[PATCH] D65143: [InstCombine] Fold '(-1 u/ %x) u< %y' to '@llvm.umul.with.overflow' + overflow bit extraction

[Dávid Bolvanský via Phabricator via llvm-commits]

xbolva00 added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp:3333
+///   (-1 u/ %x) u< %y
+/// to
+///   @llvm.umul.with.overflow(%x, %y) plus extraction of overflow bit
----------------
Just ‘x’ instead of ‘%x’ in the comments?


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp:3351
+
+    // Are we checking that overflow does not happen, or does happen?
+    switch (Pred) {
----------------
“.. whether overflow happens or not” ?


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp:3363
+  } else
+    return nullptr;
+
----------------
Early return maybe better?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D65143/new/

https://reviews.llvm.org/D65143