xref: /libCEED/doc/sphinx/source/releasenotes.md (revision 3f21f6b10abeb5d85d3454ea5cd38498737dc88a)
1bcb2dfaeSJed Brown# Changes/Release Notes
2bcb2dfaeSJed Brown
3bcb2dfaeSJed BrownOn this page we provide a summary of the main API changes, new features and examples
4bcb2dfaeSJed Brownfor each release of libCEED.
5bcb2dfaeSJed Brown
6bcb2dfaeSJed Brown(main)=
7bcb2dfaeSJed Brown
8bcb2dfaeSJed Brown## Current `main` branch
9bcb2dfaeSJed Brown
107e7773b5SJeremy L Thompson### Interface changes
117e7773b5SJeremy L Thompson
127e7773b5SJeremy L Thompson- Update {c:func}`CeedQFunctionGetFields` and {c:func}`CeedOperatorGetFields` to include number of fields.
13ce4822f6SJeremy L Thompson- Promote to the public API: QFunction and Operator field objects, `CeedQFunctionField` and `CeedOperatorField`, and associated getters, {c:func}`CeedQFunctionGetFields`; {c:func}`CeedQFunctionFieldGetName`; {c:func}`CeedQFunctionFieldGetSize`; {c:func}`CeedQFunctionFieldGetEvalMode`; {c:func}`CeedOperatorGetFields`; {c:func}`CeedOperatorFieldGetElemRestriction`; {c:func}`CeedOperatorFieldGetBasis`; and {c:func}`CeedOperatorFieldGetVector`.
14f04ea552SJeremy L Thompson- Clarify and document conditions where `CeedQFunction` and `CeedOperator` become immutable and no further fields or suboperators can be added.
1570a7ffb3SJeremy L Thompson- Add {c:func}`CeedOperatorLinearAssembleQFunctionBuildOrUpdate` to reduce object creation overhead in assembly of CeedOperator preconditioning ingredients.
164db537f9SJeremy L Thompson- Promote {c:func}`CeedOperatorCheckReady`to the public API to facilitate interactive interfaces.
17dcc1e3ecSJeremy L Thompson- Warning added when compiling OCCA backend to alert users that this backend is experimental.
189a1d3511SJeremy L Thompson- `ceed-backend.h`, `ceed-hash.h`, and `ceed-khash.h` removed. Users should use `ceed/backend.h`, `ceed/hash.h`, and `ceed/khash.h`.
1943e1b16fSJeremy L Thompson- Added {c:func}`CeedQFunctionGetKernelName`; refactored {c:func}`CeedQFunctionGetSourcePath` to exclude function kernel name.
207e7773b5SJeremy L Thompson
21f479eb23SJeremy L Thompson### New features
22f479eb23SJeremy L Thompson
23f479eb23SJeremy L Thompson- `CeedScalar` can now be set as `float` or `double` at compile time.
2430601ac0SJeremy L Thompson- Added JiT utilities in `ceed/jit-tools.h` to reduce duplicated code in GPU backends.
25fb3c7d02SJeremy L Thompson- 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.
2623dfbf5bSJeremy L Thompson- Remove need to guard library headers in QFunction source for code generation backends.
27*3f21f6b1SJeremy L Thompson- `CeedDebugEnv()` macro created to provide debugging outputs when Ceed context is not present.
28f479eb23SJeremy L Thompson
29bcb2dfaeSJed Brown### Maintainability
30bcb2dfaeSJed Brown
31bcb2dfaeSJed Brown- Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage.
32db52d626SJeremy L Thompson- `Include-what-you-use` makefile target added as `make iwyu`.
33bcb2dfaeSJed Brown
34bcb2dfaeSJed Brown(v0-9)=
35bcb2dfaeSJed Brown
36bcb2dfaeSJed Brown## v0.9 (Jul 6, 2021)
37bcb2dfaeSJed Brown
38bcb2dfaeSJed Brown### Interface changes
39bcb2dfaeSJed Brown
40bcb2dfaeSJed Brown- Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact.
41bcb2dfaeSJed Brown
42bcb2dfaeSJed Brown### New features
43bcb2dfaeSJed Brown
44bcb2dfaeSJed Brown- Add {c:func}`CeedVectorAXPY` and {c:func}`CeedVectorPointwiseMult` as a convenience for stand-alone testing and internal use.
45bcb2dfaeSJed Brown- Add `CEED_QFUNCTION_HELPER` macro to properly annotate QFunction helper functions for code generation backends.
46bcb2dfaeSJed Brown- Add `CeedPragmaOptimizeOff` macro for code that is sensitive to floating point errors from fast math optimizations.
47bcb2dfaeSJed Brown- Rust support: split `libceed-sys` crate out of `libceed` and [publish both on crates.io](https://crates.io/crates/libceed).
48bcb2dfaeSJed Brown
49bcb2dfaeSJed Brown### Performance improvements
50bcb2dfaeSJed Brown
51bcb2dfaeSJed Brown### Examples
52bcb2dfaeSJed Brown
53bcb2dfaeSJed Brown- Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations.
54bcb2dfaeSJed Brown- Fluid mechanics example adds GPU support and improves modularity.
55bcb2dfaeSJed Brown
56bcb2dfaeSJed Brown### Deprecated backends
57bcb2dfaeSJed Brown
58bcb2dfaeSJed Brown- The `/cpu/self/tmpl` and `/cpu/self/tmpl/sub` backends 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.
59bcb2dfaeSJed Brown
60bcb2dfaeSJed Brown(v0-8)=
61bcb2dfaeSJed Brown
62bcb2dfaeSJed Brown## v0.8 (Mar 31, 2021)
63bcb2dfaeSJed Brown
64bcb2dfaeSJed Brown### Interface changes
65bcb2dfaeSJed Brown
66bcb2dfaeSJed Brown- Error handling improved to include enumerated error codes for C interface return values.
