1# Changes/Release Notes 2 3On this page we provide a summary of the main API changes, new features and examples for each release of libCEED. 4 5(main)= 6 7## Current `main` branch 8 9### Interface changes 10 11- Add `bool` field type for `CeedQFunctionContext` and related interfaces to use `bool` fields. 12- `CEED_BASIS_COLLOCATED` removed; users should only use `CEED_BASIS_NONE`. 13- Remove unneeded pointer for `CeedElemRestrictionGetELayout`. 14- Change QFunction source include file handling in JiT compilers 15 - Add `CEED_RUNNING_JIT_PASS` compiler definition for wrapping header files that device JiT compilers cannot read 16 - Users should now prefer `#include <ceed/types.h>` rather than `#include <ceed.h>` in QFunction source files 17- Require use of `Ceed*Destroy()` on Ceed objects returned from `Ceed*Get*()`. 18 19### New features 20 21- Add `CeedOperatorCreateAtPoints` which evaluates the `CeedQFunction` at arbitrary locations in each element, for use in Particle in Cell, Material Point Method, and similar methods. 22- Add `CeedElemRestrictionGetLLayout` to provide L-vector layout for strided `CeedElemRestriction` created with `CEED_BACKEND_STRIDES`. 23- Add `CeedVectorReturnCeed` and similar when parent `Ceed` context for a libCEED object is only needed once in a calling scope. 24- Enable `#pragma once` for all JiT source; remove duplicate includes in JiT source string before compilation. 25- Allow user to set additional compiler options for CUDA and HIP JiT. 26Specifically, directories set with `CeedAddJitSourceRoot(ceed, "foo/bar")` will be used to set `-Ifoo/bar` and defines set with `CeedAddJitDefine(ceed, "foo=bar")` will be used to set `-Dfoo=bar`. 27- Added non-tensor basis support to code generation backends `/gpu/cuda/gen` and `/gpu/hip/gen`. 28- Added support to code generation backends `/gpu/cuda/gen` and `/gpu/hip/gen` for operators with both tensor and non-tensor bases. 29- Add `CeedGetGitVersion()` to access the Git commit and dirty state of the repository at build time. 30- Add `CeedGetBuildConfiguration()` to access compilers, flags, and related information about the build environment. 31 32### Examples 33 34- Add deal.II example with CEED BP suite. 35 36(v0-12)= 37 38## v0.12 (Oct 31, 2023) 39 40### Interface changes 41 42- Update `CeedOperatorContext*` functions to `CeedOperator*Context*` functions for consistency. 43For example, `CeedOperatorContextGetFieldLabel` was renamed to `CeedOperatorGetContextFieldLabel`. 44- Removed `CeedBasisSetNumQuadraturePoints` as redundant and bug-prone interface. 45 46### New features 47 48- Added {c:func}`CeedOperatorGetFieldByName` to access a specific `CeedOperatorField` by its name. 49- Update `/cpu/self/memcheck/*` backends to help verify `CeedVector` array access assumptions and `CeedQFunction` user output assumptions. 50- Update {c:func}`CeedOperatorLinearAssembleDiagonal` to provide default implementation that supports `CeedOperator` with multiple active bases. 51- Added Sycl backends `/gpu/sycl/ref`, `/gpu/sycl/shared`, and `/gpu/sycl/gen`. 52- Added {c:func}`CeedBasisApplyAtPoints` for evaluation of values and derivatives at arbitrary points inside elements. 53- Added support for non-tensor $H(\text{curl})$ finite element spaces with {c:func}`CeedBasisCreateHcurl`. 54- 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)). 55- Added {c:func}`CeedOperatorLinearAssemblePointBlockDiagonalSymbolic` to create COO mapping for mapping out of {c:func}`CeedOperatorLinearAssemblePointBlockDiagonal`. 56- Added support for application codes which manage multiple {ref}`Ceed` objects, parallelized across OpenMP threads. 57 58### Examples 59 60- Add `DMSwarm` example demonstrating interpolation from background mesh to swarm points and projection from swarm points to background mesh. 61 62#### {ref}`example-petsc-bps` 63 64- Requires PETSc version 3.19 or later. 65 66#### {ref}`example-petsc-navier-stokes` 67 68- Updated restart and checkpointing interface. 69- Add data-driven subgrid-stress model. 70- Add differential filtering of solution. 71- Add turbulence statistics collection over spanwise-symmetric geometries. 72- Add Taylor-Green vortex initial condition. 73- Add Riemann-based outflow boundary conditions. 74- Added vortex shedding and flow past cylinder example, including calculations for lift, drag, and heat transfer. 