[Bug tree-optimization/96715] New: Failure to optimize copysign of variable by negated variable

[gabravier at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96715

            Bug ID: 96715
           Summary: Failure to optimize copysign of variable by negated
                    variable
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gabravier at gmail dot com
  Target Milestone: ---

float f(float x, float y)
{
    return __builtin_copysignf(x, -x);
}

This can be optimized to `return -x;`. This transformation is done by LLVM, but
not by GCC.