67bcb2dfaeSJed Brown- Installed headers that will follow semantic versioning were moved to {code}`include/ceed` directory. These headers have been renamed from {code}`ceed-*.h` to {code}`ceed/*.h`. Placeholder headers with the old naming schema are currently provided, but these headers will be removed in the libCEED v0.9 release.
68bcb2dfaeSJed Brown
69bcb2dfaeSJed Brown### New features
70bcb2dfaeSJed Brown
71bcb2dfaeSJed Brown- Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features.
72bcb2dfaeSJed Brown- Static libraries can be built with `make STATIC=1` and the pkg-config file is installed accordingly.
73bcb2dfaeSJed Brown- Add {c:func}`CeedOperatorLinearAssembleSymbolic` and {c:func}`CeedOperatorLinearAssemble` to support full assembly of libCEED operators.
74bcb2dfaeSJed Brown
75bcb2dfaeSJed Brown### Performance improvements
76bcb2dfaeSJed Brown
77bcb2dfaeSJed Brown- New HIP MAGMA backends for hipMAGMA library users: `/gpu/hip/magma` and `/gpu/hip/magma/det`.
78bcb2dfaeSJed Brown- New HIP backends for improved tensor basis performance: `/gpu/hip/shared` and `/gpu/hip/gen`.
79bcb2dfaeSJed Brown
80bcb2dfaeSJed Brown### Examples
81bcb2dfaeSJed Brown
82bcb2dfaeSJed Brown- {ref}`example-petsc-elasticity` example updated with traction boundary conditions and improved Dirichlet boundary conditions.
83bcb2dfaeSJed Brown- {ref}`example-petsc-elasticity` example updated with Neo-Hookean hyperelasticity in current configuration as well as improved Neo-Hookean hyperelasticity exploring storage vs computation tradeoffs.
84bcb2dfaeSJed Brown- {ref}`example-petsc-navier-stokes` 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.
85bcb2dfaeSJed Brown- {ref}`example-petsc-navier-stokes` example updated with support for performing convergence study and plotting order of convergence by polynomial degree.
86bcb2dfaeSJed Brown
87bcb2dfaeSJed Brown(v0-7)=
88bcb2dfaeSJed Brown
89bcb2dfaeSJed Brown## v0.7 (Sep 29, 2020)
90bcb2dfaeSJed Brown
91bcb2dfaeSJed Brown### Interface changes
92bcb2dfaeSJed Brown
93bcb2dfaeSJed Brown- Replace limited {code}`CeedInterlaceMode` with more flexible component stride {code}`compstride` in {code}`CeedElemRestriction` constructors.
94bcb2dfaeSJed Brown  As a result, the {code}`indices` parameter has been replaced with {code}`offsets` and the {code}`nnodes` parameter has been replaced with {code}`lsize`.
95bcb2dfaeSJed Brown  These changes improve support for mixed finite element methods.
96bcb2dfaeSJed Brown- Replace various uses of {code}`Ceed*Get*Status` with {code}`Ceed*Is*` in the backend API to match common nomenclature.
97bcb2dfaeSJed Brown- Replace {code}`CeedOperatorAssembleLinearDiagonal` with {c:func}`CeedOperatorLinearAssembleDiagonal` for clarity.
98bcb2dfaeSJed Brown- Linear Operators can be assembled as point-block diagonal matrices with {c:func}`CeedOperatorLinearAssemblePointBlockDiagonal`, provided in row-major form in a {code}`ncomp` by {code}`ncomp` block per node.
99bcb2dfaeSJed Brown- Diagonal assemble interface changed to accept a {ref}`CeedVector` instead of a pointer to a {ref}`CeedVector` to reduce memory movement when interfacing with calling code.
100bcb2dfaeSJed Brown- Added {c:func}`CeedOperatorLinearAssembleAddDiagonal` and {c:func}`CeedOperatorLinearAssembleAddPointBlockDiagonal` for improved future integration with codes such as MFEM that compose the action of {ref}`CeedOperator`s external to libCEED.
101bcb2dfaeSJed Brown- Added {c:func}`CeedVectorTakeAray` to sync and remove libCEED read/write access to an allocated array and pass ownership of the array to the caller.
102bcb2dfaeSJed Brown  This function is recommended over {c:func}`CeedVectorSyncArray` when the {code}`CeedVector` has an array owned by the caller that was set by {c:func}`CeedVectorSetArray`.
103bcb2dfaeSJed Brown- Added {code}`CeedQFunctionContext` object to manage user QFunction context data and reduce copies between device and host memory.
104bcb2dfaeSJed Brown- Added {c:func}`CeedOperatorMultigridLevelCreate`, {c:func}`CeedOperatorMultigridLevelCreateTensorH1`, and {c:func}`CeedOperatorMultigridLevelCreateH1` to facilitate creation of multigrid prolongation, restriction, and coarse grid operators using a common quadrature space.
105bcb2dfaeSJed Brown
106bcb2dfaeSJed Brown### New features
107bcb2dfaeSJed Brown
108bcb2dfaeSJed Brown- New HIP backend: `/gpu/hip/ref`.
109bcb2dfaeSJed Brown- CeedQFunction support for user `CUfunction`s in some backends
110bcb2dfaeSJed Brown
111bcb2dfaeSJed Brown### Performance improvements
112bcb2dfaeSJed Brown
113bcb2dfaeSJed Brown- OCCA backend rebuilt to facilitate future performance enhancements.
114bcb2dfaeSJed Brown- Petsc BPs suite improved to reduce noise due to multiple calls to {code}`mpiexec`.
