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- Add `bool` field type for `CeedQFunctionContext` and related interfaces to use `bool` fields. 12 13### New features 14 15### Examples 16 17(v0-12)= 18 19## v0.12 (Oct 31, 2023) 20 21### Interface changes 22 23- Update `CeedOperatorContext*` functions to `CeedOperator*Context*` functions for consistency. 24For example, `CeedOperatorContextGetFieldLabel` was renamed to `CeedOperatorGetContextFieldLabel`. 25- Removed `CeedBasisSetNumQuadraturePoints` as redundant and bug-prone interface. 26 27### New features 28 29- Added {c:func}`CeedOperatorGetFieldByName` to access a specific `CeedOperatorField` by its name. 30- Update `/cpu/self/memcheck/*` backends to help verify `CeedVector` array access assumptions and `CeedQFunction` user output assumptions. 31- Update {c:func}`CeedOperatorLinearAssembleDiagonal` to provide default implementation that supports `CeedOperator` with multiple active bases. 32- Added Sycl backends `/gpu/sycl/ref`, `/gpu/sycl/shared`, and `/gpu/sycl/gen`. 33- Added {c:func}`CeedBasisApplyAtPoints` for evaluation of values and derivatives at arbitrary points inside elements. 34- Added support for non-tensor $H(\text{curl})$ finite element spaces with {c:func}`CeedBasisCreateHcurl`. 35- Added {c:func}`CeedElemRestrictionCreateCurlOriented`, similar to {c:func}`CeedElemRestrictionCreateOriented`, for element restrictions requiring more general element transformations such as those for high-order $H(\text{curl})$ spaces on tetrahedra (see [https://dl.acm.org/doi/pdf/10.1145/3524456](https://dl.acm.org/doi/pdf/10.1145/3524456)). 36- Added {c:func}`CeedOperatorLinearAssemblePointBlockDiagonalSymbolic` to create COO mapping for mapping out of {c:func}`CeedOperatorLinearAssemblePointBlockDiagonal`. 37- Added support for application codes which manage multiple {ref}`Ceed` objects, parallelized across OpenMP threads. 38 39### Examples 40 41- Add `DMSwarm` example demonstrating interpolation from background mesh to swarm points and projection from swarm points to background mesh. 42 43#### {ref}`example-petsc-bps` 44 45- Requires PETSc version 3.19 or later. 46 47#### {ref}`example-petsc-navier-stokes` 48 49- Updated restart and checkpointing interface. 50- Add data-driven subgrid-stress model. 51- Add differential filtering of solution. 52- Add turbulence statistics collection over spanwise-symmetric geometries. 53- Add Taylor-Green vortex initial condition. 54- Add Riemann-based outflow boundary conditions. 55- Added vortex shedding and flow past cylinder example, including calculations for lift, drag, and heat transfer. 56- Add Internal Damping Layer (IDL) for helping turbulent simulation stability. 57- Derive `CeedBasis` from `PetscFE`, and various other internal maintainability updates. 58 59(v0-11)= 60 61## v0.11 (Dec 24, 2022) 62 63### Interface changes 64 65- Added {c:func}`CeedOperatorSetName` for more readable {c:func}`CeedOperatorView` output. 66- Added {c:func}`CeedBasisCreateProjection` to facilitate interpolation between nodes for separate `CeedBases`. 67- Rename and move {c:func}`CeedCompositeOperatorGetNumSub` and {c:func}`CeedCompositeOperatorGetSubList` to public interface. 68- Renamed `CEED_BASIS_COLLOCATED` to `CEED_BASIS_NONE` for clarity. 69Some users previously misinterpreted a `CeedOperator` field using `CEED_BASIS_COLLOCATED` as meaning that the entire `CeedOperator` used a quadrature space that is collocated with the nodal space of the active bases. 70 71### New features 72 73- Update `/cpu/self/memcheck/*` backends to help verify `CeedQFunctionContext` data sizes provided by user. 74- Improved support for $H(\text{div})$ bases. 75- Added `CeedInt_FMT` to support potential future use of larger integer sizes. 76- Added `CEED_QFUNCTION_ATTR` for setting compiler attributes/pragmas to `CEED_QFUNCTION_HELPER` and `CEED_QFUNCTION`. 77- OCCA backend updated to latest OCCA release; DPC++ and OMP OCCA modes enabled. 78Due to a limitation of the OCCA parser, typedefs are required to use pointers to arrays in QFunctions with the OCCA backend. 79This issue will be fixed in a future OCCA release. 