1# Changes/Release Notes 2 3On this page we provide a summary of the main API changes, new features and examples for each release of libCEED. 4 5(main)= 6 7## Current `main` branch 8 9### Interface changes 10 11- Added {c:func}`CeedOperatorSetName` for more readable {c:func}`CeedOperatorView` output. 12- Added {c:func}`CeedBasisCreateProjection` to facilitate interpolation between nodes for separate `CeedBases`. 13 14### New features 15 16- Update `/cpu/self/memcheck/*` backends to help verify `CeedQFunctionContext` data sizes provided by user. 17- Added `CeedInt_FMT` to support potential future use of larger interger sizes. 18- Added CEED_QFUNCTION_ATTR for setting compiler attributes/pragmas to CEED_QFUNCTION_HELPER and CEED_QFUNCTION 19- OCCA backend updated to latest OCCA release; DPC++ and OMP OCCA modes enabled. 20Due to a limitation of the OCCA parser, typedefs are required to use pointers to arrays in QFunctions with the OCCA backend. 21This issue will be fixed in a future OCCA release. 22 23### Other 24 25- Switch to `clang-format` over `astyle` for automatic formatting; Makefile command changed to `make format` from `make style`. 26 27### Bugfix 28 29- Fix bug in setting device id for GPU backends. 30- Fix storing of indices for `CeedElemRestriction` on the host with GPU backends. 31- Fix `CeedElemRestriction` sizing for {c:func}`CeedOperatorAssemblePointBlockDiagonal`. 32- Fix bugs in CPU implementation of {c:func}`CeedOperatorLinearAssemble` when there are different number of active input modes and active output modes. 33 34### Examples 35 36- Added various performance enhancements for {ref}`example-petsc-navier-stokes`. 37- Refactored {ref}`example-petsc-navier-stokes` to improve code reuse. 38- Added Shock Tube, Channel, and Flat Plate boundary layer problems to {ref}`example-petsc-navier-stokes`. 39- Added ability to use QFunctions for strong STG inflow in {ref}`example-petsc-navier-stokes`. 40 41### Maintainability 42 43- Refactored `/gpu/cuda/shared` and `/gpu/cuda/gen` as well as `/gpu/hip/shared` and `/gpu/hip/gen` backend to improve maintainablity and reduce duplicated code. 44- Enabled support for `p > 8` for `/gpu/*/shared` backends. 45 46(v0-10-1)= 47 48## v0.10.1 (Apr 11, 2022) 49 50### Interface changes 51 52- Added {c:func}`CeedQFunctionSetUserFlopsEstimate` and {c:func}`CeedOperatorGetFlopsEstimate` to facilitate estimating FLOPs in operator application. 53 54### New features 55 56- Switched MAGMA backends to use runtime compilation for tensor basis kernels (and element restriction kernels, in non-deterministic `/gpu/*/magma` backends). 57This reduces time to compile the library and increases the range of parameters for which the MAGMA tensor basis kernels will work. 58 59### Bugfix 60 61- Install JiT source files in install directory to fix GPU functionality for installed libCEED. 62 63(v0-10)= 64 65## v0.10 (Mar 21, 2022) 66 67### Interface changes 68 69- Update {c:func}`CeedQFunctionGetFields` and {c:func}`CeedOperatorGetFields` to include number of fields. 70- 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`. 71- Clarify and document conditions where `CeedQFunction` and `CeedOperator` become immutable and no further fields or suboperators can be added. 72- Add {c:func}`CeedOperatorLinearAssembleQFunctionBuildOrUpdate` to reduce object creation overhead in assembly of CeedOperator preconditioning ingredients. 73- Promote {c:func}`CeedOperatorCheckReady`to the public API to facilitate interactive interfaces. 74- Warning added when compiling OCCA backend to alert users that this backend is experimental. 75- `ceed-backend.h`, `ceed-hash.h`, and `ceed-khash.h` removed. Users should use `ceed/backend.h`, `ceed/hash.h`, and `ceed/khash.h`. 76- Added {c:func}`CeedQFunctionGetKernelName`; refactored {c:func}`CeedQFunctionGetSourcePath` to exclude function kernel name. 77- 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`. 78- Added {c:func}`CeedVectorGetArrayWrite` that allows access to uninitalized arrays; require initalized data for {c:func}`CeedVectorGetArray`. 79- 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. 80- Added {c:func}`CeedQFunctionContextGetFieldDescriptions` to retreive user defined descriptions of fields that are registered with `CeedQFunctionContextRegister*`. 