[PATCH] D109201: [AMDGPU] Process any power of 2 in optimizeCompareInstr

Fri Sep 3 03:05:53 PDT 2021

foad added inline comments.

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Comment at: llvm/lib/Target/AMDGPU/SIInstrInfo.cpp:8036
+    //
+    // Signed ge/gt are not used for the sign bit.
     //
----------------
Yeah that is an ugly special case. Do we really need to handle ge/gt here at all? Can't we rely on something else canonicalizing them all to eq/ne comparisons?

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Comment at: llvm/lib/Target/AMDGPU/SIInstrInfo.cpp:8119
       .add(*SrcOp)
-      .addImm(0);
+      .addImm(Log2_64(Mask));
     Def->eraseFromParent();
----------------
Isn't this just `BitNo`?

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D109201/new/

https://reviews.llvm.org/D109201