80 81### Bugfix 82 83- Fix bug in setting device id for GPU backends. 84- Fix storing of indices for `CeedElemRestriction` on the host with GPU backends. 85- Fix `CeedElemRestriction` sizing for {c:func}`CeedOperatorAssemblePointBlockDiagonal`. 86- Fix bugs in CPU implementation of {c:func}`CeedOperatorLinearAssemble` when there are different number of active input modes and active output modes. 87 88### Examples 89 90#### {ref}`example-petsc-navier-stokes` 91 92- Various performance enhancements, analytic matrix-free and assembled Jacobian, and PETSc solver configurations for GPUs. 93- Refactored to improve code reuse and modularity. 94- Support for primitive variables for more accurate boundary layers and all-speed flow. 95- Added $YZ\beta$ shock capturing scheme and Shock Tube example. 96- Added Channel example, with comparison to analytic solutions. 97- Added Flat Plate with boundary layer mesh and compressible Blasius inflow condition based on Chebyshev collocation solution of the Blasius equations. 98- Added strong and weak synthetic turbulence generation (STG) inflow boundary conditions. 99- Added "freestream" boundary conditions based on HLLC Riemann solver. 100- Automated stabilization coefficients for different basis degree. 101 102#### {ref}`example-petsc-bps` 103 104- Support for convergence studies. 105 106### Maintainability 107 108- 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. 109- Enabled support for `p > 8` for `/gpu/*/shared` backends. 110- Switch to `clang-format` over `astyle` for automatic formatting; Makefile command changed to `make format` from `make style`. 111- Improved test harness. 112 113(v0-10-1)= 114 115## v0.10.1 (Apr 11, 2022) 116 117### Interface changes 118 119- Added {c:func}`CeedQFunctionSetUserFlopsEstimate` and {c:func}`CeedOperatorGetFlopsEstimate` to facilitate estimating FLOPs in operator application. 120 121### New features 122 123- Switched MAGMA backends to use runtime compilation for tensor basis kernels (and element restriction kernels, in non-deterministic `/gpu/*/magma` backends). 124This reduces time to compile the library and increases the range of parameters for which the MAGMA tensor basis kernels will work. 125 126### Bugfix 127 128- Install JiT source files in install directory to fix GPU functionality for installed libCEED. 129 130(v0-10)= 131 132## v0.10 (Mar 21, 2022) 133 134### Interface changes 135 136- Update {c:func}`CeedQFunctionGetFields` and {c:func}`CeedOperatorGetFields` to include number of fields. 137- 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`. 138- Clarify and document conditions where `CeedQFunction` and `CeedOperator` become immutable and no further fields or suboperators can be added. 139- Add {c:func}`CeedOperatorLinearAssembleQFunctionBuildOrUpdate` to reduce object creation overhead in assembly of CeedOperator preconditioning ingredients. 140- Promote {c:func}`CeedOperatorCheckReady`to the public API to facilitate interactive interfaces. 141- Warning added when compiling OCCA backend to alert users that this backend is experimental. 142- `ceed-backend.h`, `ceed-hash.h`, and `ceed-khash.h` removed. Users should use `ceed/backend.h`, `ceed/hash.h`, and `ceed/khash.h`. 143- Added {c:func}`CeedQFunctionGetKernelName`; refactored {c:func}`CeedQFunctionGetSourcePath` to exclude function kernel name. 144- 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`. 145- Added {c:func}`CeedVectorGetArrayWrite` that allows access to uninitialized arrays; require initialized data for {c:func}`CeedVectorGetArray`. 146- 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. 147- Added {c:func}`CeedQFunctionContextGetFieldDescriptions` to retrieve user defined descriptions of fields that are registered with `CeedQFunctionContextRegister*`. 148- Renamed `CeedElemTopology` entries for clearer namespacing between libCEED enums. 149- 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. 150- Added {c:func}`CeedOperatorSetQFunctionUpdated` to facilitate QFunction data re-use between operators sharing the same quadrature space, such as in a multigrid hierarchy. 151- Added {c:func}`CeedOperatorGetActiveVectorLengths` to get shape of CeedOperator. 