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### Interface changes 10 11- Added {c:func}`CeedOperatorSetName` for more readable {c:func}`CeedOperatorView` output. 12- Added {c:func}`CeedBasisCreateProjection` to facilitate interpolation between nodes for separate `CeedBases`. 13 14### New features 15 16- Update `/cpu/self/memcheck/*` backends to help verify `CeedQFunctionContext` data sizes provided by user. 17- Added `CeedInt_FMT` to support potential future use of larger interger sizes. 18- Added CEED_QFUNCTION_ATTR for setting compiler attributes/pragmas to CEED_QFUNCTION_HELPER and CEED_QFUNCTION 19 20### Bugfix 21 22- Fix bug in setting device id for GPU backends. 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- Refactored {ref}`example-petsc-navier-stokes` to improve code reuse. 31- Added Shock Tube, Channel, and Flat Plate boundary layer problems to {ref}`example-petsc-navier-stokes`. 32- Added ability to use QFunctions for strong STG inflow in {ref}`example-petsc-navier-stokes`. 33 34(v0-10-1)= 35 36## v0.10.1 (Apr 11, 2022) 37 38### Interface changes 39 40- Added {c:func}`CeedQFunctionSetUserFlopsEstimate` and {c:func}`CeedOperatorGetFlopsEstimate` to facilitate estimating FLOPs in operator application. 41 42### New features 43 44- Switched MAGMA backends to use runtime compilation for tensor basis kernels (and element restriction kernels, in non-deterministic `/gpu/*/magma` backends). 45This reduces time to compile the library and increases the range of parameters for which the MAGMA tensor basis kernels will work. 46 47### Bugfix 48 49- Install JiT source files in install directory to fix GPU functionality for installed libCEED. 50 51(v0-10)= 52 53## v0.10 (Mar 21, 2022) 54 55### Interface changes 56 57- Update {c:func}`CeedQFunctionGetFields` and {c:func}`CeedOperatorGetFields` to include number of fields. 58- 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`. 59- Clarify and document conditions where `CeedQFunction` and `CeedOperator` become immutable and no further fields or suboperators can be added. 60- Add {c:func}`CeedOperatorLinearAssembleQFunctionBuildOrUpdate` to reduce object creation overhead in assembly of CeedOperator preconditioning ingredients. 61- Promote {c:func}`CeedOperatorCheckReady`to the public API to facilitate interactive interfaces. 62- Warning added when compiling OCCA backend to alert users that this backend is experimental. 63- `ceed-backend.h`, `ceed-hash.h`, and `ceed-khash.h` removed. Users should use `ceed/backend.h`, `ceed/hash.h`, and `ceed/khash.h`. 64- Added {c:func}`CeedQFunctionGetKernelName`; refactored {c:func}`CeedQFunctionGetSourcePath` to exclude function kernel name. 65- 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`. 66- Added {c:func}`CeedVectorGetArrayWrite` that allows access to uninitalized arrays; require initalized data for {c:func}`CeedVectorGetArray`. 67- 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. 68- Added {c:func}`CeedQFunctionContextGetFieldDescriptions` to retreive user defined descriptions of fields that are registered with `CeedQFunctionContextRegister*`. 69- Renamed `CeedElemTopology` entries for clearer namespacing between libCEED enums. 70- 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. 71- Added {c:func}`CeedOperatorSetQFunctionUpdated` to facilitate QFunction data re-use between operators sharing the same quadrature space, such as in a multigrid hierarchy. 72- Added {c:func}`CeedOperatorGetActiveVectorLengths` to get shape of CeedOperator. 73 74### New features 75 76- `CeedScalar` can now be set as `float` or `double` at compile time. 77- Added JiT utilities in `ceed/jit-tools.h` to reduce duplicated code in GPU backends. 78- 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. 79- Remove need to guard library headers in QFunction source for code generation backends. 80- `CeedDebugEnv()` macro created to provide debugging outputs when Ceed context is not present. 81- Added {c:func}`CeedStringAllocCopy` to reduce repeated code for copying strings internally. 