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- `CEED_BASIS_COLLOCATED` removed; users should only use `CEED_BASIS_NONE`. 13 14### New features 15 16- Add `CeedOperatorCreateAtPoints` which evaluates the `CeedQFunction` at arbitrary locations in each element, for use in Particle in Cell, Material Point Method, and similar methods. 17 18### Examples 19 20(v0-12)= 21 22## v0.12 (Oct 31, 2023) 23 24### Interface changes 25 26- Update `CeedOperatorContext*` functions to `CeedOperator*Context*` functions for consistency. 27For example, `CeedOperatorContextGetFieldLabel` was renamed to `CeedOperatorGetContextFieldLabel`. 28- Removed `CeedBasisSetNumQuadraturePoints` as redundant and bug-prone interface. 29 30### New features 31 32- Added {c:func}`CeedOperatorGetFieldByName` to access a specific `CeedOperatorField` by its name. 33- Update `/cpu/self/memcheck/*` backends to help verify `CeedVector` array access assumptions and `CeedQFunction` user output assumptions. 34- Update {c:func}`CeedOperatorLinearAssembleDiagonal` to provide default implementation that supports `CeedOperator` with multiple active bases. 35- Added Sycl backends `/gpu/sycl/ref`, `/gpu/sycl/shared`, and `/gpu/sycl/gen`. 36- Added {c:func}`CeedBasisApplyAtPoints` for evaluation of values and derivatives at arbitrary points inside elements. 37- Added support for non-tensor $H(\text{curl})$ finite element spaces with {c:func}`CeedBasisCreateHcurl`. 38- 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)). 39- Added {c:func}`CeedOperatorLinearAssemblePointBlockDiagonalSymbolic` to create COO mapping for mapping out of {c:func}`CeedOperatorLinearAssemblePointBlockDiagonal`. 40- Added support for application codes which manage multiple {ref}`Ceed` objects, parallelized across OpenMP threads. 41 42### Examples 43 44- Add `DMSwarm` example demonstrating interpolation from background mesh to swarm points and projection from swarm points to background mesh. 45 46#### {ref}`example-petsc-bps` 47 48- Requires PETSc version 3.19 or later. 49 50#### {ref}`example-petsc-navier-stokes` 51 52- Updated restart and checkpointing interface. 53- Add data-driven subgrid-stress model. 54- Add differential filtering of solution. 55- Add turbulence statistics collection over spanwise-symmetric geometries. 56- Add Taylor-Green vortex initial condition. 57- Add Riemann-based outflow boundary conditions. 58- Added vortex shedding and flow past cylinder example, including calculations for lift, drag, and heat transfer. 59- Add Internal Damping Layer (IDL) for helping turbulent simulation stability. 60- Derive `CeedBasis` from `PetscFE`, and various other internal maintainability updates. 61 62(v0-11)= 63 64## v0.11 (Dec 24, 2022) 65 66### Interface changes 67 68- Added {c:func}`CeedOperatorSetName` for more readable {c:func}`CeedOperatorView` output. 69- Added {c:func}`CeedBasisCreateProjection` to facilitate interpolation between nodes for separate `CeedBases`. 70- Rename and move {c:func}`CeedCompositeOperatorGetNumSub` and {c:func}`CeedCompositeOperatorGetSubList` to public interface. 71- Renamed `CEED_BASIS_COLLOCATED` to `CEED_BASIS_NONE` for clarity. 72Some 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. 73 74### New features 75 76- Update `/cpu/self/memcheck/*` backends to help verify `CeedQFunctionContext` data sizes provided by user. 77- Improved support for $H(\text{div})$ bases. 78- Added `CeedInt_FMT` to support potential future use of larger integer sizes. 79- Added `CEED_QFUNCTION_ATTR` for setting compiler attributes/pragmas to `CEED_QFUNCTION_HELPER` and `CEED_QFUNCTION`. 80- OCCA backend updated to latest OCCA release; DPC++ and OMP OCCA modes enabled. 81Due to a limitation of the OCCA parser, typedefs are required to use pointers to arrays in QFunctions with the OCCA backend. 82This issue will be fixed in a future OCCA release. 83 84### Bugfix 85 86- Fix bug in setting device id for GPU backends. 87- Fix storing of indices for `CeedElemRestriction` on the host with GPU backends. 88- Fix `CeedElemRestriction` sizing for {c:func}`CeedOperatorAssemblePointBlockDiagonal`. 