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[Bug tree-optimization/18694] [4.0 regression] loop miscompilation at -O1 (-ftree-ch)
- From: "kazu at cs dot umass dot edu" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 9 Dec 2004 02:51:37 -0000
- Subject: [Bug tree-optimization/18694] [4.0 regression] loop miscompilation at -O1 (-ftree-ch)
- References: <20041127224610.18694.falk@debian.org>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From kazu at cs dot umass dot edu 2004-12-09 02:51 -------
Here are the PHI nodes that I am getting at L2 in thread_across_edge
called on edge L23 -> L2.
TMT.0_24 = PHI <TMT.0_26(1), TMT.0_23(5)>;
ivtmp14_6 = PHI <0(1), ivtmp14_14(5)>;
d_5 = PHI <d23_9(1), d23_2(5)>; <- defined
tmp_4 = PHI <t_8(1), d_5(5)>; <- used
d23_3 = PHI <d23_9(1), d23_2(5)>;
Note that d_5 is defined *and* used.
At this point, it's not safe to use SSA_NAME_VALUE for d_5.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18694