On Tue, Aug 15, 2017 at 4:59 PM, Richard Biener
<richard.guent...@gmail.com> wrote:
> So I'd try the "easy" way of expanding if (__builtin_cpu_supports ("sse4.1"))
> as the sse4.1 sequence is just a single instruction. The interesting part
> of the story will be to make sure we can emit that even if ! TARGET_ROUND ...
>
> Uros, any idea how to accomplish this? Or is the idea of a "local" ifunc
> better? Note the ABI boundary will be expensive but I guess the conditional
> sequence as well (and it will disturb RA even if predicted to have SSE 4.1).
TARGET_ROUND is just:
/* SSE4.1 defines round instructions */
#define OPTION_MASK_ISA_ROUND OPTION_MASK_ISA_SSE4_1
#define TARGET_ISA_ROUND ((ix86_isa_flags & OPTION_MASK_ISA_ROUND) != 0)
I don't remember the history around the #define, once upon a time
probably made sense, but nowadays it looks that it can be simply
substituted with TARGET_SSE4_1.
Uros.
