1# Changes/Release Notes 2 3On this page we provide a summary of the main API changes, new features and examples for each release of libCEED. 4 5(main)= 6 7## Current `main` branch 8 9### Bugfix 10 11- Fix bug in setting device id for GPU backends. 12 13### Interface changes 14 15- Added {c:func}`CeedOperatorSetName` for more readable {c:func}`CeedOperatorView` output. 16 17### New features 18 19- Update `/cpu/self/memcheck/*` backends to help verify `CeedQFunctionContext` data sizes provided by user. 20 21### Bugfix 22 23- Fix storing of indices for `CeedElemRestriction` on the host with GPU backends. 24- Fix `CeedElemRestriction` sizing for {c:func}`CeedOperatorAssemblePointBlockDiagonal`. 25- Fix bugs in CPU implementation of {c:func}`CeedOperatorLinearAssemble` when there are different number of active input modes and active output modes. 26 27### Examples 28 29- Added various performance enhancements for {ref}`example-petsc-navier-stokes` 30 31(v0-10-1)= 32 33## v0.10.1 (Apr 11, 2022) 34 35### Interface changes 36 37- Added {c:func}`CeedQFunctionSetUserFlopsEstimate` and {c:func}`CeedOperatorGetFlopsEstimate` to facilitate estimating FLOPs in operator application. 38 39### Bugfix 40 41- Install JiT source files in install directory to fix GPU functionality for installed libCEED. 42 43(v0-10)= 44 45## v0.10 (Mar 21, 2022) 46 47### Interface changes 48 49- Update {c:func}`CeedQFunctionGetFields` and {c:func}`CeedOperatorGetFields` to include number of fields. 50- 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`. 51- Clarify and document conditions where `CeedQFunction` and `CeedOperator` become immutable and no further fields or suboperators can be added. 52- Add {c:func}`CeedOperatorLinearAssembleQFunctionBuildOrUpdate` to reduce object creation overhead in assembly of CeedOperator preconditioning ingredients. 53- Promote {c:func}`CeedOperatorCheckReady`to the public API to facilitate interactive interfaces. 54- Warning added when compiling OCCA backend to alert users that this backend is experimental. 55- `ceed-backend.h`, `ceed-hash.h`, and `ceed-khash.h` removed. Users should use `ceed/backend.h`, `ceed/hash.h`, and `ceed/khash.h`. 56- Added {c:func}`CeedQFunctionGetKernelName`; refactored {c:func}`CeedQFunctionGetSourcePath` to exclude function kernel name. 57- 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`. 58- Added {c:func}`CeedVectorGetArrayWrite` that allows access to uninitalized arrays; require initalized data for {c:func}`CeedVectorGetArray`. 59- 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. 60- Added {c:func}`CeedQFunctionContextGetFieldDescriptions` to retreive user defined descriptions of fields that are registered with `CeedQFunctionContextRegister*`. 61- Renamed `CeedElemTopology` entries for clearer namespacing between libCEED enums. 62- 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. 63- Added {c:func}`CeedOperatorSetQFunctionUpdated` to facilitate QFunction data re-use between operators sharing the same quadrature space, such as in a multigrid hierarchy. 64- Added {c:func}`CeedOperatorGetActiveVectorLengths` to get shape of CeedOperator. 65 66### New features 67 68- `CeedScalar` can now be set as `float` or `double` at compile time. 69- Added JiT utilities in `ceed/jit-tools.h` to reduce duplicated code in GPU backends. 70- 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. 71- Remove need to guard library headers in QFunction source for code generation backends. 72- `CeedDebugEnv()` macro created to provide debugging outputs when Ceed context is not present. 73- Added {c:func}`CeedStringAllocCopy` to reduce repeated code for copying strings internally. 74- Added {c:func}`CeedPathConcatenate` to facilitate loading kernel source files with a path relative to the current file. 75- Added support for non-tensor H(div) elements, to include CPU backend implementations and {c:func}`CeedBasisCreateHdiv` convenience constructor. 76- 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. 77- Added support for element matrix assembly in GPU backends. 78 79### Maintainability 80 81- Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage. 82- `Include-what-you-use` makefile target added as `make iwyu`. 83- Create backend constant `CEED_FIELD_MAX` to reduce magic numbers in codebase. 84- Put GPU JiTed kernel source code into separate files. 85- 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. 