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From: "hubicka at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/55079] [4.8 regression] false positive -Warray-bounds (also seen at -O3 bootstrap) Date: Thu, 15 Nov 2012 01:01:00 -0000 [thread overview] Message-ID: <bug-55079-4-DKCAhdwi8h@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-55079-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55079 --- Comment #9 from Jan Hubicka <hubicka at gcc dot gnu.org> 2012-11-15 01:01:30 UTC --- This is reduced testcase from gcov.c int a[8]; int t (void) { int ix = 0; int k; int b = 0; int curr = 0; for (k = 0; k < 2; k++) { b = ix * 32; curr = a[ix++]; if (!(ix <= 8)) abort (); while (curr) { b = ix * 32; curr = a[ix++]; if (!(ix <= 8)) abort (); } } return curr + b; } jan@linux-e0ml:~/trunk/build/gcc> ./xgcc -B ./ -O2 -fprofile-use t.c -Warray-bounds -S -S -fdump-tree-cunroll-details -fdump-tree-all-details t.c: In function ‘t’: t.c:14:2: warning: incompatible implicit declaration of built-in function ‘abort’ [enabled by default] abort (); ^ t.c:25:1: note: file /home/jan/trunk/build/gcc/t.gcda not found, execution counts estimated } ^ t.c:19:15: warning: array subscript is above array bounds [-Warray-bounds] curr = a[ix++]; ^ t.c:19:15: warning: array subscript is above array bounds [-Warray-bounds] Obivously here unroller does not know that bv_ix is at least 1
next prev parent reply other threads:[~2012-11-15 1:01 UTC|newest] Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-10-26 9:56 [Bug tree-optimization/55079] New: [4.8 regeression] false positive -Warray-bounds dimhen at gmail dot com 2012-10-26 10:09 ` [Bug tree-optimization/55079] " rguenth at gcc dot gnu.org 2012-10-30 9:34 ` [Bug tree-optimization/55079] [4.8 regression] " rguenth at gcc dot gnu.org 2012-10-30 9:35 ` rguenth at gcc dot gnu.org 2012-11-02 16:35 ` hubicka at gcc dot gnu.org 2012-11-02 16:47 ` hubicka at gcc dot gnu.org 2012-11-02 18:45 ` hubicka at gcc dot gnu.org 2012-11-02 20:51 ` hubicka at gcc dot gnu.org 2012-11-14 19:31 ` [Bug tree-optimization/55079] [4.8 regression] false positive -Warray-bounds (also seen at -O3 bootstrap) hubicka at gcc dot gnu.org 2012-11-15 1:01 ` hubicka at gcc dot gnu.org [this message] 2012-12-07 12:55 ` rguenth at gcc dot gnu.org 2012-12-10 13:23 ` rguenth at gcc dot gnu.org 2012-12-10 13:50 ` rguenth at gcc dot gnu.org 2012-12-10 14:14 ` rguenth at gcc dot gnu.org 2012-12-10 16:27 ` hubicka at ucw dot cz 2012-12-11 10:06 ` rguenth at gcc dot gnu.org 2012-12-11 10:08 ` rguenth at gcc dot gnu.org 2012-12-12 9:33 ` schwab at gcc dot gnu.org
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