82- Added {c:func}`CeedPathConcatenate` to facilitate loading kernel source files with a path relative to the current file. 83- Added support for non-tensor H(div) elements, to include CPU backend implementations and {c:func}`CeedBasisCreateHdiv` convenience constructor. 84- 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. 85- Added support for element matrix assembly in GPU backends. 86 87### Maintainability 88 89- Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage. 90- `Include-what-you-use` makefile target added as `make iwyu`. 91- Create backend constant `CEED_FIELD_MAX` to reduce magic numbers in codebase. 92- Put GPU JiTed kernel source code into separate files. 93- 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. 94 95(v0-9)= 96 97## v0.9 (Jul 6, 2021) 98 99### Interface changes 100 101- Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact. 102 103### New features 104 105- Add {c:func}`CeedVectorAXPY` and {c:func}`CeedVectorPointwiseMult` as a convenience for stand-alone testing and internal use. 106- Add `CEED_QFUNCTION_HELPER` macro to properly annotate QFunction helper functions for code generation backends. 107- Add `CeedPragmaOptimizeOff` macro for code that is sensitive to floating point errors from fast math optimizations. 108- Rust support: split `libceed-sys` crate out of `libceed` and [publish both on crates.io](https://crates.io/crates/libceed). 109 110### Performance improvements 111 112### Examples 113 114- Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations. 115- Fluid mechanics example adds GPU support and improves modularity. 116 117### Deprecated backends 118 119- 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. 120 121(v0-8)= 122 123## v0.8 (Mar 31, 2021) 124 125### Interface changes 126 127- Error handling improved to include enumerated error codes for C interface return values. 128- 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. 129 130### New features 131 132- Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features. 133- Static libraries can be built with `make STATIC=1` and the pkg-config file is installed accordingly. 134- Add {c:func}`CeedOperatorLinearAssembleSymbolic` and {c:func}`CeedOperatorLinearAssemble` to support full assembly of libCEED operators. 135 136### Performance improvements 137 138- New HIP MAGMA backends for hipMAGMA library users: `/gpu/hip/magma` and `/gpu/hip/magma/det`. 139- New HIP backends for improved tensor basis performance: `/gpu/hip/shared` and `/gpu/hip/gen`. 140 141### Examples 142 143- {ref}`example-petsc-elasticity` example updated with traction boundary conditions and improved Dirichlet boundary conditions. 144- {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. 145- {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. 146- {ref}`example-petsc-navier-stokes` example updated with support for performing convergence study and plotting order of convergence by polynomial degree. 147 148(v0-7)= 149 150## v0.7 (Sep 29, 2020) 151 152### Interface changes 153 154- Replace limited {code}`CeedInterlaceMode` with more flexible component stride {code}`compstride` in {code}`CeedElemRestriction` constructors. 155 As a result, the {code}`indices` parameter has been replaced with {code}`offsets` and the {code}`nnodes` parameter has been replaced with {code}`lsize`. 156 These changes improve support for mixed finite element methods. 157- Replace various uses of {code}`Ceed*Get*Status` with {code}`Ceed*Is*` in the backend API to match common nomenclature. 158- Replace {code}`CeedOperatorAssembleLinearDiagonal` with {c:func}`CeedOperatorLinearAssembleDiagonal` for clarity. 159- 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. 160- 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. 161- 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. 162- 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. 163 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`. 164- Added {code}`CeedQFunctionContext` object to manage user QFunction context data and reduce copies between device and host memory. 