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[X86][AVX] Extend hasVEX_WPrefix bit to accept WIG value (W Ignore) + update all AVX instructions with the new value
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Authored by aymanmus on Feb 12 2017, 10:28 AM.

Details

Summary

Add WIG value to all of AVX instructions which ignore the W-bit in their encoding, instead of giving them the default value of 0.
This patch is needed for a follow up work on EVEX2VEX pass (replacing EVEX encoded instructions with their corresponding VEX version when possible).

Diff Detail

Event Timeline

aymanmus created this revision.Feb 12 2017, 10:28 AM
craig.topper edited edge metadata.Feb 12 2017, 10:42 AM

I know this is good for the disassembler. I think there's an old bug for this. But what's the evex2vex follow up?

igorb added inline comments.Feb 12 2017, 11:51 PM
lib/Target/X86/X86InstrFormats.td
321–322

please add comment

@craig.topper I'm working on replacing the manual EVEX2VEX tables with a tablegen backend that generates them.
I need this information in order to match VEX/EVEX instructions.

aymanmus updated this revision to Diff 89063.Feb 19 2017, 5:35 AM

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This revision is now accepted and ready to land.Feb 19 2017, 6:33 PM
This revision was automatically updated to reflect the committed changes.