89- Fix bugs in CPU implementation of {c:func}`CeedOperatorLinearAssemble` when there are different number of active input modes and active output modes. 90 91### Examples 92 93#### {ref}`example-petsc-navier-stokes` 94 95- Various performance enhancements, analytic matrix-free and assembled Jacobian, and PETSc solver configurations for GPUs. 96- Refactored to improve code reuse and modularity. 97- Support for primitive variables for more accurate boundary layers and all-speed flow. 98- Added $YZ\beta$ shock capturing scheme and Shock Tube example. 99- Added Channel example, with comparison to analytic solutions. 100- Added Flat Plate with boundary layer mesh and compressible Blasius inflow condition based on Chebyshev collocation solution of the Blasius equations. 101- Added strong and weak synthetic turbulence generation (STG) inflow boundary conditions. 102- Added "freestream" boundary conditions based on HLLC Riemann solver. 103- Automated stabilization coefficients for different basis degree. 104 105#### {ref}`example-petsc-bps` 106 107- Support for convergence studies. 108 109### Maintainability 110 111- 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. 112- Enabled support for `p > 8` for `/gpu/*/shared` backends. 113- Switch to `clang-format` over `astyle` for automatic formatting; Makefile command changed to `make format` from `make style`. 114- Improved test harness. 115 116(v0-10-1)= 117 118## v0.10.1 (Apr 11, 2022) 119 120### Interface changes 121 122- Added {c:func}`CeedQFunctionSetUserFlopsEstimate` and {c:func}`CeedOperatorGetFlopsEstimate` to facilitate estimating FLOPs in operator application. 123 124### New features 125 126- Switched MAGMA backends to use runtime compilation for tensor basis kernels (and element restriction kernels, in non-deterministic `/gpu/*/magma` backends). 127This reduces time to compile the library and increases the range of parameters for which the MAGMA tensor basis kernels will work. 128 129### Bugfix 130 131- Install JiT source files in install directory to fix GPU functionality for installed libCEED. 132 133(v0-10)= 134 135## v0.10 (Mar 21, 2022) 136 137### Interface changes 138 139- Update {c:func}`CeedQFunctionGetFields` and {c:func}`CeedOperatorGetFields` to include number of fields. 140- 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`. 141- Clarify and document conditions where `CeedQFunction` and `CeedOperator` become immutable and no further fields or suboperators can be added. 142- Add {c:func}`CeedOperatorLinearAssembleQFunctionBuildOrUpdate` to reduce object creation overhead in assembly of CeedOperator preconditioning ingredients. 143- Promote {c:func}`CeedOperatorCheckReady`to the public API to facilitate interactive interfaces. 144- Warning added when compiling OCCA backend to alert users that this backend is experimental. 145- `ceed-backend.h`, `ceed-hash.h`, and `ceed-khash.h` removed. Users should use `ceed/backend.h`, `ceed/hash.h`, and `ceed/khash.h`. 146- Added {c:func}`CeedQFunctionGetKernelName`; refactored {c:func}`CeedQFunctionGetSourcePath` to exclude function kernel name. 147- 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`. 148- Added {c:func}`CeedVectorGetArrayWrite` that allows access to uninitialized arrays; require initialized data for {c:func}`CeedVectorGetArray`. 149- 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. 150- Added {c:func}`CeedQFunctionContextGetFieldDescriptions` to retrieve user defined descriptions of fields that are registered with `CeedQFunctionContextRegister*`. 151- Renamed `CeedElemTopology` entries for clearer namespacing between libCEED enums. 152- 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. 153- Added {c:func}`CeedOperatorSetQFunctionUpdated` to facilitate QFunction data re-use between operators sharing the same quadrature space, such as in a multigrid hierarchy. 154- Added {c:func}`CeedOperatorGetActiveVectorLengths` to get shape of CeedOperator. 155 156### New features 157 158- `CeedScalar` can now be set as `float` or `double` at compile time. 159- Added JiT utilities in `ceed/jit-tools.h` to reduce duplicated code in GPU backends. 