public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "ramana at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/59535] [4.9 regression] -Os code size regressions for Thumb1/Thumb2 with LRA Date: Thu, 19 Dec 2013 09:26:00 -0000 [thread overview] Message-ID: <bug-59535-4-crCUrUugjV@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-59535-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59535 Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2013-12-19 CC| |ramana at gcc dot gnu.org Ever confirmed|0 |1 --- Comment #11 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> --- (In reply to Vladimir Makarov from comment #9) > (In reply to Richard Earnshaw from comment #5) > I think major problem is in wrong alternative choices as thumb lo/hi reg > usage is complicated. That is probably going to be the reason. > > I take this bug very seriously. If I cannot fix it till end of Jan (sorry, > it is a vacation time), probably we should switch to reload pass for thumb. Thanks very much for taking this so seriously. > > To be honest, I don't know why 12 is not fixed. It results in using > 12 by IRA and bigger code when even reload is used. I believe it > should fixed too. According to the ABI r12 is a caller saved register. Am I correct in understanding that we are taking out a caller-saved register to allow for lra to be able to choose other low regs and thereby prevent movements to and from r12 ? Taking out r12 will have performance implications, so any change here needs to be benchmarked very carefully on all cores with Thumb1 and Thumb2 to make sure that the impact. Additionally we shouldn't be needing to do this in ARM state, so this patchlet as it stands is not enough. regards Ramana
next prev parent reply other threads:[~2013-12-19 9:26 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-12-17 9:30 [Bug rtl-optimization/59535] New: [4.9 regression] -Os code size regressions for Thumb1/Thumb2 (with LRA)? rearnsha at gcc dot gnu.org 2013-12-17 9:32 ` [Bug rtl-optimization/59535] " rearnsha at gcc dot gnu.org 2013-12-17 9:53 ` rearnsha at gcc dot gnu.org 2013-12-17 11:14 ` [Bug rtl-optimization/59535] [4.9 regression] -Os code size regressions for Thumb1/Thumb2 with LRA rearnsha at gcc dot gnu.org 2013-12-17 11:22 ` rearnsha at gcc dot gnu.org 2013-12-17 22:47 ` yvan.roux at linaro dot org 2013-12-18 9:29 ` yvan.roux at linaro dot org 2013-12-18 16:06 ` vmakarov at gcc dot gnu.org 2013-12-18 22:14 ` vmakarov at gcc dot gnu.org 2013-12-19 9:26 ` ramana at gcc dot gnu.org [this message] 2013-12-19 9:54 ` ramana at gcc dot gnu.org 2013-12-19 12:58 ` rguenth at gcc dot gnu.org 2013-12-19 17:12 ` rearnsha at gcc dot gnu.org 2013-12-19 21:42 ` vmakarov at gcc dot gnu.org 2014-01-03 14:44 ` rearnsha at gcc dot gnu.org 2014-02-14 16:19 ` vmakarov at gcc dot gnu.org 2014-06-12 7:47 ` fredrik.hederstierna@securitas-direct.com 2014-06-13 11:44 ` ramana.radhakrishnan at arm dot com 2014-09-03 6:17 ` zhenqiang.chen at arm dot com 2014-09-03 7:45 ` fredrik.hederstierna@securitas-direct.com
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-59535-4-crCUrUugjV@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).