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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/105329] Bogus restrict warning when assigning 1-char string literal to std::string Date: Thu, 21 Apr 2022 11:15:51 +0000 [thread overview] Message-ID: <bug-105329-4-w5mIHtRGgl@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-105329-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105329 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Ever confirmed|0 |1 CC| |amacleod at redhat dot com Component|c++ |tree-optimization Status|UNCONFIRMED |NEW Keywords| |diagnostic, | |missed-optimization, | |needs-bisection Last reconfirmed| |2022-04-21 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- It warns about __builtin_memcpy (_140, _29, _28); in <bb 15> [local count: 14831835]: __nleft_49 = (const size_type) _48; __builtin_memcpy (_22, "5", __nleft_49); _28 = 1 - __nleft_49; _29 = _22 + 1; _140 = _22 + __nleft_49; __builtin_memcpy (_140, _29, _28); pretmp_145 = MEM[(const struct basic_string *)s_2(D)]._M_dataplus._M_p; goto <bb 19>; [100.00%] the block is guarded with if (_22 >= &MEM <const char[2]> [(void *)"5" + 1B]) goto <bb 10>; [50.00%] else goto <bb 11>; [50.00%] if (_22 <= "5") goto <bb 12>; [50.00%] else goto <bb 13>; [50.00%] <bb 13> [local count: 22472477]: _48 = _22 - "5"; if (_48 == 1) goto <bb 14>; [34.00%] else goto <bb 15>; [66.00%] so we're taking the path where "5" is not one character in size. We should have somehow simplified this. It looks like a missed jump-threading, not sure if we were able to catch this with the forward threader or the old VRP.
next prev parent reply other threads:[~2022-04-21 11:15 UTC|newest] Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-04-21 7:41 [Bug c++/105329] New: " boris at kolpackov dot net 2022-04-21 11:15 ` rguenth at gcc dot gnu.org [this message] 2022-04-21 20:50 ` [Bug tree-optimization/105329] " amacleod at redhat dot com 2022-04-21 22:51 ` amacleod at redhat dot com 2022-04-22 10:31 ` aldyh at gcc dot gnu.org 2022-04-25 17:50 ` amacleod at redhat dot com 2022-04-25 22:25 ` mattias.ellert at physics dot uu.se 2022-04-26 15:04 ` [Bug tree-optimization/105329] [12 Regression] Bogus restrict warning when assigning 1-char string literal to std::string since r12-3347-g8af8abfbbace49e6 marxin at gcc dot gnu.org 2022-05-02 12:44 ` [Bug tree-optimization/105329] [12/13 " rguenth at gcc dot gnu.org 2022-05-02 12:45 ` rguenth at gcc dot gnu.org 2022-05-02 12:46 ` rguenth at gcc dot gnu.org 2022-05-02 12:57 ` rguenth at gcc dot gnu.org 2022-05-02 13:22 ` rguenth at gcc dot gnu.org 2022-05-02 13:33 ` jakub at gcc dot gnu.org 2022-05-02 13:58 ` jakub at gcc dot gnu.org 2022-05-02 16:04 ` jakub at gcc dot gnu.org 2022-05-02 19:43 ` jakub at gcc dot gnu.org 2022-05-02 22:08 ` redi at gcc dot gnu.org 2022-05-06 3:59 ` mattias.ellert at physics dot uu.se 2022-05-06 8:33 ` jakub at gcc dot gnu.org 2022-05-20 8:13 ` rguenth at gcc dot gnu.org 2022-07-26 12:05 ` jakub at gcc dot gnu.org 2022-09-12 9:37 ` cvs-commit at gcc dot gnu.org 2022-09-29 15:19 ` msebor at gcc dot gnu.org 2022-09-30 16:55 ` dan at stahlke dot org 2022-09-30 17:16 ` dan at stahlke dot org 2023-02-21 18:30 ` 49tbwddbqeazdawz at chyen dot cc 2023-02-21 19:28 ` redi at gcc dot gnu.org 2023-02-22 17:28 ` 49tbwddbqeazdawz at chyen dot cc 2023-02-22 17:52 ` redi at gcc dot gnu.org 2023-02-24 14:10 ` wielkiegie at gmail dot com 2023-05-08 12:24 ` [Bug tree-optimization/105329] [12/13/14 " rguenth at gcc dot gnu.org
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