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 28### Examples 29 30- Add deal.II example with CEED BP suite. 31 32(v0-12)= 33 34## v0.12 (Oct 31, 2023) 35 36### Interface changes 37 38- Update `CeedOperatorContext*` functions to `CeedOperator*Context*` functions for consistency. 39For example, `CeedOperatorContextGetFieldLabel` was renamed to `CeedOperatorGetContextFieldLabel`. 40- Removed `CeedBasisSetNumQuadraturePoints` as redundant and bug-prone interface. 41 42### New features 43 44- Added {c:func}`CeedOperatorGetFieldByName` to access a specific `CeedOperatorField` by its name. 45- Update `/cpu/self/memcheck/*` backends to help verify `CeedVector` array access assumptions and `CeedQFunction` user output assumptions. 46- Update {c:func}`CeedOperatorLinearAssembleDiagonal` to provide default implementation that supports `CeedOperator` with multiple active bases. 47- Added Sycl backends `/gpu/sycl/ref`, `/gpu/sycl/shared`, and `/gpu/sycl/gen`. 48- Added {c:func}`CeedBasisApplyAtPoints` for evaluation of values and derivatives at arbitrary points inside elements. 49- Added support for non-tensor $H(\text{curl})$ finite element spaces with {c:func}`CeedBasisCreateHcurl`. 50- 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)). 51- Added {c:func}`CeedOperatorLinearAssemblePointBlockDiagonalSymbolic` to create COO mapping for mapping out of {c:func}`CeedOperatorLinearAssemblePointBlockDiagonal`. 52- Added support for application codes which manage multiple {ref}`Ceed` objects, parallelized across OpenMP threads. 53 54### Examples 55 56- Add `DMSwarm` example demonstrating interpolation from background mesh to swarm points and projection from swarm points to background mesh. 57 58#### {ref}`example-petsc-bps` 59 60- Requires PETSc version 3.19 or later. 61 62#### {ref}`example-petsc-navier-stokes` 63 64- Updated restart and checkpointing interface. 65- Add data-driven subgrid-stress model. 66- Add differential filtering of solution. 67- Add turbulence statistics collection over spanwise-symmetric geometries. 68- Add Taylor-Green vortex initial condition. 69- Add Riemann-based outflow boundary conditions. 70- Added vortex shedding and flow past cylinder example, including calculations for lift, drag, and heat transfer. 71- Add Internal Damping Layer (IDL) for helping turbulent simulation stability. 72- Derive `CeedBasis` from `PetscFE`, and various other internal maintainability updates. 73 74(v0-11)= 75 76## v0.11 (Dec 24, 2022) 77 78### Interface changes 79 80- Added {c:func}`CeedOperatorSetName` for more readable {c:func}`CeedOperatorView` output. 81- Added {c:func}`CeedBasisCreateProjection` to facilitate interpolation between nodes for separate `CeedBases`. 82- Rename and move {c:func}`CeedCompositeOperatorGetNumSub` and {c:func}`CeedCompositeOperatorGetSubList` to public interface. 83- Renamed `CEED_BASIS_COLLOCATED` to `CEED_BASIS_NONE` for clarity. 84Some 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. 85 86### New features 87 88- Update `/cpu/self/memcheck/*` backends to help verify `CeedQFunctionContext` data sizes provided by user. 89- Improved support for $H(\text{div})$ bases. 90- Added `CeedInt_FMT` to support potential future use of larger integer sizes. 91- Added `CEED_QFUNCTION_ATTR` for setting compiler attributes/pragmas to `CEED_QFUNCTION_HELPER` and `CEED_QFUNCTION`. 92- OCCA backend updated to latest OCCA release; DPC++ and OMP OCCA modes enabled. 93Due to a limitation of the OCCA parser, typedefs are required to use pointers to arrays in QFunctions with the OCCA backend. 94This issue will be fixed in a future OCCA release. 95 96### Bugfix 97 98- Fix bug in setting device id for GPU backends. 99- Fix storing of indices for `CeedElemRestriction` on the host with GPU backends. 100- Fix `CeedElemRestriction` sizing for {c:func}`CeedOperatorAssemblePointBlockDiagonal`. 101- Fix bugs in CPU implementation of {c:func}`CeedOperatorLinearAssemble` when there are different number of active input modes and active output modes. 102 103### Examples 104 105#### {ref}`example-petsc-navier-stokes` 106 107- Various performance enhancements, analytic matrix-free and assembled Jacobian, and PETSc solver configurations for GPUs. 108- Refactored to improve code reuse and modularity. 