115bcb2dfaeSJed Brown
116bcb2dfaeSJed Brown### Examples
117bcb2dfaeSJed Brown
118bcb2dfaeSJed Brown- {ref}`example-petsc-elasticity` example updated with strain energy computation and more flexible boundary conditions.
119bcb2dfaeSJed Brown
120bcb2dfaeSJed Brown### Deprecated backends
121bcb2dfaeSJed Brown
122bcb2dfaeSJed Brown- The `/gpu/cuda/reg` backend has been removed, with its core features moved into `/gpu/cuda/ref` and `/gpu/cuda/shared`.
123bcb2dfaeSJed Brown
124bcb2dfaeSJed Brown(v0-6)=
125bcb2dfaeSJed Brown
126bcb2dfaeSJed Brown## v0.6 (Mar 29, 2020)
127bcb2dfaeSJed Brown
128bcb2dfaeSJed BrownlibCEED v0.6 contains numerous new features and examples, as well as expanded
129bcb2dfaeSJed Browndocumentation in [this new website](https://libceed.readthedocs.io).
130bcb2dfaeSJed Brown
131bcb2dfaeSJed Brown### New features
132bcb2dfaeSJed Brown
133bcb2dfaeSJed Brown- New Python interface using [CFFI](https://cffi.readthedocs.io/) provides a nearly
134bcb2dfaeSJed Brown  1-1 correspondence with the C interface, plus some convenience features.  For instance,
135bcb2dfaeSJed Brown  data stored in the {cpp:type}`CeedVector` structure are available without copy as
136bcb2dfaeSJed Brown  {py:class}`numpy.ndarray`.  Short tutorials are provided in
137bcb2dfaeSJed Brown  [Binder](https://mybinder.org/v2/gh/CEED/libCEED/main?urlpath=lab/tree/examples/tutorials/).
138bcb2dfaeSJed Brown- Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point,
139bcb2dfaeSJed Brown  {c:func}`CeedOperatorAssembleLinearQFunction`) or to evaluate the diagonal
140bcb2dfaeSJed Brown  ({c:func}`CeedOperatorAssembleLinearDiagonal`).  These operations are useful for
141bcb2dfaeSJed Brown  preconditioning ingredients and are used in the libCEED's multigrid examples.
142bcb2dfaeSJed Brown- The inverse of separable operators can be obtained using
143bcb2dfaeSJed Brown  {c:func}`CeedOperatorCreateFDMElementInverse` and applied with
144bcb2dfaeSJed Brown  {c:func}`CeedOperatorApply`.  This is a useful preconditioning ingredient,
145bcb2dfaeSJed Brown  especially for Laplacians and related operators.
146bcb2dfaeSJed Brown- New functions: {c:func}`CeedVectorNorm`, {c:func}`CeedOperatorApplyAdd`,
147bcb2dfaeSJed Brown  {c:func}`CeedQFunctionView`, {c:func}`CeedOperatorView`.
148bcb2dfaeSJed Brown- Make public accessors for various attributes to facilitate writing composable code.
149bcb2dfaeSJed Brown- New backend: `/cpu/self/memcheck/serial`.
150bcb2dfaeSJed Brown- QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA
151bcb2dfaeSJed Brown  backends.  (Single source is coming soon for OCCA backends.)
152bcb2dfaeSJed Brown- Fix some missing edge cases in CUDA backend.
153bcb2dfaeSJed Brown
154bcb2dfaeSJed Brown### Performance Improvements
155bcb2dfaeSJed Brown
156bcb2dfaeSJed Brown- MAGMA backend performance optimization and non-tensor bases.
157bcb2dfaeSJed Brown- No-copy optimization in {c:func}`CeedOperatorApply`.
158bcb2dfaeSJed Brown
159bcb2dfaeSJed Brown### Interface changes
160bcb2dfaeSJed Brown
161bcb2dfaeSJed Brown- Replace {code}`CeedElemRestrictionCreateIdentity` and
162bcb2dfaeSJed Brown  {code}`CeedElemRestrictionCreateBlocked` with more flexible
163bcb2dfaeSJed Brown  {c:func}`CeedElemRestrictionCreateStrided` and
164bcb2dfaeSJed Brown  {c:func}`CeedElemRestrictionCreateBlockedStrided`.
165bcb2dfaeSJed Brown- Add arguments to {c:func}`CeedQFunctionCreateIdentity`.
166bcb2dfaeSJed Brown- Replace ambiguous uses of {cpp:enum}`CeedTransposeMode` for L-vector identification
167bcb2dfaeSJed Brown  with {cpp:enum}`CeedInterlaceMode`.  This is now an attribute of the
168bcb2dfaeSJed Brown  {cpp:type}`CeedElemRestriction` (see {c:func}`CeedElemRestrictionCreate`) and no
169bcb2dfaeSJed Brown  longer passed as `lmode` arguments to {c:func}`CeedOperatorSetField` and
170bcb2dfaeSJed Brown  {c:func}`CeedElemRestrictionApply`.
171bcb2dfaeSJed Brown
172bcb2dfaeSJed Brown### Examples
173bcb2dfaeSJed Brown
174bcb2dfaeSJed BrownlibCEED-0.6 contains greatly expanded examples with {ref}`new documentation <Examples>`.
175bcb2dfaeSJed BrownNotable additions include:
176bcb2dfaeSJed Brown
177bcb2dfaeSJed Brown- Standalone {ref}`ex2-surface` ({file}`examples/ceed/ex2-surface`): compute the area of
178bcb2dfaeSJed Brown  a domain in 1, 2, and 3 dimensions by applying a Laplacian.
179bcb2dfaeSJed Brown
180bcb2dfaeSJed Brown- PETSc {ref}`example-petsc-area` ({file}`examples/petsc/area.c`): computes surface area
181bcb2dfaeSJed Brown  of domains (like the cube and sphere) by direct integration on a surface mesh;
182bcb2dfaeSJed Brown  demonstrates geometric dimension different from topological dimension.