81- Renamed `CeedElemTopology` entries for clearer namespacing between libCEED enums. 82- 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. 83- Added {c:func}`CeedOperatorSetQFunctionUpdated` to facilitate QFunction data re-use between operators sharing the same quadrature space, such as in a multigrid hierarchy. 84- Added {c:func}`CeedOperatorGetActiveVectorLengths` to get shape of CeedOperator. 85 86### New features 87 88- `CeedScalar` can now be set as `float` or `double` at compile time. 89- Added JiT utilities in `ceed/jit-tools.h` to reduce duplicated code in GPU backends. 90- 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. 91- Remove need to guard library headers in QFunction source for code generation backends. 92- `CeedDebugEnv()` macro created to provide debugging outputs when Ceed context is not present. 93- Added {c:func}`CeedStringAllocCopy` to reduce repeated code for copying strings internally. 94- Added {c:func}`CeedPathConcatenate` to facilitate loading kernel source files with a path relative to the current file. 95- Added support for non-tensor H(div) elements, to include CPU backend implementations and {c:func}`CeedBasisCreateHdiv` convenience constructor. 96- 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. 97- Added support for element matrix assembly in GPU backends. 98 99### Maintainability 100 101- Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage. 102- `Include-what-you-use` makefile target added as `make iwyu`. 103- Create backend constant `CEED_FIELD_MAX` to reduce magic numbers in codebase. 104- Put GPU JiTed kernel source code into separate files. 105- 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. 106 107(v0-9)= 108 109## v0.9 (Jul 6, 2021) 110 111### Interface changes 112 113- Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact. 114 115### New features 116 117- Add {c:func}`CeedVectorAXPY` and {c:func}`CeedVectorPointwiseMult` as a convenience for stand-alone testing and internal use. 118- Add `CEED_QFUNCTION_HELPER` macro to properly annotate QFunction helper functions for code generation backends. 119- Add `CeedPragmaOptimizeOff` macro for code that is sensitive to floating point errors from fast math optimizations. 120- Rust support: split `libceed-sys` crate out of `libceed` and [publish both on crates.io](https://crates.io/crates/libceed). 121 122### Performance improvements 123 124### Examples 125 126- Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations. 127- Fluid mechanics example adds GPU support and improves modularity. 128 129### Deprecated backends 130 131- 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. 132 133(v0-8)= 134 135## v0.8 (Mar 31, 2021) 136 137### Interface changes 138 139- Error handling improved to include enumerated error codes for C interface return values. 140- 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. 141 142### New features 143 144- Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features. 145- Static libraries can be built with `make STATIC=1` and the pkg-config file is installed accordingly. 146- Add {c:func}`CeedOperatorLinearAssembleSymbolic` and {c:func}`CeedOperatorLinearAssemble` to support full assembly of libCEED operators. 147 148### Performance improvements 149 150- New HIP MAGMA backends for hipMAGMA library users: `/gpu/hip/magma` and `/gpu/hip/magma/det`. 151- New HIP backends for improved tensor basis performance: `/gpu/hip/shared` and `/gpu/hip/gen`. 152 153### Examples 154 155- {ref}`example-petsc-elasticity` example updated with traction boundary conditions and improved Dirichlet boundary conditions. 156- {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. 157- {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. 158- {ref}`example-petsc-navier-stokes` example updated with support for performing convergence study and plotting order of convergence by polynomial degree. 159 160(v0-7)= 161 162## v0.7 (Sep 29, 2020) 163 164### Interface changes 165 166- Replace limited {code}`CeedInterlaceMode` with more flexible component stride {code}`compstride` in {code}`CeedElemRestriction` constructors. 