109- Support for primitive variables for more accurate boundary layers and all-speed flow. 110- Added $YZ\beta$ shock capturing scheme and Shock Tube example. 111- Added Channel example, with comparison to analytic solutions. 112- Added Flat Plate with boundary layer mesh and compressible Blasius inflow condition based on Chebyshev collocation solution of the Blasius equations. 113- Added strong and weak synthetic turbulence generation (STG) inflow boundary conditions. 114- Added "freestream" boundary conditions based on HLLC Riemann solver. 115- Automated stabilization coefficients for different basis degree. 116 117#### {ref}`example-petsc-bps` 118 119- Support for convergence studies. 120 121### Maintainability 122 123- 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. 124- Enabled support for `p > 8` for `/gpu/*/shared` backends. 125- Switch to `clang-format` over `astyle` for automatic formatting; Makefile command changed to `make format` from `make style`. 126- Improved test harness. 127 128(v0-10-1)= 129 130## v0.10.1 (Apr 11, 2022) 131 132### Interface changes 133 134- Added {c:func}`CeedQFunctionSetUserFlopsEstimate` and {c:func}`CeedOperatorGetFlopsEstimate` to facilitate estimating FLOPs in operator application. 135 136### New features 137 138- Switched MAGMA backends to use runtime compilation for tensor basis kernels (and element restriction kernels, in non-deterministic `/gpu/*/magma` backends). 139This reduces time to compile the library and increases the range of parameters for which the MAGMA tensor basis kernels will work. 140 141### Bugfix 142 143- Install JiT source files in install directory to fix GPU functionality for installed libCEED. 144 145(v0-10)= 146 147## v0.10 (Mar 21, 2022) 148 149### Interface changes 150 151- Update {c:func}`CeedQFunctionGetFields` and {c:func}`CeedOperatorGetFields` to include number of fields. 152- 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`. 153- Clarify and document conditions where `CeedQFunction` and `CeedOperator` become immutable and no further fields or suboperators can be added. 154- Add {c:func}`CeedOperatorLinearAssembleQFunctionBuildOrUpdate` to reduce object creation overhead in assembly of CeedOperator preconditioning ingredients. 155- Promote {c:func}`CeedOperatorCheckReady`to the public API to facilitate interactive interfaces. 156- Warning added when compiling OCCA backend to alert users that this backend is experimental. 157- `ceed-backend.h`, `ceed-hash.h`, and `ceed-khash.h` removed. Users should use `ceed/backend.h`, `ceed/hash.h`, and `ceed/khash.h`. 158- Added {c:func}`CeedQFunctionGetKernelName`; refactored {c:func}`CeedQFunctionGetSourcePath` to exclude function kernel name. 159- 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`. 160- Added {c:func}`CeedVectorGetArrayWrite` that allows access to uninitialized arrays; require initialized data for {c:func}`CeedVectorGetArray`. 161- 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. 162- Added {c:func}`CeedQFunctionContextGetFieldDescriptions` to retrieve user defined descriptions of fields that are registered with `CeedQFunctionContextRegister*`. 163- Renamed `CeedElemTopology` entries for clearer namespacing between libCEED enums. 164- 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. 165- Added {c:func}`CeedOperatorSetQFunctionUpdated` to facilitate QFunction data re-use between operators sharing the same quadrature space, such as in a multigrid hierarchy. 166- Added {c:func}`CeedOperatorGetActiveVectorLengths` to get shape of CeedOperator. 167 168### New features 169 170- `CeedScalar` can now be set as `float` or `double` at compile time. 171- Added JiT utilities in `ceed/jit-tools.h` to reduce duplicated code in GPU backends. 172- 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. 173- Remove need to guard library headers in QFunction source for code generation backends. 174- `CeedDebugEnv()` macro created to provide debugging outputs when Ceed context is not present. 