public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "steven at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/17387] Redundant instructions in loop optimization Date: Thu, 27 Jan 2005 01:36:00 -0000 [thread overview] Message-ID: <20050127013618.26460.qmail@sourceware.org> (raw) In-Reply-To: <20040909235415.17387.hjl@lucon.org> ------- Additional Comments From steven at gcc dot gnu dot org 2005-01-27 01:36 ------- My first suspicion was the `register' keyword, but that's not it: -------------------------------------------------- extern unsigned int S[]; extern unsigned int state[]; unsigned int foo () { unsigned int t; int j; t=0; for (j=0; j<16; j+=4) { t = state[j + 0] ^= S[t]; t = state[j + 1] ^= S[t]; } return t; } -------------------------------------------------- --> -------------------------------------------------- foo: .LFB2: xorl %eax, %eax movl $4, %ecx movl $state, %edx .p2align 4,,7 .L2: mov %eax, %eax movl S(,%rax,4), %eax xorl (%rdx), %eax movl %eax, (%rdx) mov %eax, %eax <-- bah! movl S(,%rax,4), %eax xorl 4(%rdx), %eax movl %eax, 4(%rdx) addq $16, %rdx decl %ecx jne .L2 rep ; ret .LFE2: -------------------------------------------------- -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17387
next prev parent reply other threads:[~2005-01-27 1:36 UTC|newest] Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2004-09-09 23:54 [Bug c/17387] New: " hjl at lucon dot org 2004-09-10 0:36 ` [Bug rtl-optimization/17387] " pinskia at gcc dot gnu dot org 2004-09-10 2:50 ` law at gcc dot gnu dot org 2004-09-10 8:05 ` pinskia at gcc dot gnu dot org 2004-09-10 9:53 ` hubicka at gcc dot gnu dot org 2004-09-10 23:22 ` pinskia at gcc dot gnu dot org 2004-09-11 19:55 ` rakdver at gcc dot gnu dot org 2004-11-27 20:49 ` pinskia at gcc dot gnu dot org 2005-01-23 13:36 ` steven at gcc dot gnu dot org 2005-01-24 18:17 ` hjl at lucon dot org 2005-01-24 18:53 ` pinskia at gcc dot gnu dot org 2005-01-27 1:27 ` steven at gcc dot gnu dot org 2005-01-27 1:36 ` steven at gcc dot gnu dot org [this message] 2005-01-27 1:43 ` steven at gcc dot gnu dot org 2005-01-27 4:03 ` hjl at lucon dot org 2005-01-27 6:05 ` rth at gcc dot gnu dot org 2005-01-27 7:14 ` stevenb at suse dot de 2005-01-27 10:14 ` steven at gcc dot gnu dot org 2005-01-27 10:27 ` steven at gcc dot gnu dot org 2005-01-27 10:28 ` steven at gcc dot gnu dot org 2005-01-27 13:36 ` pinskia at gcc dot gnu dot org 2005-09-29 3:44 ` pinskia at gcc dot gnu dot org [not found] <bug-17387-682@http.gcc.gnu.org/bugzilla/> 2006-01-15 20:30 ` pinskia at gcc dot gnu dot org 2006-02-27 23:55 ` hjl at lucon dot org 2007-04-20 20:58 ` steven at gcc dot gnu dot org 2007-04-20 21:10 ` steven at gcc dot gnu dot org 2007-05-25 20:32 ` steven at gcc dot gnu dot 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=20050127013618.26460.qmail@sourceware.org \ --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).