[all-commits] [llvm/llvm-project] aa9099: [JumpThreading] Clone noalias scopes in duplicateC...

[Justin Lebar via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: aa9099a47468425b6d16613e08ae84c8c77671b7
      https://github.com/llvm/llvm-project/commit/aa9099a47468425b6d16613e08ae84c8c77671b7
  Author: Justin Lebar <justin.lebar at gmail.com>
  Date:   2026-06-03 (Wed, 03 Jun 2026)

  Changed paths:
    M llvm/lib/Transforms/Scalar/JumpThreading.cpp
    M llvm/test/Transforms/JumpThreading/noalias-scope-decl.ll

  Log Message:
  -----------
  [JumpThreading] Clone noalias scopes in duplicateCondBranchOnPHIIntoPred (#200550)

duplicateCondBranchOnPHIIntoPred clones a block into a predecessor with
its own loop. Unlike cloneInstructions (used by threadEdge), it never
cloned the duplicated noalias scope declarations. The duplicated code
therefore shared the original's !alias.scope/!noalias MDNodes, letting
AA incorrectly treat two accesses on different paths as non-aliasing.

Fix by cloning the scopes.



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