86 87(v0-9)= 88 89## v0.9 (Jul 6, 2021) 90 91### Interface changes 92 93- Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact. 94 95### New features 96 97- Add {c:func}`CeedVectorAXPY` and {c:func}`CeedVectorPointwiseMult` as a convenience for stand-alone testing and internal use. 98- Add `CEED_QFUNCTION_HELPER` macro to properly annotate QFunction helper functions for code generation backends. 99- Add `CeedPragmaOptimizeOff` macro for code that is sensitive to floating point errors from fast math optimizations. 100- Rust support: split `libceed-sys` crate out of `libceed` and [publish both on crates.io](https://crates.io/crates/libceed). 101 102### Performance improvements 103 104### Examples 105 106- Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations. 107- Fluid mechanics example adds GPU support and improves modularity. 108 109### Deprecated backends 110 111- 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. 112 113(v0-8)= 114 115## v0.8 (Mar 31, 2021) 116 117### Interface changes 118 119- Error handling improved to include enumerated error codes for C interface return values. 120- 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. 121 122### New features 123 124- Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features. 125- Static libraries can be built with `make STATIC=1` and the pkg-config file is installed accordingly. 126- Add {c:func}`CeedOperatorLinearAssembleSymbolic` and {c:func}`CeedOperatorLinearAssemble` to support full assembly of libCEED operators. 127 128### Performance improvements 129 130- New HIP MAGMA backends for hipMAGMA library users: `/gpu/hip/magma` and `/gpu/hip/magma/det`. 131- New HIP backends for improved tensor basis performance: `/gpu/hip/shared` and `/gpu/hip/gen`. 132 133### Examples 134 135- {ref}`example-petsc-elasticity` example updated with traction boundary conditions and improved Dirichlet boundary conditions. 136- {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. 137- {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. 138- {ref}`example-petsc-navier-stokes` example updated with support for performing convergence study and plotting order of convergence by polynomial degree. 139 140(v0-7)= 141 142## v0.7 (Sep 29, 2020) 143 144### Interface changes 145 146- Replace limited {code}`CeedInterlaceMode` with more flexible component stride {code}`compstride` in {code}`CeedElemRestriction` constructors. 147 As a result, the {code}`indices` parameter has been replaced with {code}`offsets` and the {code}`nnodes` parameter has been replaced with {code}`lsize`. 148 These changes improve support for mixed finite element methods. 149- Replace various uses of {code}`Ceed*Get*Status` with {code}`Ceed*Is*` in the backend API to match common nomenclature. 150- Replace {code}`CeedOperatorAssembleLinearDiagonal` with {c:func}`CeedOperatorLinearAssembleDiagonal` for clarity. 151- 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. 152- 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. 153- 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. 154- 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. 155 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`. 156- Added {code}`CeedQFunctionContext` object to manage user QFunction context data and reduce copies between device and host memory. 157- 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. 158 159### New features 160 161- New HIP backend: `/gpu/hip/ref`. 162- CeedQFunction support for user `CUfunction`s in some backends 163 164### Performance improvements 165 166- OCCA backend rebuilt to facilitate future performance enhancements. 167- Petsc BPs suite improved to reduce noise due to multiple calls to {code}`mpiexec`. 168 169### Examples 170 171- {ref}`example-petsc-elasticity` example updated with strain energy computation and more flexible boundary conditions. 172 173### Deprecated backends 174 175- The `/gpu/cuda/reg` backend has been removed, with its core features moved into `/gpu/cuda/ref` and `/gpu/cuda/shared`. 176 177(v0-6)= 178 179## v0.6 (Mar 29, 2020) 180 181libCEED v0.6 contains numerous new features and examples, as well as expanded 182documentation in [this new website](https://libceed.org). 183 184### New features 185 186- New Python interface using [CFFI](https://cffi.readthedocs.io/) provides a nearly 187 1-1 correspondence with the C interface, plus some convenience features. For instance, 188 data stored in the {cpp:type}`CeedVector` structure are available without copy as 189 {py:class}`numpy.ndarray`. Short tutorials are provided in 190 [Binder](https://mybinder.org/v2/gh/CEED/libCEED/main?urlpath=lab/tree/examples/tutorials/). 191- Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point, 192 {c:func}`CeedOperatorAssembleLinearQFunction`) or to evaluate the diagonal 193 ({c:func}`CeedOperatorAssembleLinearDiagonal`). These operations are useful for 194 preconditioning ingredients and are used in the libCEED's multigrid examples. 195- The inverse of separable operators can be obtained using 196 {c:func}`CeedOperatorCreateFDMElementInverse` and applied with 197 {c:func}`CeedOperatorApply`. This is a useful preconditioning ingredient, 198 especially for Laplacians and related operators. 199- New functions: {c:func}`CeedVectorNorm`, {c:func}`CeedOperatorApplyAdd`, 200 {c:func}`CeedQFunctionView`, {c:func}`CeedOperatorView`. 201- Make public accessors for various attributes to facilitate writing composable code. 202- New backend: `/cpu/self/memcheck/serial`. 203- QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA 204 backends. (Single source is coming soon for OCCA backends.) 205- Fix some missing edge cases in CUDA backend. 206 207### Performance Improvements 208 209- MAGMA backend performance optimization and non-tensor bases. 210- No-copy optimization in {c:func}`CeedOperatorApply`. 211 212### Interface changes 213 214- Replace {code}`CeedElemRestrictionCreateIdentity` and 215 {code}`CeedElemRestrictionCreateBlocked` with more flexible 216 {c:func}`CeedElemRestrictionCreateStrided` and 217 {c:func}`CeedElemRestrictionCreateBlockedStrided`. 218- Add arguments to {c:func}`CeedQFunctionCreateIdentity`. 219- Replace ambiguous uses of {cpp:enum}`CeedTransposeMode` for L-vector identification 220 with {cpp:enum}`CeedInterlaceMode`. This is now an attribute of the 221 {cpp:type}`CeedElemRestriction` (see {c:func}`CeedElemRestrictionCreate`) and no 222 longer passed as `lmode` arguments to {c:func}`CeedOperatorSetField` and 223 {c:func}`CeedElemRestrictionApply`. 224 225### Examples 226 227libCEED-0.6 contains greatly expanded examples with {ref}`new documentation <Examples>`. 228Notable additions include: 229 230- Standalone {ref}`ex2-surface` ({file}`examples/ceed/ex2-surface`): compute the area of 231 a domain in 1, 2, and 3 dimensions by applying a Laplacian. 232 233- PETSc {ref}`example-petsc-area` ({file}`examples/petsc/area.c`): computes surface area 234 of domains (like the cube and sphere) by direct integration on a surface mesh; 235 demonstrates geometric dimension different from topological dimension. 236 237- PETSc {ref}`example-petsc-bps`: 238 239 - {file}`examples/petsc/bpsraw.c` (formerly `bps.c`): transparent CUDA support. 240 - {file}`examples/petsc/bps.c` (formerly `bpsdmplex.c`): performance improvements 241 and transparent CUDA support. 242 - {ref}`example-petsc-bps-sphere` ({file}`examples/petsc/bpssphere.c`): 243 generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric 244 dimension different from topological dimension. 245 246- {ref}`example-petsc-multigrid` ({file}`examples/petsc/multigrid.c`): new p-multigrid 247 solver with algebraic multigrid coarse solve. 248 249- {ref}`example-petsc-navier-stokes` ({file}`examples/fluids/navierstokes.c`; formerly 250 `examples/navier-stokes`): unstructured grid support (using PETSc's `DMPlex`), 251 implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and 252 quasi-2D computational domain support. 253 254- {ref}`example-petsc-elasticity` ({file}`examples/solids/elasticity.c`): new solver for 255 linear elasticity, small-strain hyperelasticity, and globalized finite-strain 256 hyperelasticity using p-multigrid with algebraic multigrid coarse solve. 257 258(v0-5)= 259 260## v0.5 (Sep 18, 2019) 261 262For this release, several improvements were made. Two new CUDA backends were added to 263the family of backends, of which, the new `cuda-gen` backend achieves state-of-the-art 264performance using single-source {ref}`CeedQFunction`. From this release, users 265can define Q-Functions in a single source code independently of the targeted backend 266with the aid of a new macro `CEED QFUNCTION` to support JIT (Just-In-Time) and CPU 267compilation of the user provided {ref}`CeedQFunction` code. To allow a unified 268declaration, the {ref}`CeedQFunction` API has undergone a slight change: 269the `QFunctionField` parameter `ncomp` has been changed to `size`. This change 270requires setting the previous value of `ncomp` to `ncomp*dim` when adding a 271`QFunctionField` with eval mode `CEED EVAL GRAD`. 272 273Additionally, new CPU backends 274were included in this release, such as the `/cpu/self/opt/*` backends (which are 275written in pure C and use partial **E-vectors** to improve performance) and the 276`/cpu/self/ref/memcheck` backend (which relies upon the 277[Valgrind](http://valgrind.org/) Memcheck tool to help verify that user 278{ref}`CeedQFunction` have no undefined values). 