165- 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. 166 167### New features 168 169- New HIP backend: `/gpu/hip/ref`. 170- CeedQFunction support for user `CUfunction`s in some backends 171 172### Performance improvements 173 174- OCCA backend rebuilt to facilitate future performance enhancements. 175- Petsc BPs suite improved to reduce noise due to multiple calls to {code}`mpiexec`. 176 177### Examples 178 179- {ref}`example-petsc-elasticity` example updated with strain energy computation and more flexible boundary conditions. 180 181### Deprecated backends 182 183- The `/gpu/cuda/reg` backend has been removed, with its core features moved into `/gpu/cuda/ref` and `/gpu/cuda/shared`. 184 185(v0-6)= 186 187## v0.6 (Mar 29, 2020) 188 189libCEED v0.6 contains numerous new features and examples, as well as expanded 190documentation in [this new website](https://libceed.org). 191 192### New features 193 194- New Python interface using [CFFI](https://cffi.readthedocs.io/) provides a nearly 195 1-1 correspondence with the C interface, plus some convenience features. For instance, 196 data stored in the {cpp:type}`CeedVector` structure are available without copy as 197 {py:class}`numpy.ndarray`. Short tutorials are provided in 198 [Binder](https://mybinder.org/v2/gh/CEED/libCEED/main?urlpath=lab/tree/examples/tutorials/). 199- Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point, 200 {c:func}`CeedOperatorAssembleLinearQFunction`) or to evaluate the diagonal 201 ({c:func}`CeedOperatorAssembleLinearDiagonal`). These operations are useful for 202 preconditioning ingredients and are used in the libCEED's multigrid examples. 203- The inverse of separable operators can be obtained using 204 {c:func}`CeedOperatorCreateFDMElementInverse` and applied with 205 {c:func}`CeedOperatorApply`. This is a useful preconditioning ingredient, 206 especially for Laplacians and related operators. 207- New functions: {c:func}`CeedVectorNorm`, {c:func}`CeedOperatorApplyAdd`, 208 {c:func}`CeedQFunctionView`, {c:func}`CeedOperatorView`. 209- Make public accessors for various attributes to facilitate writing composable code. 210- New backend: `/cpu/self/memcheck/serial`. 211- QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA 212 backends. (Single source is coming soon for OCCA backends.) 213- Fix some missing edge cases in CUDA backend. 214 215### Performance Improvements 216 217- MAGMA backend performance optimization and non-tensor bases. 218- No-copy optimization in {c:func}`CeedOperatorApply`. 219 220### Interface changes 221 222- Replace {code}`CeedElemRestrictionCreateIdentity` and 223 {code}`CeedElemRestrictionCreateBlocked` with more flexible 224 {c:func}`CeedElemRestrictionCreateStrided` and 225 {c:func}`CeedElemRestrictionCreateBlockedStrided`. 226- Add arguments to {c:func}`CeedQFunctionCreateIdentity`. 227- Replace ambiguous uses of {cpp:enum}`CeedTransposeMode` for L-vector identification 228 with {cpp:enum}`CeedInterlaceMode`. This is now an attribute of the 229 {cpp:type}`CeedElemRestriction` (see {c:func}`CeedElemRestrictionCreate`) and no 230 longer passed as `lmode` arguments to {c:func}`CeedOperatorSetField` and 231 {c:func}`CeedElemRestrictionApply`. 232 233### Examples 234 235libCEED-0.6 contains greatly expanded examples with {ref}`new documentation <Examples>`. 236Notable additions include: 237 238- Standalone {ref}`ex2-surface` ({file}`examples/ceed/ex2-surface`): compute the area of 239 a domain in 1, 2, and 3 dimensions by applying a Laplacian. 240 241- PETSc {ref}`example-petsc-area` ({file}`examples/petsc/area.c`): computes surface area 242 of domains (like the cube and sphere) by direct integration on a surface mesh; 243 demonstrates geometric dimension different from topological dimension. 244 245- PETSc {ref}`example-petsc-bps`: 246 247 - {file}`examples/petsc/bpsraw.c` (formerly `bps.c`): transparent CUDA support. 248 - {file}`examples/petsc/bps.c` (formerly `bpsdmplex.c`): performance improvements 249 and transparent CUDA support. 