160- 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. 161- Remove need to guard library headers in QFunction source for code generation backends. 162- `CeedDebugEnv()` macro created to provide debugging outputs when Ceed context is not present. 163- Added {c:func}`CeedStringAllocCopy` to reduce repeated code for copying strings internally. 164- Added {c:func}`CeedPathConcatenate` to facilitate loading kernel source files with a path relative to the current file. 165- Added support for non-tensor $H(\text{div})$ elements, to include CPU backend implementations and {c:func}`CeedBasisCreateHdiv` convenience constructor. 166- 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. 167- Added support for element matrix assembly in GPU backends. 168 169### Maintainability 170 171- Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage. 172- `Include-what-you-use` makefile target added as `make iwyu`. 173- Create backend constant `CEED_FIELD_MAX` to reduce magic numbers in codebase. 174- Put GPU JiTed kernel source code into separate files. 175- 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. 176 177(v0-9)= 178 179## v0.9 (Jul 6, 2021) 180 181### Interface changes 182 183- Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact. 184 185### New features 186 187- Add {c:func}`CeedVectorAXPY` and {c:func}`CeedVectorPointwiseMult` as a convenience for stand-alone testing and internal use. 188- Add `CEED_QFUNCTION_HELPER` macro to properly annotate QFunction helper functions for code generation backends. 189- Add `CeedPragmaOptimizeOff` macro for code that is sensitive to floating point errors from fast math optimizations. 190- Rust support: split `libceed-sys` crate out of `libceed` and [publish both on crates.io](https://crates.io/crates/libceed). 191 192### Performance improvements 193 194### Examples 195 196- Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations. 197- Fluid mechanics example adds GPU support and improves modularity. 198 199### Deprecated backends 200 201- 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. 202 203(v0-8)= 204 205## v0.8 (Mar 31, 2021) 206 207### Interface changes 208 209- Error handling improved to include enumerated error codes for C interface return values. 210- 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. 211 212### New features 213 214- Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features. 215- Static libraries can be built with `make STATIC=1` and the pkg-config file is installed accordingly. 216- Add {c:func}`CeedOperatorLinearAssembleSymbolic` and {c:func}`CeedOperatorLinearAssemble` to support full assembly of libCEED operators. 217 218### Performance improvements 219 220- New HIP MAGMA backends for hipMAGMA library users: `/gpu/hip/magma` and `/gpu/hip/magma/det`. 221- New HIP backends for improved tensor basis performance: `/gpu/hip/shared` and `/gpu/hip/gen`. 222 223### Examples 224 225- {ref}`example-petsc-elasticity` example updated with traction boundary conditions and improved Dirichlet boundary conditions. 226- {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. 227- {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. 228- {ref}`example-petsc-navier-stokes` example updated with support for performing convergence study and plotting order of convergence by polynomial degree. 229 230(v0-7)= 231 232## v0.7 (Sep 29, 2020) 233 234### Interface changes 235 236- Replace limited {code}`CeedInterlaceMode` with more flexible component stride {code}`compstride` in {code}`CeedElemRestriction` constructors. 237 As a result, the {code}`indices` parameter has been replaced with {code}`offsets` and the {code}`nnodes` parameter has been replaced with {code}`lsize`. 238 These changes improve support for mixed finite element methods. 239- Replace various uses of {code}`Ceed*Get*Status` with {code}`Ceed*Is*` in the backend API to match common nomenclature. 240- Replace {code}`CeedOperatorAssembleLinearDiagonal` with {c:func}`CeedOperatorLinearAssembleDiagonal` for clarity. 