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[X86] Add FeatureSlowBTMem to Haswell, Broadwell, Skylake, Cannonlake, and Knights Landing CPUs.

Authored by craig.topper on Oct 13 2017, 9:23 AM.



I see nothing in Agner Fog's tables to indicate that this improved between Ivy Bridge and Haswell. It's also set for all Atom CPUs so I assume KNL should have it too.

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craig.topper created this revision.Oct 13 2017, 9:23 AM
gadi.haber edited edge metadata.Oct 15 2017, 4:52 AM

Yes. The X86 Bit Test is known to run slowly on all X86 CPUs.

gadi.haber accepted this revision.Oct 15 2017, 7:23 AM
This revision is now accepted and ready to land.Oct 15 2017, 7:23 AM
This revision was automatically updated to reflect the committed changes.