[Bug target/31897] [4.3 Regression] 30% speed regression with -m32 on Opteron with rnflow

[ubizjak at gmail dot com]

------- Comment #7 from ubizjak at gmail dot com  2007-10-19 17:53 -------
(In reply to comment #6)
> It is little bit sick, but what about implying -mfpmath=sse when
> -ftree-vectorize is used and SSE is available?

Then you will hit Core2 Duo, that shows the opposite in 32bit and 64bit mode:

-O3 -ffast-math -ftree-vectorize -funroll-loops -msse3 -m32 -mfpmath=387

user 0m22.785s

-O3 -ffast-math -ftree-vectorize -funroll-loops -msse3 -m32 -mfpmath=sse

user 0.27.886s

-O3 -ffast-math -ftree-vectorize -funroll-loops -msse3 -m64 -mfpmath=387

user 0m20.473s

-O3 -ffast-math -ftree-vectorize -funroll-loops -msse3 -m64 -mfpmath=sse

user 0.25.046s


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31897