[PATCH] D89100: [GlobalISel] Look through truncs and extends in narrowScalarShift

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


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Comment at: llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp:4189
+          getConstantVRegValWithLookThrough(Amt, MRI, true, false)) {
+    auto *DefMI = MRI.getVRegDef(VRegAndVal->VReg);
     return narrowScalarShiftByConstant(
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Why do you need to get DefMI? VRegAndVal should have the value already? (Or is this because it stores an int64_t? I've been thinking we should maybe start returning the ConstantInt or APInt instead)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89100/new/

https://reviews.llvm.org/D89100