152 153### New features 154 155- `CeedScalar` can now be set as `float` or `double` at compile time. 156- Added JiT utilities in `ceed/jit-tools.h` to reduce duplicated code in GPU backends. 157- 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. 158- Remove need to guard library headers in QFunction source for code generation backends. 159- `CeedDebugEnv()` macro created to provide debugging outputs when Ceed context is not present. 160- Added {c:func}`CeedStringAllocCopy` to reduce repeated code for copying strings internally. 161- Added {c:func}`CeedPathConcatenate` to facilitate loading kernel source files with a path relative to the current file. 162- Added support for non-tensor $H(\text{div})$ elements, to include CPU backend implementations and {c:func}`CeedBasisCreateHdiv` convenience constructor. 163- 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. 164- Added support for element matrix assembly in GPU backends. 165 166### Maintainability 167 168- Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage. 169- `Include-what-you-use` makefile target added as `make iwyu`. 170- Create backend constant `CEED_FIELD_MAX` to reduce magic numbers in codebase. 171- Put GPU JiTed kernel source code into separate files. 172- 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. 173 174(v0-9)= 175 176## v0.9 (Jul 6, 2021) 177 178### Interface changes 179 180- Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact. 181 182### New features 183 184- Add {c:func}`CeedVectorAXPY` and {c:func}`CeedVectorPointwiseMult` as a convenience for stand-alone testing and internal use. 185- Add `CEED_QFUNCTION_HELPER` macro to properly annotate QFunction helper functions for code generation backends. 186- Add `CeedPragmaOptimizeOff` macro for code that is sensitive to floating point errors from fast math optimizations. 187- Rust support: split `libceed-sys` crate out of `libceed` and [publish both on crates.io](https://crates.io/crates/libceed). 188 189### Performance improvements 190 191### Examples 192 193- Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations. 194- Fluid mechanics example adds GPU support and improves modularity. 195 196### Deprecated backends 197 198- 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. 199 200(v0-8)= 201 202## v0.8 (Mar 31, 2021) 203 204### Interface changes 205 206- Error handling improved to include enumerated error codes for C interface return values. 207- 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. 208 209### New features 210 211- Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features. 212- Static libraries can be built with `make STATIC=1` and the pkg-config file is installed accordingly. 213- Add {c:func}`CeedOperatorLinearAssembleSymbolic` and {c:func}`CeedOperatorLinearAssemble` to support full assembly of libCEED operators. 214 215### Performance improvements 216 217- New HIP MAGMA backends for hipMAGMA library users: `/gpu/hip/magma` and `/gpu/hip/magma/det`. 218- New HIP backends for improved tensor basis performance: `/gpu/hip/shared` and `/gpu/hip/gen`. 219 220### Examples 221 222- {ref}`example-petsc-elasticity` example updated with traction boundary conditions and improved Dirichlet boundary conditions. 223- {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. 224- {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. 225- {ref}`example-petsc-navier-stokes` example updated with support for performing convergence study and plotting order of convergence by polynomial degree. 226 227(v0-7)= 228 229## v0.7 (Sep 29, 2020) 230 231### Interface changes 232 233- Replace limited {code}`CeedInterlaceMode` with more flexible component stride {code}`compstride` in {code}`CeedElemRestriction` constructors. 234 As a result, the {code}`indices` parameter has been replaced with {code}`offsets` and the {code}`nnodes` parameter has been replaced with {code}`lsize`. 235 These changes improve support for mixed finite element methods. 236- Replace various uses of {code}`Ceed*Get*Status` with {code}`Ceed*Is*` in the backend API to match common nomenclature. 