175- Added {c:func}`CeedStringAllocCopy` to reduce repeated code for copying strings internally. 176- Added {c:func}`CeedPathConcatenate` to facilitate loading kernel source files with a path relative to the current file. 177- Added support for non-tensor $H(\text{div})$ elements, to include CPU backend implementations and {c:func}`CeedBasisCreateHdiv` convenience constructor. 178- 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. 179- Added support for element matrix assembly in GPU backends. 180 181### Maintainability 182 183- Refactored preconditioner support internally to facilitate future development and improve GPU completeness/test coverage. 184- `Include-what-you-use` makefile target added as `make iwyu`. 185- Create backend constant `CEED_FIELD_MAX` to reduce magic numbers in codebase. 186- Put GPU JiTed kernel source code into separate files. 187- 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. 188 189(v0-9)= 190 191## v0.9 (Jul 6, 2021) 192 193### Interface changes 194 195- Minor modification in error handling macro to silence pedantic warnings when compiling with Clang, but no functional impact. 196 197### New features 198 199- Add {c:func}`CeedVectorAXPY` and {c:func}`CeedVectorPointwiseMult` as a convenience for stand-alone testing and internal use. 200- Add `CEED_QFUNCTION_HELPER` macro to properly annotate QFunction helper functions for code generation backends. 201- Add `CeedPragmaOptimizeOff` macro for code that is sensitive to floating point errors from fast math optimizations. 202- Rust support: split `libceed-sys` crate out of `libceed` and [publish both on crates.io](https://crates.io/crates/libceed). 203 204### Performance improvements 205 206### Examples 207 208- Solid mechanics mini-app updated to explore the performance impacts of various formulations in the initial and current configurations. 209- Fluid mechanics example adds GPU support and improves modularity. 210 211### Deprecated backends 212 213- 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. 214 215(v0-8)= 216 217## v0.8 (Mar 31, 2021) 218 219### Interface changes 220 221- Error handling improved to include enumerated error codes for C interface return values. 222- 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. 223 224### New features 225 226- Julia and Rust interfaces added, providing a nearly 1-1 correspondence with the C interface, plus some convenience features. 227- Static libraries can be built with `make STATIC=1` and the pkg-config file is installed accordingly. 228- Add {c:func}`CeedOperatorLinearAssembleSymbolic` and {c:func}`CeedOperatorLinearAssemble` to support full assembly of libCEED operators. 229 230### Performance improvements 231 232- New HIP MAGMA backends for hipMAGMA library users: `/gpu/hip/magma` and `/gpu/hip/magma/det`. 233- New HIP backends for improved tensor basis performance: `/gpu/hip/shared` and `/gpu/hip/gen`. 234 235### Examples 236 237- {ref}`example-petsc-elasticity` example updated with traction boundary conditions and improved Dirichlet boundary conditions. 238- {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. 239- {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. 240- {ref}`example-petsc-navier-stokes` example updated with support for performing convergence study and plotting order of convergence by polynomial degree. 241 242(v0-7)= 243 244## v0.7 (Sep 29, 2020) 245 246### Interface changes 247 248- Replace limited {code}`CeedInterlaceMode` with more flexible component stride {code}`compstride` in {code}`CeedElemRestriction` constructors. 249 As a result, the {code}`indices` parameter has been replaced with {code}`offsets` and the {code}`nnodes` parameter has been replaced with {code}`lsize`. 250 These changes improve support for mixed finite element methods. 251- Replace various uses of {code}`Ceed*Get*Status` with {code}`Ceed*Is*` in the backend API to match common nomenclature. 252- Replace {code}`CeedOperatorAssembleLinearDiagonal` with {c:func}`CeedOperatorLinearAssembleDiagonal` for clarity. 253- 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. 254- 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. 255- 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. 