167 As a result, the {code}`indices` parameter has been replaced with {code}`offsets` and the {code}`nnodes` parameter has been replaced with {code}`lsize`. 168 These changes improve support for mixed finite element methods. 169- Replace various uses of {code}`Ceed*Get*Status` with {code}`Ceed*Is*` in the backend API to match common nomenclature. 170- Replace {code}`CeedOperatorAssembleLinearDiagonal` with {c:func}`CeedOperatorLinearAssembleDiagonal` for clarity. 171- 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. 172- 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. 173- 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. 174- 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. 175 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`. 176- Added {code}`CeedQFunctionContext` object to manage user QFunction context data and reduce copies between device and host memory. 177- 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. 178 179### New features 180 181- New HIP backend: `/gpu/hip/ref`. 182- CeedQFunction support for user `CUfunction`s in some backends 183 184### Performance improvements 185 186- OCCA backend rebuilt to facilitate future performance enhancements. 187- Petsc BPs suite improved to reduce noise due to multiple calls to {code}`mpiexec`. 188 189### Examples 190 191- {ref}`example-petsc-elasticity` example updated with strain energy computation and more flexible boundary conditions. 192 193### Deprecated backends 194 195- The `/gpu/cuda/reg` backend has been removed, with its core features moved into `/gpu/cuda/ref` and `/gpu/cuda/shared`. 196 197(v0-6)= 198 199## v0.6 (Mar 29, 2020) 200 201libCEED v0.6 contains numerous new features and examples, as well as expanded 202documentation in [this new website](https://libceed.org). 203 204### New features 205 206- New Python interface using [CFFI](https://cffi.readthedocs.io/) provides a nearly 207 1-1 correspondence with the C interface, plus some convenience features. For instance, 208 data stored in the {cpp:type}`CeedVector` structure are available without copy as 209 {py:class}`numpy.ndarray`. Short tutorials are provided in 210 [Binder](https://mybinder.org/v2/gh/CEED/libCEED/main?urlpath=lab/tree/examples/tutorials/). 211- Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point, 212 {c:func}`CeedOperatorAssembleLinearQFunction`) or to evaluate the diagonal 213 ({c:func}`CeedOperatorAssembleLinearDiagonal`). These operations are useful for 214 preconditioning ingredients and are used in the libCEED's multigrid examples. 215- The inverse of separable operators can be obtained using 216 {c:func}`CeedOperatorCreateFDMElementInverse` and applied with 217 {c:func}`CeedOperatorApply`. This is a useful preconditioning ingredient, 218 especially for Laplacians and related operators. 219- New functions: {c:func}`CeedVectorNorm`, {c:func}`CeedOperatorApplyAdd`, 220 {c:func}`CeedQFunctionView`, {c:func}`CeedOperatorView`. 221- Make public accessors for various attributes to facilitate writing composable code. 222- New backend: `/cpu/self/memcheck/serial`. 223- QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA 224 backends. (Single source is coming soon for OCCA backends.) 225- Fix some missing edge cases in CUDA backend. 226 227### Performance Improvements 228 229- MAGMA backend performance optimization and non-tensor bases. 230- No-copy optimization in {c:func}`CeedOperatorApply`. 231 232### Interface changes 233 234- Replace {code}`CeedElemRestrictionCreateIdentity` and 235 {code}`CeedElemRestrictionCreateBlocked` with more flexible 236 {c:func}`CeedElemRestrictionCreateStrided` and 237 {c:func}`CeedElemRestrictionCreateBlockedStrided`. 238- Add arguments to {c:func}`CeedQFunctionCreateIdentity`. 239- Replace ambiguous uses of {cpp:enum}`CeedTransposeMode` for L-vector identification 240 with {cpp:enum}`CeedInterlaceMode`. This is now an attribute of the 241 {cpp:type}`CeedElemRestriction` (see {c:func}`CeedElemRestrictionCreate`) and no 242 longer passed as `lmode` arguments to {c:func}`CeedOperatorSetField` and 243 {c:func}`CeedElemRestrictionApply`. 244 245### Examples 246 247libCEED-0.6 contains greatly expanded examples with {ref}`new documentation <Examples>`. 