanics mini-app example updated with Neo-Hookean hyperelasticity in current configuration as well as improved Neo-Hookean hyperelasticity exploring storage vs computation tradeoffs.
Compressible Navier-Stokes mini-app example updated with isentropic traveling vortex test case, an analytical solution to the Euler equations that is useful for testing boundary conditions, discretization stability, and order of accuracy.
Compressible Navier-Stokes mini-app example updated with support for performing convergence study and plotting order of convergence by polynomial degree.
v0.7 (Sep 29, 2020)
Interface changes
Replace limited
CeedInterlaceModewith more flexible component stridecompstrideinCeedElemRestrictionconstructors. As a result, theindicesparameter has been replaced withoffsetsand thennodesparameter has been replaced withlsize. These changes improve support for mixed finite element methods.Replace various uses of
Ceed*Get*StatuswithCeed*Is*in the backend API to match common nomenclature.Replace
CeedOperatorAssembleLinearDiagonalwithCeedOperatorLinearAssembleDiagonal()for clarity.Linear Operators can be assembled as point-block diagonal matrices with
CeedOperatorLinearAssemblePointBlockDiagonal(), provided in row-major form in ancompbyncompblock per node.Diagonal assemble interface changed to accept a CeedVector instead of a pointer to a CeedVector to reduce memory movement when interfacing with calling code.
Added
CeedOperatorLinearAssembleAddDiagonal()andCeedOperatorLinearAssembleAddPointBlockDiagonal()for improved future integration with codes such as MFEM that compose the action of CeedOperators external to libCEED.Added
CeedVectorTakeAray()to sync and remove libCEED read/write access to an allocated array and pass ownership of the array to the caller. This function is recommended overCeedVectorSyncArray()when theCeedVectorhas an array owned by the caller that was set byCeedVectorSetArray().Added
CeedQFunctionContextobject to manage user QFunction context data and reduce copies between device and host memory.Added
CeedOperatorMultigridLevelCreate(),CeedOperatorMultigridLevelCreateTensorH1(), andCeedOperatorMultigridLevelCreateH1()to facilitate creation of multigrid prolongation, restriction, and coarse grid operators using a common quadrature space.
New features
New HIP backend:
/gpu/hip/ref.CeedQFunction support for user
CUfunctions in some backends
Performance improvements
OCCA backend rebuilt to facilitate future performance enhancements.
PETSc BPs suite improved to reduce noise due to multiple calls to
mpiexec.
Examples
Solid mechanics mini-app example updated with strain energy computation and more flexible boundary conditions.
Deprecated backends
The
/gpu/cuda/regbackend has been removed, with its core features moved into/gpu/cuda/refand/gpu/cuda/shared.
v0.6 (Mar 29, 2020)
libCEED v0.6 contains numerous new features and examples, as well as expanded documentation in this new website.
New features
New Python interface using CFFI provides a nearly 1-1 correspondence with the C interface, plus some convenience features. For instance, data stored in the
CeedVectorstructure are available without copy asnumpy.ndarray. Short tutorials are provided in Binder.Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point,
CeedOperatorAssembleLinearQFunction()) or to evaluate the diagonal (CeedOperatorAssembleLinearDiagonal()). These operations are useful for preconditioning ingredients and are used in the libCEED’s multigrid examples.The inverse of separable operators can be obtained using
CeedOperatorCreateFDMElementInverse()and applied withCeedOperatorApply(). This is a useful preconditioning ingredient, especially for Laplacians and related operators.New functions:
CeedVectorNorm(),CeedOperatorApplyAdd(),CeedQFunctionView(),CeedOperatorView().Make public accessors for various attributes to facilitate writing composable code.
New backend:
/cpu/self/memcheck/serial.QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA backends. (Single source is coming soon for OCCA backends.)
Fix some missing edge cases in CUDA backend.
Performance Improvements
MAGMA backend performance optimization and non-tensor bases.