75- Add Internal Damping Layer (IDL) for helping turbulent simulation stability. 76- Derive `CeedBasis` from `PetscFE`, and various other internal maintainability updates. 77 78(v0-11)= 79 80## v0.11 (Dec 24, 2022) 81 82### Interface changes 83 84- Added {c:func}`CeedOperatorSetName` for more readable {c:func}`CeedOperatorView` output. 85- Added {c:func}`CeedBasisCreateProjection` to facilitate interpolation between nodes for separate `CeedBases`. 86- Rename and move {c:func}`CeedCompositeOperatorGetNumSub` and {c:func}`CeedCompositeOperatorGetSubList` to public interface. 87- Renamed `CEED_BASIS_COLLOCATED` to `CEED_BASIS_NONE` for clarity. 88Some 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. 89 90### New features 91 92- Update `/cpu/self/memcheck/*` backends to help verify `CeedQFunctionContext` data sizes provided by user. 93- Improved support for $H(\text{div})$ bases. 94- Added `CeedInt_FMT` to support potential future use of larger integer sizes. 95- Added `CEED_QFUNCTION_ATTR` for setting compiler attributes/pragmas to `CEED_QFUNCTION_HELPER` and `CEED_QFUNCTION`. 96- OCCA backend updated to latest OCCA release; DPC++ and OMP OCCA modes enabled. 97Due to a limitation of the OCCA parser, typedefs are required to use pointers to arrays in QFunctions with the OCCA backend. 98This issue will be fixed in a future OCCA release. 99 100### Bugfix 101 102- Fix bug in setting device id for GPU backends. 103- Fix storing of indices for `CeedElemRestriction` on the host with GPU backends. 104- Fix `CeedElemRestriction` sizing for {c:func}`CeedOperatorAssemblePointBlockDiagonal`. 105- Fix bugs in CPU implementation of {c:func}`CeedOperatorLinearAssemble` when there are different number of active input modes and active output modes. 106 107### Examples 108 109#### {ref}`example-petsc-navier-stokes` 110 111- Various performance enhancements, analytic matrix-free and assembled Jacobian, and PETSc solver configurations for GPUs. 112- Refactored to improve code reuse and modularity. 113- Support for primitive variables for more accurate boundary layers and all-speed flow. 114- Added $YZ\beta$ shock capturing scheme and Shock Tube example. 115- Added Channel example, with comparison to analytic solutions. 116- Added Flat Plate with boundary layer mesh and compressible Blasius inflow condition based on Chebyshev collocation solution of the Blasius equations. 117- Added strong and weak synthetic turbulence generation (STG) inflow boundary conditions. 118- Added "freestream" boundary conditions based on HLLC Riemann solver. 119- Automated stabilization coefficients for different basis degree. 120 121#### {ref}`example-petsc-bps` 122 123- Support for convergence studies. 124 125### Maintainability 126 127- 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. 128- Enabled support for `p > 8` for `/gpu/*/shared` backends. 129- Switch to `clang-format` over `astyle` for automatic formatting; Makefile command changed to `make format` from `make style`. 130- Improved test harness. 131 132(v0-10-1)= 133 134## v0.10.1 (Apr 11, 2022) 135 136### Interface changes 137 138- Added {c:func}`CeedQFunctionSetUserFlopsEstimate` and {c:func}`CeedOperatorGetFlopsEstimate` to facilitate estimating FLOPs in operator application. 139 140### New features 141 142- Switched MAGMA backends to use runtime compilation for tensor basis kernels (and element restriction kernels, in non-deterministic `/gpu/*/magma` backends). 143This reduces time to compile the library and increases the range of parameters for which the MAGMA tensor basis kernels will work. 144 145### Bugfix 146 147- Install JiT source files in install directory to fix GPU functionality for installed libCEED. 148 149(v0-10)= 150 151## v0.10 (Mar 21, 2022) 152 153### Interface changes 154 155- Update {c:func}`CeedQFunctionGetFields` and {c:func}`CeedOperatorGetFields` to include number of fields. 156- 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`. 157- Clarify and document conditions where `CeedQFunction` and `CeedOperator` become immutable and no further fields or suboperators can be added. 158- Add {c:func}`CeedOperatorLinearAssembleQFunctionBuildOrUpdate` to reduce object creation overhead in assembly of CeedOperator preconditioning ingredients. 