This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH] BZ #14649: Add multiarch FMA support to x86-64 libm
On Mon, 1 Oct 2012, H.J. Lu wrote:
> I think some AMD processors support both FMA and FMA4. But Intel
> processors only support FMA. My patch follows s_fma.c which prefers
> FMA over FMA4.
The patch doesn't seem to touch sysdeps/x86_64/fpu/dla.h (which deals, for
FMA4, with cases where various libm code can explicitly use fma operations
directly) - I'd think you should do something to handle __FMA__ there
similarly to __FMA4__. (Although making the generic code use
__builtin_fma, if __FP_FAST_FMA is defined, would be even better and
reduce any need for architecture-specific definitions using inline asm.)
--
Joseph S. Myers
joseph@codesourcery.com