[PATCH] D139598: [InstCombine] Fold (X << Z) / (X * Y) -> (1 << Z) / Y

[Sanjay Patel via Phabricator via llvm-commits]

spatel added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp:1057
+  // (X << Z) / (X * Y) -> (1 << Z) / Y
+  if (!IsSigned && Op0->hasOneUse() && Op1->hasOneUse() &&
+      match(Op0, m_NUWShl(m_Value(X), m_Value(Z))) &&
----------------
Do you plan to handle the signed case too? 

I'm not sure exactly what no-wrap is required, but there is some combination that works, so add a TODO comment:
https://alive2.llvm.org/ce/z/WrXmth


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D139598/new/

https://reviews.llvm.org/D139598