xref: /libCEED/doc/sphinx/source/releasenotes.md (revision 8b919e6b544da496037dee7de9325ce15d8e67f1)
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.
209c774eddSJeremy L Thompson- Clarify documentation for {c:func}`CeedVectorTakeArray`; this function will error if {c:func}`CeedVectorSetArray` with `copy_mode == CEED_USE_POINTER` was not previously called for the corresponding `CeedMemType`.
219c774eddSJeremy L Thompson- Added {c:func}`CeedVectorGetArrayWrite` that allows access to uninitalized arrays; require initalized data for {c:func}`CeedVectorGetArray`.
22c38440baSJed Brown- Added {c:func}`CeedQFunctionContextRegisterDouble` and {c:func}`CeedQFunctionContextRegisterInt32` with {c:func}`CeedQFunctionContextSetDouble` and {c:func}`CeedQFunctionContextSetInt32` to facilitate easy updating of {c:struct}`CeedQFunctionContext` data by user defined field names.
23cdf32b93SJeremy L Thompson- Added {c:func}`CeedQFunctionContextGetFieldDescriptions` to retreive user defined descriptions of fields that are registered with `CeedQFunctionContextRegister*`.
247a06ec9fSJeremy L Thompson- Renamed `CeedElemTopology` entries for clearer namespacing between libCEED enums.
25f4f98f9dSJeremy L Thompson- Added type `CeedSize` equivalent to `ptrdiff_t` for array sizes in {c:func}`CeedVectorCreate`, {c:func}`CeedVectorGetLength`, `CeedElemRestrictionCreate*`, {c:func}`CeedElemRestrictionGetLVectorSize`, and {c:func}`CeedOperatorLinearAssembleSymbolic`. This is a breaking change.
26*8b919e6bSJeremy L Thompson- Added {c:func}`CeedOperatorSetQFunctionUpdated` to facilitate QFunction data re-use between operators sharing the same quadrature space, such as in a multigrid hierarchy.
277e7773b5SJeremy L Thompson
28f479eb23SJeremy L Thompson### New features
29f479eb23SJeremy L Thompson
30f479eb23SJeremy L Thompson- `CeedScalar` can now be set as `float` or `double` at compile time.
3130601ac0SJeremy L Thompson- Added JiT utilities in `ceed/jit-tools.h` to reduce duplicated code in GPU backends.
32fb3c7d02SJeremy 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.
3323dfbf5bSJeremy L Thompson- Remove need to guard library headers in QFunction source for code generation backends.
343f21f6b1SJeremy L Thompson- `CeedDebugEnv()` macro created to provide debugging outputs when Ceed context is not present.
35f7e22acaSJeremy L Thompson- Added {c:func}`CeedStringAllocCopy` to reduce repeated code for copying strings internally.
363451974fSJeremy L Thompson- Added {c:func}`CeedPathConcatenate` to facilitate loading kernel source files with a path relative to the current file.
377a06ec9fSJeremy L Thompson- Added support for non-tensor H(div) elements, to include CPU backend implementations and {c:func}`CeedBasisCreateHdiv` convenience constructor.
38d34e270fSJeremy L Thompson- Added {c:func}`CeedQFunctionSetContextWritable` and read-only access to `CeedQFunctionContext` data as an optional feature to improve GPU performance. By default, calling the `CeedQFunctionUser` during {c:func}`CeedQFunctionApply` is assumed to write into the `CeedQFunctionContext` data, consistent with the previous behavior. Note that if a user asserts that their `CeedQFunctionUser` does not write into the `CeedQFunctionContext` data, they are responsible for the validity of this assertion.
39f479eb23SJeremy L Thompson
40bcb2dfaeSJed Brown### Maintainability
41bcb2dfaeSJed Brown
42bcb2dfaeSJed Brown- Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage.
43db52d626SJeremy L Thompson- `Include-what-you-use` makefile target added as `make iwyu`.
44bf4cb664SJeremy L Thompson- Create backend constant `CEED_FIELD_MAX` to reduce magic numbers in codebase.
453451974fSJeremy L Thompson- Put GPU JiTed kernel source code into separate files.
46f9996dfdSJeremy L Thompson- 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.
47bcb2dfaeSJed Brown
48bcb2dfaeSJed Brown(v0-9)=
49bcb2dfaeSJed Brown
50bcb2dfaeSJed Brown## v0.9 (Jul 6, 2021)
51bcb2dfaeSJed Brown
52bcb2dfaeSJed Brown### Interface changes
53bcb2dfaeSJed Brown
54bcb2dfaeSJed Brown- Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact.
55bcb2dfaeSJed Brown
56bcb2dfaeSJed Brown### New features
57bcb2dfaeSJed Brown
58bcb2dfaeSJed Brown- Add {c:func}`CeedVectorAXPY` and {c:func}`CeedVectorPointwiseMult` as a convenience for stand-alone testing and internal use.
59bcb2dfaeSJed Brown- Add `CEED_QFUNCTION_HELPER` macro to properly annotate QFunction helper functions for code generation backends.
60bcb2dfaeSJed Brown- Add `CeedPragmaOptimizeOff` macro for code that is sensitive to floating point errors from fast math optimizations.
61bcb2dfaeSJed Brown- Rust support: split `libceed-sys` crate out of `libceed` and [publish both on crates.io](https://crates.io/crates/libceed).
62bcb2dfaeSJed Brown
63bcb2dfaeSJed Brown### Performance improvements
64bcb2dfaeSJed Brown
65bcb2dfaeSJed Brown### Examples
66bcb2dfaeSJed Brown
67bcb2dfaeSJed Brown- Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations.
