[Bug tree-optimization/128458] New: wrong-code with reassoc and powers of _Float64

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128458

            Bug ID: 128458
           Summary: wrong-code with reassoc and powers of _Float64
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org
  Target Milestone: ---

extern double pow (double, double);

__attribute__((noipa)) _Float64
f (_Float64 x)
{
  return x * x * pow (x, 3.0);
}

int
main (void)
{
  if (f (2) != 32)
    __builtin_abort ();
  return 0;
}


with -Ofast reassoc handles the pow() call as if it can be replaced with powi
but as it fails it simply replaces it with 'x', dropping the power to 3.