241- 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. 242- 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. 243- 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. 244- 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. 245 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`. 246- Added {code}`CeedQFunctionContext` object to manage user QFunction context data and reduce copies between device and host memory. 247- 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. 248 249### New features 250 251- New HIP backend: `/gpu/hip/ref`. 252- CeedQFunction support for user `CUfunction`s in some backends 253 254### Performance improvements 255 256- OCCA backend rebuilt to facilitate future performance enhancements. 257- Petsc BPs suite improved to reduce noise due to multiple calls to {code}`mpiexec`. 258 259### Examples 260 261- {ref}`example-petsc-elasticity` example updated with strain energy computation and more flexible boundary conditions. 262 263### Deprecated backends 264 265- The `/gpu/cuda/reg` backend has been removed, with its core features moved into `/gpu/cuda/ref` and `/gpu/cuda/shared`. 266 267(v0-6)= 268 269## v0.6 (Mar 29, 2020) 270 271libCEED v0.6 contains numerous new features and examples, as well as expanded 272documentation in [this new website](https://libceed.org). 273 274### New features 275 276- New Python interface using [CFFI](https://cffi.readthedocs.io/) provides a nearly 277 1-1 correspondence with the C interface, plus some convenience features. For instance, 278 data stored in the {cpp:type}`CeedVector` structure are available without copy as 279 {py:class}`numpy.ndarray`. Short tutorials are provided in 280 [Binder](https://mybinder.org/v2/gh/CEED/libCEED/main?urlpath=lab/tree/examples/tutorials/). 281- Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point, 282 {c:func}`CeedOperatorAssembleLinearQFunction`) or to evaluate the diagonal 283 ({c:func}`CeedOperatorAssembleLinearDiagonal`). These operations are useful for 284 preconditioning ingredients and are used in the libCEED's multigrid examples. 285- The inverse of separable operators can be obtained using 286 {c:func}`CeedOperatorCreateFDMElementInverse` and applied with 287 {c:func}`CeedOperatorApply`. This is a useful preconditioning ingredient, 288 especially for Laplacians and related operators. 289- New functions: {c:func}`CeedVectorNorm`, {c:func}`CeedOperatorApplyAdd`, 290 {c:func}`CeedQFunctionView`, {c:func}`CeedOperatorView`. 291- Make public accessors for various attributes to facilitate writing composable code. 292- New backend: `/cpu/self/memcheck/serial`. 293- QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA 294 backends. (Single source is coming soon for OCCA backends.) 295- Fix some missing edge cases in CUDA backend. 296 297### Performance Improvements 298 299- MAGMA backend performance optimization and non-tensor bases. 300- No-copy optimization in {c:func}`CeedOperatorApply`. 301 302### Interface changes 303 304- Replace {code}`CeedElemRestrictionCreateIdentity` and 305 {code}`CeedElemRestrictionCreateBlocked` with more flexible 306 {c:func}`CeedElemRestrictionCreateStrided` and 307 {c:func}`CeedElemRestrictionCreateBlockedStrided`. 308- Add arguments to {c:func}`CeedQFunctionCreateIdentity`. 309- Replace ambiguous uses of {cpp:enum}`CeedTransposeMode` for L-vector identification 310 with {cpp:enum}`CeedInterlaceMode`. This is now an attribute of the 311 {cpp:type}`CeedElemRestriction` (see {c:func}`CeedElemRestrictionCreate`) and no 312 longer passed as `lmode` arguments to {c:func}`CeedOperatorSetField` and 313 {c:func}`CeedElemRestrictionApply`. 314 315### Examples 316 317libCEED-0.6 contains greatly expanded examples with {ref}`new documentation <Examples>`. 318Notable additions include: 319 320- Standalone {ref}`ex2-surface` ({file}`examples/ceed/ex2-surface`): compute the area of 321 a domain in 1, 2, and 3 dimensions by applying a Laplacian. 322 323- PETSc {ref}`example-petsc-area` ({file}`examples/petsc/area.c`): computes surface area 324 of domains (like the cube and sphere) by direct integration on a surface mesh; 325 demonstrates geometric dimension different from topological dimension. 