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From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/35609] [4.3/4.4 Regression] "is used uninitialized in this function" should be may warning Date: Sun, 16 Mar 2008 21:33:00 -0000 [thread overview] Message-ID: <20080316213233.29228.qmail@sourceware.org> (raw) In-Reply-To: <bug-35609-9876@http.gcc.gnu.org/bugzilla/> ------- Comment #2 from rguenth at gcc dot gnu dot org 2008-03-16 21:32 ------- The warning works as designed, the PHI node in question that causes the warning only has a single incoming edge: testfunc () { int alt_reloc; int foo.0; <bb 2>: foo.0_1 = foo; if (foo.0_1 > 19) goto <bb 5>; else goto <bb 3>; <bb 3>: if (foo.0_1 > 9) goto <bb 6>; else goto <bb 4>; <bb 4>: if (alt_reloc_4(D) != 0) goto <bb 5>; else goto <bb 6>; <bb 5>: bar = 42; <bb 6>: return; } we don't check whether the uninitialized use post-dominates the function entry. I don't know if we should. This is just a case of 4.3 optimizing better than 4.2 which makes the warning less precise. -- rguenth at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Last reconfirmed|0000-00-00 00:00:00 |2008-03-16 21:32:33 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35609
next prev parent reply other threads:[~2008-03-16 21:33 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2008-03-16 21:19 [Bug c/35609] New: [4.3/4.4 Regression] bogus "is used uninitialized in this function" warning bunk at stusta dot de 2008-03-16 21:30 ` [Bug tree-optimization/35609] [4.3/4.4 Regression] "is used uninitialized in this function" should be may warning pinskia at gcc dot gnu dot org 2008-03-16 21:30 ` pinskia at gcc dot gnu dot org 2008-03-16 21:33 ` rguenth at gcc dot gnu dot org [this message] 2008-03-18 16:54 ` rguenth at gcc dot gnu dot org 2008-03-19 10:46 ` [Bug tree-optimization/35609] [4.3 " rguenth at gcc dot gnu dot org 2008-03-19 10:46 ` [Bug tree-optimization/35609] [4.3/4.4 " rguenth at gcc dot gnu dot org 2008-03-25 10:10 ` [Bug tree-optimization/35609] [4.3 " rguenth at gcc dot gnu dot org 2008-03-25 10:11 ` rguenth at gcc dot gnu dot org
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