68bcb2dfaeSJed Brown- Fluid mechanics example adds GPU support and improves modularity.
69bcb2dfaeSJed Brown
70bcb2dfaeSJed Brown### Deprecated backends
71bcb2dfaeSJed Brown
72bcb2dfaeSJed 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.
73bcb2dfaeSJed Brown
74bcb2dfaeSJed Brown(v0-8)=
75bcb2dfaeSJed Brown
76bcb2dfaeSJed Brown## v0.8 (Mar 31, 2021)
77bcb2dfaeSJed Brown
78bcb2dfaeSJed Brown### Interface changes
79bcb2dfaeSJed Brown
80bcb2dfaeSJed Brown- Error handling improved to include enumerated error codes for C interface return values.
81bcb2dfaeSJed 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.
82bcb2dfaeSJed Brown
83bcb2dfaeSJed Brown### New features
84bcb2dfaeSJed Brown
85bcb2dfaeSJed Brown- Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features.
86bcb2dfaeSJed Brown- Static libraries can be built with `make STATIC=1` and the pkg-config file is installed accordingly.
87bcb2dfaeSJed Brown- Add {c:func}`CeedOperatorLinearAssembleSymbolic` and {c:func}`CeedOperatorLinearAssemble` to support full assembly of libCEED operators.
88bcb2dfaeSJed Brown
89bcb2dfaeSJed Brown### Performance improvements
90bcb2dfaeSJed Brown
91bcb2dfaeSJed Brown- New HIP MAGMA backends for hipMAGMA library users: `/gpu/hip/magma` and `/gpu/hip/magma/det`.
92bcb2dfaeSJed Brown- New HIP backends for improved tensor basis performance: `/gpu/hip/shared` and `/gpu/hip/gen`.
93bcb2dfaeSJed Brown
94bcb2dfaeSJed Brown### Examples
95bcb2dfaeSJed Brown
96bcb2dfaeSJed Brown- {ref}`example-petsc-elasticity` example updated with traction boundary conditions and improved Dirichlet boundary conditions.
97bcb2dfaeSJed 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.
98bcb2dfaeSJed 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.
99bcb2dfaeSJed Brown- {ref}`example-petsc-navier-stokes` example updated with support for performing convergence study and plotting order of convergence by polynomial degree.
100bcb2dfaeSJed Brown
101bcb2dfaeSJed Brown(v0-7)=
102bcb2dfaeSJed Brown
103bcb2dfaeSJed Brown## v0.7 (Sep 29, 2020)
104bcb2dfaeSJed Brown
105bcb2dfaeSJed Brown### Interface changes
106bcb2dfaeSJed Brown
107bcb2dfaeSJed Brown- Replace limited {code}`CeedInterlaceMode` with more flexible component stride {code}`compstride` in {code}`CeedElemRestriction` constructors.
108bcb2dfaeSJed 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`.
109bcb2dfaeSJed Brown  These changes improve support for mixed finite element methods.
110bcb2dfaeSJed Brown- Replace various uses of {code}`Ceed*Get*Status` with {code}`Ceed*Is*` in the backend API to match common nomenclature.
111bcb2dfaeSJed Brown- Replace {code}`CeedOperatorAssembleLinearDiagonal` with {c:func}`CeedOperatorLinearAssembleDiagonal` for clarity.
112bcb2dfaeSJed 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.
113bcb2dfaeSJed 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.
114bcb2dfaeSJed 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.
115bcb2dfaeSJed 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.
116bcb2dfaeSJed 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`.
117bcb2dfaeSJed Brown- Added {code}`CeedQFunctionContext` object to manage user QFunction context data and reduce copies between device and host memory.
118bcb2dfaeSJed 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.
119bcb2dfaeSJed Brown
120bcb2dfaeSJed Brown### New features
121bcb2dfaeSJed Brown
122bcb2dfaeSJed Brown- New HIP backend: `/gpu/hip/ref`.
123bcb2dfaeSJed Brown- CeedQFunction support for user `CUfunction`s in some backends
124bcb2dfaeSJed Brown
125bcb2dfaeSJed Brown### Performance improvements
126bcb2dfaeSJed Brown
127bcb2dfaeSJed Brown- OCCA backend rebuilt to facilitate future performance enhancements.
128bcb2dfaeSJed Brown- Petsc BPs suite improved to reduce noise due to multiple calls to {code}`mpiexec`.
129bcb2dfaeSJed Brown
130bcb2dfaeSJed Brown### Examples
131bcb2dfaeSJed Brown
132bcb2dfaeSJed Brown- {ref}`example-petsc-elasticity` example updated with strain energy computation and more flexible boundary conditions.
133bcb2dfaeSJed Brown
134bcb2dfaeSJed Brown### Deprecated backends
135bcb2dfaeSJed Brown
136bcb2dfaeSJed Brown- The `/gpu/cuda/reg` backend has been removed, with its core features moved into `/gpu/cuda/ref` and `/gpu/cuda/shared`.
137bcb2dfaeSJed Brown
138bcb2dfaeSJed Brown(v0-6)=
139bcb2dfaeSJed Brown
140bcb2dfaeSJed Brown## v0.6 (Mar 29, 2020)
141bcb2dfaeSJed Brown
142bcb2dfaeSJed BrownlibCEED v0.6 contains numerous new features and examples, as well as expanded
143bcb2dfaeSJed Browndocumentation in [this new website](https://libceed.readthedocs.io).
