[Bug tree-optimization/113411] New: ABS*ABS can be simplified to ABS

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113411

            Bug ID: 113411
           Summary: ABS<a>*ABS<b> can be simplified to ABS<a*b>
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```

static inline int abs(int a)
{
  signed b = a;
  if (a < 0)
    b = -b;
  return b;
}

int foo1(int a, int b)
{
   return abs(a) * abs(b);
}
```

foo1 can be simplified down to `abs(a*b)`.  Note I think this is only valid for
signed overflowable types and not valid with -fwrapv (but I could be wrong).
Maybe ok for real types with -ffast-math.