[MPlayer-dev-eng] [PATCH] Enable FTZ and DAZ w/ -ffast-math

[Diego Biurrun]

On Tue, Feb 10, 2009 at 12:12:23AM +0800, Zuxy Meng wrote:
> 2009/2/10 Diego Biurrun <diego at biurrun.de>:
> > On Sun, Feb 08, 2009 at 02:02:20PM +0800, Zuxy Meng wrote:
> >>
> >> 2009/2/8 Diego Biurrun <diego at biurrun.de>:
> >> > On Mon, Feb 02, 2009 at 09:33:08PM +0800, Zuxy Meng wrote:
> >> >>
> >> >> GCC does a trick to enable FTZ (flush to zero) and DAZ (denormals are
> >> >> zeroes) when either -ffast-math or -funsafe-math-optimizations is used
> >> >> by linking crtfastmath.o into the executive. It requires the presence
> >> >> of one of the options in the final linking stage.
> >> >
> >> > I don't like CFLAGS being used during the linking stage.  Add those
> >> > options to the linker flags instead.
> >>
> >> Something like COMMON_LDFLAGS += $(findstr, -ffast-math, $CFLAGS)?
> >
> > No, add it to LDFLAGS in configure in the same place where fast-math is
> > added to CFLAGS.
> 
> Do we check user specified CFLAGS?

Somewhat.  But IMO users have to make sure they add it to LDFLAGS as
well then.

Diego