183bcb2dfaeSJed Brown
184bcb2dfaeSJed Brown- PETSc {ref}`example-petsc-bps`:
185bcb2dfaeSJed Brown
186bcb2dfaeSJed Brown  - {file}`examples/petsc/bpsraw.c` (formerly `bps.c`): transparent CUDA support.
187bcb2dfaeSJed Brown  - {file}`examples/petsc/bps.c` (formerly `bpsdmplex.c`): performance improvements
188bcb2dfaeSJed Brown    and transparent CUDA support.
189bcb2dfaeSJed Brown  - {ref}`example-petsc-bps-sphere` ({file}`examples/petsc/bpssphere.c`):
190bcb2dfaeSJed Brown    generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric
191bcb2dfaeSJed Brown    dimension different from topological dimension.
192bcb2dfaeSJed Brown
193bcb2dfaeSJed Brown- {ref}`example-petsc-multigrid` ({file}`examples/petsc/multigrid.c`): new p-multigrid
194bcb2dfaeSJed Brown  solver with algebraic multigrid coarse solve.
195bcb2dfaeSJed Brown
196bcb2dfaeSJed Brown- {ref}`example-petsc-navier-stokes` ({file}`examples/fluids/navierstokes.c`; formerly
197bcb2dfaeSJed Brown  `examples/navier-stokes`): unstructured grid support (using PETSc's `DMPlex`),
198bcb2dfaeSJed Brown  implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and
199bcb2dfaeSJed Brown  quasi-2D computational domain support.
200bcb2dfaeSJed Brown
201bcb2dfaeSJed Brown- {ref}`example-petsc-elasticity` ({file}`examples/solids/elasticity.c`): new solver for
202bcb2dfaeSJed Brown  linear elasticity, small-strain hyperelasticity, and globalized finite-strain
203bcb2dfaeSJed Brown  hyperelasticity using p-multigrid with algebraic multigrid coarse solve.
204bcb2dfaeSJed Brown
205bcb2dfaeSJed Brown(v0-5)=
206bcb2dfaeSJed Brown
207bcb2dfaeSJed Brown## v0.5 (Sep 18, 2019)
208bcb2dfaeSJed Brown
209bcb2dfaeSJed BrownFor this release, several improvements were made. Two new CUDA backends were added to
210bcb2dfaeSJed Brownthe family of backends, of which, the new `cuda-gen` backend achieves state-of-the-art
211bcb2dfaeSJed Brownperformance using single-source {ref}`CeedQFunction`. From this release, users
212bcb2dfaeSJed Browncan define Q-Functions in a single source code independently of the targeted backend
213bcb2dfaeSJed Brownwith the aid of a new macro `CEED QFUNCTION` to support JIT (Just-In-Time) and CPU
214bcb2dfaeSJed Browncompilation of the user provided {ref}`CeedQFunction` code. To allow a unified
215bcb2dfaeSJed Browndeclaration, the {ref}`CeedQFunction` API has undergone a slight change:
216bcb2dfaeSJed Brownthe `QFunctionField` parameter `ncomp` has been changed to `size`. This change
217bcb2dfaeSJed Brownrequires setting the previous value of `ncomp` to `ncomp*dim` when adding a
218bcb2dfaeSJed Brown`QFunctionField` with eval mode `CEED EVAL GRAD`.
219bcb2dfaeSJed Brown
220bcb2dfaeSJed BrownAdditionally, new CPU backends
221bcb2dfaeSJed Brownwere included in this release, such as the `/cpu/self/opt/*` backends (which are
222bcb2dfaeSJed Brownwritten in pure C and use partial **E-vectors** to improve performance) and the
223bcb2dfaeSJed Brown`/cpu/self/ref/memcheck` backend (which relies upon the
224bcb2dfaeSJed Brown[Valgrind](http://valgrind.org/) Memcheck tool to help verify that user
225bcb2dfaeSJed Brown{ref}`CeedQFunction` have no undefined values).
226bcb2dfaeSJed BrownThis release also included various performance improvements, bug fixes, new examples,
227bcb2dfaeSJed Brownand improved tests. Among these improvements, vectorized instructions for
228bcb2dfaeSJed Brown{ref}`CeedQFunction` code compiled for CPU were enhanced by using `CeedPragmaSIMD`
229bcb2dfaeSJed Browninstead of `CeedPragmaOMP`, implementation of a {ref}`CeedQFunction` gallery and
230bcb2dfaeSJed Brownidentity Q-Functions were introduced, and the PETSc benchmark problems were expanded
231bcb2dfaeSJed Brownto include unstructured meshes handling were. For this expansion, the prior version of
232bcb2dfaeSJed Brownthe PETSc BPs, which only included data associated with structured geometries, were
233bcb2dfaeSJed Brownrenamed `bpsraw`, and the new version of the BPs, which can handle data associated
234bcb2dfaeSJed Brownwith any unstructured geometry, were called `bps`. Additionally, other benchmark
235bcb2dfaeSJed Brownproblems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively),
236bcb2dfaeSJed Brownand BP5 and BP6 (the collocated versions---for which the quadrature points are the same
237bcb2dfaeSJed Brownas the Gauss Lobatto nodes---of BP3 and BP4 respectively) were added to the PETSc
238bcb2dfaeSJed Brownexamples. Furthermoew, another standalone libCEED example, called `ex2`, which
239bcb2dfaeSJed Browncomputes the surface area of a given mesh was added to this release.