248Notable additions include: 249 250- Standalone {ref}`ex2-surface` ({file}`examples/ceed/ex2-surface`): compute the area of 251 a domain in 1, 2, and 3 dimensions by applying a Laplacian. 252 253- PETSc {ref}`example-petsc-area` ({file}`examples/petsc/area.c`): computes surface area 254 of domains (like the cube and sphere) by direct integration on a surface mesh; 255 demonstrates geometric dimension different from topological dimension. 256 257- PETSc {ref}`example-petsc-bps`: 258 259 - {file}`examples/petsc/bpsraw.c` (formerly `bps.c`): transparent CUDA support. 260 - {file}`examples/petsc/bps.c` (formerly `bpsdmplex.c`): performance improvements 261 and transparent CUDA support. 262 - {ref}`example-petsc-bps-sphere` ({file}`examples/petsc/bpssphere.c`): 263 generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric 264 dimension different from topological dimension. 265 266- {ref}`example-petsc-multigrid` ({file}`examples/petsc/multigrid.c`): new p-multigrid 267 solver with algebraic multigrid coarse solve. 268 269- {ref}`example-petsc-navier-stokes` ({file}`examples/fluids/navierstokes.c`; formerly 270 `examples/navier-stokes`): unstructured grid support (using PETSc's `DMPlex`), 271 implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and 272 quasi-2D computational domain support. 273 274- {ref}`example-petsc-elasticity` ({file}`examples/solids/elasticity.c`): new solver for 275 linear elasticity, small-strain hyperelasticity, and globalized finite-strain 276 hyperelasticity using p-multigrid with algebraic multigrid coarse solve. 277 278(v0-5)= 279 280## v0.5 (Sep 18, 2019) 281 282For this release, several improvements were made. Two new CUDA backends were added to 283the family of backends, of which, the new `cuda-gen` backend achieves state-of-the-art 284performance using single-source {ref}`CeedQFunction`. From this release, users 285can define Q-Functions in a single source code independently of the targeted backend 286with the aid of a new macro `CEED QFUNCTION` to support JIT (Just-In-Time) and CPU 287compilation of the user provided {ref}`CeedQFunction` code. To allow a unified 288declaration, the {ref}`CeedQFunction` API has undergone a slight change: 289the `QFunctionField` parameter `ncomp` has been changed to `size`. This change 290requires setting the previous value of `ncomp` to `ncomp*dim` when adding a 291`QFunctionField` with eval mode `CEED EVAL GRAD`. 292 293Additionally, new CPU backends 294were included in this release, such as the `/cpu/self/opt/*` backends (which are 295written in pure C and use partial **E-vectors** to improve performance) and the 296`/cpu/self/ref/memcheck` backend (which relies upon the 297[Valgrind](http://valgrind.org/) Memcheck tool to help verify that user 298{ref}`CeedQFunction` have no undefined values). 299This release also included various performance improvements, bug fixes, new examples, 300and improved tests. Among these improvements, vectorized instructions for 301{ref}`CeedQFunction` code compiled for CPU were enhanced by using `CeedPragmaSIMD` 302instead of `CeedPragmaOMP`, implementation of a {ref}`CeedQFunction` gallery and 303identity Q-Functions were introduced, and the PETSc benchmark problems were expanded 304to include unstructured meshes handling were. For this expansion, the prior version of 305the PETSc BPs, which only included data associated with structured geometries, were 306renamed `bpsraw`, and the new version of the BPs, which can handle data associated 307with any unstructured geometry, were called `bps`. Additionally, other benchmark 308problems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively), 309and BP5 and BP6 (the collocated versions---for which the quadrature points are the same 310as the Gauss Lobatto nodes---of BP3 and BP4 respectively) were added to the PETSc 311examples. Furthermoew, another standalone libCEED example, called `ex2`, which 312computes the surface area of a given mesh was added to this release. 