Re: Large slowdown with gfortran vs f77 (x7)

2009-09-08 Thread James Cloos
> "Jeremy" == Jeremy Sanders writes: Jeremy> You can see the very large speed differences by telling gfortran Jeremy> to always use double precision numbers. Jeremy> This can be replicated with this simple program: Jeremy> Compiled with gfortran -O2: Jeremy> real0m29.921s Jeremy> user

Re: Large slowdown with gfortran vs f77 (x7)

2009-09-04 Thread Tobias Burnus
On 09/04/2009 05:04 PM, FX wrote: > -- it's unarguably a glibc issue: if exp() is fast and expf() is > slow, why doesn't glibc implement expf() by calling exp()? (yes, there > can be other issues like rounding or so, but they can also be dealt > with separately) If I recall correctly, it is most

Re: Large slowdown with gfortran vs f77 (x7)

2009-09-04 Thread FX
Hi Jeremy, -- it's unarguably a glibc issue: if exp() is fast and expf() is slow, why doesn't glibc implement expf() by calling exp()? (yes, there can be other issues like rounding or so, but they can also be dealt with separately) -- a similar bug was already reported a year and a half