No-copy optimization in
CeedOperatorApply().
Interface changes
Replace
CeedElemRestrictionCreateIdentityandCeedElemRestrictionCreateBlockedwith more flexibleCeedElemRestrictionCreateStrided()andCeedElemRestrictionCreateBlockedStrided().Add arguments to
CeedQFunctionCreateIdentity().Replace ambiguous uses of
CeedTransposeModefor L-vector identification withCeedInterlaceMode. This is now an attribute of theCeedElemRestriction(seeCeedElemRestrictionCreate()) and no longer passed aslmodearguments toCeedOperatorSetField()andCeedElemRestrictionApply().
Examples
libCEED-0.6 contains greatly expanded examples with new documentation. Notable additions include:
Standalone Ex2-Surface (
examples/ceed/ex2-surface): compute the area of a domain in 1, 2, and 3 dimensions by applying a Laplacian.PETSc Area (
examples/petsc/area.c): computes surface area of domains (like the cube and sphere) by direct integration on a surface mesh; demonstrates geometric dimension different from topological dimension.PETSc Bakeoff problems and generalizations:
examples/petsc/bpsraw.c(formerlybps.c): transparent CUDA support.examples/petsc/bps.c(formerlybpsdmplex.c): performance improvements and transparent CUDA support.Bakeoff problems on the cubed-sphere (
examples/petsc/bpssphere.c): generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric dimension different from topological dimension.
Multigrid (
examples/petsc/multigrid.c): new p-multigrid solver with algebraic multigrid coarse solve.Compressible Navier-Stokes mini-app (
examples/fluids/navierstokes.c; formerlyexamples/navier-stokes): unstructured grid support (using PETSc’sDMPlex), implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and quasi-2D computational domain support.Solid mechanics mini-app (
examples/solids/elasticity.c): new solver for linear elasticity, small-strain hyperelasticity, and globalized finite-strain hyperelasticity using p-multigrid with algebraic multigrid coarse solve.
v0.5 (Sep 18, 2019)
For this release, several improvements were made. Two new CUDA backends were added to
the family of backends, of which, the new cuda-gen backend achieves state-of-the-art
performance using single-source CeedQFunction. From this release, users
can define Q-Functions in a single source code independently of the targeted backend
with the aid of a new macro CEED QFUNCTION to support JIT (Just-In-Time) and CPU
compilation of the user provided CeedQFunction code. To allow a unified
declaration, the CeedQFunction API has undergone a slight change:
the QFunctionField parameter ncomp has been changed to size. This change
requires setting the previous value of ncomp to ncomp*dim when adding a
QFunctionField with eval mode CEED EVAL GRAD.
Additionally, new CPU backends
were included in this release, such as the /cpu/self/opt/* backends (which are
written in pure C and use partial E-vectors to improve performance) and the
/cpu/self/ref/memcheck backend (which relies upon the
Valgrind Memcheck tool to help verify that user
CeedQFunction have no undefined values).
This release also included various performance improvements, bug fixes, new examples,
and improved tests. Among these improvements, vectorized instructions for
CeedQFunction code compiled for CPU were enhanced by using CeedPragmaSIMD
instead of CeedPragmaOMP, implementation of a CeedQFunction gallery and
identity Q-Functions were introduced, and the PETSc benchmark problems were expanded
to include unstructured meshes handling were. For this expansion, the prior version of
the PETSc BPs, which only included data associated with structured geometries, were
renamed bpsraw, and the new version of the BPs, which can handle data associated
with any unstructured geometry, were called bps. Additionally, other benchmark
problems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively),
and BP5 and BP6 (the collocated versions—for which the quadrature points are the same
as the Gauss Lobatto nodes—of BP3 and BP4 respectively) were added to the PETSc
examples. Furthermoew, another standalone libCEED example, called ex2, which
computes the surface area of a given mesh was added to this release.