256- 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. 257 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`. 258- Added {code}`CeedQFunctionContext` object to manage user QFunction context data and reduce copies between device and host memory. 259- 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. 260 261### New features 262 263- New HIP backend: `/gpu/hip/ref`. 264- CeedQFunction support for user `CUfunction`s in some backends 265 266### Performance improvements 267 268- OCCA backend rebuilt to facilitate future performance enhancements. 269- PETSc BPs suite improved to reduce noise due to multiple calls to {code}`mpiexec`. 270 271### Examples 272 273- {ref}`example-petsc-elasticity` example updated with strain energy computation and more flexible boundary conditions. 274 275### Deprecated backends 276 277- The `/gpu/cuda/reg` backend has been removed, with its core features moved into `/gpu/cuda/ref` and `/gpu/cuda/shared`. 278 279(v0-6)= 280 281## v0.6 (Mar 29, 2020) 282 283libCEED v0.6 contains numerous new features and examples, as well as expanded 284documentation in [this new website](https://libceed.org). 285 286### New features 287 288- New Python interface using [CFFI](https://cffi.readthedocs.io/) provides a nearly 289 1-1 correspondence with the C interface, plus some convenience features. For instance, 290 data stored in the {cpp:type}`CeedVector` structure are available without copy as 291 {py:class}`numpy.ndarray`. Short tutorials are provided in 292 [Binder](https://mybinder.org/v2/gh/CEED/libCEED/main?urlpath=lab/tree/examples/tutorials/). 293- Linear QFunctions can be assembled as block-diagonal matrices (per quadrature point, 294 {c:func}`CeedOperatorAssembleLinearQFunction`) or to evaluate the diagonal 295 ({c:func}`CeedOperatorAssembleLinearDiagonal`). These operations are useful for 296 preconditioning ingredients and are used in the libCEED's multigrid examples. 297- The inverse of separable operators can be obtained using 298 {c:func}`CeedOperatorCreateFDMElementInverse` and applied with 299 {c:func}`CeedOperatorApply`. This is a useful preconditioning ingredient, 300 especially for Laplacians and related operators. 301- New functions: {c:func}`CeedVectorNorm`, {c:func}`CeedOperatorApplyAdd`, 302 {c:func}`CeedQFunctionView`, {c:func}`CeedOperatorView`. 303- Make public accessors for various attributes to facilitate writing composable code. 304- New backend: `/cpu/self/memcheck/serial`. 305- QFunctions using variable-length array (VLA) pointer constructs can be used with CUDA 306 backends. (Single source is coming soon for OCCA backends.) 307- Fix some missing edge cases in CUDA backend. 308 309### Performance Improvements 310 311- MAGMA backend performance optimization and non-tensor bases. 312- No-copy optimization in {c:func}`CeedOperatorApply`. 313 314### Interface changes 315 316- Replace {code}`CeedElemRestrictionCreateIdentity` and 317 {code}`CeedElemRestrictionCreateBlocked` with more flexible 318 {c:func}`CeedElemRestrictionCreateStrided` and 319 {c:func}`CeedElemRestrictionCreateBlockedStrided`. 320- Add arguments to {c:func}`CeedQFunctionCreateIdentity`. 321- Replace ambiguous uses of {cpp:enum}`CeedTransposeMode` for L-vector identification 322 with {cpp:enum}`CeedInterlaceMode`. This is now an attribute of the 323 {cpp:type}`CeedElemRestriction` (see {c:func}`CeedElemRestrictionCreate`) and no 324 longer passed as `lmode` arguments to {c:func}`CeedOperatorSetField` and 325 {c:func}`CeedElemRestrictionApply`. 326 327### Examples 328 329libCEED-0.6 contains greatly expanded examples with {ref}`new documentation <Examples>`. 330Notable additions include: 331 332- Standalone {ref}`ex2-surface` ({file}`examples/ceed/ex2-surface`): compute the area of 333 a domain in 1, 2, and 3 dimensions by applying a Laplacian. 334 335- PETSc {ref}`example-petsc-area` ({file}`examples/petsc/area.c`): computes surface area 336 of domains (like the cube and sphere) by direct integration on a surface mesh; 337 demonstrates geometric dimension different from topological dimension. 338 339- PETSc {ref}`example-petsc-bps`: 340 341 - {file}`examples/petsc/bpsraw.c` (formerly `bps.c`): transparent CUDA support. 