159- Promote {c:func}`CeedOperatorCheckReady`to the public API to facilitate interactive interfaces. 160- Warning added when compiling OCCA backend to alert users that this backend is experimental. 161- `ceed-backend.h`, `ceed-hash.h`, and `ceed-khash.h` removed. Users should use `ceed/backend.h`, `ceed/hash.h`, and `ceed/khash.h`. 162- Added {c:func}`CeedQFunctionGetKernelName`; refactored {c:func}`CeedQFunctionGetSourcePath` to exclude function kernel name. 163- 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`. 164- Added {c:func}`CeedVectorGetArrayWrite` that allows access to uninitialized arrays; require initialized data for {c:func}`CeedVectorGetArray`. 165- 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. 166- Added {c:func}`CeedQFunctionContextGetFieldDescriptions` to retrieve user defined descriptions of fields that are registered with `CeedQFunctionContextRegister*`. 167- Renamed `CeedElemTopology` entries for clearer namespacing between libCEED enums. 168- 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. 169- Added {c:func}`CeedOperatorSetQFunctionUpdated` to facilitate QFunction data re-use between operators sharing the same quadrature space, such as in a multigrid hierarchy. 170- Added {c:func}`CeedOperatorGetActiveVectorLengths` to get shape of CeedOperator. 171 172### New features 173 174- `CeedScalar` can now be set as `float` or `double` at compile time. 175- Added JiT utilities in `ceed/jit-tools.h` to reduce duplicated code in GPU backends. 176- 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. 177- Remove need to guard library headers in QFunction source for code generation backends. 178- `CeedDebugEnv()` macro created to provide debugging outputs when Ceed context is not present. 179- Added {c:func}`CeedStringAllocCopy` to reduce repeated code for copying strings internally. 180- Added {c:func}`CeedPathConcatenate` to facilitate loading kernel source files with a path relative to the current file. 181- Added support for non-tensor $H(\text{div})$ elements, to include CPU backend implementations and {c:func}`CeedBasisCreateHdiv` convenience constructor. 182- 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. 183- Added support for element matrix assembly in GPU backends. 184 185### Maintainability 186 187- Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage. 188- `Include-what-you-use` makefile target added as `make iwyu`. 189- Create backend constant `CEED_FIELD_MAX` to reduce magic numbers in codebase. 190- Put GPU JiTed kernel source code into separate files. 191- 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. 192 193(v0-9)= 194 195## v0.9 (Jul 6, 2021) 196 197### Interface changes 198 199- Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact. 200 201### New features 202 203- Add {c:func}`CeedVectorAXPY` and {c:func}`CeedVectorPointwiseMult` as a convenience for stand-alone testing and internal use. 204- Add `CEED_QFUNCTION_HELPER` macro to properly annotate QFunction helper functions for code generation backends. 205- Add `CeedPragmaOptimizeOff` macro for code that is sensitive to floating point errors from fast math optimizations. 206- Rust support: split `libceed-sys` crate out of `libceed` and [publish both on crates.io](https://crates.io/crates/libceed). 207 208### Performance improvements 209 210### Examples 211 212- Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations. 213- Fluid mechanics example adds GPU support and improves modularity. 214 215### Deprecated backends 216 217- 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. 218 219(v0-8)= 220 221## v0.8 (Mar 31, 2021) 222 223### Interface changes 224 225- Error handling improved to include enumerated error codes for C interface return values. 226- 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. 227 228### New features 229 230- Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features. 231- Static libraries can be built with `make STATIC=1` and the pkg-config file is installed accordingly. 232- Add {c:func}`CeedOperatorLinearAssembleSymbolic` and {c:func}`CeedOperatorLinearAssemble` to support full assembly of libCEED operators. 233 234### Performance improvements 235 236- New HIP MAGMA backends for hipMAGMA library users: `/gpu/hip/magma` and `/gpu/hip/magma/det`. 237- New HIP backends for improved tensor basis performance: `/gpu/hip/shared` and `/gpu/hip/gen`. 