237- Replace {code}`CeedOperatorAssembleLinearDiagonal` with {c:func}`CeedOperatorLinearAssembleDiagonal` for clarity. 238- 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. 239- 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. 240- 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. 241- 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. 242 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`. 243- Added {code}`CeedQFunctionContext` object to manage user QFunction context data and reduce copies between device and host memory. 244- 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. 245 246### New features 247 248- New HIP backend: `/gpu/hip/ref`. 249- CeedQFunction support for user `CUfunction`s in some backends 250 251### Performance improvements 252 253- OCCA backend rebuilt to facilitate future performance enhancements. 254- Petsc BPs suite improved to reduce noise due to multiple calls to {code}`mpiexec`. 255 256### Examples 257 258- {ref}`example-petsc-elasticity` example updated with strain energy computation and more flexible boundary conditions. 259 260### Deprecated backends 261 262- The `/gpu/cuda/reg` backend has been removed, with its core features moved into `/gpu/cuda/ref` and `/gpu/cuda/shared`. 263 264(v0-6)= 265 266## v0.6 (Mar 29, 2020) 267 268libCEED v0.6 contains numerous new features and examples, as well as expanded 269documentation in [this new website](https://libceed.org). 270 271### New features 272 273- New Python interface using [CFFI](https://cffi.readthedocs.io/) provides a nearly 274 1-1 correspondence with the C interface, plus some convenience features. For instance, 275 data stored in the {cpp:type}`CeedVector` structure are available without copy as 276 {py:class}`numpy.ndarray`. Short tutorials are provided in 277 [Binder](https://mybinder.org/v2/gh/CEED/libCEED/main?urlpath=lab/tree/examples/tutorials/). 278- Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point, 279 {c:func}`CeedOperatorAssembleLinearQFunction`) or to evaluate the diagonal 280 ({c:func}`CeedOperatorAssembleLinearDiagonal`). These operations are useful for 281 preconditioning ingredients and are used in the libCEED's multigrid examples. 282- The inverse of separable operators can be obtained using 283 {c:func}`CeedOperatorCreateFDMElementInverse` and applied with 284 {c:func}`CeedOperatorApply`. This is a useful preconditioning ingredient, 285 especially for Laplacians and related operators. 286- New functions: {c:func}`CeedVectorNorm`, {c:func}`CeedOperatorApplyAdd`, 287 {c:func}`CeedQFunctionView`, {c:func}`CeedOperatorView`. 288- Make public accessors for various attributes to facilitate writing composable code. 289- New backend: `/cpu/self/memcheck/serial`. 290- QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA 291 backends. (Single source is coming soon for OCCA backends.) 292- Fix some missing edge cases in CUDA backend. 293 294### Performance Improvements 295 296- MAGMA backend performance optimization and non-tensor bases. 297- No-copy optimization in {c:func}`CeedOperatorApply`. 298 299### Interface changes 300 301- Replace {code}`CeedElemRestrictionCreateIdentity` and 302 {code}`CeedElemRestrictionCreateBlocked` with more flexible 303 {c:func}`CeedElemRestrictionCreateStrided` and 304 {c:func}`CeedElemRestrictionCreateBlockedStrided`. 305- Add arguments to {c:func}`CeedQFunctionCreateIdentity`. 306- Replace ambiguous uses of {cpp:enum}`CeedTransposeMode` for L-vector identification 307 with {cpp:enum}`CeedInterlaceMode`. This is now an attribute of the 308 {cpp:type}`CeedElemRestriction` (see {c:func}`CeedElemRestrictionCreate`) and no 309 longer passed as `lmode` arguments to {c:func}`CeedOperatorSetField` and 310 {c:func}`CeedElemRestrictionApply`. 311 312### Examples 313 314libCEED-0.6 contains greatly expanded examples with {ref}`new documentation <Examples>`. 315Notable additions include: 316 317- Standalone {ref}`ex2-surface` ({file}`examples/ceed/ex2-surface`): compute the area of 318 a domain in 1, 2, and 3 dimensions by applying a Laplacian. 319 320- PETSc {ref}`example-petsc-area` ({file}`examples/petsc/area.c`): computes surface area 321 of domains (like the cube and sphere) by direct integration on a surface mesh; 322 demonstrates geometric dimension different from topological dimension. 