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