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

Wed Jul 27 21:50:40 PDT 2022

craig.topper added inline comments.

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Comment at: llvm/test/Transforms/ExpandLargeDivRem/urem129.ll:14
+; CHECK-NEXT:    [[TMP5:%.*]] = icmp ugt i129 [[TMP4]], 128
+; CHECK-NEXT:    [[TMP6:%.*]] = or i1 [[TMP1]], [[TMP5]]
+; CHECK-NEXT:    [[TMP7:%.*]] = icmp eq i129 [[TMP4]], 128
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craig.topper wrote:
> Is this code handling the possible poison result from the ctlz's incorrectly? If [A] is zero then [TMP3] is poison, [TMP4] is poison, [TMP5] is poison, [TMP6] being an or won't block the poison. Assuming I understand poison correctly.
> 
> I don't think that was caused by this patch. It's an issue in the existing code.
Patch for the poison issue https://reviews.llvm.org/D130680

Repository:
  rG LLVM Github Monorepo

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

https://reviews.llvm.org/D126644