326 327- PETSc {ref}`example-petsc-bps`: 328 329 - {file}`examples/petsc/bpsraw.c` (formerly `bps.c`): transparent CUDA support. 330 - {file}`examples/petsc/bps.c` (formerly `bpsdmplex.c`): performance improvements 331 and transparent CUDA support. 332 - {ref}`example-petsc-bps-sphere` ({file}`examples/petsc/bpssphere.c`): 333 generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric 334 dimension different from topological dimension. 335 336- {ref}`example-petsc-multigrid` ({file}`examples/petsc/multigrid.c`): new p-multigrid 337 solver with algebraic multigrid coarse solve. 338 339- {ref}`example-petsc-navier-stokes` ({file}`examples/fluids/navierstokes.c`; formerly 340 `examples/navier-stokes`): unstructured grid support (using PETSc's `DMPlex`), 341 implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and 342 quasi-2D computational domain support. 343 344- {ref}`example-petsc-elasticity` ({file}`examples/solids/elasticity.c`): new solver for 345 linear elasticity, small-strain hyperelasticity, and globalized finite-strain 346 hyperelasticity using p-multigrid with algebraic multigrid coarse solve. 347 348(v0-5)= 349 350## v0.5 (Sep 18, 2019) 351 352For this release, several improvements were made. Two new CUDA backends were added to 353the family of backends, of which, the new `cuda-gen` backend achieves state-of-the-art 354performance using single-source {ref}`CeedQFunction`. From this release, users 355can define Q-Functions in a single source code independently of the targeted backend 356with the aid of a new macro `CEED QFUNCTION` to support JIT (Just-In-Time) and CPU 357compilation of the user provided {ref}`CeedQFunction` code. To allow a unified 358declaration, the {ref}`CeedQFunction` API has undergone a slight change: 359the `QFunctionField` parameter `ncomp` has been changed to `size`. This change 360requires setting the previous value of `ncomp` to `ncomp*dim` when adding a 361`QFunctionField` with eval mode `CEED EVAL GRAD`. 362 363Additionally, new CPU backends 364were included in this release, such as the `/cpu/self/opt/*` backends (which are 365written in pure C and use partial **E-vectors** to improve performance) and the 366`/cpu/self/ref/memcheck` backend (which relies upon the 367[Valgrind](http://valgrind.org/) Memcheck tool to help verify that user 368{ref}`CeedQFunction` have no undefined values). 369This release also included various performance improvements, bug fixes, new examples, 370and improved tests. Among these improvements, vectorized instructions for 371{ref}`CeedQFunction` code compiled for CPU were enhanced by using `CeedPragmaSIMD` 372instead of `CeedPragmaOMP`, implementation of a {ref}`CeedQFunction` gallery and 373identity Q-Functions were introduced, and the PETSc benchmark problems were expanded 374to include unstructured meshes handling were. For this expansion, the prior version of 375the PETSc BPs, which only included data associated with structured geometries, were 376renamed `bpsraw`, and the new version of the BPs, which can handle data associated 377with any unstructured geometry, were called `bps`. Additionally, other benchmark 378problems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively), 379and BP5 and BP6 (the collocated versions---for which the quadrature points are the same 380as the Gauss Lobatto nodes---of BP3 and BP4 respectively) were added to the PETSc 381examples. Furthermoew, another standalone libCEED example, called `ex2`, which 382computes the surface area of a given mesh was added to this release. 