[PATCH] D130517: [GlobalISel] Add sdiv exact (X, constant) -> mul combine.

[Jay Foad via Phabricator via llvm-commits]

foad added inline comments.


================
Comment at: llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp:5037
+
+  // Shift the value upfront if it is even, so the LSB is one.
+  if (UseSRA)
----------------
Comment is misleading. You're shifting the dividend based on trailing zeros in the divisor, so we don't know that the value is even before shifting, and we don't know the LSB is one after shifting.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D130517/new/

https://reviews.llvm.org/D130517