240bcb2dfaeSJed Brown
241bcb2dfaeSJed BrownBackends available in this release:
242bcb2dfaeSJed Brown
24368e843eeSJed Brown| CEED resource (`-ceed`)  | Backend                                             |
24468e843eeSJed Brown|--------------------------|-----------------------------------------------------|
24568e843eeSJed Brown| `/cpu/self/ref/serial`   | Serial reference implementation                     |
24668e843eeSJed Brown| `/cpu/self/ref/blocked`  | Blocked reference implementation                    |
24768e843eeSJed Brown| `/cpu/self/ref/memcheck` | Memcheck backend, undefined value checks            |
24868e843eeSJed Brown| `/cpu/self/opt/serial`   | Serial optimized C implementation                   |
24968e843eeSJed Brown| `/cpu/self/opt/blocked`  | Blocked optimized C implementation                  |
25068e843eeSJed Brown| `/cpu/self/avx/serial`   | Serial AVX implementation                           |
25168e843eeSJed Brown| `/cpu/self/avx/blocked`  | Blocked AVX implementation                          |
25268e843eeSJed Brown| `/cpu/self/xsmm/serial`  | Serial LIBXSMM implementation                       |
25368e843eeSJed Brown| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation                      |
25468e843eeSJed Brown| `/cpu/occa`              | Serial OCCA kernels                                 |
25568e843eeSJed Brown| `/gpu/occa`              | CUDA OCCA kernels                                   |
25668e843eeSJed Brown| `/omp/occa`              | OpenMP OCCA kernels                                 |
25768e843eeSJed Brown| `/ocl/occa`              | OpenCL OCCA kernels                                 |
25868e843eeSJed Brown| `/gpu/cuda/ref`          | Reference pure CUDA kernels                         |
25968e843eeSJed Brown| `/gpu/cuda/reg`          | Pure CUDA kernels using one thread per element      |
26068e843eeSJed Brown| `/gpu/cuda/shared`       | Optimized pure CUDA kernels using shared memory     |
26168e843eeSJed Brown| `/gpu/cuda/gen`          | Optimized pure CUDA kernels using code generation   |
26268e843eeSJed Brown| `/gpu/magma`             | CUDA MAGMA kernels                                  |
263bcb2dfaeSJed Brown
264bcb2dfaeSJed BrownExamples available in this release:
265bcb2dfaeSJed Brown
26668e843eeSJed Brown:::{list-table}
26768e843eeSJed Brown:header-rows: 1
26868e843eeSJed Brown:widths: auto
26968e843eeSJed Brown* - User code
27068e843eeSJed Brown  - Example
27168e843eeSJed Brown* - `ceed`
27268e843eeSJed Brown  - * ex1 (volume)
27368e843eeSJed Brown    * ex2 (surface)
27468e843eeSJed Brown* - `mfem`
27568e843eeSJed Brown  - * BP1 (scalar mass operator)
27668e843eeSJed Brown    * BP3 (scalar Laplace operator)
27768e843eeSJed Brown* - `petsc`
27868e843eeSJed Brown  - * BP1 (scalar mass operator)
27968e843eeSJed Brown    * BP2 (vector mass operator)
28068e843eeSJed Brown    * BP3 (scalar Laplace operator)
28168e843eeSJed Brown    * BP4 (vector Laplace operator)
28268e843eeSJed Brown    * BP5 (collocated scalar Laplace operator)
28368e843eeSJed Brown    * BP6 (collocated vector Laplace operator)
28468e843eeSJed Brown    * Navier-Stokes
28568e843eeSJed Brown* - `nek5000`
28668e843eeSJed Brown  - * BP1 (scalar mass operator)
28768e843eeSJed Brown    * BP3 (scalar Laplace operator)
28868e843eeSJed Brown:::
289bcb2dfaeSJed Brown
290bcb2dfaeSJed Brown(v0-4)=
291bcb2dfaeSJed Brown
292bcb2dfaeSJed Brown## v0.4 (Apr 1, 2019)
293bcb2dfaeSJed Brown
294bcb2dfaeSJed BrownlibCEED v0.4 was made again publicly available in the second full CEED software
295bcb2dfaeSJed Browndistribution, release CEED 2.0. This release contained notable features, such as
296bcb2dfaeSJed Brownfour new CPU backends, two new GPU backends, CPU backend optimizations, initial
297bcb2dfaeSJed Brownsupport for operator composition, performance benchmarking, and a Navier-Stokes demo.
298bcb2dfaeSJed BrownThe new CPU backends in this release came in two families. The `/cpu/self/*/serial`
299bcb2dfaeSJed Brownbackends process one element at a time and are intended for meshes with a smaller number
300bcb2dfaeSJed Brownof high order elements. The `/cpu/self/*/blocked` backends process blocked batches of
301bcb2dfaeSJed Browneight interlaced elements and are intended for meshes with higher numbers of elements.
302bcb2dfaeSJed BrownThe `/cpu/self/avx/*` backends rely upon AVX instructions to provide vectorized CPU
303bcb2dfaeSJed Brownperformance. The `/cpu/self/xsmm/*` backends rely upon the
304bcb2dfaeSJed Brown[LIBXSMM](http://github.com/hfp/libxsmm) package to provide vectorized CPU
305bcb2dfaeSJed Brownperformance. The `/gpu/cuda/*` backends provide GPU performance strictly using CUDA.
306bcb2dfaeSJed BrownThe `/gpu/cuda/ref` backend is a reference CUDA backend, providing reasonable
307bcb2dfaeSJed Brownperformance for most problem configurations. The `/gpu/cuda/reg` backend uses a simple
308bcb2dfaeSJed Brownparallelization approach, where each thread treats a finite element. Using just in time
309bcb2dfaeSJed Browncompilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this
310bcb2dfaeSJed Brownbackend unroll loops and map memory address to registers. The `/gpu/cuda/reg` backend
311bcb2dfaeSJed Brownachieve good peak performance for 1D, 2D, and low order 3D problems, but performance
312bcb2dfaeSJed Browndeteriorates very quickly when threads run out of registers.