250 - {ref}`example-petsc-bps-sphere` ({file}`examples/petsc/bpssphere.c`): 251 generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric 252 dimension different from topological dimension. 253 254- {ref}`example-petsc-multigrid` ({file}`examples/petsc/multigrid.c`): new p-multigrid 255 solver with algebraic multigrid coarse solve. 256 257- {ref}`example-petsc-navier-stokes` ({file}`examples/fluids/navierstokes.c`; formerly 258 `examples/navier-stokes`): unstructured grid support (using PETSc's `DMPlex`), 259 implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and 260 quasi-2D computational domain support. 261 262- {ref}`example-petsc-elasticity` ({file}`examples/solids/elasticity.c`): new solver for 263 linear elasticity, small-strain hyperelasticity, and globalized finite-strain 264 hyperelasticity using p-multigrid with algebraic multigrid coarse solve. 265 266(v0-5)= 267 268## v0.5 (Sep 18, 2019) 269 270For this release, several improvements were made. Two new CUDA backends were added to 271the family of backends, of which, the new `cuda-gen` backend achieves state-of-the-art 272performance using single-source {ref}`CeedQFunction`. From this release, users 273can define Q-Functions in a single source code independently of the targeted backend 274with the aid of a new macro `CEED QFUNCTION` to support JIT (Just-In-Time) and CPU 275compilation of the user provided {ref}`CeedQFunction` code. To allow a unified 276declaration, the {ref}`CeedQFunction` API has undergone a slight change: 277the `QFunctionField` parameter `ncomp` has been changed to `size`. This change 278requires setting the previous value of `ncomp` to `ncomp*dim` when adding a 279`QFunctionField` with eval mode `CEED EVAL GRAD`. 280 281Additionally, new CPU backends 282were included in this release, such as the `/cpu/self/opt/*` backends (which are 283written in pure C and use partial **E-vectors** to improve performance) and the 284`/cpu/self/ref/memcheck` backend (which relies upon the 285[Valgrind](http://valgrind.org/) Memcheck tool to help verify that user 286{ref}`CeedQFunction` have no undefined values). 287This release also included various performance improvements, bug fixes, new examples, 288and improved tests. Among these improvements, vectorized instructions for 289{ref}`CeedQFunction` code compiled for CPU were enhanced by using `CeedPragmaSIMD` 290instead of `CeedPragmaOMP`, implementation of a {ref}`CeedQFunction` gallery and 291identity Q-Functions were introduced, and the PETSc benchmark problems were expanded 292to include unstructured meshes handling were. For this expansion, the prior version of 293the PETSc BPs, which only included data associated with structured geometries, were 294renamed `bpsraw`, and the new version of the BPs, which can handle data associated 295with any unstructured geometry, were called `bps`. Additionally, other benchmark 296problems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively), 297and BP5 and BP6 (the collocated versions---for which the quadrature points are the same 298as the Gauss Lobatto nodes---of BP3 and BP4 respectively) were added to the PETSc 299examples. Furthermoew, another standalone libCEED example, called `ex2`, which 300computes the surface area of a given mesh was added to this release. 301 302Backends available in this release: 303 304| CEED resource (`-ceed`) | Backend | 305|--------------------------|-----------------------------------------------------| 306| `/cpu/self/ref/serial` | Serial reference implementation | 307| `/cpu/self/ref/blocked` | Blocked reference implementation | 308| `/cpu/self/ref/memcheck` | Memcheck backend, undefined value checks | 309| `/cpu/self/opt/serial` | Serial optimized C implementation | 310| `/cpu/self/opt/blocked` | Blocked optimized C implementation | 311| `/cpu/self/avx/serial` | Serial AVX implementation | 312| `/cpu/self/avx/blocked` | Blocked AVX implementation | 313| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 314| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 315| `/cpu/occa` | Serial OCCA kernels | 