238 239### Examples 240 241- {ref}`example-petsc-elasticity` example updated with traction boundary conditions and improved Dirichlet boundary conditions. 242- {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. 243- {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. 244- {ref}`example-petsc-navier-stokes` example updated with support for performing convergence study and plotting order of convergence by polynomial degree. 245 246(v0-7)= 247 248## v0.7 (Sep 29, 2020) 249 250### Interface changes 251 252- Replace limited {code}`CeedInterlaceMode` with more flexible component stride {code}`compstride` in {code}`CeedElemRestriction` constructors. 253 As a result, the {code}`indices` parameter has been replaced with {code}`offsets` and the {code}`nnodes` parameter has been replaced with {code}`lsize`. 254 These changes improve support for mixed finite element methods. 255- Replace various uses of {code}`Ceed*Get*Status` with {code}`Ceed*Is*` in the backend API to match common nomenclature. 256- Replace {code}`CeedOperatorAssembleLinearDiagonal` with {c:func}`CeedOperatorLinearAssembleDiagonal` for clarity. 257- 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. 258- 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. 259- 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. 260- 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. 261 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`. 262- Added {code}`CeedQFunctionContext` object to manage user QFunction context data and reduce copies between device and host memory. 263- 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. 264 265### New features 266 267- New HIP backend: `/gpu/hip/ref`. 268- CeedQFunction support for user `CUfunction`s in some backends 269 270### Performance improvements 271 272- OCCA backend rebuilt to facilitate future performance enhancements. 273- PETSc BPs suite improved to reduce noise due to multiple calls to {code}`mpiexec`. 274 275### Examples 276 277- {ref}`example-petsc-elasticity` example updated with strain energy computation and more flexible boundary conditions. 278 279### Deprecated backends 280 281- The `/gpu/cuda/reg` backend has been removed, with its core features moved into `/gpu/cuda/ref` and `/gpu/cuda/shared`. 282 283(v0-6)= 284 285## v0.6 (Mar 29, 2020) 286 287libCEED v0.6 contains numerous new features and examples, as well as expanded 288documentation in [this new website](https://libceed.org). 289 290### New features 291 292- New Python interface using [CFFI](https://cffi.readthedocs.io/) provides a nearly 293 1-1 correspondence with the C interface, plus some convenience features. For instance, 294 data stored in the {cpp:type}`CeedVector` structure are available without copy as 295 {py:class}`numpy.ndarray`. Short tutorials are provided in 296 [Binder](https://mybinder.org/v2/gh/CEED/libCEED/main?urlpath=lab/tree/examples/tutorials/). 297- Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point, 298 {c:func}`CeedOperatorAssembleLinearQFunction`) or to evaluate the diagonal 299 ({c:func}`CeedOperatorAssembleLinearDiagonal`). These operations are useful for 300 preconditioning ingredients and are used in the libCEED's multigrid examples. 301- The inverse of separable operators can be obtained using 302 {c:func}`CeedOperatorCreateFDMElementInverse` and applied with 303 {c:func}`CeedOperatorApply`. This is a useful preconditioning ingredient, 304 especially for Laplacians and related operators. 305- New functions: {c:func}`CeedVectorNorm`, {c:func}`CeedOperatorApplyAdd`, 306 {c:func}`CeedQFunctionView`, {c:func}`CeedOperatorView`. 307- Make public accessors for various attributes to facilitate writing composable code. 308- New backend: `/cpu/self/memcheck/serial`. 309- QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA 310 backends. (Single source is coming soon for OCCA backends.) 311- Fix some missing edge cases in CUDA backend. 312 313### Performance Improvements 314 315- MAGMA backend performance optimization and non-tensor bases. 316- No-copy optimization in {c:func}`CeedOperatorApply`. 317 318### Interface changes 319 320- Replace {code}`CeedElemRestrictionCreateIdentity` and 321 {code}`CeedElemRestrictionCreateBlocked` with more flexible 322 {c:func}`CeedElemRestrictionCreateStrided` and 323 {c:func}`CeedElemRestrictionCreateBlockedStrided`. 