[Bug fortran/30388] gfortran42 is slower than g77 3.4 about 10%

[rguenth at gcc dot gnu dot org]

------- Comment #10 from rguenth at gcc dot gnu dot org  2007-01-06 10:17 -------
Well, it all boils down to differences in induction variable choices.  The
choice made by 3.4 (for i686) doesn't look too good to me compared to 4.1.2
here.

4.1: MFLOPS:   990.4130       time(s):   28.10176
3.4: MFLOPS:  449.016235  time(s):  59.8477402

(-O2 -ffast-math -funroll-loops -fomit-frame-pointer)

The predcomm branch should be able to do a lot better here.

With SSE math I get

4.1: MFLOPS:   954.2382       time(s):   31.46597
3.4: MFLOPS:  467.92215  time(s):  59.1876984


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
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                 CC|                            |rakdver at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30388