[Bug tree-optimization/30137] New: Missed folding of pointer comparison

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

Compiler:
GNU C version 4.3.0 20061210 (experimental) (x86_64-unknown-linux-gnu)

Test case:
----------------------
struct { long base; } *s;
int foo1 (void) { return (s == &s->base); }
int foo2 (void) { return ((void *)s == (void *) &s->base); }
----------------------

.final_cleanup dump:
----------------------
;; Function foo1 (foo1)

foo1 ()
{
  struct
  {
    long int base;
  } * s.0;

<bb 2>:
  s.0 = s;
  return s.0 == &s.0->base;

}



;; Function foo2 (foo2)

foo2 ()
{
  struct
  {
    long int base;
  } * s.1;

<bb 2>:
  s.1 = s;
  return s.1 == &s.1->base;

}
----------------------

.s output:
----------------------
.globl foo1
        .type   foo1, @function
foo1:
.LFB2:
        movl    $1, %eax
        ret
.LFE2:
        .size   foo1, .-foo1
        .p2align 4,,15
.globl foo2
        .type   foo2, @function
foo2:
.LFB3:
        movl    $1, %eax
        ret
.LFE3:
        .size   foo2, .-foo2
(etc.)
----------------------


-- 
           Summary: Missed folding of pointer comparison
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, TREE
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: steven at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30137