324- Add arguments to {c:func}`CeedQFunctionCreateIdentity`. 325- Replace ambiguous uses of {cpp:enum}`CeedTransposeMode` for L-vector identification 326 with {cpp:enum}`CeedInterlaceMode`. This is now an attribute of the 327 {cpp:type}`CeedElemRestriction` (see {c:func}`CeedElemRestrictionCreate`) and no 328 longer passed as `lmode` arguments to {c:func}`CeedOperatorSetField` and 329 {c:func}`CeedElemRestrictionApply`. 330 331### Examples 332 333libCEED-0.6 contains greatly expanded examples with {ref}`new documentation <Examples>`. 334Notable additions include: 335 336- Standalone {ref}`ex2-surface` ({file}`examples/ceed/ex2-surface`): compute the area of 337 a domain in 1, 2, and 3 dimensions by applying a Laplacian. 338 339- PETSc {ref}`example-petsc-area` ({file}`examples/petsc/area.c`): computes surface area 340 of domains (like the cube and sphere) by direct integration on a surface mesh; 341 demonstrates geometric dimension different from topological dimension. 342 343- PETSc {ref}`example-petsc-bps`: 344 345 - {file}`examples/petsc/bpsraw.c` (formerly `bps.c`): transparent CUDA support. 346 - {file}`examples/petsc/bps.c` (formerly `bpsdmplex.c`): performance improvements 347 and transparent CUDA support. 348 - {ref}`example-petsc-bps-sphere` ({file}`examples/petsc/bpssphere.c`): 349 generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric 350 dimension different from topological dimension. 351 352- {ref}`example-petsc-multigrid` ({file}`examples/petsc/multigrid.c`): new p-multigrid 353 solver with algebraic multigrid coarse solve. 354 355- {ref}`example-petsc-navier-stokes` ({file}`examples/fluids/navierstokes.c`; formerly 356 `examples/navier-stokes`): unstructured grid support (using PETSc's `DMPlex`), 357 implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and 358 quasi-2D computational domain support. 359 360- {ref}`example-petsc-elasticity` ({file}`examples/solids/elasticity.c`): new solver for 361 linear elasticity, small-strain hyperelasticity, and globalized finite-strain 362 hyperelasticity using p-multigrid with algebraic multigrid coarse solve. 363 364(v0-5)= 365 366## v0.5 (Sep 18, 2019) 367 368For this release, several improvements were made. Two new CUDA backends were added to 369the family of backends, of which, the new `cuda-gen` backend achieves state-of-the-art 370performance using single-source {ref}`CeedQFunction`. From this release, users 371can define Q-Functions in a single source code independently of the targeted backend 372with the aid of a new macro `CEED QFUNCTION` to support JIT (Just-In-Time) and CPU 373compilation of the user provided {ref}`CeedQFunction` code. To allow a unified 374declaration, the {ref}`CeedQFunction` API has undergone a slight change: 375the `QFunctionField` parameter `ncomp` has been changed to `size`. This change 376requires setting the previous value of `ncomp` to `ncomp*dim` when adding a 377`QFunctionField` with eval mode `CEED EVAL GRAD`. 378 379Additionally, new CPU backends 380were included in this release, such as the `/cpu/self/opt/*` backends (which are 381written in pure C and use partial **E-vectors** to improve performance) and the 382`/cpu/self/ref/memcheck` backend (which relies upon the 383[Valgrind](http://valgrind.org/) Memcheck tool to help verify that user 384{ref}`CeedQFunction` have no undefined values). 385This release also included various performance improvements, bug fixes, new examples, 386and improved tests. Among these improvements, vectorized instructions for 387{ref}`CeedQFunction` code compiled for CPU were enhanced by using `CeedPragmaSIMD` 388instead of `CeedPragmaOMP`, implementation of a {ref}`CeedQFunction` gallery and 389identity Q-Functions were introduced, and the PETSc benchmark problems were expanded 390to include unstructured meshes handling were. For this expansion, the prior version of 391the PETSc BPs, which only included data associated with structured geometries, were 392renamed `bpsraw`, and the new version of the BPs, which can handle data associated 393with any unstructured geometry, were called `bps`. Additionally, other benchmark 394problems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively), 395and BP5 and BP6 (the collocated versions---for which the quadrature points are the same 396as the Gauss Lobatto nodes---of BP3 and BP4 respectively) were added to the PETSc 397examples. Furthermoew, another standalone libCEED example, called `ex2`, which 398computes the surface area of a given mesh was added to this release. 