316| `/gpu/occa` | CUDA OCCA kernels | 317| `/omp/occa` | OpenMP OCCA kernels | 318| `/ocl/occa` | OpenCL OCCA kernels | 319| `/gpu/cuda/ref` | Reference pure CUDA kernels | 320| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 321| `/gpu/cuda/shared` | Optimized pure CUDA kernels using shared memory | 322| `/gpu/cuda/gen` | Optimized pure CUDA kernels using code generation | 323| `/gpu/magma` | CUDA MAGMA kernels | 324 325Examples available in this release: 326 327:::{list-table} 328:header-rows: 1 329:widths: auto 330* - User code 331 - Example 332* - `ceed` 333 - * ex1 (volume) 334 * ex2 (surface) 335* - `mfem` 336 - * BP1 (scalar mass operator) 337 * BP3 (scalar Laplace operator) 338* - `petsc` 339 - * BP1 (scalar mass operator) 340 * BP2 (vector mass operator) 341 * BP3 (scalar Laplace operator) 342 * BP4 (vector Laplace operator) 343 * BP5 (collocated scalar Laplace operator) 344 * BP6 (collocated vector Laplace operator) 345 * Navier-Stokes 346* - `nek5000` 347 - * BP1 (scalar mass operator) 348 * BP3 (scalar Laplace operator) 349::: 350 351(v0-4)= 352 353## v0.4 (Apr 1, 2019) 354 355libCEED v0.4 was made again publicly available in the second full CEED software 356distribution, release CEED 2.0. This release contained notable features, such as 357four new CPU backends, two new GPU backends, CPU backend optimizations, initial 358support for operator composition, performance benchmarking, and a Navier-Stokes demo. 359The new CPU backends in this release came in two families. The `/cpu/self/*/serial` 360backends process one element at a time and are intended for meshes with a smaller number 361of high order elements. The `/cpu/self/*/blocked` backends process blocked batches of 362eight interlaced elements and are intended for meshes with higher numbers of elements. 363The `/cpu/self/avx/*` backends rely upon AVX instructions to provide vectorized CPU 364performance. The `/cpu/self/xsmm/*` backends rely upon the 365[LIBXSMM](http://github.com/hfp/libxsmm) package to provide vectorized CPU 366performance. The `/gpu/cuda/*` backends provide GPU performance strictly using CUDA. 367The `/gpu/cuda/ref` backend is a reference CUDA backend, providing reasonable 368performance for most problem configurations. The `/gpu/cuda/reg` backend uses a simple 369parallelization approach, where each thread treats a finite element. Using just in time 370compilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this 371backend unroll loops and map memory address to registers. The `/gpu/cuda/reg` backend 372achieve good peak performance for 1D, 2D, and low order 3D problems, but performance 373deteriorates very quickly when threads run out of registers. 374 375A new explicit time-stepping Navier-Stokes solver was added to the family of libCEED 376examples in the `examples/petsc` directory (see {ref}`example-petsc-navier-stokes`). 377This example solves the time-dependent Navier-Stokes equations of compressible gas 378dynamics in a static Eulerian three-dimensional frame, using structured high-order 379finite/spectral element spatial discretizations and explicit high-order time-stepping 380(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc, 381so that the pointwise physics (defined at quadrature points) is separated from the 382parallelization and meshing concerns. 383 384Backends available in this release: 385 386| CEED resource (`-ceed`) | Backend | 387|--------------------------|-----------------------------------------------------| 388| `/cpu/self/ref/serial` | Serial reference implementation | 389| `/cpu/self/ref/blocked` | Blocked reference implementation | 390| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 391| `/cpu/self/avx/serial` | Serial AVX implementation | 392| `/cpu/self/avx/blocked` | Blocked AVX implementation | 393| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 394| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 395| `/cpu/occa` | Serial OCCA kernels | 396| `/gpu/occa` | CUDA OCCA kernels | 397| `/omp/occa` | OpenMP OCCA kernels | 398| `/ocl/occa` | OpenCL OCCA kernels | 399| `/gpu/cuda/ref` | Reference pure CUDA kernels | 400| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 401| `/gpu/magma` | CUDA MAGMA kernels | 402 403Examples available in this release: 404 405:::{list-table} 406:header-rows: 1 407:widths: auto 408* - User code 409 - Example 410* - `ceed` 411 - * ex1 (volume) 412* - `mfem` 413 - * BP1 (scalar mass operator) 414 * BP3 (scalar Laplace operator) 415* - `petsc` 416 - * BP1 (scalar mass operator) 417 * BP3 (scalar Laplace operator) 418 * Navier-Stokes 419* - `nek5000` 420 - * BP1 (scalar mass operator) 421 * BP3 (scalar Laplace operator) 422::: 423 424(v0-3)= 425 426## v0.3 (Sep 30, 2018) 427 428Notable features in this release include active/passive field interface, support for 429non-tensor bases, backend optimization, and improved Fortran interface. This release 430also focused on providing improved continuous integration, and many new tests with code 431coverage reports of about 90%. This release also provided a significant change to the 432public interface: a {ref}`CeedQFunction` can take any number of named input and output 433arguments while {ref}`CeedOperator` connects them to the actual data, which may be 434supplied explicitly to `CeedOperatorApply()` (active) or separately via 435`CeedOperatorSetField()` (passive). This interface change enables reusable libraries 436of CeedQFunctions and composition of block solvers constructed using 437{ref}`CeedOperator`. A concept of blocked restriction was added to this release and 438used in an optimized CPU backend. Although this is typically not visible to the user, 439it enables effective use of arbitrary-length SIMD while maintaining cache locality. 440This CPU backend also implements an algebraic factorization of tensor product gradients 441to perform fewer operations than standard application of interpolation and 442differentiation from nodes to quadrature points. This algebraic formulation 443automatically supports non-polynomial and non-interpolatory bases, thus is more general 444than the more common derivation in terms of Lagrange polynomials on the quadrature points. 445 446Backends available in this release: 447 448| CEED resource (`-ceed`) | Backend | 449|-------------------------|-----------------------------------------------------| 450| `/cpu/self/blocked` | Blocked reference implementation | 451| `/cpu/self/ref` | Serial reference implementation | 452| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 453| `/cpu/occa` | Serial OCCA kernels | 454| `/gpu/occa` | CUDA OCCA kernels | 455| `/omp/occa` | OpenMP OCCA kernels | 456| `/ocl/occa` | OpenCL OCCA kernels | 457| `/gpu/magma` | CUDA MAGMA kernels | 458 459Examples available in this release: 460 461:::{list-table} 462:header-rows: 1 463:widths: auto 464* - User code 465 - Example 466* - `ceed` 467 - * ex1 (volume) 468* - `mfem` 469 - * BP1 (scalar mass operator) 470 * BP3 (scalar Laplace operator) 471* - `petsc` 472 - * BP1 (scalar mass operator) 473 * BP3 (scalar Laplace operator) 474* - `nek5000` 475 - * BP1 (scalar mass operator) 476 * BP3 (scalar Laplace operator) 477::: 478 479(v0-21)= 480 481## v0.21 (Sep 30, 2018) 482 483A MAGMA backend (which relies upon the 484[MAGMA](https://bitbucket.org/icl/magma) package) was integrated in libCEED for this 485release. This initial integration set up the framework of using MAGMA and provided the 486libCEED functionality through MAGMA kernels as one of libCEED’s computational backends. 487As any other backend, the MAGMA backend provides extended basic data structures for 488{ref}`CeedVector`, {ref}`CeedElemRestriction`, and {ref}`CeedOperator`, and implements 489the fundamental CEED building blocks to work with the new data structures. 