public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "steven at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/55623] [ARM] GCC should not prefer long dependency chains, they inhibit performance on superscalar processors Date: Sun, 09 Dec 2012 12:13:00 -0000 [thread overview] Message-ID: <bug-55623-4-AwUC8pRBF8@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-55623-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55623 Steven Bosscher <steven at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |steven at gcc dot gnu.org --- Comment #6 from Steven Bosscher <steven at gcc dot gnu.org> 2012-12-09 12:13:03 UTC --- Can you try using -frename-registers? Without vs with -frename-registers: mov r3, r0, lsr #2 mov r3, r0, lsr #2 add r3, r3, r0, lsr #1 | add r1, r3, r0, lsr #1 add r3, r3, r0, lsr #3 | add r2, r1, r0, lsr #3 add r3, r3, r0, lsr #4 | add ip, r2, r0, lsr #4 add r3, r3, r0, lsr #5 | add r3, ip, r0, lsr #5 add r3, r3, r0, lsr #6 | add r1, r3, r0, lsr #6 add r3, r3, r0, lsr #7 | add r2, r1, r0, lsr #7 add r3, r3, r0, lsr #8 | add ip, r2, r0, lsr #8 add r3, r3, r0, lsr #9 | add r3, ip, r0, lsr #9 add r3, r3, r0, lsr #10 | add r1, r3, r0, lsr #10 add r3, r3, r0, lsr #11 | add r2, r1, r0, lsr #11 add r3, r3, r0, lsr #12 | add ip, r2, r0, lsr #12 add r3, r3, r0, lsr #13 | add r3, ip, r0, lsr #13 add r3, r3, r0, lsr #14 | add r1, r3, r0, lsr #14 add r3, r3, r0, lsr #15 | add r2, r1, r0, lsr #15 add r3, r3, r0, lsr #16 | add ip, r2, r0, lsr #16 add r3, r3, r0, lsr #17 | add r3, ip, r0, lsr #17 add r3, r3, r0, lsr #18 | add r1, r3, r0, lsr #18 add r3, r3, r0, lsr #19 | add r2, r1, r0, lsr #19 add r3, r3, r0, lsr #20 | add ip, r2, r0, lsr #20 add r3, r3, r0, lsr #21 | add r3, ip, r0, lsr #21 add r3, r3, r0, lsr #22 | add r1, r3, r0, lsr #22 add r3, r3, r0, lsr #23 | add r2, r1, r0, lsr #23 add r0, r3, r0, lsr #24 | add r0, r2, r0, lsr #24 bx lr bx lr
next prev parent reply other threads:[~2012-12-09 12:13 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-12-09 10:00 [Bug tree-optimization/55623] New: " siarhei.siamashka at gmail dot com 2012-12-09 10:01 ` [Bug tree-optimization/55623] " siarhei.siamashka at gmail dot com 2012-12-09 10:48 ` [Bug middle-end/55623] " pinskia at gcc dot gnu.org 2012-12-09 11:19 ` siarhei.siamashka at gmail dot com 2012-12-09 11:22 ` siarhei.siamashka at gmail dot com 2012-12-09 11:36 ` steven at gcc dot gnu.org 2012-12-09 12:13 ` steven at gcc dot gnu.org [this message] 2012-12-09 12:15 ` steven at gcc dot gnu.org 2012-12-10 9:47 ` rguenth at gcc dot gnu.org 2012-12-11 16:33 ` ramana 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-55623-4-AwUC8pRBF8@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).