399 400Backends available in this release: 401 402| CEED resource (`-ceed`) | Backend | 403|--------------------------|-----------------------------------------------------| 404| `/cpu/self/ref/serial` | Serial reference implementation | 405| `/cpu/self/ref/blocked` | Blocked reference implementation | 406| `/cpu/self/ref/memcheck` | Memcheck backend, undefined value checks | 407| `/cpu/self/opt/serial` | Serial optimized C implementation | 408| `/cpu/self/opt/blocked` | Blocked optimized C implementation | 409| `/cpu/self/avx/serial` | Serial AVX implementation | 410| `/cpu/self/avx/blocked` | Blocked AVX implementation | 411| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 412| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 413| `/cpu/occa` | Serial OCCA kernels | 414| `/gpu/occa` | CUDA OCCA kernels | 415| `/omp/occa` | OpenMP OCCA kernels | 416| `/ocl/occa` | OpenCL OCCA kernels | 417| `/gpu/cuda/ref` | Reference pure CUDA kernels | 418| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 419| `/gpu/cuda/shared` | Optimized pure CUDA kernels using shared memory | 420| `/gpu/cuda/gen` | Optimized pure CUDA kernels using code generation | 421| `/gpu/magma` | CUDA MAGMA kernels | 422 423Examples available in this release: 424 425:::{list-table} 426:header-rows: 1 427:widths: auto 428* - User code 429 - Example 430* - `ceed` 431 - * ex1 (volume) 432 * ex2 (surface) 433* - `mfem` 434 - * BP1 (scalar mass operator) 435 * BP3 (scalar Laplace operator) 436* - `petsc` 437 - * BP1 (scalar mass operator) 438 * BP2 (vector mass operator) 439 * BP3 (scalar Laplace operator) 440 * BP4 (vector Laplace operator) 441 * BP5 (collocated scalar Laplace operator) 442 * BP6 (collocated vector Laplace operator) 443 * Navier-Stokes 444* - `nek5000` 445 - * BP1 (scalar mass operator) 446 * BP3 (scalar Laplace operator) 447::: 448 449(v0-4)= 450 451## v0.4 (Apr 1, 2019) 452 453libCEED v0.4 was made again publicly available in the second full CEED software 454distribution, release CEED 2.0. This release contained notable features, such as 455four new CPU backends, two new GPU backends, CPU backend optimizations, initial 456support for operator composition, performance benchmarking, and a Navier-Stokes demo. 457The new CPU backends in this release came in two families. The `/cpu/self/*/serial` 458backends process one element at a time and are intended for meshes with a smaller number 459of high order elements. The `/cpu/self/*/blocked` backends process blocked batches of 460eight interlaced elements and are intended for meshes with higher numbers of elements. 461The `/cpu/self/avx/*` backends rely upon AVX instructions to provide vectorized CPU 462performance. The `/cpu/self/xsmm/*` backends rely upon the 463[LIBXSMM](http://github.com/hfp/libxsmm) package to provide vectorized CPU 464performance. The `/gpu/cuda/*` backends provide GPU performance strictly using CUDA. 465The `/gpu/cuda/ref` backend is a reference CUDA backend, providing reasonable 466performance for most problem configurations. The `/gpu/cuda/reg` backend uses a simple 467parallelization approach, where each thread treats a finite element. Using just in time 468compilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this 469backend unroll loops and map memory address to registers. The `/gpu/cuda/reg` backend 470achieve good peak performance for 1D, 2D, and low order 3D problems, but performance 471deteriorates very quickly when threads run out of registers. 472 473A new explicit time-stepping Navier-Stokes solver was added to the family of libCEED 474examples in the `examples/petsc` directory (see {ref}`example-petsc-navier-stokes`). 475This example solves the time-dependent Navier-Stokes equations of compressible gas 476dynamics in a static Eulerian three-dimensional frame, using structured high-order 477finite/spectral element spatial discretizations and explicit high-order time-stepping 478(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc, 479so that the pointwise physics (defined at quadrature points) is separated from the 480parallelization and meshing concerns. 