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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/101145] New: niter analysis fails for until-wrap condition Date: Mon, 21 Jun 2021 08:59:46 +0000 [thread overview] Message-ID: <bug-101145-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101145 Bug ID: 101145 Summary: niter analysis fails for until-wrap condition Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: rguenth at gcc dot gnu.org Target Milestone: --- unsigned foo(unsigned val, unsigned start) { unsigned cnt = 0; for (unsigned i = start; i > val; ++i) cnt++; return cnt; } fails niter analysis. At least for the following variant the number of iterations should be about UINT_MAX - start. unsigned foo(unsigned val, unsigned start) { unsigned cnt = 0; if (start > val) { unsigned i = start; do { cnt++; } while (++i > val); } return cnt; }
next reply other threads:[~2021-06-21 8:59 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-21 8:59 rguenth at gcc dot gnu.org [this message] 2021-06-21 9:02 ` [Bug tree-optimization/101145] " rguenth at gcc dot gnu.org 2021-06-24 15:39 ` amker at gcc dot gnu.org 2021-06-25 1:28 ` guojiufu at gcc dot gnu.org 2021-06-25 1:34 ` amker at gcc dot gnu.org 2021-06-25 10:13 ` guojiufu at gcc dot gnu.org 2021-06-25 12:24 ` guojiufu at gcc dot gnu.org 2021-06-26 2:53 ` amker at gcc dot gnu.org 2021-07-01 3:42 ` guojiufu at gcc dot gnu.org 2021-08-25 8:39 ` cvs-commit at gcc dot gnu.org 2021-08-31 13:27 ` cvs-commit at gcc dot gnu.org 2021-09-17 10:01 ` marxin at gcc dot gnu.org 2021-12-01 19:59 ` cvs-commit at gcc dot gnu.org
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