[PATCH] D59450: [ValueTracking] Use ConstantRange overflow check for signed add (NFC)

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added inline comments.


================
Comment at: llvm/lib/Analysis/ValueTracking.cpp:4104-4105
+  APInt Lower = Known.One, Upper = ~Known.Zero;
+  Lower.setSignBit();
+  Upper.clearSignBit();
+  return ConstantRange(Lower, Upper + 1);
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This seems like the only non-obvious place here.
There are tests that will fail if it is written **any** other way?


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D59450/new/

https://reviews.llvm.org/D59450