[Bug tree-optimization/22254] New: We never call may_alias_p for PARM_DECL's

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

Given a simple testcase
/* Two int arrays testcase for ipaa.  */

#define N 11

void f ();
void g (int* g1, int* g2);

main ()
{
  f();
  return; 
}

void f ()
{
  int a[N];
  int b[N];
  g(a,b);
  return; 
}

void g (int* g1, int* g2)
{
  int i;
  for (i=0; i < N; i++)
    g1[i] = g2[i];
}

may_alias_p is never called.

However, Interprocedural Alias Analysis can tell us these formals never alias.

We need to be able to take this kind of analysis into account in our representation.

-- 
           Summary: We never call may_alias_p for PARM_DECL's
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dberlin at gcc dot gnu dot org
                CC: dnovillo at gcc dot gnu dot org,gcc-bugs at gcc dot gnu
                    dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22254