342 - {file}`examples/petsc/bps.c` (formerly `bpsdmplex.c`): performance improvements 343 and transparent CUDA support. 344 - {ref}`example-petsc-bps-sphere` ({file}`examples/petsc/bpssphere.c`): 345 generalizations of all CEED BPs to the surface of the sphere; demonstrates geometric 346 dimension different from topological dimension. 347 348- {ref}`example-petsc-multigrid` ({file}`examples/petsc/multigrid.c`): new p-multigrid 349 solver with algebraic multigrid coarse solve. 350 351- {ref}`example-petsc-navier-stokes` ({file}`examples/fluids/navierstokes.c`; formerly 352 `examples/navier-stokes`): unstructured grid support (using PETSc's `DMPlex`), 353 implicit time integration, SU/SUPG stabilization, free-slip boundary conditions, and 354 quasi-2D computational domain support. 355 356- {ref}`example-petsc-elasticity` ({file}`examples/solids/elasticity.c`): new solver for 357 linear elasticity, small-strain hyperelasticity, and globalized finite-strain 358 hyperelasticity using p-multigrid with algebraic multigrid coarse solve. 359 360(v0-5)= 361 362## v0.5 (Sep 18, 2019) 363 364For this release, several improvements were made. Two new CUDA backends were added to 365the family of backends, of which, the new `cuda-gen` backend achieves state-of-the-art 366performance using single-source {ref}`CeedQFunction`. From this release, users 367can define Q-Functions in a single source code independently of the targeted backend 368with the aid of a new macro `CEED QFUNCTION` to support JIT (Just-In-Time) and CPU 369compilation of the user provided {ref}`CeedQFunction` code. To allow a unified 370declaration, the {ref}`CeedQFunction` API has undergone a slight change: 371the `QFunctionField` parameter `ncomp` has been changed to `size`. This change 372requires setting the previous value of `ncomp` to `ncomp*dim` when adding a 373`QFunctionField` with eval mode `CEED EVAL GRAD`. 374 375Additionally, new CPU backends 376were included in this release, such as the `/cpu/self/opt/*` backends (which are 377written in pure C and use partial **E-vectors** to improve performance) and the 378`/cpu/self/ref/memcheck` backend (which relies upon the 379[Valgrind](http://valgrind.org/) Memcheck tool to help verify that user 380{ref}`CeedQFunction` have no undefined values). 381This release also included various performance improvements, bug fixes, new examples, 382and improved tests. Among these improvements, vectorized instructions for 383{ref}`CeedQFunction` code compiled for CPU were enhanced by using `CeedPragmaSIMD` 384instead of `CeedPragmaOMP`, implementation of a {ref}`CeedQFunction` gallery and 385identity Q-Functions were introduced, and the PETSc benchmark problems were expanded 386to include unstructured meshes handling were. For this expansion, the prior version of 387the PETSc BPs, which only included data associated with structured geometries, were 388renamed `bpsraw`, and the new version of the BPs, which can handle data associated 389with any unstructured geometry, were called `bps`. Additionally, other benchmark 390problems, namely BP2 and BP4 (the vector-valued versions of BP1 and BP3, respectively), 391and BP5 and BP6 (the collocated versions---for which the quadrature points are the same 392as the Gauss Lobatto nodes---of BP3 and BP4 respectively) were added to the PETSc 393examples. Furthermoew, another standalone libCEED example, called `ex2`, which 394computes the surface area of a given mesh was added to this release. 395 396Backends available in this release: 397 398| CEED resource (`-ceed`) | Backend | 399|--------------------------|-----------------------------------------------------| 400| `/cpu/self/ref/serial` | Serial reference implementation | 401| `/cpu/self/ref/blocked` | Blocked reference implementation | 402| `/cpu/self/ref/memcheck` | Memcheck backend, undefined value checks | 403| `/cpu/self/opt/serial` | Serial optimized C implementation | 404| `/cpu/self/opt/blocked` | Blocked optimized C implementation | 405| `/cpu/self/avx/serial` | Serial AVX implementation | 406| `/cpu/self/avx/blocked` | Blocked AVX implementation | 407| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 408| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 409| `/cpu/occa` | Serial OCCA kernels | 410| `/gpu/occa` | CUDA OCCA kernels | 411| `/omp/occa` | OpenMP OCCA kernels | 412| `/ocl/occa` | OpenCL OCCA kernels | 413| `/gpu/cuda/ref` | Reference pure CUDA kernels | 414| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 415| `/gpu/cuda/shared` | Optimized pure CUDA kernels using shared memory | 416| `/gpu/cuda/gen` | Optimized pure CUDA kernels using code generation | 417| `/gpu/magma` | CUDA MAGMA kernels | 418 419Examples available in this release: 420 421:::{list-table} 422:header-rows: 1 423:widths: auto 424* - User code 425 - Example 426* - `ceed` 427 - * ex1 (volume) 428 * ex2 (surface) 429* - `mfem` 430 - * BP1 (scalar mass operator) 431 * BP3 (scalar Laplace operator) 432* - `petsc` 433 - * BP1 (scalar mass operator) 434 * BP2 (vector mass operator) 435 * BP3 (scalar Laplace operator) 436 * BP4 (vector Laplace operator) 437 * BP5 (collocated scalar Laplace operator) 438 * BP6 (collocated vector Laplace operator) 439 * Navier-Stokes 440* - `nek5000` 441 - * BP1 (scalar mass operator) 442 * BP3 (scalar Laplace operator) 443::: 444 445(v0-4)= 446 447## v0.4 (Apr 1, 2019) 448 449libCEED v0.4 was made again publicly available in the second full CEED software 450distribution, release CEED 2.0. This release contained notable features, such as 451four new CPU backends, two new GPU backends, CPU backend optimizations, initial 452support for operator composition, performance benchmarking, and a Navier-Stokes demo. 453The new CPU backends in this release came in two families. The `/cpu/self/*/serial` 454backends process one element at a time and are intended for meshes with a smaller number 455of high order elements. The `/cpu/self/*/blocked` backends process blocked batches of 456eight interlaced elements and are intended for meshes with higher numbers of elements. 457The `/cpu/self/avx/*` backends rely upon AVX instructions to provide vectorized CPU 458performance. The `/cpu/self/xsmm/*` backends rely upon the 459[LIBXSMM](http://github.com/hfp/libxsmm) package to provide vectorized CPU 460performance. The `/gpu/cuda/*` backends provide GPU performance strictly using CUDA. 461The `/gpu/cuda/ref` backend is a reference CUDA backend, providing reasonable 462performance for most problem configurations. The `/gpu/cuda/reg` backend uses a simple 463parallelization approach, where each thread treats a finite element. Using just in time 464compilation, provided by nvrtc (NVidia Runtime Compiler), and runtime parameters, this 465backend unroll loops and map memory address to registers. The `/gpu/cuda/reg` backend 466achieve good peak performance for 1D, 2D, and low order 3D problems, but performance 467deteriorates very quickly when threads run out of registers. 468 469A new explicit time-stepping Navier-Stokes solver was added to the family of libCEED 470examples in the `examples/petsc` directory (see {ref}`example-petsc-navier-stokes`). 471This example solves the time-dependent Navier-Stokes equations of compressible gas 472dynamics in a static Eulerian three-dimensional frame, using structured high-order 473finite/spectral element spatial discretizations and explicit high-order time-stepping 474(available in PETSc). Moreover, the Navier-Stokes example was developed using PETSc, 475so that the pointwise physics (defined at quadrature points) is separated from the 476parallelization and meshing concerns. 477 478Backends available in this release: 479 480| CEED resource (`-ceed`) | Backend | 481|--------------------------|-----------------------------------------------------| 482| `/cpu/self/ref/serial` | Serial reference implementation | 483| `/cpu/self/ref/blocked` | Blocked reference implementation | 484| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 485| `/cpu/self/avx/serial` | Serial AVX implementation | 486| `/cpu/self/avx/blocked` | Blocked AVX implementation | 487| `/cpu/self/xsmm/serial` | Serial LIBXSMM implementation | 488| `/cpu/self/xsmm/blocked` | Blocked LIBXSMM implementation | 489| `/cpu/occa` | Serial