[MPlayer-dev-eng] [PATCH] Enable FTZ/DAZ for SSE

[Zuxy Meng]

Hi,

2007/5/18, Dominik 'Rathann' Mierzejewski <dominik at rangers.eu.org>:
> On Friday, 18 May 2007 at 10:35, Zuxy Meng wrote:
> > Hi,
> >
> > 2007/5/18, Diego Biurrun <diego at biurrun.de>:
> > > Rejected, CFLAGS do not belong in a linker command.
> >
> > Hmm...I don't know if putting '-ffast-math' into COMMON_LDFLAGS is uglier.
>
> We certainly need them there for gcc to link in the correct
> object file for SSE support, right?

It'll link an object which greatly improves SSE floating performance
when floating underflow happens; such behavior isn't strictly
compliant to IEEE 754 standard, so it should only be turned on when
-ffast-math or -funsafe-math-optimizations is in CFLAGS.

By default configure will set CFLAGS appropriately. But, mplayer users
can still choose CFLAGS themselves, although not recommended. If we
put -ffast-math in COMMON_LDFLAGS, then the user can never get a
binary which is fully IEEE 754 compliant.
-- 
Zuxy
Beauty is truth,
While truth is beauty.
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