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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/94905] [10/11 Regression] Bogus warning -Werror=maybe-uninitialized Date: Fri, 21 Jan 2022 13:41:52 +0000 [thread overview] Message-ID: <bug-94905-4-Z9r3UyB0B3@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-94905-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94905 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |msebor at gcc dot gnu.org Known to fail| |11.2.1 Known to work| |12.0 Keywords| |needs-bisection Last reconfirmed|2020-09-03 00:00:00 |2022-1-21 Summary|[10/11/12 Regression] Bogus |[10/11 Regression] Bogus |warning |warning |-Werror=maybe-uninitialized |-Werror=maybe-uninitialized --- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> --- The diagnostic is gone with GCC 12 as we there pattern-recognize a memcpy: <bb 2> [local count: 119292720]: insert_axis_len.0_1 = insert_axis_len; ret ={v} {CLOBBER}; ret.rho[0] = insert_axis_len.0_1; __builtin_memcpy (_3(D), &ret, 32); ret ={v} {CLOBBER}; return _3(D); and the partial uninitialized read from it is not what the uninit pass can diagnose (it's memory walking stops at the first may-def, it does not prune must-def ranges). But even with -fno-tree-loop-distribute-patterns -fno-tree-vectorize where we get similar IL as with GCC 11 we do not warn so I wonder what fixed it on trunk (when you add those options).
next prev parent reply other threads:[~2022-01-21 13:41 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-01 16:25 [Bug c++/94905] New: " bug-apl at gnu dot org 2020-05-01 22:41 ` [Bug c++/94905] " glisse at gcc dot gnu.org 2020-05-03 13:28 ` bug-apl at gnu dot org 2020-05-03 15:02 ` asolokha at gmx dot com 2020-05-03 16:10 ` bug-apl at gnu dot org 2020-05-03 16:16 ` bug-apl at gnu dot org 2020-05-03 16:26 ` asolokha at gmx dot com 2020-07-02 15:47 ` moller at mollerware dot com 2020-07-02 15:51 ` moller at mollerware dot com 2020-09-03 18:34 ` manu at gcc dot gnu.org 2020-09-03 18:46 ` [Bug c++/94905] [10 Regression] " manu at gcc dot gnu.org 2021-04-08 16:34 ` [Bug tree-optimization/94905] [10/11 " jason at gcc dot gnu.org 2022-01-21 13:41 ` rguenth at gcc dot gnu.org [this message] 2022-01-21 13:41 ` rguenth at gcc dot gnu.org 2022-01-21 13:43 ` rguenth at gcc dot gnu.org 2022-01-31 14:50 ` marxin at gcc dot gnu.org 2022-04-07 9:39 ` rguenth at gcc dot gnu.org 2022-04-07 10:01 ` jakub at gcc dot gnu.org 2022-06-28 10:40 ` jakub at gcc dot gnu.org 2023-07-07 10:37 ` [Bug tree-optimization/94905] [11 " rguenth at gcc dot gnu.org
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