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