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[Bug debug/55585] compile time hog at -O1 -fboundscheck -g


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55585

--- Comment #4 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> 2012-12-04 10:43:10 UTC ---
Interestingly, the magic switch is -fstrict-aliasing... 20x speedup. for a
Fortran code quite a surprise.

> time gfortran -c -O1 -fbounds-check -g -fstrict-aliasing slow.f90 
real    0m11.483s

I think for Fortran -fstrict-aliasing could well be the default at -O1, but
maybe there is an underlying reason why this flag is needed ?


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