[llvm-bugs] [Bug 45691] New: Failure to detect abs pattern using multiplication

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=45691

            Bug ID: 45691
           Summary: Failure to detect abs pattern using multiplication
           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

unsigned r(int v)
{
    return (1 | -(v < 0)) * v;
}

`r` is equivalent to `abs(v)`. LLVM does not make the transformation to an
`abs`.

Example of the optimization not being done : https://godbolt.org/z/9Lwxoc

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