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### Maintainability 35 36- Refactored `/gpu/cuda/shared` and `/gpu/cuda/gen` as well as `/gpu/hip/shared` and `/gpu/hip/gen` backend to improve maintainablity and reduce duplicated code. 37- Enabled support for `p > 8` for `/gpu/*/shared` backends. 38 39(v0-10-1)= 40 41## v0.10.1 (Apr 11, 2022) 42 43### Interface changes 44 45- Added {c:func}`CeedQFunctionSetUserFlopsEstimate` and {c:func}`CeedOperatorGetFlopsEstimate` to facilitate estimating FLOPs in operator application. 46 47### New features 48 49- Switched MAGMA backends to use runtime compilation for tensor basis kernels (and element restriction kernels, in non-deterministic `/gpu/*/magma` backends). 50This reduces time to compile the library and increases the range of parameters for which the MAGMA tensor basis kernels will work. 51 52### Bugfix 53 54- Install JiT source files in install directory to fix GPU functionality for installed libCEED. 55 56(v0-10)= 57 58## v0.10 (Mar 21, 2022) 59 60### Interface changes 61 62- Update {c:func}`CeedQFunctionGetFields` and {c:func}`CeedOperatorGetFields` to include number of fields. 63- 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`. 64- Clarify and document conditions where `CeedQFunction` and `CeedOperator` become immutable and no further fields or suboperators can be added. 65- Add {c:func}`CeedOperatorLinearAssembleQFunctionBuildOrUpdate` to reduce object creation overhead in assembly of CeedOperator preconditioning ingredients. 66- Promote {c:func}`CeedOperatorCheckReady`to the public API to facilitate interactive interfaces. 67- Warning added when compiling OCCA backend to alert users that this backend is experimental. 68- `ceed-backend.h`, `ceed-hash.h`, and `ceed-khash.h` removed. Users should use `ceed/backend.h`, `ceed/hash.h`, and `ceed/khash.h`. 69- Added {c:func}`CeedQFunctionGetKernelName`; refactored {c:func}`CeedQFunctionGetSourcePath` to exclude function kernel name. 70- 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`. 71- Added {c:func}`CeedVectorGetArrayWrite` that allows access to uninitalized arrays; require initalized data for {c:func}`CeedVectorGetArray`. 72- 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. 73- Added {c:func}`CeedQFunctionContextGetFieldDescriptions` to retreive user defined descriptions of fields that are registered with `CeedQFunctionContextRegister*`. 74- Renamed `CeedElemTopology` entries for clearer namespacing between libCEED enums. 75- 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. 76- Added {c:func}`CeedOperatorSetQFunctionUpdated` to facilitate QFunction data re-use between operators sharing the same quadrature space, such as in a multigrid hierarchy. 77- Added {c:func}`CeedOperatorGetActiveVectorLengths` to get shape of CeedOperator. 78 79### New features 80 81- `CeedScalar` can now be set as `float` or `double` at compile time. 82- Added JiT utilities in `ceed/jit-tools.h` to reduce duplicated code in GPU backends. 83- 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. 84- Remove need to guard library headers in QFunction source for code generation backends. 85- `CeedDebugEnv()` macro created to provide debugging outputs when Ceed context is not present. 86- Added {c:func}`CeedStringAllocCopy` to reduce repeated code for copying strings internally. 87- Added {c:func}`CeedPathConcatenate` to facilitate loading kernel source files with a path relative to the current file. 88- Added support for non-tensor H(div) elements, to include CPU backend implementations and {c:func}`CeedBasisCreateHdiv` convenience constructor. 89- 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. 90- Added support for element matrix assembly in GPU backends. 91 92### Maintainability 93 94- Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage. 95- `Include-what-you-use` makefile target added as `make iwyu`. 96- Create backend constant `CEED_FIELD_MAX` to reduce magic numbers in codebase. 97- Put GPU JiTed kernel source code into separate files. 98- 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. 99 100(v0-9)= 101 102## v0.9 (Jul 6, 2021) 103 104### Interface changes 105 106- Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact. 107 108### New features 109 110- Add {c:func}`CeedVectorAXPY` and {c:func}`CeedVectorPointwiseMult` as a convenience for stand-alone testing and internal use. 111- Add `CEED_QFUNCTION_HELPER` macro to properly annotate QFunction helper functions for code generation backends. 112- Add `CeedPragmaOptimizeOff` macro for code that is sensitive to floating point errors from fast math optimizations. 