313 314Backends available in this release: 315 316| CEED resource (`-ceed`) | Backend | 317|--------------------------|-----------------------------------------------------| 318| `/cpu/self/ref/serial` | Serial reference implementation | 319| `/cpu/self/ref/blocked` | Blocked reference implementation | 320| `/cpu/self/ref/memcheck` | Memcheck backend, undefined value checks | 321| `/cpu/self/opt/serial` | Serial optimized C implementation | 322| `/cpu/self/opt/blocked` | Blocked optimized C implementation | 323| `/cpu/self/avx/serial` | Serial AVX implementation | 324| `/cpu/self/avx/blocked` | Blocked AVX implementation | 325| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 326| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 327| `/cpu/occa` | Serial OCCA kernels | 328| `/gpu/occa` | CUDA OCCA kernels | 329| `/omp/occa` | OpenMP OCCA kernels | 330| `/ocl/occa` | OpenCL OCCA kernels | 331| `/gpu/cuda/ref` | Reference pure CUDA kernels | 332| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 333| `/gpu/cuda/shared` | Optimized pure CUDA kernels using shared memory | 334| `/gpu/cuda/gen` | Optimized pure CUDA kernels using code generation | 335| `/gpu/magma` | CUDA MAGMA kernels | 336 337Examples available in this release: 338 339:::{list-table} 340:header-rows: 1 341:widths: auto 342* - User code 343 - Example 344* - `ceed` 345 - * ex1 (volume) 346 * ex2 (surface) 347* - `mfem` 348 - * BP1 (scalar mass operator) 349 * BP3 (scalar Laplace operator) 350* - `petsc` 351 - * BP1 (scalar mass operator) 352 * BP2 (vector mass operator) 353 * BP3 (scalar Laplace operator) 354 * BP4 (vector Laplace operator) 355 * BP5 (collocated scalar Laplace operator) 356 * BP6 (collocated vector Laplace operator) 357 * Navier-Stokes 358* - `nek5000` 359 - * BP1 (scalar mass operator) 360 * BP3 (scalar Laplace operator) 361::: 362 363(v0-4)= 364 365## v0.4 (Apr 1, 2019) 366 367libCEED v0.4 was made again publicly available in the second full CEED software 368distribution, release CEED 2.0. This release contained notable features, such as 369four new CPU backends, two new GPU backends, CPU backend optimizations, initial 370support for operator composition, performance benchmarking, and a Navier-Stokes demo. 371The new CPU backends in this release came in two families. The `/cpu/self/*/serial` 372backends process one element at a time and are intended for meshes with a smaller number 373of high order elements. The `/cpu/self/*/blocked` backends process blocked batches of 374eight interlaced elements and are intended for meshes with higher numbers of elements. 375The `/cpu/self/avx/*` backends rely upon AVX instructions to provide vectorized CPU 376performance. The `/cpu/self/xsmm/*` backends rely upon the 377[LIBXSMM](http://github.com/hfp/libxsmm) package to provide vectorized CPU 378performance. The `/gpu/cuda/*` backends provide GPU performance strictly using CUDA. 379The `/gpu/cuda/ref` backend is a reference CUDA backend, providing reasonable 380performance for most problem configurations. The `/gpu/cuda/reg` backend uses a simple 381parallelization approach, where each thread treats a finite element. Using just in time 382compilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this 383backend unroll loops and map memory address to registers. The `/gpu/cuda/reg` backend 384achieve good peak performance for 1D, 2D, and low order 3D problems, but performance 385deteriorates very quickly when threads run out of registers. 386 387A new explicit time-stepping Navier-Stokes solver was added to the family of libCEED 388examples in the `examples/petsc` directory (see {ref}`example-petsc-navier-stokes`). 389This example solves the time-dependent Navier-Stokes equations of compressible gas 390dynamics in a static Eulerian three-dimensional frame, using structured high-order 391finite/spectral element spatial discretizations and explicit high-order time-stepping 392(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc, 393so that the pointwise physics (defined at quadrature points) is separated from the 394parallelization and meshing concerns. 