144bcb2dfaeSJed Brown
145bcb2dfaeSJed Brown### New features
146bcb2dfaeSJed Brown
147bcb2dfaeSJed Brown- New Python interface using [CFFI](https://cffi.readthedocs.io/) provides a nearly
148bcb2dfaeSJed Brown  1-1 correspondence with the C interface, plus some convenience features.  For instance,
149bcb2dfaeSJed Brown  data stored in the {cpp:type}`CeedVector` structure are available without copy as
150bcb2dfaeSJed Brown  {py:class}`numpy.ndarray`.  Short tutorials are provided in
151bcb2dfaeSJed Brown  [Binder](https://mybinder.org/v2/gh/CEED/libCEED/main?urlpath=lab/tree/examples/tutorials/).
152bcb2dfaeSJed Brown- Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point,
153bcb2dfaeSJed Brown  {c:func}`CeedOperatorAssembleLinearQFunction`) or to evaluate the diagonal
154bcb2dfaeSJed Brown  ({c:func}`CeedOperatorAssembleLinearDiagonal`).  These operations are useful for
155bcb2dfaeSJed Brown  preconditioning ingredients and are used in the libCEED's multigrid examples.
156bcb2dfaeSJed Brown- The inverse of separable operators can be obtained using
157bcb2dfaeSJed Brown  {c:func}`CeedOperatorCreateFDMElementInverse` and applied with
158bcb2dfaeSJed Brown  {c:func}`CeedOperatorApply`.  This is a useful preconditioning ingredient,
159bcb2dfaeSJed Brown  especially for Laplacians and related operators.
160bcb2dfaeSJed Brown- New functions: {c:func}`CeedVectorNorm`, {c:func}`CeedOperatorApplyAdd`,
161bcb2dfaeSJed Brown  {c:func}`CeedQFunctionView`, {c:func}`CeedOperatorView`.
162bcb2dfaeSJed Brown- Make public accessors for various attributes to facilitate writing composable code.
163bcb2dfaeSJed Brown- New backend: `/cpu/self/memcheck/serial`.
164bcb2dfaeSJed Brown- QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA
165bcb2dfaeSJed Brown  backends.  (Single source is coming soon for OCCA backends.)
166bcb2dfaeSJed Brown- Fix some missing edge cases in CUDA backend.
167bcb2dfaeSJed Brown
168bcb2dfaeSJed Brown### Performance Improvements
169bcb2dfaeSJed Brown
170bcb2dfaeSJed Brown- MAGMA backend performance optimization and non-tensor bases.
171bcb2dfaeSJed Brown- No-copy optimization in {c:func}`CeedOperatorApply`.
172bcb2dfaeSJed Brown
173bcb2dfaeSJed Brown### Interface changes
174bcb2dfaeSJed Brown
175bcb2dfaeSJed Brown- Replace {code}`CeedElemRestrictionCreateIdentity` and
176bcb2dfaeSJed Brown  {code}`CeedElemRestrictionCreateBlocked` with more flexible
177bcb2dfaeSJed Brown  {c:func}`CeedElemRestrictionCreateStrided` and
178bcb2dfaeSJed Brown  {c:func}`CeedElemRestrictionCreateBlockedStrided`.
179bcb2dfaeSJed Brown- Add arguments to {c:func}`CeedQFunctionCreateIdentity`.
180bcb2dfaeSJed Brown- Replace ambiguous uses of {cpp:enum}`CeedTransposeMode` for L-vector identification
181bcb2dfaeSJed Brown  with {cpp:enum}`CeedInterlaceMode`.  This is now an attribute of the
182bcb2dfaeSJed Brown  {cpp:type}`CeedElemRestriction` (see {c:func}`CeedElemRestrictionCreate`) and no
183bcb2dfaeSJed Brown  longer passed as `lmode` arguments to {c:func}`CeedOperatorSetField` and
184bcb2dfaeSJed Brown  {c:func}`CeedElemRestrictionApply`.
185bcb2dfaeSJed Brown
186bcb2dfaeSJed Brown### Examples
187bcb2dfaeSJed Brown
188bcb2dfaeSJed BrownlibCEED-0.6 contains greatly expanded examples with {ref}`new documentation <Examples>`.
189bcb2dfaeSJed BrownNotable additions include:
190bcb2dfaeSJed Brown
191bcb2dfaeSJed Brown- Standalone {ref}`ex2-surface` ({file}`examples/ceed/ex2-surface`): compute the area of
192bcb2dfaeSJed Brown  a domain in 1, 2, and 3 dimensions by applying a Laplacian.
193bcb2dfaeSJed Brown
194bcb2dfaeSJed Brown- PETSc {ref}`example-petsc-area` ({file}`examples/petsc/area.c`): computes surface area
195bcb2dfaeSJed Brown  of domains (like the cube and sphere) by direct integration on a surface mesh;
196bcb2dfaeSJed Brown  demonstrates geometric dimension different from topological dimension.
197bcb2dfaeSJed Brown
198bcb2dfaeSJed Brown- PETSc {ref}`example-petsc-bps`:
199bcb2dfaeSJed Brown
200bcb2dfaeSJed Brown  - {file}`examples/petsc/bpsraw.c` (formerly `bps.c`): transparent CUDA support.
201bcb2dfaeSJed Brown  - {file}`examples/petsc/bps.c` (formerly `bpsdmplex.c`): performance improvements
202bcb2dfaeSJed Brown    and transparent CUDA support.
203bcb2dfaeSJed Brown  - {ref}`example-petsc-bps-sphere` ({file}`examples/petsc/bpssphere.c`):
204bcb2dfaeSJed Brown    generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric
205bcb2dfaeSJed Brown    dimension different from topological dimension.