490In general, the MAGMA-specific data structures keep the libCEED pointers to CPU data 491but also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled 492internally, and thus seamlessly to the user, through the functions/methods that are 493provided to support them. 494 495Backends available in this release: 496 497| CEED resource (`-ceed`) | Backend | 498|-------------------------|---------------------------------| 499| `/cpu/self` | Serial reference implementation | 500| `/cpu/occa` | Serial OCCA kernels | 501| `/gpu/occa` | CUDA OCCA kernels | 502| `/omp/occa` | OpenMP OCCA kernels | 503| `/ocl/occa` | OpenCL OCCA kernels | 504| `/gpu/magma` | CUDA MAGMA kernels | 505 506Examples available in this release: 507 508:::{list-table} 509:header-rows: 1 510:widths: auto 511* - User code 512 - Example 513* - `ceed` 514 - * ex1 (volume) 515* - `mfem` 516 - * BP1 (scalar mass operator) 517 * BP3 (scalar Laplace operator) 518* - `petsc` 519 - * BP1 (scalar mass operator) 520* - `nek5000` 521 - * BP1 (scalar mass operator) 522::: 523 524(v0-2)= 525 526## v0.2 (Mar 30, 2018) 527 528libCEED was made publicly available the first full CEED software distribution, release 529CEED 1.0. The distribution was made available using the Spack package manager to provide 530a common, easy-to-use build environment, where the user can build the CEED distribution 531with all dependencies. This release included a new Fortran interface for the library. 532This release also contained major improvements in the OCCA backend (including a new 533`/ocl/occa` backend) and new examples. The standalone libCEED example was modified to 534compute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an 535`examples/ceed` subfolder. A new `mfem` example to perform BP3 (with the application 536of the Laplace operator) was also added to this release. 537 538Backends available in this release: 539 540| CEED resource (`-ceed`) | Backend | 541|-------------------------|---------------------------------| 542| `/cpu/self` | Serial reference implementation | 543| `/cpu/occa` | Serial OCCA kernels | 544| `/gpu/occa` | CUDA OCCA kernels | 545| `/omp/occa` | OpenMP OCCA kernels | 546| `/ocl/occa` | OpenCL OCCA kernels | 547 548Examples available in this release: 549 550:::{list-table} 551:header-rows: 1 552:widths: auto 553* - User code 554 - Example 555* - `ceed` 556 - * ex1 (volume) 557* - `mfem` 558 - * BP1 (scalar mass operator) 559 * BP3 (scalar Laplace operator) 560* - `petsc` 561 - * BP1 (scalar mass operator) 562* - `nek5000` 563 - * BP1 (scalar mass operator) 564::: 565 566(v0-1)= 567 568## v0.1 (Jan 3, 2018) 569 570Initial low-level API of the CEED project. The low-level API provides a set of Finite 571Elements kernels and components for writing new low-level kernels. Examples include: 572vector and sparse linear algebra, element matrix assembly over a batch of elements, 573partial assembly and action for efficient high-order operators like mass, diffusion, 574advection, etc. The main goal of the low-level API is to establish the basis for the 575high-level API. Also, identifying such low-level kernels and providing a reference 576implementation for them serves as the basis for specialized backend implementations. 577This release contained several backends: `/cpu/self`, and backends which rely upon the 578[OCCA](http://github.com/libocca/occa) package, such as `/cpu/occa`, 579`/gpu/occa`, and `/omp/occa`. 580It also included several examples, in the `examples` folder: 581A standalone code that shows the usage of libCEED (with no external 582dependencies) to apply the Laplace operator, `ex1`; an `mfem` example to perform BP1 583(with the application of the mass operator); and a `petsc` example to perform BP1 584(with the application of the mass operator). 585 586Backends available in this release: 587 588| CEED resource (`-ceed`) | Backend | 589|-------------------------|---------------------------------| 590| `/cpu/self` | Serial reference implementation | 591| `/cpu/occa` | Serial OCCA kernels | 592| `/gpu/occa` | CUDA OCCA kernels | 593| `/omp/occa` | OpenMP OCCA kernels | 594 595Examples available in this release: 596 597| User code | Example | 598|-----------------------|-----------------------------------| 599| `ceed` | ex1 (scalar Laplace operator) | 600| `mfem` | BP1 (scalar mass operator) | 601| `petsc` | BP1 (scalar mass operator) | 602``` 603