113- Rust support: split `libceed-sys` crate out of `libceed` and [publish both on crates.io](https://crates.io/crates/libceed). 114 115### Performance improvements 116 117### Examples 118 119- Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations. 120- Fluid mechanics example adds GPU support and improves modularity. 121 122### Deprecated backends 123 124- 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. 125 126(v0-8)= 127 128## v0.8 (Mar 31, 2021) 129 130### Interface changes 131 132- Error handling improved to include enumerated error codes for C interface return values. 133- 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. 134 135### New features 136 137- Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features. 138- Static libraries can be built with `make STATIC=1` and the pkg-config file is installed accordingly. 139- Add {c:func}`CeedOperatorLinearAssembleSymbolic` and {c:func}`CeedOperatorLinearAssemble` to support full assembly of libCEED operators. 140 141### Performance improvements 142 143- New HIP MAGMA backends for hipMAGMA library users: `/gpu/hip/magma` and `/gpu/hip/magma/det`. 144- New HIP backends for improved tensor basis performance: `/gpu/hip/shared` and `/gpu/hip/gen`. 145 146### Examples 147 148- {ref}`example-petsc-elasticity` example updated with traction boundary conditions and improved Dirichlet boundary conditions. 149- {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. 150- {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. 151- {ref}`example-petsc-navier-stokes` example updated with support for performing convergence study and plotting order of convergence by polynomial degree. 152 153(v0-7)= 154 155## v0.7 (Sep 29, 2020) 156 157### Interface changes 158 159- Replace limited {code}`CeedInterlaceMode` with more flexible component stride {code}`compstride` in {code}`CeedElemRestriction` constructors. 160 As a result, the {code}`indices` parameter has been replaced with {code}`offsets` and the {code}`nnodes` parameter has been replaced with {code}`lsize`. 161 These changes improve support for mixed finite element methods. 162- Replace various uses of {code}`Ceed*Get*Status` with {code}`Ceed*Is*` in the backend API to match common nomenclature. 163- Replace {code}`CeedOperatorAssembleLinearDiagonal` with {c:func}`CeedOperatorLinearAssembleDiagonal` for clarity. 164- 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. 165- 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. 166- 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. 167- 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. 168 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`. 169- Added {code}`CeedQFunctionContext` object to manage user QFunction context data and reduce copies between device and host memory. 170- 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. 171 172### New features 173 174- New HIP backend: `/gpu/hip/ref`. 175- CeedQFunction support for user `CUfunction`s in some backends 176 177### Performance improvements 178 179- OCCA backend rebuilt to facilitate future performance enhancements. 180- Petsc BPs suite improved to reduce noise due to multiple calls to {code}`mpiexec`. 181 182### Examples 183 184- {ref}`example-petsc-elasticity` example updated with strain energy computation and more flexible boundary conditions. 185 186### Deprecated backends 187 188- The `/gpu/cuda/reg` backend has been removed, with its core features moved into `/gpu/cuda/ref` and `/gpu/cuda/shared`. 189 190(v0-6)= 191 192## v0.6 (Mar 29, 2020) 193 194libCEED v0.6 contains numerous new features and examples, as well as expanded 195documentation in [this new website](https://libceed.org). 196 197### New features 198 199- New Python interface using [CFFI](https://cffi.readthedocs.io/) provides a nearly 200 1-1 correspondence with the C interface, plus some convenience features. For instance, 201 data stored in the {cpp:type}`CeedVector` structure are available without copy as 202 {py:class}`numpy.ndarray`. Short tutorials are provided in 203 [Binder](https://mybinder.org/v2/gh/CEED/libCEED/main?urlpath=lab/tree/examples/tutorials/). 204- Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point, 205 {c:func}`CeedOperatorAssembleLinearQFunction`) or to evaluate the diagonal 206 ({c:func}`CeedOperatorAssembleLinearDiagonal`). These operations are useful for 207 preconditioning ingredients and are used in the libCEED's multigrid examples. 