206bcb2dfaeSJed Brown
207bcb2dfaeSJed Brown- {ref}`example-petsc-multigrid` ({file}`examples/petsc/multigrid.c`): new p-multigrid
208bcb2dfaeSJed Brown  solver with algebraic multigrid coarse solve.
209bcb2dfaeSJed Brown
210bcb2dfaeSJed Brown- {ref}`example-petsc-navier-stokes` ({file}`examples/fluids/navierstokes.c`; formerly
211bcb2dfaeSJed Brown  `examples/navier-stokes`): unstructured grid support (using PETSc's `DMPlex`),
212bcb2dfaeSJed Brown  implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and
213bcb2dfaeSJed Brown  quasi-2D computational domain support.
214bcb2dfaeSJed Brown
215bcb2dfaeSJed Brown- {ref}`example-petsc-elasticity` ({file}`examples/solids/elasticity.c`): new solver for
216bcb2dfaeSJed Brown  linear elasticity, small-strain hyperelasticity, and globalized finite-strain
217bcb2dfaeSJed Brown  hyperelasticity using p-multigrid with algebraic multigrid coarse solve.
218bcb2dfaeSJed Brown
219bcb2dfaeSJed Brown(v0-5)=
220bcb2dfaeSJed Brown
221bcb2dfaeSJed Brown## v0.5 (Sep 18, 2019)
222bcb2dfaeSJed Brown
223bcb2dfaeSJed BrownFor this release, several improvements were made. Two new CUDA backends were added to
224bcb2dfaeSJed Brownthe family of backends, of which, the new `cuda-gen` backend achieves state-of-the-art
225bcb2dfaeSJed Brownperformance using single-source {ref}`CeedQFunction`. From this release, users
226bcb2dfaeSJed Browncan define Q-Functions in a single source code independently of the targeted backend
227bcb2dfaeSJed Brownwith the aid of a new macro `CEED QFUNCTION` to support JIT (Just-In-Time) and CPU
228bcb2dfaeSJed Browncompilation of the user provided {ref}`CeedQFunction` code. To allow a unified
229bcb2dfaeSJed Browndeclaration, the {ref}`CeedQFunction` API has undergone a slight change:
230bcb2dfaeSJed Brownthe `QFunctionField` parameter `ncomp` has been changed to `size`. This change
231bcb2dfaeSJed Brownrequires setting the previous value of `ncomp` to `ncomp*dim` when adding a
232bcb2dfaeSJed Brown`QFunctionField` with eval mode `CEED EVAL GRAD`.
233bcb2dfaeSJed Brown
234bcb2dfaeSJed BrownAdditionally, new CPU backends
235bcb2dfaeSJed Brownwere included in this release, such as the `/cpu/self/opt/*` backends (which are
236bcb2dfaeSJed Brownwritten in pure C and use partial **E-vectors** to improve performance) and the
237bcb2dfaeSJed Brown`/cpu/self/ref/memcheck` backend (which relies upon the
238bcb2dfaeSJed Brown[Valgrind](http://valgrind.org/) Memcheck tool to help verify that user
239bcb2dfaeSJed Brown{ref}`CeedQFunction` have no undefined values).
240bcb2dfaeSJed BrownThis release also included various performance improvements, bug fixes, new examples,
241bcb2dfaeSJed Brownand improved tests. Among these improvements, vectorized instructions for
242bcb2dfaeSJed Brown{ref}`CeedQFunction` code compiled for CPU were enhanced by using `CeedPragmaSIMD`
243bcb2dfaeSJed Browninstead of `CeedPragmaOMP`, implementation of a {ref}`CeedQFunction` gallery and
244bcb2dfaeSJed Brownidentity Q-Functions were introduced, and the PETSc benchmark problems were expanded
245bcb2dfaeSJed Brownto include unstructured meshes handling were. For this expansion, the prior version of
246bcb2dfaeSJed Brownthe PETSc BPs, which only included data associated with structured geometries, were
247bcb2dfaeSJed Brownrenamed `bpsraw`, and the new version of the BPs, which can handle data associated
248bcb2dfaeSJed Brownwith any unstructured geometry, were called `bps`. Additionally, other benchmark
249bcb2dfaeSJed Brownproblems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively),
250bcb2dfaeSJed Brownand BP5 and BP6 (the collocated versions---for which the quadrature points are the same
251bcb2dfaeSJed Brownas the Gauss Lobatto nodes---of BP3 and BP4 respectively) were added to the PETSc
252bcb2dfaeSJed Brownexamples. Furthermoew, another standalone libCEED example, called `ex2`, which
253bcb2dfaeSJed Browncomputes the surface area of a given mesh was added to this release.
