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