[PATCH] D101074: [X86] Canonicalize SGT/UGT compares with constants to use SGE/UGE to reduce the number of EFLAGs reads. (PR48760)

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/lib/Target/X86/X86ISelLowering.cpp:23472
   if (Op0.getSimpleValueType().isInteger()) {
+    // Attempt to canonicalize SGT/UGT -> SGE/UGE compares with constant which
+    // reduces the number of EFLAGs reads. The equivalent for SLE/ULE -> SLT/ULT
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craig.topper wrote:
> Should this be inside emitFlagsForSetcc? That way setcc+brcond works. LowerBRCOND doesn't call LowerSETCC.
Yes, I was hoping to move it inside TranslateX86CC later (see TODO) - as it felt like this caused far too many diffs as an initial patch - I'll can try again now that the SLT/ULT handling has been dropped.


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  https://reviews.llvm.org/D101074/new/

https://reviews.llvm.org/D101074