[PATCH] D126644: [llvm/CodeGen] Add ExpandLargeDivRem pass

Mon Jul 18 15:40:45 PDT 2022

arsenm added inline comments.

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Comment at: llvm/lib/CodeGen/TargetPassConfig.cpp:1115
   addPass(createPreISelIntrinsicLoweringPass());
+  addPass(createExpandLargeDivRemPass());
   PM->add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
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This doesn't belong in this patch. Currently this is lacking in legality checks for the expansion. I would prefer to see a separate patch which adds the pass and checks the legality per target, rather than relying on the arbitrary command line threshold

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Comment at: llvm/test/Transforms/ExpandLargeDivRem/sdiv129.ll:11
+
+; CHECK-LABEL: @sdiv129(
+; CHECK-NEXT:  _udiv-special-cases:
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The positioning of the checks looks weird. Usually update_test_checks put these comments inside the function?

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D126644/new/

https://reviews.llvm.org/D126644