http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38306
--- Comment #23 from Joost VandeVondele <Joost.VandeVondele at pci dot uzh.ch> 2011-02-21 12:53:30 UTC --- (In reply to comment #22) > What is the performance with 4.3 -O2? 4.3: > gfortran -O2 -march=native -funroll-loops -ffast-math test.f90 ; ./a.out Time for evaluation [s]: 4.373 4.6: > gfortran -O2 -march=native -funroll-loops -ffast-math test.f90 ; ./a.out Time for evaluation [s]: 4.347 so, same performance. Given that vectorization only happens at -O3, it is an important optimization level for numerical codes. Nevertheless, I would propose to remove the regression tag, and instead refocus the bug on the what current trunk does at -O3 vs -O2 -ftree-vectorize as noted in comment #21 > gfortran -O2 -march=native -funroll-loops -ffast-math -ftree-vectorize > test.f90 ; ./a.out Time for evaluation [s]: 2.694 > gfortran -O3 -march=native -funroll-loops -ffast-math -ftree-vectorize > test.f90 ; ./a.out Time for evaluation [s]: 4.536