313bcb2dfaeSJed Brown
314bcb2dfaeSJed BrownA new explicit time-stepping Navier-Stokes solver was added to the family of libCEED
315bcb2dfaeSJed Brownexamples in the `examples/petsc` directory (see {ref}`example-petsc-navier-stokes`).
316bcb2dfaeSJed BrownThis example solves the time-dependent Navier-Stokes equations of compressible gas
317bcb2dfaeSJed Browndynamics in a static Eulerian three-dimensional frame, using structured high-order
318bcb2dfaeSJed Brownfinite/spectral element spatial discretizations and explicit high-order time-stepping
319bcb2dfaeSJed Brown(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc,
320bcb2dfaeSJed Brownso that the pointwise physics (defined at quadrature points) is separated from the
321bcb2dfaeSJed Brownparallelization and meshing concerns.
322bcb2dfaeSJed Brown
323bcb2dfaeSJed BrownBackends available in this release:
324bcb2dfaeSJed Brown
32568e843eeSJed Brown| CEED resource (`-ceed`)  | Backend                                             |
32668e843eeSJed Brown|--------------------------|-----------------------------------------------------|
32768e843eeSJed Brown| `/cpu/self/ref/serial`   | Serial reference implementation                     |
32868e843eeSJed Brown| `/cpu/self/ref/blocked`  | Blocked reference implementation                    |
32968e843eeSJed Brown| `/cpu/self/tmpl`         | Backend template, defaults to `/cpu/self/blocked`   |
33068e843eeSJed Brown| `/cpu/self/avx/serial`   | Serial AVX implementation                           |
33168e843eeSJed Brown| `/cpu/self/avx/blocked`  | Blocked AVX implementation                          |
33268e843eeSJed Brown| `/cpu/self/xsmm/serial`  | Serial LIBXSMM implementation                       |
33368e843eeSJed Brown| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation                      |
33468e843eeSJed Brown| `/cpu/occa`              | Serial OCCA kernels                                 |
33568e843eeSJed Brown| `/gpu/occa`              | CUDA OCCA kernels                                   |
33668e843eeSJed Brown| `/omp/occa`              | OpenMP OCCA kernels                                 |
33768e843eeSJed Brown| `/ocl/occa`              | OpenCL OCCA kernels                                 |
33868e843eeSJed Brown| `/gpu/cuda/ref`          | Reference pure CUDA kernels                         |
33968e843eeSJed Brown| `/gpu/cuda/reg`          | Pure CUDA kernels using one thread per element      |
34068e843eeSJed Brown| `/gpu/magma`             | CUDA MAGMA kernels                                  |
341bcb2dfaeSJed Brown
342bcb2dfaeSJed BrownExamples available in this release:
343bcb2dfaeSJed Brown
34468e843eeSJed Brown:::{list-table}
34568e843eeSJed Brown:header-rows: 1
34668e843eeSJed Brown:widths: auto
34768e843eeSJed Brown* - User code
34868e843eeSJed Brown  - Example
34968e843eeSJed Brown* - `ceed`
35068e843eeSJed Brown  - * ex1 (volume)
35168e843eeSJed Brown* - `mfem`
35268e843eeSJed Brown  - * BP1 (scalar mass operator)
35368e843eeSJed Brown    * BP3 (scalar Laplace operator)
35468e843eeSJed Brown* - `petsc`
35568e843eeSJed Brown  - * BP1 (scalar mass operator)
35668e843eeSJed Brown    * BP3 (scalar Laplace operator)
35768e843eeSJed Brown    * Navier-Stokes
35868e843eeSJed Brown* - `nek5000`
35968e843eeSJed Brown  - * BP1 (scalar mass operator)
36068e843eeSJed Brown    * BP3 (scalar Laplace operator)
36168e843eeSJed Brown:::
362bcb2dfaeSJed Brown
363bcb2dfaeSJed Brown(v0-3)=
364bcb2dfaeSJed Brown
365bcb2dfaeSJed Brown## v0.3 (Sep 30, 2018)
366bcb2dfaeSJed Brown
367bcb2dfaeSJed BrownNotable features in this release include active/passive field interface, support for
368bcb2dfaeSJed Brownnon-tensor bases, backend optimization, and improved Fortran interface. This release
369bcb2dfaeSJed Brownalso focused on providing improved continuous integration, and many new tests with code
370bcb2dfaeSJed Browncoverage reports of about 90%. This release also provided a significant change to the
371bcb2dfaeSJed Brownpublic interface: a {ref}`CeedQFunction` can take any number of named input and output
372bcb2dfaeSJed Brownarguments while {ref}`CeedOperator` connects them to the actual data, which may be
373bcb2dfaeSJed Brownsupplied explicitly to `CeedOperatorApply()` (active) or separately via
374bcb2dfaeSJed Brown`CeedOperatorSetField()` (passive). This interface change enables reusable libraries
375bcb2dfaeSJed Brownof CeedQFunctions and composition of block solvers constructed using
376bcb2dfaeSJed Brown{ref}`CeedOperator`. A concept of blocked restriction was added to this release and
377bcb2dfaeSJed Brownused in an optimized CPU backend. Although this is typically not visible to the user,
378bcb2dfaeSJed Brownit enables effective use of arbitrary-length SIMD while maintaining cache locality.
379bcb2dfaeSJed BrownThis CPU backend also implements an algebraic factorization of tensor product gradients
380bcb2dfaeSJed Brownto perform fewer operations than standard application of interpolation and
381bcb2dfaeSJed Browndifferentiation from nodes to quadrature points. This algebraic formulation
382bcb2dfaeSJed Brownautomatically supports non-polynomial and non-interpolatory bases, thus is more general
383bcb2dfaeSJed Brownthan the more common derivation in terms of Lagrange polynomials on the quadrature points.