481 482Backends available in this release: 483 484| CEED resource (`-ceed`) | Backend | 485|--------------------------|-----------------------------------------------------| 486| `/cpu/self/ref/serial` | Serial reference implementation | 487| `/cpu/self/ref/blocked` | Blocked reference implementation | 488| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 489| `/cpu/self/avx/serial` | Serial AVX implementation | 490| `/cpu/self/avx/blocked` | Blocked AVX implementation | 491| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 492| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 493| `/cpu/occa` | Serial OCCA kernels | 494| `/gpu/occa` | CUDA OCCA kernels | 495| `/omp/occa` | OpenMP OCCA kernels | 496| `/ocl/occa` | OpenCL OCCA kernels | 497| `/gpu/cuda/ref` | Reference pure CUDA kernels | 498| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 499| `/gpu/magma` | CUDA MAGMA kernels | 500 501Examples available in this release: 502 503:::{list-table} 504:header-rows: 1 505:widths: auto 506* - User code 507 - Example 508* - `ceed` 509 - * ex1 (volume) 510* - `mfem` 511 - * BP1 (scalar mass operator) 512 * BP3 (scalar Laplace operator) 513* - `petsc` 514 - * BP1 (scalar mass operator) 515 * BP3 (scalar Laplace operator) 516 * Navier-Stokes 517* - `nek5000` 518 - * BP1 (scalar mass operator) 519 * BP3 (scalar Laplace operator) 520::: 521 522(v0-3)= 523 524## v0.3 (Sep 30, 2018) 525 526Notable features in this release include active/passive field interface, support for 527non-tensor bases, backend optimization, and improved Fortran interface. This release 528also focused on providing improved continuous integration, and many new tests with code 529coverage reports of about 90%. This release also provided a significant change to the 530public interface: a {ref}`CeedQFunction` can take any number of named input and output 531arguments while {ref}`CeedOperator` connects them to the actual data, which may be 532supplied explicitly to `CeedOperatorApply()` (active) or separately via 533`CeedOperatorSetField()` (passive). This interface change enables reusable libraries 534of CeedQFunctions and composition of block solvers constructed using 535{ref}`CeedOperator`. A concept of blocked restriction was added to this release and 536used in an optimized CPU backend. Although this is typically not visible to the user, 537it enables effective use of arbitrary-length SIMD while maintaining cache locality. 538This CPU backend also implements an algebraic factorization of tensor product gradients 539to perform fewer operations than standard application of interpolation and 540differentiation from nodes to quadrature points. This algebraic formulation 541automatically supports non-polynomial and non-interpolatory bases, thus is more general 542than the more common derivation in terms of Lagrange polynomials on the quadrature points. 543 544Backends available in this release: 545 546| CEED resource (`-ceed`) | Backend | 547|-------------------------|-----------------------------------------------------| 548| `/cpu/self/blocked` | Blocked reference implementation | 549| `/cpu/self/ref` | Serial reference implementation | 550| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 551| `/cpu/occa` | Serial OCCA kernels | 552| `/gpu/occa` | CUDA OCCA kernels | 553| `/omp/occa` | OpenMP OCCA kernels | 554| `/ocl/occa` | OpenCL OCCA kernels | 555| `/gpu/magma` | CUDA MAGMA kernels | 556 557Examples available in this release: 558 559:::{list-table} 560:header-rows: 1 561:widths: auto 562* - User code 563 - Example 564* - `ceed` 565 - * ex1 (volume) 566* - `mfem` 567 - * BP1 (scalar mass operator) 568 * BP3 (scalar Laplace operator) 569* - `petsc` 570 - * BP1 (scalar mass operator) 571 * BP3 (scalar Laplace operator) 572* - `nek5000` 573 - * BP1 (scalar mass operator) 574 * BP3 (scalar Laplace operator) 575::: 576 577(v0-21)= 578 579## v0.21 (Sep 30, 2018) 580 581A MAGMA backend (which relies upon the 582[MAGMA](https://bitbucket.org/icl/magma) package) was integrated in libCEED for this 583release. This initial integration set up the framework of using MAGMA and provided the 584libCEED functionality through MAGMA kernels as one of libCEED’s computational backends. 