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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/56151] [4.8 Regression] Performance degradation after r194054 on x86 Atom.
Date: Mon, 04 Feb 2013 12:04:00 -0000 [thread overview]
Message-ID: <bug-56151-4-6zk3XYawkA@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-56151-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56151
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org,
| |uros at gcc dot gnu.org
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-02-04 12:03:52 UTC ---
Well, we already have peephole2s for MEM op= ARG (the TARGET_READ_MODIFY_WRITE
guarded peephole2s), the reason why it doesn't trigger in this case is that ARG
in this case ends up being a MEM, and
MEM op= MEM2 isn't a valid insn:
(insn 95 94 96 11 (set (reg:SI 3 bx [orig:135 D.1801 ] [135])
(mem:SI (reg/f:SI 4 si [orig:86 D.1803 ] [86]) [2 *_41+0 S4 A32]))
pr56151.c:32 89 {*movsi_internal}
(nil))
(insn 96 95 97 11 (parallel [
(set (reg:SI 3 bx [orig:135 D.1801 ] [135])
(ior:SI (reg:SI 3 bx [orig:135 D.1801 ] [135])
(mem:SI (plus:SI (mult:SI (reg:SI 6 bp [orig:132 D.1801 ]
[132])
(const_int 4 [0x4]))
(symbol_ref:SI ("setmask") <var_decl
0x7f587927a390 setmask>)) [2 setmask S4 A32])))
(clobber (reg:CC 17 flags))
]) pr56151.c:32 421 {*iorsi_1}
(expr_list:REG_DEAD (reg:SI 6 bp [orig:132 D.1801 ] [132])
(nil)))
(insn 97 96 98 11 (set (mem:SI (reg/f:SI 4 si [orig:86 D.1803 ] [86]) [2 *_41+0
S4 A32])
(reg:SI 3 bx [orig:135 D.1801 ] [135])) pr56151.c:32 89
{*movsi_internal}
(expr_list:REG_DEAD (reg:SI 3 bx [orig:135 D.1801 ] [135])
(expr_list:REG_DEAD (reg/f:SI 4 si [orig:86 D.1803 ] [86])
(nil))))
I guess for temp = MEM; temp op= MEM2; MEM = temp; for temp dead afterwards
(this case), we could as well just add another set of the (up to 3?)
peephole2's, that would transform that into
temp = MEM2;
MEM op= temp;
instead.
next prev parent reply other threads:[~2013-02-04 12:04 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-30 15:18 [Bug tree-optimization/56151] New: " ysrumyan at gmail dot com
2013-01-30 15:20 ` [Bug tree-optimization/56151] " ysrumyan at gmail dot com
2013-01-30 16:04 ` [Bug rtl-optimization/56151] " rguenth at gcc dot gnu.org
2013-01-31 9:24 ` [Bug rtl-optimization/56151] [4.8 Regression] " rguenth at gcc dot gnu.org
2013-02-03 0:46 ` steven at gcc dot gnu.org
2013-02-03 1:05 ` steven at gcc dot gnu.org
2013-02-04 10:34 ` ebotcazou at gcc dot gnu.org
2013-02-04 12:04 ` jakub at gcc dot gnu.org [this message]
2013-02-04 17:14 ` jakub at gcc dot gnu.org
2013-02-04 17:59 ` steven at gcc dot gnu.org
2013-02-04 18:20 ` jakub at gcc dot gnu.org
2013-02-08 15:23 ` rguenth at gcc dot gnu.org
2013-02-08 15:29 ` jakub at gcc dot gnu.org
2013-02-11 15:42 ` jakub at gcc dot gnu.org
2013-02-12 10:38 ` jakub at gcc dot gnu.org
2013-02-12 10:39 ` jakub at gcc dot gnu.org
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