Backends available in this release:
CEED resource ( |
Backend |
|---|---|
|
Serial reference implementation |
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Blocked reference implementation |
|
Memcheck backend, undefined value checks |
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Serial optimized C implementation |
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Blocked optimized C implementation |
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Serial AVX implementation |
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Blocked AVX implementation |
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Serial LIBXSMM implementation |
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Blocked LIBXSMM implementation |
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Serial OCCA kernels |
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CUDA OCCA kernels |
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OpenMP OCCA kernels |
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OpenCL OCCA kernels |
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Reference pure CUDA kernels |
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Pure CUDA kernels using one thread per element |
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Optimized pure CUDA kernels using shared memory |
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Optimized pure CUDA kernels using code generation |
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CUDA MAGMA kernels |
Examples available in this release:
User code |
Example |
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v0.4 (Apr 1, 2019)
libCEED v0.4 was made again publicly available in the second full CEED software
distribution, release CEED 2.0. This release contained notable features, such as
four new CPU backends, two new GPU backends, CPU backend optimizations, initial
support for operator composition, performance benchmarking, and a Navier-Stokes demo.
The new CPU backends in this release came in two families. The /cpu/self/*/serial
backends process one element at a time and are intended for meshes with a smaller number
of high order elements. The /cpu/self/*/blocked backends process blocked batches of
eight interlaced elements and are intended for meshes with higher numbers of elements.
The /cpu/self/avx/* backends rely upon AVX instructions to provide vectorized CPU
performance. The /cpu/self/xsmm/* backends rely upon the
LIBXSMM package to provide vectorized CPU
performance. The /gpu/cuda/* backends provide GPU performance strictly using CUDA.
The /gpu/cuda/ref backend is a reference CUDA backend, providing reasonable
performance for most problem configurations. The /gpu/cuda/reg backend uses a simple
parallelization approach, where each thread treats a finite element. Using just in time
compilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this
backend unroll loops and map memory address to registers. The /gpu/cuda/reg backend
achieve good peak performance for 1D, 2D, and low order 3D problems, but performance
deteriorates very quickly when threads run out of registers.
A new explicit time-stepping Navier-Stokes solver was added to the family of libCEED
examples in the examples/petsc directory (see Compressible Navier-Stokes mini-app).
This example solves the time-dependent Navier-Stokes equations of compressible gas
dynamics in a static Eulerian three-dimensional frame, using structured high-order
finite/spectral element spatial discretizations and explicit high-order time-stepping
(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc,
so that the pointwise physics (defined at quadrature points) is separated from the
parallelization and meshing concerns.
Backends available in this release:
CEED resource ( |
Backend |
|---|---|
|
Serial reference implementation |
|
Blocked reference implementation |
|
Backend template, defaults to |
|
Serial AVX implementation |
|
Blocked AVX implementation |
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Serial LIBXSMM implementation |
|
Blocked LIBXSMM implementation |
|
Serial OCCA kernels |
|
CUDA OCCA kernels |
|
OpenMP OCCA kernels |
|
OpenCL OCCA kernels |
|
Reference pure CUDA kernels |
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Pure CUDA kernels using one thread per element |
|
CUDA MAGMA kernels |
Examples available in this release:
User code |
Example |
|---|---|
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v0.3 (Sep 30, 2018)
Notable features in this release include active/passive field interface, support for
non-tensor bases, backend optimization, and improved Fortran interface. This release
also focused on providing improved continuous integration, and many new tests with code
coverage reports of about 90%. This release also provided a significant change to the
public interface: a CeedQFunction can take any number of named input and output
arguments while CeedOperator connects them to the actual data, which may be
supplied explicitly to CeedOperatorApply() (active) or separately via
CeedOperatorSetField() (passive). This interface change enables reusable libraries
of CeedQFunctions and composition of block solvers constructed using
CeedOperator. A concept of blocked restriction was added to this release and
used in an optimized CPU backend. Although this is typically not visible to the user,
it enables effective use of arbitrary-length SIMD while maintaining cache locality.