323 324- PETSc {ref}`example-petsc-bps`: 325 326 - {file}`examples/petsc/bpsraw.c` (formerly `bps.c`): transparent CUDA support. 327 - {file}`examples/petsc/bps.c` (formerly `bpsdmplex.c`): performance improvements 328 and transparent CUDA support. 329 - {ref}`example-petsc-bps-sphere` ({file}`examples/petsc/bpssphere.c`): 330 generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric 331 dimension different from topological dimension. 332 333- {ref}`example-petsc-multigrid` ({file}`examples/petsc/multigrid.c`): new p-multigrid 334 solver with algebraic multigrid coarse solve. 335 336- {ref}`example-petsc-navier-stokes` ({file}`examples/fluids/navierstokes.c`; formerly 337 `examples/navier-stokes`): unstructured grid support (using PETSc's `DMPlex`), 338 implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and 339 quasi-2D computational domain support. 340 341- {ref}`example-petsc-elasticity` ({file}`examples/solids/elasticity.c`): new solver for 342 linear elasticity, small-strain hyperelasticity, and globalized finite-strain 343 hyperelasticity using p-multigrid with algebraic multigrid coarse solve. 344 345(v0-5)= 346 347## v0.5 (Sep 18, 2019) 348 349For this release, several improvements were made. Two new CUDA backends were added to 350the family of backends, of which, the new `cuda-gen` backend achieves state-of-the-art 351performance using single-source {ref}`CeedQFunction`. From this release, users 352can define Q-Functions in a single source code independently of the targeted backend 353with the aid of a new macro `CEED QFUNCTION` to support JIT (Just-In-Time) and CPU 354compilation of the user provided {ref}`CeedQFunction` code. To allow a unified 355declaration, the {ref}`CeedQFunction` API has undergone a slight change: 356the `QFunctionField` parameter `ncomp` has been changed to `size`. This change 357requires setting the previous value of `ncomp` to `ncomp*dim` when adding a 358`QFunctionField` with eval mode `CEED EVAL GRAD`. 359 360Additionally, new CPU backends 361were included in this release, such as the `/cpu/self/opt/*` backends (which are 362written in pure C and use partial **E-vectors** to improve performance) and the 363`/cpu/self/ref/memcheck` backend (which relies upon the 364[Valgrind](http://valgrind.org/) Memcheck tool to help verify that user 365{ref}`CeedQFunction` have no undefined values). 366This release also included various performance improvements, bug fixes, new examples, 367and improved tests. Among these improvements, vectorized instructions for 368{ref}`CeedQFunction` code compiled for CPU were enhanced by using `CeedPragmaSIMD` 369instead of `CeedPragmaOMP`, implementation of a {ref}`CeedQFunction` gallery and 370identity Q-Functions were introduced, and the PETSc benchmark problems were expanded 371to include unstructured meshes handling were. For this expansion, the prior version of 372the PETSc BPs, which only included data associated with structured geometries, were 373renamed `bpsraw`, and the new version of the BPs, which can handle data associated 374with any unstructured geometry, were called `bps`. Additionally, other benchmark 375problems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively), 376and BP5 and BP6 (the collocated versions---for which the quadrature points are the same 377as the Gauss Lobatto nodes---of BP3 and BP4 respectively) were added to the PETSc 378examples. Furthermoew, another standalone libCEED example, called `ex2`, which 379computes the surface area of a given mesh was added to this release. 