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From: "qrzhang at gatech dot edu" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/101445] New: wrong code at -O3 on x86_64-linux-gnu Date: Wed, 14 Jul 2021 02:50:09 +0000 [thread overview] Message-ID: <bug-101445-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101445 Bug ID: 101445 Summary: wrong code at -O3 on x86_64-linux-gnu Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: qrzhang at gatech dot edu Target Milestone: --- It appears to be a recent regression. Note that -O2 works fine. $ gcc-trunk -v Supported LTO compression algorithms: zlib gcc version 12.0.0 20210713 (experimental) [master revision 7670b6633e5:d2f95d2ac56:1583b8bff0be7e41aa721dde79f90ca0763bd4e2] (GCC) $ gcc-trunk abc.c ; ./a.out 0 0 0 0 0 0 0 $ gcc-trunk -O3 abc.c ; ./a.out 0 0 3 0 0 0 0 $ cat abc.c int a[35] = {1, 1, 3}; char b = 4; int c, d; int main() { char e; for (; b >= 0; b--) { e = 3; for (; e >= 0; e--) a[b * 5 + e] = a[b * 5 + e + 1]; } for (; c < 5; c++) ; for (; d < 7; d++) printf("%d\n", a[c * d]); }
next reply other threads:[~2021-07-14 2:50 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-14 2:50 qrzhang at gatech dot edu [this message] 2021-07-14 2:50 ` [Bug tree-optimization/101445] " qrzhang at gatech dot edu 2021-07-14 2:58 ` [Bug tree-optimization/101445] [11/12 Regression] " pinskia at gcc dot gnu.org 2021-07-14 6:12 ` rguenth at gcc dot gnu.org 2021-07-14 8:58 ` rguenth at gcc dot gnu.org 2021-07-14 10:31 ` cvs-commit at gcc dot gnu.org 2021-07-14 11:09 ` cvs-commit at gcc dot gnu.org 2021-07-14 11:09 ` rguenth at gcc dot gnu.org
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