OCCA kernels | 490| `/gpu/occa` | CUDA OCCA kernels | 491| `/omp/occa` | OpenMP OCCA kernels | 492| `/ocl/occa` | OpenCL OCCA kernels | 493| `/gpu/cuda/ref` | Reference pure CUDA kernels | 494| `/gpu/cuda/reg` | Pure CUDA kernels using one thread per element | 495| `/gpu/magma` | CUDA MAGMA kernels | 496 497Examples available in this release: 498 499:::{list-table} 500:header-rows: 1 501:widths: auto 502* - User code 503 - Example 504* - `ceed` 505 - * ex1 (volume) 506* - `mfem` 507 - * BP1 (scalar mass operator) 508 * BP3 (scalar Laplace operator) 509* - `petsc` 510 - * BP1 (scalar mass operator) 511 * BP3 (scalar Laplace operator) 512 * Navier-Stokes 513* - `nek5000` 514 - * BP1 (scalar mass operator) 515 * BP3 (scalar Laplace operator) 516::: 517 518(v0-3)= 519 520## v0.3 (Sep 30, 2018) 521 522Notable features in this release include active/passive field interface, support for 523non-tensor bases, backend optimization, and improved Fortran interface. This release 524also focused on providing improved continuous integration, and many new tests with code 525coverage reports of about 90%. This release also provided a significant change to the 526public interface: a {ref}`CeedQFunction` can take any number of named input and output 527arguments while {ref}`CeedOperator` connects them to the actual data, which may be 528supplied explicitly to `CeedOperatorApply()` (active) or separately via 529`CeedOperatorSetField()` (passive). This interface change enables reusable libraries 530of CeedQFunctions and composition of block solvers constructed using 531{ref}`CeedOperator`. A concept of blocked restriction was added to this release and 532used in an optimized CPU backend. Although this is typically not visible to the user, 533it enables effective use of arbitrary-length SIMD while maintaining cache locality. 534This CPU backend also implements an algebraic factorization of tensor product gradients 535to perform fewer operations than standard application of interpolation and 536differentiation from nodes to quadrature points. This algebraic formulation 537automatically supports non-polynomial and non-interpolatory bases, thus is more general 538than the more common derivation in terms of Lagrange polynomials on the quadrature points. 539 540Backends available in this release: 541 542| CEED resource (`-ceed`) | Backend | 543|-------------------------|-----------------------------------------------------| 544| `/cpu/self/blocked` | Blocked reference implementation | 545| `/cpu/self/ref` | Serial reference implementation | 546| `/cpu/self/tmpl` | Backend template, defaults to `/cpu/self/blocked` | 547| `/cpu/occa` | Serial OCCA kernels | 548| `/gpu/occa` | CUDA OCCA kernels | 549| `/omp/occa` | OpenMP OCCA kernels | 550| `/ocl/occa` | OpenCL OCCA kernels | 551| `/gpu/magma` | CUDA MAGMA kernels | 552 553Examples available in this release: 554 555:::{list-table} 556:header-rows: 1 557:widths: auto 558* - User code 559 - Example 560* - `ceed` 561 - * ex1 (volume) 562* - `mfem` 563 - * BP1 (scalar mass operator) 564 * BP3 (scalar Laplace operator) 565* - `petsc` 566 - * BP1 (scalar mass operator) 567 * BP3 (scalar Laplace operator) 568* - `nek5000` 569 - * BP1 (scalar mass operator) 570 * BP3 (scalar Laplace operator) 571::: 572 573(v0-21)= 574 575## v0.21 (Sep 30, 2018) 576 577A MAGMA backend (which relies upon the 578[MAGMA](https://bitbucket.org/icl/magma) package) was integrated in libCEED for this 579release. This initial integration set up the framework of using MAGMA and provided the 580libCEED functionality through MAGMA kernels as one of libCEED’s computational backends. 581As any other backend, the MAGMA backend provides extended basic data structures for 582{ref}`CeedVector`, {ref}`CeedElemRestriction`, and {ref}`CeedOperator`, and implements 583the fundamental CEED building blocks to work with the new data structures. 