This CPU backend also implements an algebraic factorization of tensor product gradients
to perform fewer operations than standard application of interpolation and
differentiation from nodes to quadrature points. This algebraic formulation
automatically supports non-polynomial and non-interpolatory bases, thus is more general
than the more common derivation in terms of Lagrange polynomials on the quadrature points.
Backends available in this release:
CEED resource ( |
Backend |
|---|---|
|
Blocked reference implementation |
|
Serial reference implementation |
|
Backend template, defaults to |
|
Serial OCCA kernels |
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CUDA OCCA kernels |
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OpenMP OCCA kernels |
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OpenCL OCCA kernels |
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CUDA MAGMA kernels |
Examples available in this release:
User code |
Example |
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v0.21 (Sep 30, 2018)
A MAGMA backend (which relies upon the MAGMA package) was integrated in libCEED for this release. This initial integration set up the framework of using MAGMA and provided the libCEED functionality through MAGMA kernels as one of libCEED’s computational backends. As any other backend, the MAGMA backend provides extended basic data structures for CeedVector, CeedElemRestriction, and CeedOperator, and implements the fundamental CEED building blocks to work with the new data structures. In general, the MAGMA-specific data structures keep the libCEED pointers to CPU data but also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled internally, and thus seamlessly to the user, through the functions/methods that are provided to support them.
Backends available in this release:
CEED resource ( |
Backend |
|---|---|
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Serial reference implementation |
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Serial OCCA kernels |
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CUDA OCCA kernels |
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OpenMP OCCA kernels |
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OpenCL OCCA kernels |
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CUDA MAGMA kernels |
Examples available in this release:
User code |
Example |
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v0.2 (Mar 30, 2018)
libCEED was made publicly available the first full CEED software distribution, release
CEED 1.0. The distribution was made available using the Spack package manager to provide
a common, easy-to-use build environment, where the user can build the CEED distribution
with all dependencies. This release included a new Fortran interface for the library.
This release also contained major improvements in the OCCA backend (including a new
/ocl/occa backend) and new examples. The standalone libCEED example was modified to
compute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an
examples/ceed subfolder. A new mfem example to perform BP3 (with the application
of the Laplace operator) was also added to this release.
Backends available in this release:
CEED resource ( |
Backend |
|---|---|
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Serial reference implementation |
|
Serial OCCA kernels |
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CUDA OCCA kernels |
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OpenMP OCCA kernels |
|
OpenCL OCCA kernels |
Examples available in this release:
User code |
Example |
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v0.1 (Jan 3, 2018)
Initial low-level API of the CEED project. The low-level API provides a set of Finite
Elements kernels and components for writing new low-level kernels. Examples include:
vector and sparse linear algebra, element matrix assembly over a batch of elements,
partial assembly and action for efficient high-order operators like mass, diffusion,
advection, etc. The main goal of the low-level API is to establish the basis for the
high-level API. Also, identifying such low-level kernels and providing a reference
implementation for them serves as the basis for specialized backend implementations.
This release contained several backends: /cpu/self, and backends which rely upon the
OCCA package, such as /cpu/occa,
/gpu/occa, and /omp/occa.
It also included several examples, in the examples folder:
A standalone code that shows the usage of libCEED (with no external
dependencies) to apply the Laplace operator, ex1; an mfem example to perform BP1
(with the application of the mass operator); and a petsc example to perform BP1
(with the application of the mass operator).
Backends available in this release:
CEED resource ( |
Backend |
|---|---|
|
Serial reference implementation |
|
Serial OCCA kernels |
|
CUDA OCCA kernels |
|
OpenMP OCCA kernels |
Examples available in this release:
User code |
Example |
|---|---|
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ex1 (scalar Laplace operator) |
|
BP1 (scalar mass operator) |
|
BP1 (scalar mass operator) |