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[Bug tree-optimization/13761] [tree-ssa] component refs to the same struct should not alias
- 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: 6 Mar 2006 14:39:23 -0000
- Subject: [Bug tree-optimization/13761] [tree-ssa] component refs to the same struct should not alias
- References: <bug-13761-1008@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #15 from rguenth at gcc dot gnu dot org 2006-03-06 14:39 -------
The problem for the original testcase is that we don't even try to build SFTs
required for structure aliasing analysis for incoming pointers:
foo0 (f)
{
int D.1529;
<bb 2>:
# SMT.4_4 = V_MAY_DEF <SMT.4_3>;
f_1->s = 1;
# SMT.4_5 = V_MAY_DEF <SMT.4_4>;
f_1->s2 = 2;
which is required to turn these into V_MUST_DEFs. Of course we still can do
propagation of the values in ccp or copyprop if we walk the virtual use-def
chains there and disabmiguate the offsets.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13761