279This release also included various performance improvements, bug fixes, new examples, 280and improved tests. Among these improvements, vectorized instructions for 281{ref}`CeedQFunction` code compiled for CPU were enhanced by using `CeedPragmaSIMD` 282instead of `CeedPragmaOMP`, implementation of a {ref}`CeedQFunction` gallery and 283identity Q-Functions were introduced, and the PETSc benchmark problems were expanded 284to include unstructured meshes handling were. For this expansion, the prior version of 285the PETSc BPs, which only included data associated with structured geometries, were 286renamed `bpsraw`, and the new version of the BPs, which can handle data associated 287with any unstructured geometry, were called `bps`. Additionally, other benchmark 288problems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively), 289and BP5 and BP6 (the collocated versions---for which the quadrature points are the same 290as the Gauss Lobatto nodes---of BP3 and BP4 respectively) were added to the PETSc 291examples. Furthermoew, another standalone libCEED example, called `ex2`, which 292computes the surface area of a given mesh was added to this release. 293 294Backends available in this release: 295 296| CEED resource (`-ceed`) | Backend | 297|--------------------------|-----------------------------------------------------| 298| `/cpu/self/ref/serial` | Serial reference implementation | 299| `/cpu/self/ref/blocked` | Blocked reference implementation | 300| `/cpu/self/ref/memcheck` | Memcheck backend, undefined value checks | 301| `/cpu/self/opt/serial` | Serial optimized C implementation | 302| `/cpu/self/opt/blocked` | Blocked optimized C implementation | 303| `/cpu/self/avx/serial` | Serial AVX implementation | 304| `/cpu/self/avx/blocked` | Blocked AVX implementation | 305| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 306| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 307| `/cpu/occa` | Serial OCCA kernels | 308| `/gpu/occa` | CUDA OCCA kernels | 309| `/omp/occa` | OpenMP OCCA kernels | 310| `/ocl/occa` | OpenCL OCCA kernels | 311| `/gpu/cuda/ref` | Reference pure CUDA kernels | 312| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 313| `/gpu/cuda/shared` | Optimized pure CUDA kernels using shared memory | 314| `/gpu/cuda/gen` | Optimized pure CUDA kernels using code generation | 315| `/gpu/magma` | CUDA MAGMA kernels | 316 317Examples available in this release: 318 319:::{list-table} 320:header-rows: 1 321:widths: auto 322* - User code 323 - Example 324* - `ceed` 325 - * ex1 (volume) 326 * ex2 (surface) 327* - `mfem` 328 - * BP1 (scalar mass operator) 329 * BP3 (scalar Laplace operator) 330* - `petsc` 331 - * BP1 (scalar mass operator) 332 * BP2 (vector mass operator) 333 * BP3 (scalar Laplace operator) 334 * BP4 (vector Laplace operator) 335 * BP5 (collocated scalar Laplace operator) 336 * BP6 (collocated vector Laplace operator) 337 * Navier-Stokes 338* - `nek5000` 339 - * BP1 (scalar mass operator) 340 * BP3 (scalar Laplace operator) 341::: 342 343(v0-4)= 344 345## v0.4 (Apr 1, 2019) 346 347libCEED v0.4 was made again publicly available in the second full CEED software 348distribution, release CEED 2.0. This release contained notable features, such as 349four new CPU backends, two new GPU backends, CPU backend optimizations, initial 350support for operator composition, performance benchmarking, and a Navier-Stokes demo. 351The new CPU backends in this release came in two families. The `/cpu/self/*/serial` 352backends process one element at a time and are intended for meshes with a smaller number 353of high order elements. The `/cpu/self/*/blocked` backends process blocked batches of 354eight interlaced elements and are intended for meshes with higher numbers of elements. 355The `/cpu/self/avx/*` backends rely upon AVX instructions to provide vectorized CPU 356performance. The `/cpu/self/xsmm/*` backends rely upon the 357[LIBXSMM](http://github.com/hfp/libxsmm) package to provide vectorized CPU 358performance. The `/gpu/cuda/*` backends provide GPU performance strictly using CUDA. 359The `/gpu/cuda/ref` backend is a reference CUDA backend, providing reasonable 360performance for most problem configurations. The `/gpu/cuda/reg` backend uses a simple 361parallelization approach, where each thread treats a finite element. Using just in time 362compilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this 363backend unroll loops and map memory address to registers. The `/gpu/cuda/reg` backend 364achieve good peak performance for 1D, 2D, and low order 3D problems, but performance 365deteriorates very quickly when threads run out of registers. 