380 381Backends available in this release: 382 383| CEED resource (`-ceed`) | Backend | 384|--------------------------|-----------------------------------------------------| 385| `/cpu/self/ref/serial` | Serial reference implementation | 386| `/cpu/self/ref/blocked` | Blocked reference implementation | 387| `/cpu/self/ref/memcheck` | Memcheck backend, undefined value checks | 388| `/cpu/self/opt/serial` | Serial optimized C implementation | 389| `/cpu/self/opt/blocked` | Blocked optimized C implementation | 390| `/cpu/self/avx/serial` | Serial AVX implementation | 391| `/cpu/self/avx/blocked` | Blocked AVX implementation | 392| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 393| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 394| `/cpu/occa` | Serial OCCA kernels | 395| `/gpu/occa` | CUDA OCCA kernels | 396| `/omp/occa` | OpenMP OCCA kernels | 397| `/ocl/occa` | OpenCL OCCA kernels | 398| `/gpu/cuda/ref` | Reference pure CUDA kernels | 399| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 400| `/gpu/cuda/shared` | Optimized pure CUDA kernels using shared memory | 401| `/gpu/cuda/gen` | Optimized pure CUDA kernels using code generation | 402| `/gpu/magma` | CUDA MAGMA kernels | 403 404Examples available in this release: 405 406:::{list-table} 407:header-rows: 1 408:widths: auto 409* - User code 410 - Example 411* - `ceed` 412 - * ex1 (volume) 413 * ex2 (surface) 414* - `mfem` 415 - * BP1 (scalar mass operator) 416 * BP3 (scalar Laplace operator) 417* - `petsc` 418 - * BP1 (scalar mass operator) 419 * BP2 (vector mass operator) 420 * BP3 (scalar Laplace operator) 421 * BP4 (vector Laplace operator) 422 * BP5 (collocated scalar Laplace operator) 423 * BP6 (collocated vector Laplace operator) 424 * Navier-Stokes 425* - `nek5000` 426 - * BP1 (scalar mass operator) 427 * BP3 (scalar Laplace operator) 428::: 429 430(v0-4)= 431 432## v0.4 (Apr 1, 2019) 433 434libCEED v0.4 was made again publicly available in the second full CEED software 435distribution, release CEED 2.0. This release contained notable features, such as 436four new CPU backends, two new GPU backends, CPU backend optimizations, initial 437support for operator composition, performance benchmarking, and a Navier-Stokes demo. 438The new CPU backends in this release came in two families. The `/cpu/self/*/serial` 439backends process one element at a time and are intended for meshes with a smaller number 440of high order elements. The `/cpu/self/*/blocked` backends process blocked batches of 441eight interlaced elements and are intended for meshes with higher numbers of elements. 442The `/cpu/self/avx/*` backends rely upon AVX instructions to provide vectorized CPU 443performance. The `/cpu/self/xsmm/*` backends rely upon the 444[LIBXSMM](http://github.com/hfp/libxsmm) package to provide vectorized CPU 445performance. The `/gpu/cuda/*` backends provide GPU performance strictly using CUDA. 446The `/gpu/cuda/ref` backend is a reference CUDA backend, providing reasonable 447performance for most problem configurations. The `/gpu/cuda/reg` backend uses a simple 448parallelization approach, where each thread treats a finite element. Using just in time 449compilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this 450backend unroll loops and map memory address to registers. The `/gpu/cuda/reg` backend 451achieve good peak performance for 1D, 2D, and low order 3D problems, but performance 452deteriorates very quickly when threads run out of registers. 453 454A new explicit time-stepping Navier-Stokes solver was added to the family of libCEED 455examples in the `examples/petsc` directory (see {ref}`example-petsc-navier-stokes`). 456This example solves the time-dependent Navier-Stokes equations of compressible gas 457dynamics in a static Eulerian three-dimensional frame, using structured high-order 458finite/spectral element spatial discretizations and explicit high-order time-stepping 459(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc, 460so that the pointwise physics (defined at quadrature points) is separated from the 461parallelization and meshing concerns. 