203. Use ifort -fast or gfortran -O3 -march=native for speed.

topic: Compiling

Note

This tip is a draft1.

Use the ifort -fast and gfortran -O3 -march=native options to increase speed. Gfortran -Ofast turns on -ffast-math and can give a further 2x speedup in some cases, but it can also give incorrect results and should be used with care. Use gfortran -Og to debug.

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Use the ifort -fast and gfortran -O3 -march=native options to increase speed. Gfortran -Ofast turns on -ffast-math and can give a further 2x speedup in some cases, but it can also give incorrect results and should be used with care. Use gfortran -Og to debug.

— FortranTip (@fortrantip) April 28, 2022

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1

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