384bcb2dfaeSJed Brown
385bcb2dfaeSJed BrownBackends available in this release:
386bcb2dfaeSJed Brown
38768e843eeSJed Brown| CEED resource (`-ceed`) | Backend                                             |
38868e843eeSJed Brown|-------------------------|-----------------------------------------------------|
38968e843eeSJed Brown| `/cpu/self/blocked`     | Blocked reference implementation                    |
39068e843eeSJed Brown| `/cpu/self/ref`         | Serial reference implementation                     |
39168e843eeSJed Brown| `/cpu/self/tmpl`        | Backend template, defaults to `/cpu/self/blocked`   |
39268e843eeSJed Brown| `/cpu/occa`             | Serial OCCA kernels                                 |
39368e843eeSJed Brown| `/gpu/occa`             | CUDA OCCA kernels                                   |
39468e843eeSJed Brown| `/omp/occa`             | OpenMP OCCA kernels                                 |
39568e843eeSJed Brown| `/ocl/occa`             | OpenCL OCCA kernels                                 |
39668e843eeSJed Brown| `/gpu/magma`            | CUDA MAGMA kernels                                  |
397bcb2dfaeSJed Brown
398bcb2dfaeSJed BrownExamples available in this release:
399bcb2dfaeSJed Brown
40068e843eeSJed Brown:::{list-table}
40168e843eeSJed Brown:header-rows: 1
40268e843eeSJed Brown:widths: auto
40368e843eeSJed Brown* - User code
40468e843eeSJed Brown  - Example
40568e843eeSJed Brown* - `ceed`
40668e843eeSJed Brown  - * ex1 (volume)
40768e843eeSJed Brown* - `mfem`
40868e843eeSJed Brown  - * BP1 (scalar mass operator)
40968e843eeSJed Brown    * BP3 (scalar Laplace operator)
41068e843eeSJed Brown* - `petsc`
41168e843eeSJed Brown  - * BP1 (scalar mass operator)
41268e843eeSJed Brown    * BP3 (scalar Laplace operator)
41368e843eeSJed Brown* - `nek5000`
41468e843eeSJed Brown  - * BP1 (scalar mass operator)
41568e843eeSJed Brown    * BP3 (scalar Laplace operator)
41668e843eeSJed Brown:::
417bcb2dfaeSJed Brown
418bcb2dfaeSJed Brown(v0-21)=
419bcb2dfaeSJed Brown
420bcb2dfaeSJed Brown## v0.21 (Sep 30, 2018)
421bcb2dfaeSJed Brown
422bcb2dfaeSJed BrownA MAGMA backend (which relies upon the
423bcb2dfaeSJed Brown[MAGMA](https://bitbucket.org/icl/magma) package) was integrated in libCEED for this
424bcb2dfaeSJed Brownrelease. This initial integration set up the framework of using MAGMA and provided the
425bcb2dfaeSJed BrownlibCEED functionality through MAGMA kernels as one of libCEED’s computational backends.
426bcb2dfaeSJed BrownAs any other backend, the MAGMA backend provides extended basic data structures for
427bcb2dfaeSJed Brown{ref}`CeedVector`, {ref}`CeedElemRestriction`, and {ref}`CeedOperator`, and implements
428bcb2dfaeSJed Brownthe fundamental CEED building blocks to work with the new data structures.
429bcb2dfaeSJed BrownIn general, the MAGMA-specific data structures keep the libCEED pointers to CPU data
430bcb2dfaeSJed Brownbut also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled
431bcb2dfaeSJed Browninternally, and thus seamlessly to the user, through the functions/methods that are
432bcb2dfaeSJed Brownprovided to support them.
433bcb2dfaeSJed Brown
434bcb2dfaeSJed BrownBackends available in this release:
435bcb2dfaeSJed Brown
43668e843eeSJed Brown| CEED resource (`-ceed`) | Backend                         |
43768e843eeSJed Brown|-------------------------|---------------------------------|
43868e843eeSJed Brown| `/cpu/self`             | Serial reference implementation |
43968e843eeSJed Brown| `/cpu/occa`             | Serial OCCA kernels             |
44068e843eeSJed Brown| `/gpu/occa`             | CUDA OCCA kernels               |
44168e843eeSJed Brown| `/omp/occa`             | OpenMP OCCA kernels             |
44268e843eeSJed Brown| `/ocl/occa`             | OpenCL OCCA kernels             |
44368e843eeSJed Brown| `/gpu/magma`            | CUDA MAGMA kernels              |
444bcb2dfaeSJed Brown
445bcb2dfaeSJed BrownExamples available in this release:
446bcb2dfaeSJed Brown
44768e843eeSJed Brown:::{list-table}
44868e843eeSJed Brown:header-rows: 1
44968e843eeSJed Brown:widths: auto
45068e843eeSJed Brown* - User code
45168e843eeSJed Brown  - Example
45268e843eeSJed Brown* - `ceed`
45368e843eeSJed Brown  - * ex1 (volume)
45468e843eeSJed Brown* - `mfem`
45568e843eeSJed Brown  - * BP1 (scalar mass operator)
45668e843eeSJed Brown    * BP3 (scalar Laplace operator)
45768e843eeSJed Brown* - `petsc`
45868e843eeSJed Brown  - * BP1 (scalar mass operator)
45968e843eeSJed Brown* - `nek5000`
46068e843eeSJed Brown  - * BP1 (scalar mass operator)
46168e843eeSJed Brown:::
462bcb2dfaeSJed Brown
463bcb2dfaeSJed Brown(v0-2)=
464bcb2dfaeSJed Brown
465bcb2dfaeSJed Brown## v0.2 (Mar 30, 2018)
466bcb2dfaeSJed Brown
467bcb2dfaeSJed BrownlibCEED was made publicly available the first full CEED software distribution, release
468bcb2dfaeSJed BrownCEED 1.0. The distribution was made available using the Spack package manager to provide
469bcb2dfaeSJed Browna common, easy-to-use build environment, where the user can build the CEED distribution
470bcb2dfaeSJed Brownwith all dependencies. This release included a new Fortran interface for the library.
