[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
gcc-bugzilla@gcc.gnu.org
Sun Feb 1 21:34:00 GMT 2009
------- 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
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