[Bug tree-optimization/26609] New: may aliasing set is set too large

["pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

Testcase:
int h(int *);
struct a1
{
   int i[2];
};
void link_error();
int f(struct a1 a, int i,int *c)
{
  int b;
  void *g = &a.i[i];
  *(int*)g = 1;
  h(&b);
  if (a.i[i] !=1)
    link_error();
  return b+c[i*2];
}

-------
  #   VUSE <b_19>;
  #   VUSE <SFT.3_20>;
  #   VUSE <SFT.4_21>;
  D.1996_14 = *D.1995_13;

That is very imprecise and actually stays throught the whole compiling.

This is a reduced testcase from tramp3d, the void* comes from inlining inplace
operator new.


-- 
           Summary: may aliasing set is set too large
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, memory-hog, compile-time-hog
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26609