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/ref/memcheck` | Memcheck backend, undefined value checks | 391| `/cpu/self/opt/serial` | Serial optimized C implementation | 392| `/cpu/self/opt/blocked` | Blocked optimized C implementation | 393| `/cpu/self/avx/serial` | Serial AVX implementation | 394| `/cpu/self/avx/blocked` | Blocked AVX implementation | 395| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 396| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 397| `/cpu/occa` | Serial OCCA kernels | 398| `/gpu/occa` | CUDA OCCA kernels | 399| `/omp/occa` | OpenMP OCCA kernels | 400| `/ocl/occa` | OpenCL OCCA kernels | 401| `/gpu/cuda/ref` | Reference pure CUDA kernels | 402| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 403| `/gpu/cuda/shared` | Optimized pure CUDA kernels using shared memory | 404| `/gpu/cuda/gen` | Optimized pure CUDA kernels using code generation | 405| `/gpu/magma` | CUDA MAGMA kernels | 406 407Examples available in this release: 408 409:::{list-table} 410:header-rows: 1 411:widths: auto 412* - User code 413 - Example 414* - `ceed` 415 - * ex1 (volume) 416 * ex2 (surface) 417* - `mfem` 418 - * BP1 (scalar mass operator) 419 * BP3 (scalar Laplace operator) 420* - `petsc` 421 - * BP1 (scalar mass operator) 422 * BP2 (vector mass operator) 423 * BP3 (scalar Laplace operator) 424 * BP4 (vector Laplace operator) 425 * BP5 (collocated scalar Laplace operator) 426 * BP6 (collocated vector Laplace operator) 427 * Navier-Stokes 428* - `nek5000` 429 - * BP1 (scalar mass operator) 430 * BP3 (scalar Laplace operator) 431::: 432 433(v0-4)= 434 435## v0.4 (Apr 1, 2019) 436 437libCEED v0.4 was made again publicly available in the second full CEED software 438distribution, release CEED 2.0. This release contained notable features, such as 439four new CPU backends, two new GPU backends, CPU backend optimizations, initial 440support for operator composition, performance benchmarking, and a Navier-Stokes demo. 441The new CPU backends in this release came in two families. The `/cpu/self/*/serial` 442backends process one element at a time and are intended for meshes with a smaller number 443of high order elements. The `/cpu/self/*/blocked` backends process blocked batches of 444eight interlaced elements and are intended for meshes with higher numbers of elements. 445The `/cpu/self/avx/*` backends rely upon AVX instructions to provide vectorized CPU 446performance. The `/cpu/self/xsmm/*` backends rely upon the 447[LIBXSMM](http://github.com/hfp/libxsmm) package to provide vectorized CPU 448performance. The `/gpu/cuda/*` backends provide GPU performance strictly using CUDA. 449The `/gpu/cuda/ref` backend is a reference CUDA backend, providing reasonable 450performance for most problem configurations. The `/gpu/cuda/reg` backend uses a simple 451parallelization approach, where each thread treats a finite element. Using just in time 452compilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this 453backend unroll loops and map memory address to registers. The `/gpu/cuda/reg` backend 454achieve good peak performance for 1D, 2D, and low order 3D problems, but performance 455deteriorates very quickly when threads run out of registers. 456 457A new explicit time-stepping Navier-Stokes solver was added to the family of libCEED 458examples in the `examples/petsc` directory (see {ref}`example-petsc-navier-stokes`). 459This example solves the time-dependent Navier-Stokes equations of compressible gas 460dynamics in a static Eulerian three-dimensional frame, using structured high-order 461finite/spectral element spatial discretizations and explicit high-order time-stepping 462(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc, 463so that the pointwise physics (defined at quadrature points) is separated from the 464parallelization and meshing concerns. 465 466Backends available in this release: 467 468| CEED resource (`-ceed`) | Backend | 469|--------------------------|-----------------------------------------------------| 470| `/cpu/self/ref/serial` | Serial reference implementation | 471| `/cpu/self/ref/blocked` | Blocked reference implementation | 472| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 473| `/cpu/self/avx/serial` | Serial AVX implementation | 474| `/cpu/self/avx/blocked` | Blocked AVX implementation | 475| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 476| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 477| `/cpu/occa` | Serial OCCA kernels | 478| `/gpu/occa` | CUDA OCCA kernels | 479| `/omp/occa` | OpenMP