462 463Backends available in this release: 464 465| CEED resource (`-ceed`) | Backend | 466|--------------------------|-----------------------------------------------------| 467| `/cpu/self/ref/serial` | Serial reference implementation | 468| `/cpu/self/ref/blocked` | Blocked reference implementation | 469| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 470| `/cpu/self/avx/serial` | Serial AVX implementation | 471| `/cpu/self/avx/blocked` | Blocked AVX implementation | 472| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 473| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 474| `/cpu/occa` | Serial OCCA kernels | 475| `/gpu/occa` | CUDA OCCA kernels | 476| `/omp/occa` | OpenMP OCCA kernels | 477| `/ocl/occa` | OpenCL OCCA kernels | 478| `/gpu/cuda/ref` | Reference pure CUDA kernels | 479| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 480| `/gpu/magma` | CUDA MAGMA kernels | 481 482Examples available in this release: 483 484:::{list-table} 485:header-rows: 1 486:widths: auto 487* - User code 488 - Example 489* - `ceed` 490 - * ex1 (volume) 491* - `mfem` 492 - * BP1 (scalar mass operator) 493 * BP3 (scalar Laplace operator) 494* - `petsc` 495 - * BP1 (scalar mass operator) 496 * BP3 (scalar Laplace operator) 497 * Navier-Stokes 498* - `nek5000` 499 - * BP1 (scalar mass operator) 500 * BP3 (scalar Laplace operator) 501::: 502 503(v0-3)= 504 505## v0.3 (Sep 30, 2018) 506 507Notable features in this release include active/passive field interface, support for 508non-tensor bases, backend optimization, and improved Fortran interface. This release 509also focused on providing improved continuous integration, and many new tests with code 510coverage reports of about 90%. This release also provided a significant change to the 511public interface: a {ref}`CeedQFunction` can take any number of named input and output 512arguments while {ref}`CeedOperator` connects them to the actual data, which may be 513supplied explicitly to `CeedOperatorApply()` (active) or separately via 514`CeedOperatorSetField()` (passive). This interface change enables reusable libraries 515of CeedQFunctions and composition of block solvers constructed using 516{ref}`CeedOperator`. A concept of blocked restriction was added to this release and 517used in an optimized CPU backend. Although this is typically not visible to the user, 518it enables effective use of arbitrary-length SIMD while maintaining cache locality. 519This CPU backend also implements an algebraic factorization of tensor product gradients 520to perform fewer operations than standard application of interpolation and 521differentiation from nodes to quadrature points. This algebraic formulation 522automatically supports non-polynomial and non-interpolatory bases, thus is more general 523than the more common derivation in terms of Lagrange polynomials on the quadrature points. 524 525Backends available in this release: 526 527| CEED resource (`-ceed`) | Backend | 528|-------------------------|-----------------------------------------------------| 529| `/cpu/self/blocked` | Blocked reference implementation | 530| `/cpu/self/ref` | Serial reference implementation | 531| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 532| `/cpu/occa` | Serial OCCA kernels | 533| `/gpu/occa` | CUDA OCCA kernels | 534| `/omp/occa` | OpenMP OCCA kernels | 535| `/ocl/occa` | OpenCL OCCA kernels | 536| `/gpu/magma` | CUDA MAGMA kernels | 537 538Examples available in this release: 539 540:::{list-table} 541:header-rows: 1 542:widths: auto 543* - User code 544 - Example 545* - `ceed` 546 - * ex1 (volume) 547* - `mfem` 548 - * BP1 (scalar mass operator) 549 * BP3 (scalar Laplace operator) 550* - `petsc` 551 - * BP1 (scalar mass operator) 552 * BP3 (scalar Laplace operator) 553* - `nek5000` 554 - * BP1 (scalar mass operator) 555 * BP3 (scalar Laplace operator) 556::: 557 558(v0-21)= 559 560## v0.21 (Sep 30, 2018) 561 562A MAGMA backend (which relies upon the 563[MAGMA](https://bitbucket.org/icl/magma) package) was integrated in libCEED for this 564release. This initial integration set up the framework of using MAGMA and provided the 565libCEED functionality through MAGMA kernels as one of libCEED’s computational backends. 566As any other backend, the MAGMA backend provides extended basic data structures for 567{ref}`CeedVector`, {ref}`CeedElemRestriction`, and {ref}`CeedOperator`, and implements 568the fundamental CEED building blocks to work with the new data structures. 