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Re: RFC: Define __FPMATH_387__ and __FPMATH_SSE__
On Thu, Mar 02, 2006 at 07:38:47AM -0800, H. J. Lu wrote:
> Yes. That is for float and double functions in libm.
> > to touch x387
> > flags for XFmode long long operations.
> I assume you meant long double. If the library knows it doesn't long
> double, it doesn't need to touch x87 unit control.
But if you call one of the standard fenv.h functions, they
are supposed to affect not just the calling routine (where you
could through preprocessor magic tell what it uses, though e.g.
not for inline asm), but for the whole process. And I don't understand
how you can prove that if you call fesetround or similar from
-mfpmath=sse compiled source file that the program doesn't anywhere
in some other library or in the main binary use x87 unit (or vice versa).