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