[PATCH] D131873: [PowerPC] Optimize compare by using record form in post-RA.

[ChenZheng via Phabricator via llvm-commits]

shchenz added a comment.

Look almost good to me now. Thanks for adding this folding.



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Comment at: llvm/lib/Target/PowerPC/PPCInstrInfo.cpp:2791
+
+  // Rotates with record form are expensive instructions.
+  int SrcMIOpc = SrcMI->getOpcode();
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Have you seen any perf impact due to this pattern? If so, there are many other record form rotate and shift instructions on PowerPC target, like RLDICL/RLDICR(not complete.)


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Comment at: llvm/lib/Target/PowerPC/PPCInstrInfo.cpp:2822
+  // Fix up killed/dead flag for SrcReg after transformation.
+  if (OtherUse_SrcReg || CmpMI.getOperand(1).isKill())
+    fixupIsDeadOrKill(SrcMI, &CmpMI, SrcReg);
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Can we add a MIR case for this?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D131873/new/

https://reviews.llvm.org/D131873