366 367A new explicit time-stepping Navier-Stokes solver was added to the family of libCEED 368examples in the `examples/petsc` directory (see {ref}`example-petsc-navier-stokes`). 369This example solves the time-dependent Navier-Stokes equations of compressible gas 370dynamics in a static Eulerian three-dimensional frame, using structured high-order 371finite/spectral element spatial discretizations and explicit high-order time-stepping 372(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc, 373so that the pointwise physics (defined at quadrature points) is separated from the 374parallelization and meshing concerns. 375 376Backends available in this release: 377 378| CEED resource (`-ceed`) | Backend | 379|--------------------------|-----------------------------------------------------| 380| `/cpu/self/ref/serial` | Serial reference implementation | 381| `/cpu/self/ref/blocked` | Blocked reference implementation | 382| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 383| `/cpu/self/avx/serial` | Serial AVX implementation | 384| `/cpu/self/avx/blocked` | Blocked AVX implementation | 385| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 386| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 387| `/cpu/occa` | Serial OCCA kernels | 388| `/gpu/occa` | CUDA OCCA kernels | 389| `/omp/occa` | OpenMP OCCA kernels | 390| `/ocl/occa` | OpenCL OCCA kernels | 391| `/gpu/cuda/ref` | Reference pure CUDA kernels | 392| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 393| `/gpu/magma` | CUDA MAGMA kernels | 394 395Examples available in this release: 396 397:::{list-table} 398:header-rows: 1 399:widths: auto 400* - User code 401 - Example 402* - `ceed` 403 - * ex1 (volume) 404* - `mfem` 405 - * BP1 (scalar mass operator) 406 * BP3 (scalar Laplace operator) 407* - `petsc` 408 - * BP1 (scalar mass operator) 409 * BP3 (scalar Laplace operator) 410 * Navier-Stokes 411* - `nek5000` 412 - * BP1 (scalar mass operator) 413 * BP3 (scalar Laplace operator) 414::: 415 416(v0-3)= 417 418## v0.3 (Sep 30, 2018) 419 420Notable features in this release include active/passive field interface, support for 421non-tensor bases, backend optimization, and improved Fortran interface. This release 422also focused on providing improved continuous integration, and many new tests with code 423coverage reports of about 90%. This release also provided a significant change to the 424public interface: a {ref}`CeedQFunction` can take any number of named input and output 425arguments while {ref}`CeedOperator` connects them to the actual data, which may be 426supplied explicitly to `CeedOperatorApply()` (active) or separately via 427`CeedOperatorSetField()` (passive). This interface change enables reusable libraries 428of CeedQFunctions and composition of block solvers constructed using 429{ref}`CeedOperator`. A concept of blocked restriction was added to this release and 430used in an optimized CPU backend. Although this is typically not visible to the user, 431it enables effective use of arbitrary-length SIMD while maintaining cache locality. 432This CPU backend also implements an algebraic factorization of tensor product gradients 433to perform fewer operations than standard application of interpolation and 434differentiation from nodes to quadrature points. This algebraic formulation 435automatically supports non-polynomial and non-interpolatory bases, thus is more general 436than the more common derivation in terms of Lagrange polynomials on the quadrature points. 437 438Backends available in this release: 439 440| CEED resource (`-ceed`) | Backend | 441|-------------------------|-----------------------------------------------------| 442| `/cpu/self/blocked` | Blocked reference implementation | 443| `/cpu/self/ref` | Serial reference implementation | 444| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 445| `/cpu/occa` | Serial OCCA kernels | 446| `/gpu/occa` | CUDA OCCA kernels | 447| `/omp/occa` | OpenMP OCCA kernels | 448| `/ocl/occa` | OpenCL OCCA kernels | 449| `/gpu/magma` | CUDA MAGMA kernels | 450 451Examples available in this release: 452 453:::{list-table} 454:header-rows: 1 455:widths: auto 456* - User code 457 - Example 458* - `ceed` 459 - * ex1 (volume) 460* - `mfem` 461 - * BP1 (scalar mass operator) 462 * BP3 (scalar Laplace operator) 463* - `petsc` 464 - * BP1 (scalar mass operator) 465 * BP3 (scalar Laplace operator) 466* - `nek5000` 467 - * BP1 (scalar mass operator) 468 * BP3 (scalar Laplace operator) 469::: 470 471(v0-21)= 472 473## v0.21 (Sep 30, 2018) 474 475A MAGMA backend (which relies upon the 476[MAGMA](https://bitbucket.org/icl/magma) package) was integrated in libCEED for this 477release. This initial integration set up the framework of using MAGMA and provided the 478libCEED functionality through MAGMA kernels as one of libCEED’s computational backends. 