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