FFTW: Always initialize FFTW for users when OMP is on#4861
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ax3l merged 7 commits intoAMReX-Codes:developmentfrom Jan 5, 2026
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FFTW: Always initialize FFTW for users when OMP is on#4861ax3l merged 7 commits intoAMReX-Codes:developmentfrom
ax3l merged 7 commits intoAMReX-Codes:developmentfrom
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Thank you! This looks great, but I have a few questions about:
- external init/finalize
- small update to third-party requirements (CMake)
- macro guards w/o FFT option enabled
Probably all quick to resolve next week :)
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Co-authored-by: Axel Huebl <[email protected]>
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| LIBRARIES += -Wl,-rpath,$(FFTW_HOME)/lib | ||
| endif | ||
| ifeq ($(USE_OMP),TRUE) | ||
| LIBRARIES += -lfftw3f_omp -lfftw3_omp |
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If you like to 100% mirror the CMake logic:
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| LIBRARIES += -lfftw3f_omp -lfftw3_omp | |
| DEFINES += -DAMREX_FFTW_OMP=1 | |
| LIBRARIES += -lfftw3f_omp -lfftw3_omp |
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It's a define, keep to style.
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LGTM, a small minor suggestion for a simpler/explicitly controlled FFTW w/ OpenMP macro.
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Close AMReX-Codes#4856 Co-authored-by: Axel Huebl <[email protected]>
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@WeiqunZhang I just realized if I pass Will PR in #4941 |
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## Summary In some corner cases, we sometimes work around broken FFTW installs: for some (temporary) reason we cannot have any threading in FFTW, neither with OpenMP nor threads. In those cases, when we still want to thread the rest of AMReX with OpenMP, we can set our AMReX transitive FFTW OpenMP requirements explicitly off, e.g., via CMake `-DAMReX_FFTW_IGNORE_OMP=ON`. But this is not yet implemented consistently and since #4861 exposes undefined FFTW symbols when used. This enables this work-around. - [x] macro - [x] CMake - [x] GNUmake - [x] `AMReX_Config.H` ## Additional background #4861 (comment) ## Checklist The proposed changes: - [x] fix a bug or incorrect behavior in AMReX - [ ] add new capabilities to AMReX - [ ] changes answers in the test suite to more than roundoff level - [ ] are likely to significantly affect the results of downstream AMReX users - [ ] include documentation in the code and/or rst files, if appropriate --------- Co-authored-by: Weiqun Zhang <[email protected]>
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Close #4856