479As any other backend, the MAGMA backend provides extended basic data structures for 480{ref}`CeedVector`, {ref}`CeedElemRestriction`, and {ref}`CeedOperator`, and implements 481the fundamental CEED building blocks to work with the new data structures. 482In general, the MAGMA-specific data structures keep the libCEED pointers to CPU data 483but also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled 484internally, and thus seamlessly to the user, through the functions/methods that are 485provided to support them. 486 487Backends available in this release: 488 489| CEED resource (`-ceed`) | Backend | 490|-------------------------|---------------------------------| 491| `/cpu/self` | Serial reference implementation | 492| `/cpu/occa` | Serial OCCA kernels | 493| `/gpu/occa` | CUDA OCCA kernels | 494| `/omp/occa` | OpenMP OCCA kernels | 495| `/ocl/occa` | OpenCL OCCA kernels | 496| `/gpu/magma` | CUDA MAGMA 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(v0-2)= 517 518## v0.2 (Mar 30, 2018) 519 520libCEED was made publicly available the first full CEED software distribution, release 521CEED 1.0. The distribution was made available using the Spack package manager to provide 522a common, easy-to-use build environment, where the user can build the CEED distribution 523with all dependencies. This release included a new Fortran interface for the library. 524This release also contained major improvements in the OCCA backend (including a new 525`/ocl/occa` backend) and new examples. The standalone libCEED example was modified to 526compute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an 527`examples/ceed` subfolder. A new `mfem` example to perform BP3 (with the application 528of the Laplace operator) was also added to this release. 529 530Backends available in this release: 531 532| CEED resource (`-ceed`) | Backend | 533|-------------------------|---------------------------------| 534| `/cpu/self` | Serial reference implementation | 535| `/cpu/occa` | Serial OCCA kernels | 536| `/gpu/occa` | CUDA OCCA kernels | 537| `/omp/occa` | OpenMP OCCA kernels | 538| `/ocl/occa` | OpenCL OCCA kernels | 539 540Examples available in this release: 541 542:::{list-table} 543:header-rows: 1 544:widths: auto 545* - User code 546 - Example 547* - `ceed` 548 - * ex1 (volume) 549* - `mfem` 550 - * BP1 (scalar mass operator) 551 * BP3 (scalar Laplace operator) 552* - `petsc` 553 - * BP1 (scalar mass operator) 554* - `nek5000` 555 - * BP1 (scalar mass operator) 556::: 557 558(v0-1)= 559 560## v0.1 (Jan 3, 2018) 561 562Initial low-level API of the CEED project. The low-level API provides a set of Finite 563Elements kernels and components for writing new low-level kernels. Examples include: 564vector and sparse linear algebra, element matrix assembly over a batch of elements, 565partial assembly and action for efficient high-order operators like mass, diffusion, 566advection, etc. The main goal of the low-level API is to establish the basis for the 567high-level API. Also, identifying such low-level kernels and providing a reference 568implementation for them serves as the basis for specialized backend implementations. 569This release contained several backends: `/cpu/self`, and backends which rely upon the 570[OCCA](http://github.com/libocca/occa) package, such as `/cpu/occa`, 571`/gpu/occa`, and `/omp/occa`. 572It also included several examples, in the `examples` folder: 573A standalone code that shows the usage of libCEED (with no external 574dependencies) to apply the Laplace operator, `ex1`; an `mfem` example to perform BP1 575(with the application of the mass operator); and a `petsc` example to perform BP1 576(with the application of the mass operator). 577 578Backends available in this release: 579 580| CEED resource (`-ceed`) | Backend | 581|-------------------------|---------------------------------| 582| `/cpu/self` | Serial reference implementation | 583| `/cpu/occa` | Serial OCCA kernels | 584| `/gpu/occa` | CUDA OCCA kernels | 585| `/omp/occa` | OpenMP OCCA kernels | 586 587Examples available in this release: 588 589| User code | Example | 590|-----------------------|-----------------------------------| 591| `ceed` | ex1 (scalar Laplace operator) | 592| `mfem` | BP1 (scalar mass operator) | 593| `petsc` | BP1 (scalar mass operator) | 594``` 595