> On 9/17/07, Uros Bizjak <[EMAIL PROTECTED]> wrote:
> > Hello!
> >
> > I have tripped over a problem, where #defines from libc
> > (bits/mathinline.h) interfere badly with gcc's intrinsics.
> >
> > The problem (note the #include):
> >
> > --cut here--
> > #include <math.h>
> >
> > double test (double x)
> > {
> > return ceil(x);
> > }
> > --cut here--
> >
> > when compiled with -O2 -ffast-math -msse2 -mfpmath=sse, compiles to
> > asm that involves x87 insns from mathinline.h. Adding
> > -D__NO_MATH_INLINES compiles to expected SSE code.
> >
> > As recent gcc implements all libc math intrinsics as its own builtin
> > intrinsics, and due to the above interference, I'd like to propose
> > that gcc defines __NO_MATH_INLINES on x86_32 target for -ffast-math,
> > for both -mfpmath=sse and -mfpmath=x87.
>
> This "problem" has come up before and instead of gcc glibc should be fixed.
> Do we make glibc aware of the user specifying -mfpmath=sse somehow?
If we really implement all of glibc logic, I think we should just teach
glibc header to disable itself based on GCC version, I don't think this
should be handled on GCC side.
We already define __SSE_MATH__ and __SSE2_MATH__
Honza
>
> Richard.
