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From: "kazu at cs dot umass dot edu" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/11877] gcc should use xor trick with -Os Date: Wed, 31 Dec 2003 21:39:00 -0000 [thread overview] Message-ID: <20031231211929.21877.qmail@sources.redhat.com> (raw) In-Reply-To: <20030810154728.11877.debian-gcc@lists.debian.org> ------- Additional Comments From kazu at cs dot umass dot edu 2003-12-31 21:19 ------- (set (mem:DI ...) (const_int 0)) is split into two moves in SImode after reload. We could delay the split until after peephole2. In peephole2, if a scratch reg is available, load 0 into it with XOR and then copy that reg to two mem:SI locations. Reduced to: void foo (long long *p) { *p = 0; } The reduction from 13 bytes down to 7 bytes sounds impressive. My proposed solution would still leave two XORs, though. -- What |Removed |Added ---------------------------------------------------------------------------- CC| |kazu at cs dot umass dot edu AssignedTo|unassigned at gcc dot gnu |kazu at cs dot umass dot edu |dot org | Status|NEW |ASSIGNED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11877
next prev parent reply other threads:[~2003-12-31 21:19 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top 2003-08-10 15:47 [Bug target/11877] New: " debian-gcc at lists dot debian dot org 2003-08-10 16:03 ` [Bug target/11877] " pinskia at gcc dot gnu dot org 2003-08-23 1:15 ` dhazeghi at yahoo dot com 2003-12-31 21:39 ` kazu at cs dot umass dot edu [this message] 2004-01-04 6:55 ` kazu at cs dot umass dot edu 2004-01-04 7:50 ` pinskia at gcc dot gnu dot org 2004-02-01 17:24 ` kazu at cs dot umass dot edu 2004-03-25 19:16 ` kazu at cs dot umass dot edu 2005-08-12 5:28 ` pinskia at gcc dot gnu dot org 2005-08-12 5:28 ` pinskia at gcc dot gnu dot org [not found] <bug-11877-5724@http.gcc.gnu.org/bugzilla/> 2006-01-05 20:22 ` dann at godzilla dot ics dot uci dot edu [not found] <bug-11877-4@http.gcc.gnu.org/bugzilla/> 2021-06-21 7:56 ` cvs-commit at gcc dot gnu.org 2021-06-22 8:18 ` cvs-commit at gcc dot gnu.org 2021-07-10 8:24 ` roger at nextmovesoftware dot com 2021-07-26 18:54 ` pinskia at gcc dot gnu.org 2021-07-26 18:57 ` pinskia at gcc dot gnu.org 2021-07-26 22:20 ` pinskia at gcc dot gnu.org
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