395 396Backends available in this release: 397 398| CEED resource (`-ceed`) | Backend | 399|--------------------------|-----------------------------------------------------| 400| `/cpu/self/ref/serial` | Serial reference implementation | 401| `/cpu/self/ref/blocked` | Blocked reference implementation | 402| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 403| `/cpu/self/avx/serial` | Serial AVX implementation | 404| `/cpu/self/avx/blocked` | Blocked AVX implementation | 405| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 406| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 407| `/cpu/occa` | Serial OCCA kernels | 408| `/gpu/occa` | CUDA OCCA kernels | 409| `/omp/occa` | OpenMP OCCA kernels | 410| `/ocl/occa` | OpenCL OCCA kernels | 411| `/gpu/cuda/ref` | Reference pure CUDA kernels | 412| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 413| `/gpu/magma` | CUDA MAGMA kernels | 414 415Examples available in this release: 416 417:::{list-table} 418:header-rows: 1 419:widths: auto 420* - User code 421 - Example 422* - `ceed` 423 - * ex1 (volume) 424* - `mfem` 425 - * BP1 (scalar mass operator) 426 * BP3 (scalar Laplace operator) 427* - `petsc` 428 - * BP1 (scalar mass operator) 429 * BP3 (scalar Laplace operator) 430 * Navier-Stokes 431* - `nek5000` 432 - * BP1 (scalar mass operator) 433 * BP3 (scalar Laplace operator) 434::: 435 436(v0-3)= 437 438## v0.3 (Sep 30, 2018) 439 440Notable features in this release include active/passive field interface, support for 441non-tensor bases, backend optimization, and improved Fortran interface. This release 442also focused on providing improved continuous integration, and many new tests with code 443coverage reports of about 90%. This release also provided a significant change to the 444public interface: a {ref}`CeedQFunction` can take any number of named input and output 445arguments while {ref}`CeedOperator` connects them to the actual data, which may be 446supplied explicitly to `CeedOperatorApply()` (active) or separately via 447`CeedOperatorSetField()` (passive). This interface change enables reusable libraries 448of CeedQFunctions and composition of block solvers constructed using 449{ref}`CeedOperator`. A concept of blocked restriction was added to this release and 450used in an optimized CPU backend. Although this is typically not visible to the user, 451it enables effective use of arbitrary-length SIMD while maintaining cache locality. 452This CPU backend also implements an algebraic factorization of tensor product gradients 453to perform fewer operations than standard application of interpolation and 454differentiation from nodes to quadrature points. This algebraic formulation 455automatically supports non-polynomial and non-interpolatory bases, thus is more general 456than the more common derivation in terms of Lagrange polynomials on the quadrature points. 457 458Backends available in this release: 459 460| CEED resource (`-ceed`) | Backend | 461|-------------------------|-----------------------------------------------------| 462| `/cpu/self/blocked` | Blocked reference implementation | 463| `/cpu/self/ref` | Serial reference implementation | 464| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 465| `/cpu/occa` | Serial OCCA kernels | 466| `/gpu/occa` | CUDA OCCA kernels | 467| `/omp/occa` | OpenMP OCCA kernels | 468| `/ocl/occa` | OpenCL OCCA kernels | 469| `/gpu/magma` | CUDA MAGMA kernels | 470 471Examples available in this release: 472 473:::{list-table} 474:header-rows: 1 475:widths: auto 476* - User code 477 - Example 478* - `ceed` 479 - * ex1 (volume) 480* - `mfem` 481 - * BP1 (scalar mass operator) 482 * BP3 (scalar Laplace operator) 483* - `petsc` 484 - * BP1 (scalar mass operator) 485 * BP3 (scalar Laplace operator) 486* - `nek5000` 487 - * BP1 (scalar mass operator) 488 * BP3 (scalar Laplace operator) 489::: 490 491(v0-21)= 492 493## v0.21 (Sep 30, 2018) 494 495A MAGMA backend (which relies upon the 496[MAGMA](https://bitbucket.org/icl/magma) package) was integrated in libCEED for this 497release. This initial integration set up the framework of using MAGMA and provided the 498libCEED functionality through MAGMA kernels as one of libCEED’s computational backends. 499As any other backend, the MAGMA backend provides extended basic data structures for 500{ref}`CeedVector`, {ref}`CeedElemRestriction`, and {ref}`CeedOperator`, and implements 501the fundamental CEED building blocks to work with the new data structures. 