208- The inverse of separable operators can be obtained using 209 {c:func}`CeedOperatorCreateFDMElementInverse` and applied with 210 {c:func}`CeedOperatorApply`. This is a useful preconditioning ingredient, 211 especially for Laplacians and related operators. 212- New functions: {c:func}`CeedVectorNorm`, {c:func}`CeedOperatorApplyAdd`, 213 {c:func}`CeedQFunctionView`, {c:func}`CeedOperatorView`. 214- Make public accessors for various attributes to facilitate writing composable code. 215- New backend: `/cpu/self/memcheck/serial`. 216- QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA 217 backends. (Single source is coming soon for OCCA backends.) 218- Fix some missing edge cases in CUDA backend. 219 220### Performance Improvements 221 222- MAGMA backend performance optimization and non-tensor bases. 223- No-copy optimization in {c:func}`CeedOperatorApply`. 224 225### Interface changes 226 227- Replace {code}`CeedElemRestrictionCreateIdentity` and 228 {code}`CeedElemRestrictionCreateBlocked` with more flexible 229 {c:func}`CeedElemRestrictionCreateStrided` and 230 {c:func}`CeedElemRestrictionCreateBlockedStrided`. 231- Add arguments to {c:func}`CeedQFunctionCreateIdentity`. 232- Replace ambiguous uses of {cpp:enum}`CeedTransposeMode` for L-vector identification 233 with {cpp:enum}`CeedInterlaceMode`. This is now an attribute of the 234 {cpp:type}`CeedElemRestriction` (see {c:func}`CeedElemRestrictionCreate`) and no 235 longer passed as `lmode` arguments to {c:func}`CeedOperatorSetField` and 236 {c:func}`CeedElemRestrictionApply`. 237 238### Examples 239 240libCEED-0.6 contains greatly expanded examples with {ref}`new documentation <Examples>`. 241Notable additions include: 242 243- Standalone {ref}`ex2-surface` ({file}`examples/ceed/ex2-surface`): compute the area of 244 a domain in 1, 2, and 3 dimensions by applying a Laplacian. 245 246- PETSc {ref}`example-petsc-area` ({file}`examples/petsc/area.c`): computes surface area 247 of domains (like the cube and sphere) by direct integration on a surface mesh; 248 demonstrates geometric dimension different from topological dimension. 249 250- PETSc {ref}`example-petsc-bps`: 251 252 - {file}`examples/petsc/bpsraw.c` (formerly `bps.c`): transparent CUDA support. 253 - {file}`examples/petsc/bps.c` (formerly `bpsdmplex.c`): performance improvements 254 and transparent CUDA support. 255 - {ref}`example-petsc-bps-sphere` ({file}`examples/petsc/bpssphere.c`): 256 generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric 257 dimension different from topological dimension. 258 259- {ref}`example-petsc-multigrid` ({file}`examples/petsc/multigrid.c`): new p-multigrid 260 solver with algebraic multigrid coarse solve. 261 262- {ref}`example-petsc-navier-stokes` ({file}`examples/fluids/navierstokes.c`; formerly 263 `examples/navier-stokes`): unstructured grid support (using PETSc's `DMPlex`), 264 implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and 265 quasi-2D computational domain support. 266 267- {ref}`example-petsc-elasticity` ({file}`examples/solids/elasticity.c`): new solver for 268 linear elasticity, small-strain hyperelasticity, and globalized finite-strain 269 hyperelasticity using p-multigrid with algebraic multigrid coarse solve. 270 271(v0-5)= 272 273## v0.5 (Sep 18, 2019) 274 275For this release, several improvements were made. Two new CUDA backends were added to 276the family of backends, of which, the new `cuda-gen` backend achieves state-of-the-art 277performance using single-source {ref}`CeedQFunction`. From this release, users 278can define Q-Functions in a single source code independently of the targeted backend 279with the aid of a new macro `CEED QFUNCTION` to support JIT (Just-In-Time) and CPU 280compilation of the user provided {ref}`CeedQFunction` code. To allow a unified 281declaration, the {ref}`CeedQFunction` API has undergone a slight change: 282the `QFunctionField` parameter `ncomp` has been changed to `size`. This change 283requires setting the previous value of `ncomp` to `ncomp*dim` when adding a 284`QFunctionField` with eval mode `CEED EVAL GRAD`. 285 286Additionally, new CPU backends 287were included in this release, such as the `/cpu/self/opt/*` backends (which are 288written in pure C and use partial **E-vectors** to improve performance) and the 289`/cpu/self/ref/memcheck` backend (which relies upon the 290[Valgrind](http://valgrind.org/) Memcheck tool to help verify that user 291{ref}`CeedQFunction` have no undefined values). 