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