254bcb2dfaeSJed Brown
255bcb2dfaeSJed BrownBackends available in this release:
256bcb2dfaeSJed Brown
25768e843eeSJed Brown| CEED resource (`-ceed`)  | Backend                                             |
25868e843eeSJed Brown|--------------------------|-----------------------------------------------------|
25968e843eeSJed Brown| `/cpu/self/ref/serial`   | Serial reference implementation                     |
26068e843eeSJed Brown| `/cpu/self/ref/blocked`  | Blocked reference implementation                    |
26168e843eeSJed Brown| `/cpu/self/ref/memcheck` | Memcheck backend, undefined value checks            |
26268e843eeSJed Brown| `/cpu/self/opt/serial`   | Serial optimized C implementation                   |
26368e843eeSJed Brown| `/cpu/self/opt/blocked`  | Blocked optimized C implementation                  |
26468e843eeSJed Brown| `/cpu/self/avx/serial`   | Serial AVX implementation                           |
26568e843eeSJed Brown| `/cpu/self/avx/blocked`  | Blocked AVX implementation                          |
26668e843eeSJed Brown| `/cpu/self/xsmm/serial`  | Serial LIBXSMM implementation                       |
26768e843eeSJed Brown| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation                      |
26868e843eeSJed Brown| `/cpu/occa`              | Serial OCCA kernels                                 |
26968e843eeSJed Brown| `/gpu/occa`              | CUDA OCCA kernels                                   |
27068e843eeSJed Brown| `/omp/occa`              | OpenMP OCCA kernels                                 |
27168e843eeSJed Brown| `/ocl/occa`              | OpenCL OCCA kernels                                 |
27268e843eeSJed Brown| `/gpu/cuda/ref`          | Reference pure CUDA kernels                         |
27368e843eeSJed Brown| `/gpu/cuda/reg`          | Pure CUDA kernels using one thread per element      |
27468e843eeSJed Brown| `/gpu/cuda/shared`       | Optimized pure CUDA kernels using shared memory     |
27568e843eeSJed Brown| `/gpu/cuda/gen`          | Optimized pure CUDA kernels using code generation   |
27668e843eeSJed Brown| `/gpu/magma`             | CUDA MAGMA kernels                                  |
277bcb2dfaeSJed Brown
278bcb2dfaeSJed BrownExamples available in this release:
279bcb2dfaeSJed Brown
28068e843eeSJed Brown:::{list-table}
28168e843eeSJed Brown:header-rows: 1
28268e843eeSJed Brown:widths: auto
28368e843eeSJed Brown* - User code
28468e843eeSJed Brown  - Example
28568e843eeSJed Brown* - `ceed`
28668e843eeSJed Brown  - * ex1 (volume)
28768e843eeSJed Brown    * ex2 (surface)
28868e843eeSJed Brown* - `mfem`
28968e843eeSJed Brown  - * BP1 (scalar mass operator)
29068e843eeSJed Brown    * BP3 (scalar Laplace operator)
29168e843eeSJed Brown* - `petsc`
29268e843eeSJed Brown  - * BP1 (scalar mass operator)
29368e843eeSJed Brown    * BP2 (vector mass operator)
29468e843eeSJed Brown    * BP3 (scalar Laplace operator)
29568e843eeSJed Brown    * BP4 (vector Laplace operator)
29668e843eeSJed Brown    * BP5 (collocated scalar Laplace operator)
29768e843eeSJed Brown    * BP6 (collocated vector Laplace operator)
29868e843eeSJed Brown    * Navier-Stokes
29968e843eeSJed Brown* - `nek5000`
30068e843eeSJed Brown  - * BP1 (scalar mass operator)
30168e843eeSJed Brown    * BP3 (scalar Laplace operator)
30268e843eeSJed Brown:::
303bcb2dfaeSJed Brown
304bcb2dfaeSJed Brown(v0-4)=
305bcb2dfaeSJed Brown
306bcb2dfaeSJed Brown## v0.4 (Apr 1, 2019)
307bcb2dfaeSJed Brown
308bcb2dfaeSJed BrownlibCEED v0.4 was made again publicly available in the second full CEED software
309bcb2dfaeSJed Browndistribution, release CEED 2.0. This release contained notable features, such as
310bcb2dfaeSJed Brownfour new CPU backends, two new GPU backends, CPU backend optimizations, initial
311bcb2dfaeSJed Brownsupport for operator composition, performance benchmarking, and a Navier-Stokes demo.
312bcb2dfaeSJed BrownThe new CPU backends in this release came in two families. The `/cpu/self/*/serial`
313bcb2dfaeSJed Brownbackends process one element at a time and are intended for meshes with a smaller number
314bcb2dfaeSJed Brownof high order elements. The `/cpu/self/*/blocked` backends process blocked batches of
315bcb2dfaeSJed Browneight interlaced elements and are intended for meshes with higher numbers of elements.
316bcb2dfaeSJed BrownThe `/cpu/self/avx/*` backends rely upon AVX instructions to provide vectorized CPU
317bcb2dfaeSJed Brownperformance. The `/cpu/self/xsmm/*` backends rely upon the
318bcb2dfaeSJed Brown[LIBXSMM](http://github.com/hfp/libxsmm) package to provide vectorized CPU
319bcb2dfaeSJed Brownperformance. The `/gpu/cuda/*` backends provide GPU performance strictly using CUDA.
320bcb2dfaeSJed BrownThe `/gpu/cuda/ref` backend is a reference CUDA backend, providing reasonable
321bcb2dfaeSJed Brownperformance for most problem configurations. The `/gpu/cuda/reg` backend uses a simple
322bcb2dfaeSJed Brownparallelization approach, where each thread treats a finite element. Using just in time
323bcb2dfaeSJed Browncompilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this
324bcb2dfaeSJed Brownbackend unroll loops and map memory address to registers. The `/gpu/cuda/reg` backend
325bcb2dfaeSJed Brownachieve good peak performance for 1D, 2D, and low order 3D problems, but performance
326bcb2dfaeSJed Browndeteriorates very quickly when threads run out of registers.
327bcb2dfaeSJed Brown
328bcb2dfaeSJed BrownA new explicit time-stepping Navier-Stokes solver was added to the family of libCEED
329bcb2dfaeSJed Brownexamples in the `examples/petsc` directory (see {ref}`example-petsc-navier-stokes`).