584In general, the MAGMA-specific data structures keep the libCEED pointers to CPU data 585but also add corresponding device (e.g., GPU) pointers to the data. Coherency is handled 586internally, and thus seamlessly to the user, through the functions/methods that are 587provided to support them. 588 589Backends available in this release: 590 591| CEED resource (`-ceed`) | Backend | 592|-------------------------|---------------------------------| 593| `/cpu/self` | Serial reference implementation | 594| `/cpu/occa` | Serial OCCA kernels | 595| `/gpu/occa` | CUDA OCCA kernels | 596| `/omp/occa` | OpenMP OCCA kernels | 597| `/ocl/occa` | OpenCL OCCA kernels | 598| `/gpu/magma` | CUDA MAGMA kernels | 599 600Examples available in this release: 601 602:::{list-table} 603:header-rows: 1 604:widths: auto 605* - User code 606 - Example 607* - `ceed` 608 - * ex1 (volume) 609* - `mfem` 610 - * BP1 (scalar mass operator) 611 * BP3 (scalar Laplace operator) 612* - `petsc` 613 - * BP1 (scalar mass operator) 614* - `nek5000` 615 - * BP1 (scalar mass operator) 616::: 617 618(v0-2)= 619 620## v0.2 (Mar 30, 2018) 621 622libCEED was made publicly available the first full CEED software distribution, release 623CEED 1.0. The distribution was made available using the Spack package manager to provide 624a common, easy-to-use build environment, where the user can build the CEED distribution 625with all dependencies. This release included a new Fortran interface for the library. 626This release also contained major improvements in the OCCA backend (including a new 627`/ocl/occa` backend) and new examples. The standalone libCEED example was modified to 628compute the volume volume of a given mesh (in 1D, 2D, or 3D) and placed in an 629`examples/ceed` subfolder. A new `mfem` example to perform BP3 (with the application 630of the Laplace operator) was also added to this release. 631 632Backends available in this release: 633 634| CEED resource (`-ceed`) | Backend | 635|-------------------------|---------------------------------| 636| `/cpu/self` | Serial reference implementation | 637| `/cpu/occa` | Serial OCCA kernels | 638| `/gpu/occa` | CUDA OCCA kernels | 639| `/omp/occa` | OpenMP OCCA kernels | 640| `/ocl/occa` | OpenCL OCCA kernels | 641 642Examples available in this release: 643 644:::{list-table} 645:header-rows: 1 646:widths: auto 647* - User code 648 - Example 649* - `ceed` 650 - * ex1 (volume) 651* - `mfem` 652 - * BP1 (scalar mass operator) 653 * BP3 (scalar Laplace operator) 654* - `petsc` 655 - * BP1 (scalar mass operator) 656* - `nek5000` 657 - * BP1 (scalar mass operator) 658::: 659 660(v0-1)= 661 662## v0.1 (Jan 3, 2018) 663 664Initial low-level API of the CEED project. The low-level API provides a set of Finite 665Elements kernels and components for writing new low-level kernels. Examples include: 666vector and sparse linear algebra, element matrix assembly over a batch of elements, 667partial assembly and action for efficient high-order operators like mass, diffusion, 668advection, etc. The main goal of the low-level API is to establish the basis for the 669high-level API. Also, identifying such low-level kernels and providing a reference 670implementation for them serves as the basis for specialized backend implementations. 671This release contained several backends: `/cpu/self`, and backends which rely upon the 672[OCCA](http://github.com/libocca/occa) package, such as `/cpu/occa`, 673`/gpu/occa`, and `/omp/occa`. 674It also included several examples, in the `examples` folder: 675A standalone code that shows the usage of libCEED (with no external 676dependencies) to apply the Laplace operator, `ex1`; an `mfem` example to perform BP1 677(with the application of the mass operator); and a `petsc` example to perform BP1 678(with the application of the mass operator). 679 680Backends available in this release: 681 682| CEED resource (`-ceed`) | Backend | 683|-------------------------|---------------------------------| 684| `/cpu/self` | Serial reference implementation | 685| `/cpu/occa` | Serial OCCA kernels | 686| `/gpu/occa` | CUDA OCCA kernels | 687| `/omp/occa` | OpenMP OCCA kernels | 688 689Examples available in this release: 690 691| User code | Example | 692|-----------------------|-----------------------------------| 693| `ceed` | ex1 (scalar Laplace operator) | 694| `mfem` | BP1 (scalar mass operator) | 695| `petsc` | BP1 (scalar mass operator) | 696``` 697