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[Bug tree-optimization/19938] Missed jump threading opportunity due to signedness difference
- From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 13 Feb 2005 18:04:41 -0000
- Subject: [Bug tree-optimization/19938] Missed jump threading opportunity due to signedness difference
- References: <20050213175801.19938.kazu@cs.umass.edu>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-02-13 18:04 -------
Confirmed, but note the following in the tree level is really invalid:
D.1187_17 = (unsigned int) length_4;
if (j_16 != D.1187_17) goto <L2>; else goto <L4>;
as j_16 is signed and we are comparing against an unsigned type.
In which case this is an IV-OPT problem, very closely related to PR 19937 (which by the way is a wrong-
code regression).
If someone would add more checking we would have caught this earlier.
--
What |Removed |Added
----------------------------------------------------------------------------
BugsThisDependsOn| |19937
Severity|enhancement |normal
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2005-02-13 18:04:35
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19938