[PATCH] D59218: [LSR] Fix signed overflow in GenerateCrossUseConstantOffsets.

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


================
Comment at: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp:4152
+        //        See PR41034.
+        Imms.lower_bound(((uint64_t)Imms.begin()->first + std::prev(Imms.end())->first) /
                          2)
----------------
This code is trying to compute (x+y)/2.  Mathematically, this can't overflow, so this shouldn't require a bitwidth to produce a meaningful result.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D59218/new/

https://reviews.llvm.org/D59218