OCCA kernels | 480| `/ocl/occa` | OpenCL OCCA kernels | 481| `/gpu/cuda/ref` | Reference pure CUDA kernels | 482| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 483| `/gpu/magma` | CUDA MAGMA kernels | 484 485Examples available in this release: 486 487:::{list-table} 488:header-rows: 1 489:widths: auto 490* - User code 491 - Example 492* - `ceed` 493 - * ex1 (volume) 494* - `mfem` 495 - * BP1 (scalar mass operator) 496 * BP3 (scalar Laplace operator) 497* - `petsc` 498 - * BP1 (scalar mass operator) 499 * BP3 (scalar Laplace operator) 500 * Navier-Stokes 501* - `nek5000` 502 - * BP1 (scalar mass operator) 503 * BP3 (scalar Laplace operator) 504::: 505 506(v0-3)= 507 508## v0.3 (Sep 30, 2018) 509 510Notable features in this release include active/passive field interface, support for 511non-tensor bases, backend optimization, and improved Fortran interface. This release 512also focused on providing improved continuous integration, and many new tests with code 513coverage reports of about 90%. This release also provided a significant change to the 514public interface: a {ref}`CeedQFunction` can take any number of named input and output 515arguments while {ref}`CeedOperator` connects them to the actual data, which may be 516supplied explicitly to `CeedOperatorApply()` (active) or separately via 517`CeedOperatorSetField()` (passive). This interface change enables reusable libraries 518of CeedQFunctions and composition of block solvers constructed using 519{ref}`CeedOperator`. A concept of blocked restriction was added to this release and 520used in an optimized CPU backend. Although this is typically not visible to the user, 521it enables effective use of arbitrary-length SIMD while maintaining cache locality. 522This CPU backend also implements an algebraic factorization of tensor product gradients 523to perform fewer operations than standard application of interpolation and 524differentiation from nodes to quadrature points. This algebraic formulation 525automatically supports non-polynomial and non-interpolatory bases, thus is more general 526than the more common derivation in terms of Lagrange polynomials on the quadrature points. 527 528Backends available in this release: 529 530| CEED resource (`-ceed`) | Backend | 531|-------------------------|-----------------------------------------------------| 532| `/cpu/self/blocked` | Blocked reference implementation | 533| `/cpu/self/ref` | Serial reference implementation | 534| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 535| `/cpu/occa` | Serial OCCA kernels | 536| `/gpu/occa` | CUDA OCCA kernels | 537| `/omp/occa` | OpenMP OCCA kernels | 538| `/ocl/occa` | OpenCL OCCA kernels | 539| `/gpu/magma` | CUDA MAGMA kernels | 540 541Examples available in this release: 542 543:::{list-table} 544:header-rows: 1 545:widths: auto 546* - User code 547 - Example 548* - `ceed` 549 - * ex1 (volume) 550* - `mfem` 551 - * BP1 (scalar mass operator) 552 * BP3 (scalar Laplace operator) 553* - `petsc` 554 - * BP1 (scalar mass operator) 555 * BP3 (scalar Laplace operator) 556* - `nek5000` 557 - * BP1 (scalar mass operator) 558 * BP3 (scalar Laplace operator) 559::: 560 561(v0-21)= 562 563## v0.21 (Sep 30, 2018) 564 565A MAGMA backend (which relies upon the 566[MAGMA](https://bitbucket.org/icl/magma) package) was integrated in libCEED for this 567release. This initial integration set up the framework of using MAGMA and provided the 568libCEED functionality through MAGMA kernels as one of libCEED’s computational backends. 569As any other backend, the MAGMA backend provides extended basic data structures for 570{ref}`CeedVector`, {ref}`CeedElemRestriction`, and {ref}`CeedOperator`, and implements 571the fundamental CEED building blocks to work with the new data structures. 