292This release also included various performance improvements, bug fixes, new examples, 293and improved tests. Among these improvements, vectorized instructions for 294{ref}`CeedQFunction` code compiled for CPU were enhanced by using `CeedPragmaSIMD` 295instead of `CeedPragmaOMP`, implementation of a {ref}`CeedQFunction` gallery and 296identity Q-Functions were introduced, and the PETSc benchmark problems were expanded 297to include unstructured meshes handling were. For this expansion, the prior version of 298the PETSc BPs, which only included data associated with structured geometries, were 299renamed `bpsraw`, and the new version of the BPs, which can handle data associated 300with any unstructured geometry, were called `bps`. Additionally, other benchmark 301problems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively), 302and BP5 and BP6 (the collocated versions---for which the quadrature points are the same 303as the Gauss Lobatto nodes---of BP3 and BP4 respectively) were added to the PETSc 304examples. Furthermoew, another standalone libCEED example, called `ex2`, which 305computes the surface area of a given mesh was added to this release. 306 307Backends available in this release: 308 309| CEED resource (`-ceed`) | Backend | 310|--------------------------|-----------------------------------------------------| 311| `/cpu/self/ref/serial` | Serial reference implementation | 312| `/cpu/self/ref/blocked` | Blocked reference implementation | 313| `/cpu/self/ref/memcheck` | Memcheck backend, undefined value checks | 314| `/cpu/self/opt/serial` | Serial optimized C implementation | 315| `/cpu/self/opt/blocked` | Blocked optimized C implementation | 316| `/cpu/self/avx/serial` | Serial AVX implementation | 317| `/cpu/self/avx/blocked` | Blocked AVX implementation | 318| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 319| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 320| `/cpu/occa` | Serial OCCA kernels | 321| `/gpu/occa` | CUDA OCCA kernels | 322| `/omp/occa` | OpenMP OCCA kernels | 323| `/ocl/occa` | OpenCL OCCA kernels | 324| `/gpu/cuda/ref` | Reference pure CUDA kernels | 325| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 326| `/gpu/cuda/shared` | Optimized pure CUDA kernels using shared memory | 327| `/gpu/cuda/gen` | Optimized pure CUDA kernels using code generation | 328| `/gpu/magma` | CUDA MAGMA kernels | 329 330Examples available in this release: 331 332:::{list-table} 333:header-rows: 1 334:widths: auto 335* - User code 336 - Example 337* - `ceed` 338 - * ex1 (volume) 339 * ex2 (surface) 340* - `mfem` 341 - * BP1 (scalar mass operator) 342 * BP3 (scalar Laplace operator) 343* - `petsc` 344 - * BP1 (scalar mass operator) 345 * BP2 (vector mass operator) 346 * BP3 (scalar Laplace operator) 347 * BP4 (vector Laplace operator) 348 * BP5 (collocated scalar Laplace operator) 349 * BP6 (collocated vector Laplace operator) 350 * Navier-Stokes 351* - `nek5000` 352 - * BP1 (scalar mass operator) 353 * BP3 (scalar Laplace operator) 354::: 355 356(v0-4)= 357 358## v0.4 (Apr 1, 2019) 359 360libCEED v0.4 was made again publicly available in the second full CEED software 361distribution, release CEED 2.0. This release contained notable features, such as 362four new CPU backends, two new GPU backends, CPU backend optimizations, initial 363support for operator composition, performance benchmarking, and a Navier-Stokes demo. 364The new CPU backends in this release came in two families. The `/cpu/self/*/serial` 365backends process one element at a time and are intended for meshes with a smaller number 366of high order elements. The `/cpu/self/*/blocked` backends process blocked batches of 367eight interlaced elements and are intended for meshes with higher numbers of elements. 368The `/cpu/self/avx/*` backends rely upon AVX instructions to provide vectorized CPU 369performance. The `/cpu/self/xsmm/*` backends rely upon the 370[LIBXSMM](http://github.com/hfp/libxsmm) package to provide vectorized CPU 371performance. The `/gpu/cuda/*` backends provide GPU performance strictly using CUDA. 372The `/gpu/cuda/ref` backend is a reference CUDA backend, providing reasonable 373performance for most problem configurations. The `/gpu/cuda/reg` backend uses a simple 374parallelization approach, where each thread treats a finite element. Using just in time 375compilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this 376backend unroll loops and map memory address to registers. The `/gpu/cuda/reg` backend 377achieve good peak performance for 1D, 2D, and low order 3D problems, but performance 378deteriorates very quickly when threads run out of registers. 379 380A new explicit time-stepping Navier-Stokes solver was added to the family of libCEED 381examples in the `examples/petsc` directory (see {ref}`example-petsc-navier-stokes`). 