This intrinsic clears the upper bits starting at a specified index. If the index is a constant we can do some simplifications.
This could be in InstSimplify, but we don't handle any target specific intrinsics there today.
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[X86][InstCombine] Add some constant folding for BZHI intrinsics ClosedPublic Authored by craig.topper on Jul 30 2017, 6:51 PM.
Details Summary This intrinsic clears the upper bits starting at a specified index. If the index is a constant we can do some simplifications. This could be in InstSimplify, but we don't handle any target specific intrinsics there today.
Diff Detail Event TimelineComment Actions LGTM with minor comments.
This revision is now accepted and ready to land.Jul 31 2017, 12:23 AM
Comment Actions LGTM
Closed by commit rL309604: [X86][InstCombine] Add some simplifications for BZHI intrinsics (authored by ctopper). · Explain WhyJul 31 2017, 11:53 AM This revision was automatically updated to reflect the committed changes.
Revision Contents
Diff 108849 lib/Transforms/InstCombine/InstCombineCalls.cpp
test/Transforms/InstCombine/X86/x86-bmi-tbm.ll
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Minor: this is not constant-folding - it's a simplification, so consider updating the comment.