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