382This example solves the time-dependent Navier-Stokes equations of compressible gas 383dynamics in a static Eulerian three-dimensional frame, using structured high-order 384finite/spectral element spatial discretizations and explicit high-order time-stepping 385(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc, 386so that the pointwise physics (defined at quadrature points) is separated from the 387parallelization and meshing concerns. 388 389Backends available in this release: 390 391| CEED resource (`-ceed`) | Backend | 392|--------------------------|-----------------------------------------------------| 393| `/cpu/self/ref/serial` | Serial reference implementation | 394| `/cpu/self/ref/blocked` | Blocked reference implementation | 395| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 396| `/cpu/self/avx/serial` | Serial AVX implementation | 397| `/cpu/self/avx/blocked` | Blocked AVX implementation | 398| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 399| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 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/cuda/ref` | Reference pure CUDA kernels | 405| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 406| `/gpu/magma` | CUDA MAGMA kernels | 407 408Examples available in this release: 409 410:::{list-table} 411:header-rows: 1 412:widths: auto 413* - User code 414 - Example 415* - `ceed` 416 - * ex1 (volume) 417* - `mfem` 418 - * BP1 (scalar mass operator) 419 * BP3 (scalar Laplace operator) 420* - `petsc` 421 - * BP1 (scalar mass operator) 422 * BP3 (scalar Laplace operator) 423 * Navier-Stokes 424* - `nek5000` 425 - * BP1 (scalar mass operator) 426 * BP3 (scalar Laplace operator) 427::: 428 429(v0-3)= 430 431## v0.3 (Sep 30, 2018) 432 433Notable features in this release include active/passive field interface, support for 434non-tensor bases, backend optimization, and improved Fortran interface. This release 435also focused on providing improved continuous integration, and many new tests with code 436coverage reports of about 90%. This release also provided a significant change to the 437public interface: a {ref}`CeedQFunction` can take any number of named input and output 438arguments while {ref}`CeedOperator` connects them to the actual data, which may be 439supplied explicitly to `CeedOperatorApply()` (active) or separately via 440`CeedOperatorSetField()` (passive). This interface change enables reusable libraries 441of CeedQFunctions and composition of block solvers constructed using 442{ref}`CeedOperator`. A concept of blocked restriction was added to this release and 443used in an optimized CPU backend. Although this is typically not visible to the user, 444it enables effective use of arbitrary-length SIMD while maintaining cache locality. 445This CPU backend also implements an algebraic factorization of tensor product gradients 446to perform fewer operations than standard application of interpolation and 447differentiation from nodes to quadrature points. This algebraic formulation 448automatically supports non-polynomial and non-interpolatory bases, thus is more general 449than the more common derivation in terms of Lagrange polynomials on the quadrature points. 450 451Backends available in this release: 452 453| CEED resource (`-ceed`) | Backend | 454|-------------------------|-----------------------------------------------------| 455| `/cpu/self/blocked` | Blocked reference implementation | 456| `/cpu/self/ref` | Serial reference implementation | 457| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 458| `/cpu/occa` | Serial OCCA kernels | 459| `/gpu/occa` | CUDA OCCA kernels | 460| `/omp/occa` | OpenMP OCCA kernels | 461| `/ocl/occa` | OpenCL OCCA kernels | 462| `/gpu/magma` | CUDA MAGMA kernels | 463 464Examples available in this release: 465 466:::{list-table} 467:header-rows: 1 468:widths: auto 469* - User code 470 - Example 471* - `ceed` 472 - * ex1 (volume) 473* - `mfem` 474 - * BP1 (scalar mass operator) 475 * BP3 (scalar Laplace operator) 476* - `petsc` 477 - * BP1 (scalar mass operator) 478 * BP3 (scalar Laplace operator) 479* - `nek5000` 480 - * BP1 (scalar mass operator) 481 * BP3 (scalar Laplace operator) 482::: 483 484(v0-21)= 485 486## v0.21 (Sep 30, 2018) 487 488A MAGMA backend (which relies upon the 489[MAGMA](https://bitbucket.org/icl/magma) package) was integrated in libCEED for this 490release. This initial integration set up the framework of using MAGMA and provided the 491libCEED functionality through MAGMA kernels as one of libCEED’s computational backends. 