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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/107699] [12/13 Regression] False positive -Warray-bounds, non-existent offset reported by GCC Date: Tue, 29 Nov 2022 13:22:03 +0000 [thread overview] Message-ID: <bug-107699-4-vWFKgdPo8w@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-107699-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107699 --- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- At the point of the diagnostic we see <bb 2> [local count: 1073741824]: data._M_elems[0] = 3; data._M_elems[1] = 2; data._M_elems[2] = 1; _8 = getCount (); _1 = _8 * 4; _2 = &data._M_elems + _1; if (&data._M_elems != _2) goto <bb 3>; [53.47%] else goto <bb 12>; [46.53%] that should possibly be optimized to if (_1 != 0) but we cannot statically decide this jump. There's a later dynamic jump based on the very same _1, a check whether that's > 16, guarded by that we diagnose # .MEM_35 = VDEF <.MEM_34> std::__insertion_sort.isra (&data._M_elems, &MEM <int[3]> [(void *)&data + 64B]); where we complain about forming the (void *)&data + 64 address. I can't see a way to suppress the diagnostic completely but it should be possible to re-word it. Note using a global getCount without a conditional that this bound is inside 'data' bounds is not good programming practice.
next prev parent reply other threads:[~2022-11-29 13:22 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-11-15 14:10 [Bug c++/107699] New: " carlosgalvezp at gmail dot com 2022-11-16 13:34 ` [Bug tree-optimization/107699] " rguenth at gcc dot gnu.org 2022-11-16 13:34 ` [Bug tree-optimization/107699] 12/13 Regression] " rguenth at gcc dot gnu.org 2022-11-16 14:54 ` [Bug tree-optimization/107699] [12/13 " carlosgalvezp at gmail dot com 2022-11-23 3:00 ` hp at gcc dot gnu.org 2022-11-29 13:22 ` rguenth at gcc dot gnu.org [this message] 2022-11-29 13:41 ` carlosgalvezp at gmail dot com 2022-11-29 13:46 ` carlosgalvezp at gmail dot com 2022-11-29 17:54 ` rguenther at suse dot de 2022-11-29 17:58 ` carlosgalvezp at gmail dot com 2022-12-08 10:58 ` cvs-commit at gcc dot gnu.org 2022-12-08 10:59 ` rguenth at gcc dot gnu.org 2023-02-16 10:37 ` carlosgalvezp at gmail dot com 2023-05-08 12:26 ` [Bug tree-optimization/107699] [12/13/14 " rguenth at gcc dot gnu.org 2023-12-15 13:57 ` rguenth at gcc dot gnu.org
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