[PATCH] D82540: [TargetLowering] Improve expansion of FSHL/FSHR by non-zero amount

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp:6105
+// Check that (every element of) Z is undef or not an exact multiple of BW.
+static bool isNonZeroModBitWidth(SDValue Z, unsigned BW) {
+  return ISD::matchUnaryPredicate(
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arsenm wrote:
> !isDivisibleByBitWidth()?
I don't think that's a good idea because it's a tri-state question: is Z known to be divisible by BW, or known to be non-zero mod BW, or unknown?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D82540/new/

https://reviews.llvm.org/D82540