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[Bug tree-optimization/30708] [4.1 Regression] Aliasing miscompilation
- From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 5 Feb 2007 14:19:20 -0000
- Subject: [Bug tree-optimization/30708] [4.1 Regression] Aliasing miscompilation
- References: <bug-30708-87@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #1 from rguenth at gcc dot gnu dot org 2007-02-05 14:19 -------
Confirmed. Maybe related to PR30088. The first alias dump at -O2 (-O
-fstrict-aliasing is fine) has
<bb 0>:
# common_head_5 = V_MUST_DEF <common_head_4>;
common_head = 0B;
...
<L0>:;
p_10 = &common_head;
goto <bb 4> (<L3>);
<L1>:;
# VUSE <TMT.6_24>;
D.1631_16 = sym_1->size;
# VUSE <HEAP.5_22>;
D.1632_17 = *p_2;
...
# p_2 = PHI <p_10(1), p_21(3)>;
<L3>:;
# VUSE <HEAP.5_22>;
D.1632_11 = *p_2;
if (D.1632_11 != 0B) goto <L1>; else goto <L4>;
so we have both HEAP.5 and common_head_5 used as tags for common_heap.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Keywords| |alias, wrong-code
Last reconfirmed|0000-00-00 00:00:00 |2007-02-05 14:19:20
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30708