572In general, the MAGMA-specific data structures keep the libCEED pointers to CPU data 573but also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled 574internally, and thus seamlessly to the user, through the functions/methods that are 575provided to support them. 576 577Backends available in this release: 578 579| CEED resource (`-ceed`) | Backend | 580|-------------------------|---------------------------------| 581| `/cpu/self` | Serial reference implementation | 582| `/cpu/occa` | Serial OCCA kernels | 583| `/gpu/occa` | CUDA OCCA kernels | 584| `/omp/occa` | OpenMP OCCA kernels | 585| `/ocl/occa` | OpenCL OCCA kernels | 586| `/gpu/magma` | CUDA MAGMA kernels | 587 588Examples available in this release: 589 590:::{list-table} 591:header-rows: 1 592:widths: auto 593* - User code 594 - Example 595* - `ceed` 596 - * ex1 (volume) 597* - `mfem` 598 - * BP1 (scalar mass operator) 599 * BP3 (scalar Laplace operator) 600* - `petsc` 601 - * BP1 (scalar mass operator) 602* - `nek5000` 603 - * BP1 (scalar mass operator) 604::: 605 606(v0-2)= 607 608## v0.2 (Mar 30, 2018) 609 610libCEED was made publicly available the first full CEED software distribution, release 611CEED 1.0. The distribution was made available using the Spack package manager to provide 612a common, easy-to-use build environment, where the user can build the CEED distribution 613with all dependencies. This release included a new Fortran interface for the library. 614This release also contained major improvements in the OCCA backend (including a new 615`/ocl/occa` backend) and new examples. The standalone libCEED example was modified to 616compute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an 617`examples/ceed` subfolder. A new `mfem` example to perform BP3 (with the application 618of the Laplace operator) was also added to this release. 619 620Backends available in this release: 621 622| CEED resource (`-ceed`) | Backend | 623|-------------------------|---------------------------------| 624| `/cpu/self` | Serial reference implementation | 625| `/cpu/occa` | Serial OCCA kernels | 626| `/gpu/occa` | CUDA OCCA kernels | 627| `/omp/occa` | OpenMP OCCA kernels | 628| `/ocl/occa` | OpenCL OCCA kernels | 629 630Examples available in this release: 631 632:::{list-table} 633:header-rows: 1 634:widths: auto 635* - User code 636 - Example 637* - `ceed` 638 - * ex1 (volume) 639* - `mfem` 640 - * BP1 (scalar mass operator) 641 * BP3 (scalar Laplace operator) 642* - `petsc` 643 - * BP1 (scalar mass operator) 644* - `nek5000` 645 - * BP1 (scalar mass operator) 646::: 647 648(v0-1)= 649 650## v0.1 (Jan 3, 2018) 651 652Initial low-level API of the CEED project. The low-level API provides a set of Finite 653Elements kernels and components for writing new low-level kernels. Examples include: 654vector and sparse linear algebra, element matrix assembly over a batch of elements, 655partial assembly and action for efficient high-order operators like mass, diffusion, 656advection, etc. The main goal of the low-level API is to establish the basis for the 657high-level API. Also, identifying such low-level kernels and providing a reference 658implementation for them serves as the basis for specialized backend implementations. 659This release contained several backends: `/cpu/self`, and backends which rely upon the 660[OCCA](http://github.com/libocca/occa) package, such as `/cpu/occa`, 661`/gpu/occa`, and `/omp/occa`. 662It also included several examples, in the `examples` folder: 663A standalone code that shows the usage of libCEED (with no external 664dependencies) to apply the Laplace operator, `ex1`; an `mfem` example to perform BP1 665(with the application of the mass operator); and a `petsc` example to perform BP1 666(with the application of the mass operator). 667 668Backends available in this release: 669 670| CEED resource (`-ceed`) | Backend | 671|-------------------------|---------------------------------| 672| `/cpu/self` | Serial reference implementation | 673| `/cpu/occa` | Serial OCCA kernels | 674| `/gpu/occa` | CUDA OCCA kernels | 675| `/omp/occa` | OpenMP OCCA kernels | 676 677Examples available in this release: 678 679| User code | Example | 680|-----------------------|-----------------------------------| 681| `ceed` | ex1 (scalar Laplace operator) | 682| `mfem` | BP1 (scalar mass operator) | 683| `petsc` | BP1 (scalar mass operator) | 684``` 685