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