[Bug tree-optimization/38984] [4.2/4.3 Regression] NULL pointers always considered distinct by PTA, even with -fno-delete-null-pointer-checks

[rguenth at gcc dot gnu dot org]

------- Comment #14 from rguenth at gcc dot gnu dot org  2009-02-01 21:34 
-------
Hm, on the alias-improvements branch I now XPASS the not return 1 check, but -
why do you think we should have two dereferences to *p?

Hm, because:

  # VUSE <.MEM_6(D)>
  a = *p;
  # .MEM_7 = VDEF <.MEM_6(D)>
  *0B = 5;
  return *p == a;

in optimized.

  # VUSE <.MEM_6(D)>
  a_2 = *p_1(D);
  # .MEM_7 = VDEF <.MEM_6(D)>
  *0B = 5;
  # VUSE <.MEM_7>
  D.1236_4 = *p_1(D);


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38984