492As any other backend, the MAGMA backend provides extended basic data structures for 493{ref}`CeedVector`, {ref}`CeedElemRestriction`, and {ref}`CeedOperator`, and implements 494the fundamental CEED building blocks to work with the new data structures. 495In general, the MAGMA-specific data structures keep the libCEED pointers to CPU data 496but also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled 497internally, and thus seamlessly to the user, through the functions/methods that are 498provided to support them. 499 500Backends available in this release: 501 502| CEED resource (`-ceed`) | Backend | 503|-------------------------|---------------------------------| 504| `/cpu/self` | Serial reference implementation | 505| `/cpu/occa` | Serial OCCA kernels | 506| `/gpu/occa` | CUDA OCCA kernels | 507| `/omp/occa` | OpenMP OCCA kernels | 508| `/ocl/occa` | OpenCL OCCA kernels | 509| `/gpu/magma` | CUDA MAGMA kernels | 510 511Examples available in this release: 512 513:::{list-table} 514:header-rows: 1 515:widths: auto 516* - User code 517 - Example 518* - `ceed` 519 - * ex1 (volume) 520* - `mfem` 521 - * BP1 (scalar mass operator) 522 * BP3 (scalar Laplace operator) 523* - `petsc` 524 - * BP1 (scalar mass operator) 525* - `nek5000` 526 - * BP1 (scalar mass operator) 527::: 528 529(v0-2)= 530 531## v0.2 (Mar 30, 2018) 532 533libCEED was made publicly available the first full CEED software distribution, release 534CEED 1.0. The distribution was made available using the Spack package manager to provide 535a common, easy-to-use build environment, where the user can build the CEED distribution 536with all dependencies. This release included a new Fortran interface for the library. 537This release also contained major improvements in the OCCA backend (including a new 538`/ocl/occa` backend) and new examples. The standalone libCEED example was modified to 539compute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an 540`examples/ceed` subfolder. A new `mfem` example to perform BP3 (with the application 541of the Laplace operator) was also added to this release. 542 543Backends available in this release: 544 545| CEED resource (`-ceed`) | Backend | 546|-------------------------|---------------------------------| 547| `/cpu/self` | Serial reference implementation | 548| `/cpu/occa` | Serial OCCA kernels | 549| `/gpu/occa` | CUDA OCCA kernels | 550| `/omp/occa` | OpenMP OCCA kernels | 551| `/ocl/occa` | OpenCL OCCA kernels | 552 553Examples available in this release: 554 555:::{list-table} 556:header-rows: 1 557:widths: auto 558* - User code 559 - Example 560* - `ceed` 561 - * ex1 (volume) 562* - `mfem` 563 - * BP1 (scalar mass operator) 564 * BP3 (scalar Laplace operator) 565* - `petsc` 566 - * BP1 (scalar mass operator) 567* - `nek5000` 568 - * BP1 (scalar mass operator) 569::: 570 571(v0-1)= 572 573## v0.1 (Jan 3, 2018) 574 575Initial low-level API of the CEED project. The low-level API provides a set of Finite 576Elements kernels and components for writing new low-level kernels. Examples include: 577vector and sparse linear algebra, element matrix assembly over a batch of elements, 578partial assembly and action for efficient high-order operators like mass, diffusion, 579advection, etc. The main goal of the low-level API is to establish the basis for the 580high-level API. Also, identifying such low-level kernels and providing a reference 581implementation for them serves as the basis for specialized backend implementations. 582This release contained several backends: `/cpu/self`, and backends which rely upon the 583[OCCA](http://github.com/libocca/occa) package, such as `/cpu/occa`, 584`/gpu/occa`, and `/omp/occa`. 585It also included several examples, in the `examples` folder: 586A standalone code that shows the usage of libCEED (with no external 587dependencies) to apply the Laplace operator, `ex1`; an `mfem` example to perform BP1 588(with the application of the mass operator); and a `petsc` example to perform BP1 589(with the application of the mass operator). 590 591Backends available in this release: 592 593| CEED resource (`-ceed`) | Backend | 594|-------------------------|---------------------------------| 595| `/cpu/self` | Serial reference implementation | 596| `/cpu/occa` | Serial OCCA kernels | 597| `/gpu/occa` | CUDA OCCA kernels | 598| `/omp/occa` | OpenMP OCCA kernels | 599 600Examples available in this release: 601 602| User code | Example | 603|-----------------------|-----------------------------------| 604| `ceed` | ex1 (scalar Laplace operator) | 605| `mfem` | BP1 (scalar mass operator) | 606| `petsc` | BP1 (scalar mass operator) | 607``` 608