public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/57488] [4.9 regression] loop terminates early at -O3 Date: Thu, 20 Jun 2013 11:19:00 -0000 [thread overview] Message-ID: <bug-57488-4-y6JnVSFu8I@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-57488-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57488 --- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> --- -fno-tree-partial-pre fixes this, partial PRE figures that v on entry to the l loop is invariant in the outer loop. Thus it does tem = v; for (k = 1; k >= 0; k--) { int l; bar (0); v = tem; for (l = 1; l < 5; l++) { int m; for (m = 6; m; m--) { v--; *ps = *pc; } } } effectively cutting the number of decrements in half.
next prev parent reply other threads:[~2013-06-20 11:19 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-05-31 19:41 [Bug tree-optimization/57488] New: " dhazeghi at yahoo dot com 2013-05-31 20:50 ` [Bug tree-optimization/57488] " jakub at gcc dot gnu.org 2013-06-03 8:38 ` rguenth at gcc dot gnu.org 2013-06-20 11:19 ` rguenth at gcc dot gnu.org [this message] 2013-06-20 13:04 ` rguenth at gcc dot gnu.org 2013-06-24 10:22 ` rguenth at gcc dot gnu.org 2013-10-23 11:59 ` rguenth at gcc dot gnu.org 2013-10-23 11:59 ` rguenth at gcc dot gnu.org
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=bug-57488-4-y6JnVSFu8I@http.gcc.gnu.org/bugzilla/ \ --to=gcc-bugzilla@gcc.gnu.org \ --cc=gcc-bugs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).