https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97142
--- Comment #9 from Peter Bergner <bergner at gcc dot gnu.org> --- (In reply to Segher Boessenkool from comment #8) > I don't think we have an instruction for that? But we can inline the > code we need instead of doing a library call, which is much faster. > (We probably can use FMAs here usefully, btw; maybe even without needing > -ffast-math.) Yes, I was mistaken we had a hw insn. I do see xlc does not expand __builtin_fmod (x, y), so it's only xlf that does this optimization. Agreed on the inlining thing. It's interesting that even libm's fmod() routine on ppc just calls a C function and doesn't have an optimized asm routine.
