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From: "muecker at gwdg dot de" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug lto/112716] New: LTO optimization with struct of variable ssize Date: Sun, 26 Nov 2023 17:46:53 +0000 [thread overview] Message-ID: <bug-112716-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112716 Bug ID: 112716 Summary: LTO optimization with struct of variable ssize Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: lto Assignee: unassigned at gcc dot gnu.org Reporter: muecker at gwdg dot de CC: marxin at gcc dot gnu.org Target Milestone: --- The following code using a GNU extension gets miscompiled due to incorrect aliasing assumptions with -flto and -O2: gcc -flto -O2 y.c y2.c -DT1="int[n]" -DT2="int[n]" // y.c void bar(void*); [[gnu::noinline,gnu::noipa]] int foo(void *p, void *q) { int n = 5; struct foo { int x; typeof(T1) y; } *p2 = p; p2->x = 1; bar(q); return p2->x; } int main() { int n = 5; void *p = __builtin_malloc(sizeof(struct foo { int x; typeof(T1) y; })); if (!p) return 0; if (2 != foo(p, p)) __builtin_abort(); return 0; } // y2 void bar(void* q) { int n = 5; struct foo { int x; typeof(T2) y; } *q2 = q; q2->x = 2; }
next reply other threads:[~2023-11-26 17:46 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-11-26 17:46 muecker at gwdg dot de [this message] 2023-11-26 17:54 ` [Bug lto/112716] " pinskia at gcc dot gnu.org 2023-11-26 18:17 ` uecker at gcc dot gnu.org 2023-11-26 18:26 ` sjames at gcc dot gnu.org 2023-11-27 8:13 ` [Bug lto/112716] LTO optimization with struct with variable size rguenth at gcc dot gnu.org 2023-11-27 14:00 ` muecker at gwdg dot de 2023-11-27 14:26 ` rguenther at suse dot de 2023-11-27 15:47 ` uecker at gcc dot gnu.org 2023-11-28 8:02 ` rguenth at gcc dot gnu.org 2023-11-28 15:19 ` muecker at gwdg dot de
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