[amontoison]

Implements RFC0015, Fortran Bindings Split (update) for hipFFT: bindings/fortran/hipfft/ is a standalone CMake project that builds the generated Fortran binding against an installed hipFFT. The library is untouched: no option, no add_subdirectory, no change to projects/hipfft/.

Draft until ROCm/rocm-systems#11923 (HIP Fortran binding, which the tests use) merges.

What lands

• The hipFFT API split as CUDA Fortran's cufft and cufftXt modules, so that use cufftXt hipifies to use hipfftxt. Generated from the hipFFT headers with feat(hipfft): bind the Xt and Mp API in a hipfftxt module beside hipfft rocm-fortran-generator#17 (not merged yet) and marked linguist-generated:
  • bindings/fortran/hipfft/hipfft.F90 (1 683 lines): module hipfft, the hipfft* functions of hipfft.h, with the enum constants, the hipfftCheck helper and array overloads.
  • bindings/fortran/hipfft/hipfftxt.F90 (651 lines): module hipfftxt, every hipfftXt* and hipfftMp* function, as in CUDA Fortran's cufftXt (so hipfftXtSetWorkArea too, although hipfft.h declares it), with the Xt enums and the hipXtDesc / hipLibXtDesc types of hiplibxt.h. It uses hipfft and re-exports it, so use hipfftxt alone gives the whole API, as #include <hipfft/hipfftXt.h> does in C. Fortran is case-insensitive, so use hipfftXt works too.
  • bindings/fortran/hipfft/hipfftw.F90 (3 021 lines): the FFTW3-compatible module hipfftw, from hipfftw.h, with the FFTW_* flags and the fftw_iodim / fftw_iodim64 types.
• metadata/hipfft.toml, metadata/hipfftxt.toml, metadata/hipfftw.toml: the generator metadata they were generated with.
• test/: 36 CTest tests, 23 .f03 tests of the C interfaces and 13 .f08 tests of the array overloads (registered as <name>_f2008). hipfft_xt_descriptor_z skips (return code 77) on fewer than two GPUs. They also install: the executables in bin/, and a CTestTestfile.cmake with the same tests and properties in bin/hipfft-fortran/, for ctest --test-dir.
• hipfft and hipfftxt build into one archive, libhipfft_fortran.a (target hip::hipfft_fortran, package hipfft-fortran). hipfftw does not use hipfft, so it has its own target (hip::hipfftw_fortran), archive and config package (hipfftw-fortran); both build together.
• CMakeLists.txt, the hipfft-fortran and hipfftw-fortran config templates, cmake/ROCmFortranCompiler.cmake (the same in every binding: ROCm's amdflang is preferred over the first compiler on PATH unless CMAKE_Fortran_COMPILER or FC is set), cmake/toolchains/ and the binding's CHANGELOG.md.
• .github/CODEOWNERS: /bindings/fortran/hipfft/ @ROCm/rocm-fortran-maintainers @ROCm/fft-reviewers.
• .github/repos-config.json: a bindings/fortran entry, so CI detects changes to the binding. Each binding PR appends its entry at the end of the list, so all but the first to merge need a trivial rebase.

A consumer uses find_package(hipfft-fortran) or find_package(hipfftw-fortran) and links hip::hipfft_fortran or hip::hipfftw_fortran. The archive and .mod files install per compiler under lib/fortran/<compiler>/ and include/fortran/<compiler>/; HIPFFT_FORTRAN_COMPILER_DIR names that directory. The archive has one section per procedure, so a program linked with -Wl,--gc-sections keeps only the wrappers it calls.

Options

Option	Default	Effect
BUILD_FORTRAN_BINDINGS	${UNIX}	builds the binding; skipped without a Fortran compiler
BUILD_FORTRAN_CLIENTS	ON	builds and installs the tests in test/; off under BUILD_ADDRESS_SANITIZER
FORTRAN_ARRAY_INTERFACES	assumed-shape	none / assumed-shape / assumed-rank array overloads

In TheRock

ROCm/TheRock#9446 builds bindings/fortran/hipfft as the hipfft-fortran subproject against the hipFFT it built, with -DBUILD_FORTRAN_BINDINGS=ON -DBUILD_FORTRAN_CLIENTS=${THEROCK_BUILD_TESTING}, ships it in the fft-fortran artifact and runs the installed tests in its hipfft-fortran GPU test job.

Follow-ups

hipFFT never shipped a Fortran module, so there is nothing to deprecate.

Build and test

From the repository root, with $PREFIX the install prefix:

lib=hipfft
cmake -S bindings/fortran/$lib -B build/$lib-fortran \
  -DCMAKE_PREFIX_PATH="/opt/rocm;$HIP_FORTRAN_PREFIX" -DCMAKE_INSTALL_PREFIX="$PREFIX"
cmake --build build/$lib-fortran
ctest --test-dir build/$lib-fortran
cmake --install build/$lib-fortran
ctest --test-dir "$PREFIX/bin/$lib-fortran"

$HIP_FORTRAN_PREFIX holds the HIP Fortran binding (hip-fortran) built with the same compiler; without it the tests are skipped.

Verification

Standalone against ROCm 10.1 on one GPU, with amdflang and with gfortran: 36 tests, 35 pass, 1 skipped. From the install tree, ctest --test-dir $PREFIX/bin/hipfft-fortran gives the same result.

JIRA ID: ROCM-31390

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop   #12367      +/-   ##
===========================================
+ Coverage    75.95%   75.97%   +0.02%     
===========================================
  Files         2880     2880              
  Lines       479025   478959      -66     
  Branches     71958    71942      -16     
===========================================
+ Hits        363828   363852      +24     
+ Misses       90338    90255      -83     
+ Partials     24859    24852       -7     

Flag	Coverage Δ		*Carryforward flag
TensileLite-CPP	48.93% <ø> (ø)		Carriedforward from 38cb114
TensileLite-Unit	83.68% <ø> (ø)		Carriedforward from 38cb114
hipBLAS	90.62% <ø> (ø)		Carriedforward from 38cb114
hipBLASLt	64.43% <ø> (ø)		Carriedforward from 38cb114
hipCUB	82.68% <ø> (ø)		Carriedforward from 38cb114
hipDNN	86.78% <ø> (ø)		Carriedforward from 38cb114
hipFFT	43.09% <ø> (+1.09%)	⬆️
hipRAND	76.12% <ø> (ø)		Carriedforward from 38cb114
hipSOLVER	69.67% <ø> (ø)		Carriedforward from 38cb114
hipSPARSE	86.99% <ø> (ø)		Carriedforward from 38cb114
rocBLAS	68.73% <ø> (ø)		Carriedforward from 38cb114
rocFFT	48.10% <ø> (ø)		Carriedforward from 38cb114
rocRAND	57.30% <ø> (ø)		Carriedforward from 38cb114
rocSOLVER	76.74% <ø> (ø)		Carriedforward from 38cb114
rocSPARSE	76.92% <ø> (ø)		Carriedforward from 38cb114
rocThrust	93.15% <ø> (ø)		Carriedforward from 38cb114

*This pull request uses carry forward flags. Click here to find out more.
see 6 files with indirect coverage changes

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