585As any other backend, the MAGMA backend provides extended basic data structures for 586{ref}`CeedVector`, {ref}`CeedElemRestriction`, and {ref}`CeedOperator`, and implements 587the fundamental CEED building blocks to work with the new data structures. 588In general, the MAGMA-specific data structures keep the libCEED pointers to CPU data 589but also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled 590internally, and thus seamlessly to the user, through the functions/methods that are 591provided to support them. 592 593Backends available in this release: 594 595| CEED resource (`-ceed`) | Backend | 596|-------------------------|---------------------------------| 597| `/cpu/self` | Serial reference implementation | 598| `/cpu/occa` | Serial OCCA kernels | 599| `/gpu/occa` | CUDA OCCA kernels | 600| `/omp/occa` | OpenMP OCCA kernels | 601| `/ocl/occa` | OpenCL OCCA kernels | 602| `/gpu/magma` | CUDA MAGMA kernels | 603 604Examples available in this release: 605 606:::{list-table} 607:header-rows: 1 608:widths: auto 609* - User code 610 - Example 611* - `ceed` 612 - * ex1 (volume) 613* - `mfem` 614 - * BP1 (scalar mass operator) 615 * BP3 (scalar Laplace operator) 616* - `petsc` 617 - * BP1 (scalar mass operator) 618* - `nek5000` 619 - * BP1 (scalar mass operator) 620::: 621 622(v0-2)= 623 624## v0.2 (Mar 30, 2018) 625 626libCEED was made publicly available the first full CEED software distribution, release 627CEED 1.0. The distribution was made available using the Spack package manager to provide 628a common, easy-to-use build environment, where the user can build the CEED distribution 629with all dependencies. This release included a new Fortran interface for the library. 630This release also contained major improvements in the OCCA backend (including a new 631`/ocl/occa` backend) and new examples. The standalone libCEED example was modified to 632compute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an 633`examples/ceed` subfolder. A new `mfem` example to perform BP3 (with the application 634of the Laplace operator) was also added to this release. 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| `/ocl/occa` | OpenCL OCCA kernels | 645 646Examples available in this release: 647 648:::{list-table} 649:header-rows: 1 650:widths: auto 651* - User code 652 - Example 653* - `ceed` 654 - * ex1 (volume) 655* - `mfem` 656 - * BP1 (scalar mass operator) 657 * BP3 (scalar Laplace operator) 658* - `petsc` 659 - * BP1 (scalar mass operator) 660* - `nek5000` 661 - * BP1 (scalar mass operator) 662::: 663 664(v0-1)= 665 666## v0.1 (Jan 3, 2018) 667 668Initial low-level API of the CEED project. The low-level API provides a set of Finite 669Elements kernels and components for writing new low-level kernels. Examples include: 670vector and sparse linear algebra, element matrix assembly over a batch of elements, 671partial assembly and action for efficient high-order operators like mass, diffusion, 672advection, etc. The main goal of the low-level API is to establish the basis for the 673high-level API. Also, identifying such low-level kernels and providing a reference 674implementation for them serves as the basis for specialized backend implementations. 675This release contained several backends: `/cpu/self`, and backends which rely upon the 676[OCCA](http://github.com/libocca/occa) package, such as `/cpu/occa`, 677`/gpu/occa`, and `/omp/occa`. 678It also included several examples, in the `examples` folder: 679A standalone code that shows the usage of libCEED (with no external 680dependencies) to apply the Laplace operator, `ex1`; an `mfem` example to perform BP1 681(with the application of the mass operator); and a `petsc` example to perform BP1 682(with the application of the mass operator). 683 684Backends available in this release: 685 686| CEED resource (`-ceed`) | Backend | 687|-------------------------|---------------------------------| 688| `/cpu/self` | Serial reference implementation | 689| `/cpu/occa` | Serial OCCA kernels | 690| `/gpu/occa` | CUDA OCCA kernels | 691| `/omp/occa` | OpenMP OCCA kernels | 692 693Examples available in this release: 694 695| User code | Example | 696|-----------------------|-----------------------------------| 697| `ceed` | ex1 (scalar Laplace operator) | 698| `mfem` | BP1 (scalar mass operator) | 699| `petsc` | BP1 (scalar mass operator) | 700``` 701