[llvm-bugs] [Bug 46001] New: Failure to optimize out movzx by reordering & 1 to be last operation

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=46001

            Bug ID: 46001
           Summary: Failure to optimize out movzx by reordering & 1 to be
                    last operation
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Scalar Optimizations
          Assignee: unassignedbugs at nondot.org
          Reporter: gabravier at gmail.com
                CC: llvm-bugs at lists.llvm.org

int f(int a, int b)
{
    return ((a & 1) != 0) != (b != 0);
}

With -O3, LLVM outputs this :

f(int, int): # @f(int, int)
  test esi, esi
  setne al
  and dil, 1
  xor dil, al
  movzx eax, dil
  ret

It should be capable of outputting this :

f(int, int):
  test esi, esi
  setne al
  xor eax, edi
  and eax, 1
  ret

But it isn't.

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