569In general, the MAGMA-specific data structures keep the libCEED pointers to CPU data 570but also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled 571internally, and thus seamlessly to the user, through the functions/methods that are 572provided to support them. 573 574Backends available in this release: 575 576| CEED resource (`-ceed`) | Backend | 577|-------------------------|---------------------------------| 578| `/cpu/self` | Serial reference implementation | 579| `/cpu/occa` | Serial OCCA kernels | 580| `/gpu/occa` | CUDA OCCA kernels | 581| `/omp/occa` | OpenMP OCCA kernels | 582| `/ocl/occa` | OpenCL OCCA kernels | 583| `/gpu/magma` | CUDA MAGMA kernels | 584 585Examples available in this release: 586 587:::{list-table} 588:header-rows: 1 589:widths: auto 590* - User code 591 - Example 592* - `ceed` 593 - * ex1 (volume) 594* - `mfem` 595 - * BP1 (scalar mass operator) 596 * BP3 (scalar Laplace operator) 597* - `petsc` 598 - * BP1 (scalar mass operator) 599* - `nek5000` 600 - * BP1 (scalar mass operator) 601::: 602 603(v0-2)= 604 605## v0.2 (Mar 30, 2018) 606 607libCEED was made publicly available the first full CEED software distribution, release 608CEED 1.0. The distribution was made available using the Spack package manager to provide 609a common, easy-to-use build environment, where the user can build the CEED distribution 610with all dependencies. This release included a new Fortran interface for the library. 611This release also contained major improvements in the OCCA backend (including a new 612`/ocl/occa` backend) and new examples. The standalone libCEED example was modified to 613compute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an 614`examples/ceed` subfolder. A new `mfem` example to perform BP3 (with the application 615of the Laplace operator) was also added to this release. 616 617Backends available in this release: 618 619| CEED resource (`-ceed`) | Backend | 620|-------------------------|---------------------------------| 621| `/cpu/self` | Serial reference implementation | 622| `/cpu/occa` | Serial OCCA kernels | 623| `/gpu/occa` | CUDA OCCA kernels | 624| `/omp/occa` | OpenMP OCCA kernels | 625| `/ocl/occa` | OpenCL OCCA kernels | 626 627Examples available in this release: 628 629:::{list-table} 630:header-rows: 1 631:widths: auto 632* - User code 633 - Example 634* - `ceed` 635 - * ex1 (volume) 636* - `mfem` 637 - * BP1 (scalar mass operator) 638 * BP3 (scalar Laplace operator) 639* - `petsc` 640 - * BP1 (scalar mass operator) 641* - `nek5000` 642 - * BP1 (scalar mass operator) 643::: 644 645(v0-1)= 646 647## v0.1 (Jan 3, 2018) 648 649Initial low-level API of the CEED project. The low-level API provides a set of Finite 650Elements kernels and components for writing new low-level kernels. Examples include: 651vector and sparse linear algebra, element matrix assembly over a batch of elements, 652partial assembly and action for efficient high-order operators like mass, diffusion, 653advection, etc. The main goal of the low-level API is to establish the basis for the 654high-level API. Also, identifying such low-level kernels and providing a reference 655implementation for them serves as the basis for specialized backend implementations. 656This release contained several backends: `/cpu/self`, and backends which rely upon the 657[OCCA](http://github.com/libocca/occa) package, such as `/cpu/occa`, 658`/gpu/occa`, and `/omp/occa`. 659It also included several examples, in the `examples` folder: 660A standalone code that shows the usage of libCEED (with no external 661dependencies) to apply the Laplace operator, `ex1`; an `mfem` example to perform BP1 662(with the application of the mass operator); and a `petsc` example to perform BP1 663(with the application of the mass operator). 664 665Backends available in this release: 666 667| CEED resource (`-ceed`) | Backend | 668|-------------------------|---------------------------------| 669| `/cpu/self` | Serial reference implementation | 670| `/cpu/occa` | Serial OCCA kernels | 671| `/gpu/occa` | CUDA OCCA kernels | 672| `/omp/occa` | OpenMP OCCA kernels | 673 674Examples available in this release: 675 676| User code | Example | 677|-----------------------|-----------------------------------| 678| `ceed` | ex1 (scalar Laplace operator) | 679| `mfem` | BP1 (scalar mass operator) | 680| `petsc` | BP1 (scalar mass operator) | 681``` 682