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Re: x86 -ffast-math problem on SPEC CPU 2K
On Thu, Feb 23, 2006 at 11:00:33AM -0800, Dale Johannesen wrote:
>
> On Feb 23, 2006, at 8:54 AM, H. J. Lu wrote:
>
> >When I use -O2 -mtune=pentium4 -ffast-math on SPEC CPU 2K on Linux/x86
> >with gcc 4.2, I get
> >
> >*** Miscompare of 200.s, see
> >/export/spec/src/2000/spec/benchspec/CINT2000/176.gcc/run/00000004/
> >200.s.mis
> >*** Miscompare of scilab.s, see
> >/export/spec/src/2000/spec/benchspec/CINT2000/176.gcc/run/00000004/
> >scilab.s.mis
> >
> >Is that a known issue?
>
> This is what you get if the benchmark source thinks the host is of the
> wrong endianness.
> Do you have -DHOST_WORDS_BIG_ENDIAN in your config file perhaps?
No.
BTW, "-O2 -mtune=pentium4" generates correct results for SPEC CPU 2K.
The only difference is -ffast-math.
H.J.