330bcb2dfaeSJed BrownThis example solves the time-dependent Navier-Stokes equations of compressible gas
331bcb2dfaeSJed Browndynamics in a static Eulerian three-dimensional frame, using structured high-order
332bcb2dfaeSJed Brownfinite/spectral element spatial discretizations and explicit high-order time-stepping
333bcb2dfaeSJed Brown(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc,
334bcb2dfaeSJed Brownso that the pointwise physics (defined at quadrature points) is separated from the
335bcb2dfaeSJed Brownparallelization and meshing concerns.
336bcb2dfaeSJed Brown
337bcb2dfaeSJed BrownBackends available in this release:
338bcb2dfaeSJed Brown
33968e843eeSJed Brown| CEED resource (`-ceed`)  | Backend                                             |
34068e843eeSJed Brown|--------------------------|-----------------------------------------------------|
34168e843eeSJed Brown| `/cpu/self/ref/serial`   | Serial reference implementation                     |
34268e843eeSJed Brown| `/cpu/self/ref/blocked`  | Blocked reference implementation                    |
34368e843eeSJed Brown| `/cpu/self/tmpl`         | Backend template, defaults to `/cpu/self/blocked`   |
34468e843eeSJed Brown| `/cpu/self/avx/serial`   | Serial AVX implementation                           |
34568e843eeSJed Brown| `/cpu/self/avx/blocked`  | Blocked AVX implementation                          |
34668e843eeSJed Brown| `/cpu/self/xsmm/serial`  | Serial LIBXSMM implementation                       |
34768e843eeSJed Brown| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation                      |
34868e843eeSJed Brown| `/cpu/occa`              | Serial OCCA kernels                                 |
34968e843eeSJed Brown| `/gpu/occa`              | CUDA OCCA kernels                                   |
35068e843eeSJed Brown| `/omp/occa`              | OpenMP OCCA kernels                                 |
35168e843eeSJed Brown| `/ocl/occa`              | OpenCL OCCA kernels                                 |
35268e843eeSJed Brown| `/gpu/cuda/ref`          | Reference pure CUDA kernels                         |
35368e843eeSJed Brown| `/gpu/cuda/reg`          | Pure CUDA kernels using one thread per element      |
35468e843eeSJed Brown| `/gpu/magma`             | CUDA MAGMA kernels                                  |
355bcb2dfaeSJed Brown
356bcb2dfaeSJed BrownExamples available in this release:
357bcb2dfaeSJed Brown
35868e843eeSJed Brown:::{list-table}
35968e843eeSJed Brown:header-rows: 1
36068e843eeSJed Brown:widths: auto
36168e843eeSJed Brown* - User code
36268e843eeSJed Brown  - Example
36368e843eeSJed Brown* - `ceed`
36468e843eeSJed Brown  - * ex1 (volume)
36568e843eeSJed Brown* - `mfem`
36668e843eeSJed Brown  - * BP1 (scalar mass operator)
36768e843eeSJed Brown    * BP3 (scalar Laplace operator)
36868e843eeSJed Brown* - `petsc`
36968e843eeSJed Brown  - * BP1 (scalar mass operator)
37068e843eeSJed Brown    * BP3 (scalar Laplace operator)
37168e843eeSJed Brown    * Navier-Stokes
37268e843eeSJed Brown* - `nek5000`
37368e843eeSJed Brown  - * BP1 (scalar mass operator)
37468e843eeSJed Brown    * BP3 (scalar Laplace operator)
37568e843eeSJed Brown:::
376bcb2dfaeSJed Brown
377bcb2dfaeSJed Brown(v0-3)=
378bcb2dfaeSJed Brown
379bcb2dfaeSJed Brown## v0.3 (Sep 30, 2018)
380bcb2dfaeSJed Brown
381bcb2dfaeSJed BrownNotable features in this release include active/passive field interface, support for
382bcb2dfaeSJed Brownnon-tensor bases, backend optimization, and improved Fortran interface. This release
383bcb2dfaeSJed Brownalso focused on providing improved continuous integration, and many new tests with code
384bcb2dfaeSJed Browncoverage reports of about 90%. This release also provided a significant change to the
385bcb2dfaeSJed Brownpublic interface: a {ref}`CeedQFunction` can take any number of named input and output
386bcb2dfaeSJed Brownarguments while {ref}`CeedOperator` connects them to the actual data, which may be
387bcb2dfaeSJed Brownsupplied explicitly to `CeedOperatorApply()` (active) or separately via
388bcb2dfaeSJed Brown`CeedOperatorSetField()` (passive). This interface change enables reusable libraries
389bcb2dfaeSJed Brownof CeedQFunctions and composition of block solvers constructed using
390bcb2dfaeSJed Brown{ref}`CeedOperator`. A concept of blocked restriction was added to this release and
391bcb2dfaeSJed Brownused in an optimized CPU backend. Although this is typically not visible to the user,
392bcb2dfaeSJed Brownit enables effective use of arbitrary-length SIMD while maintaining cache locality.
393bcb2dfaeSJed BrownThis CPU backend also implements an algebraic factorization of tensor product gradients
394bcb2dfaeSJed Brownto perform fewer operations than standard application of interpolation and
395bcb2dfaeSJed Browndifferentiation from nodes to quadrature points. This algebraic formulation
396bcb2dfaeSJed Brownautomatically supports non-polynomial and non-interpolatory bases, thus is more general
397bcb2dfaeSJed Brownthan the more common derivation in terms of Lagrange polynomials on the quadrature points.