471bcb2dfaeSJed BrownThis release also contained major improvements in the OCCA backend (including a new
472bcb2dfaeSJed Brown`/ocl/occa` backend) and new examples. The standalone libCEED example was modified to
473bcb2dfaeSJed Browncompute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an
474bcb2dfaeSJed Brown`examples/ceed` subfolder. A new `mfem` example to perform BP3 (with the application
475bcb2dfaeSJed Brownof the Laplace operator) was also added to this release.
476bcb2dfaeSJed Brown
477bcb2dfaeSJed BrownBackends available in this release:
478bcb2dfaeSJed Brown
47968e843eeSJed Brown| CEED resource (`-ceed`) | Backend                         |
48068e843eeSJed Brown|-------------------------|---------------------------------|
48168e843eeSJed Brown| `/cpu/self`             | Serial reference implementation |
48268e843eeSJed Brown| `/cpu/occa`             | Serial OCCA kernels             |
48368e843eeSJed Brown| `/gpu/occa`             | CUDA OCCA kernels               |
48468e843eeSJed Brown| `/omp/occa`             | OpenMP OCCA kernels             |
48568e843eeSJed Brown| `/ocl/occa`             | OpenCL OCCA kernels             |
486bcb2dfaeSJed Brown
487bcb2dfaeSJed BrownExamples available in this release:
488bcb2dfaeSJed Brown
48968e843eeSJed Brown:::{list-table}
49068e843eeSJed Brown:header-rows: 1
49168e843eeSJed Brown:widths: auto
49268e843eeSJed Brown* - User code
49368e843eeSJed Brown  - Example
49468e843eeSJed Brown* - `ceed`
49568e843eeSJed Brown  - * ex1 (volume)
49668e843eeSJed Brown* - `mfem`
49768e843eeSJed Brown  - * BP1 (scalar mass operator)
49868e843eeSJed Brown    * BP3 (scalar Laplace operator)
49968e843eeSJed Brown* - `petsc`
50068e843eeSJed Brown  - * BP1 (scalar mass operator)
50168e843eeSJed Brown* - `nek5000`
50268e843eeSJed Brown  - * BP1 (scalar mass operator)
50368e843eeSJed Brown:::
504bcb2dfaeSJed Brown
505bcb2dfaeSJed Brown(v0-1)=
506bcb2dfaeSJed Brown
507bcb2dfaeSJed Brown## v0.1 (Jan 3, 2018)
508bcb2dfaeSJed Brown
509bcb2dfaeSJed BrownInitial low-level API of the CEED project. The low-level API provides a set of Finite
510bcb2dfaeSJed BrownElements kernels and components for writing new low-level kernels. Examples include:
511bcb2dfaeSJed Brownvector and sparse linear algebra, element matrix assembly over a batch of elements,
512bcb2dfaeSJed Brownpartial assembly and action for efficient high-order operators like mass, diffusion,
513bcb2dfaeSJed Brownadvection, etc. The main goal of the low-level API is to establish the basis for the
514bcb2dfaeSJed Brownhigh-level API. Also, identifying such low-level kernels and providing a reference
515bcb2dfaeSJed Brownimplementation for them serves as the basis for specialized backend implementations.
516bcb2dfaeSJed BrownThis release contained several backends: `/cpu/self`, and backends which rely upon the
517bcb2dfaeSJed Brown[OCCA](http://github.com/libocca/occa) package, such as `/cpu/occa`,
518bcb2dfaeSJed Brown`/gpu/occa`, and `/omp/occa`.
519bcb2dfaeSJed BrownIt also included several examples, in the `examples` folder:
520bcb2dfaeSJed BrownA standalone code that shows the usage of libCEED (with no external
521bcb2dfaeSJed Browndependencies) to apply the Laplace operator, `ex1`; an `mfem` example to perform BP1
522bcb2dfaeSJed Brown(with the application of the mass operator); and a `petsc` example to perform BP1
523bcb2dfaeSJed Brown(with the application of the mass operator).
524bcb2dfaeSJed Brown
525bcb2dfaeSJed BrownBackends available in this release:
526bcb2dfaeSJed Brown
52768e843eeSJed Brown| CEED resource (`-ceed`) | Backend                         |
52868e843eeSJed Brown|-------------------------|---------------------------------|
52968e843eeSJed Brown| `/cpu/self`             | Serial reference implementation |
53068e843eeSJed Brown| `/cpu/occa`             | Serial OCCA kernels             |
53168e843eeSJed Brown| `/gpu/occa`             | CUDA OCCA kernels               |
53268e843eeSJed Brown| `/omp/occa`             | OpenMP OCCA kernels             |
533bcb2dfaeSJed Brown
534bcb2dfaeSJed BrownExamples available in this release:
535bcb2dfaeSJed Brown
536bcb2dfaeSJed Brown| User code             | Example                           |
53768e843eeSJed Brown|-----------------------|-----------------------------------|
53868e843eeSJed Brown| `ceed`                | ex1 (scalar Laplace operator)     |
53968e843eeSJed Brown| `mfem`                | BP1 (scalar mass operator)        |
54068e843eeSJed Brown| `petsc`               | BP1 (scalar mass operator)        |
541bcb2dfaeSJed Brown```
542