[Bug target/94915] MAX_EXPR weirdly optimized on x86 with -mtune=core2

rguenth at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Mon May 4 06:35:30 GMT 2020


Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
             Target|                            |x86_64-*-*

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
We now can move integer operations over to SSE which in some cases (max/min vs.
cmov can be quite a bit faster).  This isolated case is probably not of such
kind (but how can you know w/o benchmarking ...).  On AMD archs the
GPR <-> xmm moves make this unprofitable but those are "free" on intel which
makes costing prefer the pmaxsd variant.

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