398bcb2dfaeSJed Brown
399bcb2dfaeSJed BrownBackends available in this release:
400bcb2dfaeSJed Brown
40168e843eeSJed Brown| CEED resource (`-ceed`) | Backend                                             |
40268e843eeSJed Brown|-------------------------|-----------------------------------------------------|
40368e843eeSJed Brown| `/cpu/self/blocked`     | Blocked reference implementation                    |
40468e843eeSJed Brown| `/cpu/self/ref`         | Serial reference implementation                     |
40568e843eeSJed Brown| `/cpu/self/tmpl`        | Backend template, defaults to `/cpu/self/blocked`   |
40668e843eeSJed Brown| `/cpu/occa`             | Serial OCCA kernels                                 |
40768e843eeSJed Brown| `/gpu/occa`             | CUDA OCCA kernels                                   |
40868e843eeSJed Brown| `/omp/occa`             | OpenMP OCCA kernels                                 |
40968e843eeSJed Brown| `/ocl/occa`             | OpenCL OCCA kernels                                 |
41068e843eeSJed Brown| `/gpu/magma`            | CUDA MAGMA kernels                                  |
411bcb2dfaeSJed Brown
412bcb2dfaeSJed BrownExamples available in this release:
413bcb2dfaeSJed Brown
41468e843eeSJed Brown:::{list-table}
41568e843eeSJed Brown:header-rows: 1
41668e843eeSJed Brown:widths: auto
41768e843eeSJed Brown* - User code
41868e843eeSJed Brown  - Example
41968e843eeSJed Brown* - `ceed`
42068e843eeSJed Brown  - * ex1 (volume)
42168e843eeSJed Brown* - `mfem`
42268e843eeSJed Brown  - * BP1 (scalar mass operator)
42368e843eeSJed Brown    * BP3 (scalar Laplace operator)
42468e843eeSJed Brown* - `petsc`
42568e843eeSJed Brown  - * BP1 (scalar mass operator)
42668e843eeSJed Brown    * BP3 (scalar Laplace operator)
42768e843eeSJed Brown* - `nek5000`
42868e843eeSJed Brown  - * BP1 (scalar mass operator)
42968e843eeSJed Brown    * BP3 (scalar Laplace operator)
43068e843eeSJed Brown:::
431bcb2dfaeSJed Brown
432bcb2dfaeSJed Brown(v0-21)=
433bcb2dfaeSJed Brown
434bcb2dfaeSJed Brown## v0.21 (Sep 30, 2018)
435bcb2dfaeSJed Brown
436bcb2dfaeSJed BrownA MAGMA backend (which relies upon the
437bcb2dfaeSJed Brown[MAGMA](https://bitbucket.org/icl/magma) package) was integrated in libCEED for this
438bcb2dfaeSJed Brownrelease. This initial integration set up the framework of using MAGMA and provided the
439bcb2dfaeSJed BrownlibCEED functionality through MAGMA kernels as one of libCEED’s computational backends.
440bcb2dfaeSJed BrownAs any other backend, the MAGMA backend provides extended basic data structures for
441bcb2dfaeSJed Brown{ref}`CeedVector`, {ref}`CeedElemRestriction`, and {ref}`CeedOperator`, and implements
442bcb2dfaeSJed Brownthe fundamental CEED building blocks to work with the new data structures.
443bcb2dfaeSJed BrownIn general, the MAGMA-specific data structures keep the libCEED pointers to CPU data
444bcb2dfaeSJed Brownbut also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled
445bcb2dfaeSJed Browninternally, and thus seamlessly to the user, through the functions/methods that are
446bcb2dfaeSJed Brownprovided to support them.
447bcb2dfaeSJed Brown
448bcb2dfaeSJed BrownBackends available in this release:
449bcb2dfaeSJed Brown
45068e843eeSJed Brown| CEED resource (`-ceed`) | Backend                         |
45168e843eeSJed Brown|-------------------------|---------------------------------|
45268e843eeSJed Brown| `/cpu/self`             | Serial reference implementation |
45368e843eeSJed Brown| `/cpu/occa`             | Serial OCCA kernels             |
45468e843eeSJed Brown| `/gpu/occa`             | CUDA OCCA kernels               |
45568e843eeSJed Brown| `/omp/occa`             | OpenMP OCCA kernels             |
45668e843eeSJed Brown| `/ocl/occa`             | OpenCL OCCA kernels             |
45768e843eeSJed Brown| `/gpu/magma`            | CUDA MAGMA kernels              |
458bcb2dfaeSJed Brown
459bcb2dfaeSJed BrownExamples available in this release:
460bcb2dfaeSJed Brown
46168e843eeSJed Brown:::{list-table}
46268e843eeSJed Brown:header-rows: 1
46368e843eeSJed Brown:widths: auto
46468e843eeSJed Brown* - User code
46568e843eeSJed Brown  - Example
46668e843eeSJed Brown* - `ceed`
46768e843eeSJed Brown  - * ex1 (volume)
46868e843eeSJed Brown* - `mfem`
46968e843eeSJed Brown  - * BP1 (scalar mass operator)
47068e843eeSJed Brown    * BP3 (scalar Laplace operator)
47168e843eeSJed Brown* - `petsc`
47268e843eeSJed Brown  - * BP1 (scalar mass operator)
47368e843eeSJed Brown* - `nek5000`
47468e843eeSJed Brown  - * BP1 (scalar mass operator)
47568e843eeSJed Brown:::
476bcb2dfaeSJed Brown
477bcb2dfaeSJed Brown(v0-2)=
478bcb2dfaeSJed Brown
479bcb2dfaeSJed Brown## v0.2 (Mar 30, 2018)
480bcb2dfaeSJed Brown
481bcb2dfaeSJed BrownlibCEED was made publicly available the first full CEED software distribution, release
482bcb2dfaeSJed BrownCEED 1.0. The distribution was made available using the Spack package manager to provide
483bcb2dfaeSJed Browna common, easy-to-use build environment, where the user can build the CEED distribution
484bcb2dfaeSJed Brownwith all dependencies. This release included a new Fortran interface for the library.
