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