502In general, the MAGMA-specific data structures keep the libCEED pointers to CPU data 503but also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled 504internally, and thus seamlessly to the user, through the functions/methods that are 505provided to support them. 506 507Backends available in this release: 508 509| CEED resource (`-ceed`) | Backend | 510|-------------------------|---------------------------------| 511| `/cpu/self` | Serial reference implementation | 512| `/cpu/occa` | Serial OCCA kernels | 513| `/gpu/occa` | CUDA OCCA kernels | 514| `/omp/occa` | OpenMP OCCA kernels | 515| `/ocl/occa` | OpenCL OCCA kernels | 516| `/gpu/magma` | CUDA MAGMA kernels | 517 518Examples available in this release: 519 520:::{list-table} 521:header-rows: 1 522:widths: auto 523* - User code 524 - Example 525* - `ceed` 526 - * ex1 (volume) 527* - `mfem` 528 - * BP1 (scalar mass operator) 529 * BP3 (scalar Laplace operator) 530* - `petsc` 531 - * BP1 (scalar mass operator) 532* - `nek5000` 533 - * BP1 (scalar mass operator) 534::: 535 536(v0-2)= 537 538## v0.2 (Mar 30, 2018) 539 540libCEED was made publicly available the first full CEED software distribution, release 541CEED 1.0. The distribution was made available using the Spack package manager to provide 542a common, easy-to-use build environment, where the user can build the CEED distribution 543with all dependencies. This release included a new Fortran interface for the library. 544This release also contained major improvements in the OCCA backend (including a new 545`/ocl/occa` backend) and new examples. The standalone libCEED example was modified to 546compute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an 547`examples/ceed` subfolder. A new `mfem` example to perform BP3 (with the application 548of the Laplace operator) was also added to this release. 549 550Backends available in this release: 551 552| CEED resource (`-ceed`) | Backend | 553|-------------------------|---------------------------------| 554| `/cpu/self` | Serial reference implementation | 555| `/cpu/occa` | Serial OCCA kernels | 556| `/gpu/occa` | CUDA OCCA kernels | 557| `/omp/occa` | OpenMP OCCA kernels | 558| `/ocl/occa` | OpenCL OCCA kernels | 559 560Examples available in this release: 561 562:::{list-table} 563:header-rows: 1 564:widths: auto 565* - User code 566 - Example 567* - `ceed` 568 - * ex1 (volume) 569* - `mfem` 570 - * BP1 (scalar mass operator) 571 * BP3 (scalar Laplace operator) 572* - `petsc` 573 - * BP1 (scalar mass operator) 574* - `nek5000` 575 - * BP1 (scalar mass operator) 576::: 577 578(v0-1)= 579 580## v0.1 (Jan 3, 2018) 581 582Initial low-level API of the CEED project. The low-level API provides a set of Finite 583Elements kernels and components for writing new low-level kernels. Examples include: 584vector and sparse linear algebra, element matrix assembly over a batch of elements, 585partial assembly and action for efficient high-order operators like mass, diffusion, 586advection, etc. The main goal of the low-level API is to establish the basis for the 587high-level API. Also, identifying such low-level kernels and providing a reference 588implementation for them serves as the basis for specialized backend implementations. 589This release contained several backends: `/cpu/self`, and backends which rely upon the 590[OCCA](http://github.com/libocca/occa) package, such as `/cpu/occa`, 591`/gpu/occa`, and `/omp/occa`. 592It also included several examples, in the `examples` folder: 593A standalone code that shows the usage of libCEED (with no external 594dependencies) to apply the Laplace operator, `ex1`; an `mfem` example to perform BP1 595(with the application of the mass operator); and a `petsc` example to perform BP1 596(with the application of the mass operator). 597 598Backends available in this release: 599 600| CEED resource (`-ceed`) | Backend | 601|-------------------------|---------------------------------| 602| `/cpu/self` | Serial reference implementation | 603| `/cpu/occa` | Serial OCCA kernels | 604| `/gpu/occa` | CUDA OCCA kernels | 605| `/omp/occa` | OpenMP OCCA kernels | 606 607Examples available in this release: 608 609| User code | Example | 610|-----------------------|-----------------------------------| 611| `ceed` | ex1 (scalar Laplace operator) | 612| `mfem` | BP1 (scalar mass operator) | 613| `petsc` | BP1 (scalar mass operator) | 614``` 615