485bcb2dfaeSJed BrownThis release also contained major improvements in the OCCA backend (including a new
486bcb2dfaeSJed Brown`/ocl/occa` backend) and new examples. The standalone libCEED example was modified to
487bcb2dfaeSJed Browncompute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an
488bcb2dfaeSJed Brown`examples/ceed` subfolder. A new `mfem` example to perform BP3 (with the application
489bcb2dfaeSJed Brownof the Laplace operator) was also added to this release.
490bcb2dfaeSJed Brown
491bcb2dfaeSJed BrownBackends available in this release:
492bcb2dfaeSJed Brown
49368e843eeSJed Brown| CEED resource (`-ceed`) | Backend                         |
49468e843eeSJed Brown|-------------------------|---------------------------------|
49568e843eeSJed Brown| `/cpu/self`             | Serial reference implementation |
49668e843eeSJed Brown| `/cpu/occa`             | Serial OCCA kernels             |
49768e843eeSJed Brown| `/gpu/occa`             | CUDA OCCA kernels               |
49868e843eeSJed Brown| `/omp/occa`             | OpenMP OCCA kernels             |
49968e843eeSJed Brown| `/ocl/occa`             | OpenCL OCCA kernels             |
500bcb2dfaeSJed Brown
501bcb2dfaeSJed BrownExamples available in this release:
502bcb2dfaeSJed Brown
50368e843eeSJed Brown:::{list-table}
50468e843eeSJed Brown:header-rows: 1
50568e843eeSJed Brown:widths: auto
50668e843eeSJed Brown* - User code
50768e843eeSJed Brown  - Example
50868e843eeSJed Brown* - `ceed`
50968e843eeSJed Brown  - * ex1 (volume)
51068e843eeSJed Brown* - `mfem`
51168e843eeSJed Brown  - * BP1 (scalar mass operator)
51268e843eeSJed Brown    * BP3 (scalar Laplace operator)
51368e843eeSJed Brown* - `petsc`
51468e843eeSJed Brown  - * BP1 (scalar mass operator)
51568e843eeSJed Brown* - `nek5000`
51668e843eeSJed Brown  - * BP1 (scalar mass operator)
51768e843eeSJed Brown:::
518bcb2dfaeSJed Brown
519bcb2dfaeSJed Brown(v0-1)=
520bcb2dfaeSJed Brown
521bcb2dfaeSJed Brown## v0.1 (Jan 3, 2018)
522bcb2dfaeSJed Brown
523bcb2dfaeSJed BrownInitial low-level API of the CEED project. The low-level API provides a set of Finite
524bcb2dfaeSJed BrownElements kernels and components for writing new low-level kernels. Examples include:
525bcb2dfaeSJed Brownvector and sparse linear algebra, element matrix assembly over a batch of elements,
526bcb2dfaeSJed Brownpartial assembly and action for efficient high-order operators like mass, diffusion,
527bcb2dfaeSJed Brownadvection, etc. The main goal of the low-level API is to establish the basis for the
528bcb2dfaeSJed Brownhigh-level API. Also, identifying such low-level kernels and providing a reference
529bcb2dfaeSJed Brownimplementation for them serves as the basis for specialized backend implementations.
530bcb2dfaeSJed BrownThis release contained several backends: `/cpu/self`, and backends which rely upon the
531bcb2dfaeSJed Brown[OCCA](http://github.com/libocca/occa) package, such as `/cpu/occa`,
532bcb2dfaeSJed Brown`/gpu/occa`, and `/omp/occa`.
533bcb2dfaeSJed BrownIt also included several examples, in the `examples` folder:
534bcb2dfaeSJed BrownA standalone code that shows the usage of libCEED (with no external
535bcb2dfaeSJed Browndependencies) to apply the Laplace operator, `ex1`; an `mfem` example to perform BP1
536bcb2dfaeSJed Brown(with the application of the mass operator); and a `petsc` example to perform BP1
537bcb2dfaeSJed Brown(with the application of the mass operator).
538bcb2dfaeSJed Brown
539bcb2dfaeSJed BrownBackends available in this release:
540bcb2dfaeSJed Brown
54168e843eeSJed Brown| CEED resource (`-ceed`) | Backend                         |
54268e843eeSJed Brown|-------------------------|---------------------------------|
54368e843eeSJed Brown| `/cpu/self`             | Serial reference implementation |
54468e843eeSJed Brown| `/cpu/occa`             | Serial OCCA kernels             |
54568e843eeSJed Brown| `/gpu/occa`             | CUDA OCCA kernels               |
54668e843eeSJed Brown| `/omp/occa`             | OpenMP OCCA kernels             |
547bcb2dfaeSJed Brown
548bcb2dfaeSJed BrownExamples available in this release:
549bcb2dfaeSJed Brown
550bcb2dfaeSJed Brown| User code             | Example                           |
55168e843eeSJed Brown|-----------------------|-----------------------------------|
55268e843eeSJed Brown| `ceed`                | ex1 (scalar Laplace operator)     |
55368e843eeSJed Brown| `mfem`                | BP1 (scalar mass operator)        |
55468e843eeSJed Brown| `petsc`               | BP1 (scalar mass operator)        |
555bcb2dfaeSJed Brown```
556