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From: "mital at mitalashok dot co.uk" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/114937] New: [11 regression] -ftree-vrp optimizes out range check before conditional increment Date: Fri, 03 May 2024 13:41:31 +0000 [thread overview] Message-ID: <bug-114937-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114937 Bug ID: 114937 Summary: [11 regression] -ftree-vrp optimizes out range check before conditional increment Product: gcc Version: 11.4.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: mital at mitalashok dot co.uk Target Milestone: --- https://godbolt.org/z/fdMGWa4nq int f(int x) { const int y = x; if (x != INT_MAX) { ++x; } return (x > y) ? x : 0; } int z = INT_MAX; int main(void) { // Prints INT_MIN when it should print 0 __builtin_printf("%d\n", f(z)); } `f` is miscompiled at `-O1 -ftree-vrp` (also `-O2`) in GCC10/11 to return `x+1` unconditionally. The same happens with `if (x != INT_MIN) --x; return (x < y) ? x : 0;`. This does not happen in GCC9 or GCC12+
next reply other threads:[~2024-05-03 13:41 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-05-03 13:41 mital at mitalashok dot co.uk [this message] 2024-05-03 13:50 ` [Bug tree-optimization/114937] " rguenth at gcc dot gnu.org 2024-05-03 13:54 ` rguenth at gcc dot gnu.org 2024-05-03 14:21 ` mital at mitalashok dot co.uk 2024-05-06 10:50 ` rguenth at gcc dot gnu.org 2024-05-12 10:35 ` mikpelinux at gmail dot com
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