[Bug tree-optimization/41428] New: CCP doesn't fold all comparisons it could

[rguenth at gcc dot gnu dot org]

extern "C" void abort (void);
inline void *operator new (__SIZE_TYPE__, void *__p) throw () { return __p; }

int __attribute__((noinline))
foo(void)
{
  float f = 0;
  int *i = new (&f) int (1);
  return *(int *)&f;
}

CCP produces

<bb 2>:
  f = 0.0;
  D.2121_3 = &f;
  D.2107_4 = (int *) &f;
  if (D.2107_4 != 0B)
    goto <bb 3>;
  else
    goto <bb 4>;

and while it knows during propagation that D.2107_4 != 0B is true this
doesn't have any effect during substitute_and_fold.


-- 
           Summary: CCP doesn't fold all comparisons it could
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rguenth at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41428