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From: "aldyh at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/104475] [12 Regression] Wstringop-overflow + atomics incorrect warning on dynamic object Date: Thu, 03 Mar 2022 14:00:53 +0000 [thread overview] Message-ID: <bug-104475-4-9pr5wdKAbr@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-104475-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104475 Aldy Hernandez <aldyh at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |amacleod at redhat dot com --- Comment #3 from Aldy Hernandez <aldyh at gcc dot gnu.org> --- This isn't the threader but VRP/ranger. What happens is that the threader isolates the path, making it easier for VRP to see the equivalence, and then CCP4 folds the constant into the problematic call. This is from the .ccp4 pass: Folding statement: __atomic_or_fetch_4 (pretmp_29, 64, 0); Folded into: __atomic_or_fetch_4 (184B, 64, 0); In VRP2 the ranger is folding: Folding statement: pretmp_29 = &MEM[(struct __atomic_base *)_1 + 184B]._M_i; Folded into: pretmp_29 = 184B; The ranger is determining that _1 is 0 because it has determined that since _2 is 0 on the 2->3 edge, so is _1, as m_mutex is the first field of _1: =========== BB 2 ============ Imports: _1 Exports: _1 _2 _2 : _1(I) <bb 2> [local count: 1073741824]: _1 = this_10(D)->d; _2 = &_1->m_mutex; MEM[(struct __as_base &)&lock] ={v} {CLOBBER}; if (_2 != 0B) goto <bb 5>; [90.00%] else goto <bb 3>; [10.00%] 2->5 (T) _1 : struct QFutureInterfaceBasePrivate * [1B, +INF] 2->5 (T) _2 : struct QMutex * [1B, +INF] 2->3 (F) _1 : struct QFutureInterfaceBasePrivate * [0B, 0B] 2->3 (F) _2 : struct QMutex * [0B, 0B] Andrew, how/where is that we relate _1 and _2 here? I can't seem to find it. My gut feeling is that special casing anything in the ranger for this is wrong.
next prev parent reply other threads:[~2022-03-03 14:00 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-02-09 19:37 [Bug c++/104475] New: " thiago at kde dot org 2022-02-09 20:14 ` [Bug tree-optimization/104475] [12 Regression] " pinskia at gcc dot gnu.org 2022-02-09 23:48 ` msebor at gcc dot gnu.org 2022-02-16 14:56 ` jakub at gcc dot gnu.org 2022-03-03 14:00 ` aldyh at gcc dot gnu.org [this message] 2022-03-03 16:09 ` amacleod at redhat dot com 2022-03-03 17:55 ` amacleod at redhat dot com 2022-03-04 14:47 ` amacleod at redhat dot com 2022-03-09 13:13 ` rguenth at gcc dot gnu.org 2022-03-12 9:39 ` aldyh at gcc dot gnu.org 2022-03-23 12:47 ` rguenth at gcc dot gnu.org 2022-03-23 17:23 ` aldyh at gcc dot gnu.org 2022-05-06 8:32 ` [Bug tree-optimization/104475] [12/13 " jakub at gcc dot gnu.org 2022-07-26 12:59 ` rguenth at gcc dot gnu.org 2022-12-05 15:50 ` rguenth at gcc dot gnu.org 2022-12-05 16:36 ` thiago at kde dot org 2022-12-06 8:17 ` rguenth at gcc dot gnu.org 2022-12-06 9:11 ` rguenth at gcc dot gnu.org 2022-12-06 10:22 ` cvs-commit at gcc dot gnu.org 2022-12-06 10:26 ` rguenth at gcc dot gnu.org 2022-12-06 18:03 ` thiago at kde dot org 2022-12-07 9:46 ` rguenth at gcc dot gnu.org 2022-12-07 9:48 ` rguenth at gcc dot gnu.org 2022-12-07 9:49 ` rguenth at gcc dot gnu.org 2022-12-07 9:54 ` rguenth at gcc dot gnu.org 2022-12-07 11:25 ` rguenth at gcc dot gnu.org 2023-01-17 17:37 ` jason at gcc dot gnu.org 2023-05-08 12:23 ` [Bug tree-optimization/104475] [12/13/14 " rguenth at gcc dot gnu.org 2023-09-18 9:19 ` aph at gcc dot gnu.org 2023-09-18 10:04 ` rguenth at gcc dot gnu.org
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