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From: "jv244 at cam dot ac dot uk" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/38306] [4.4 Regression] 15% slowdown w.r.t. 4.3 of computational kernel on some architectures
Date: Wed, 11 Feb 2009 19:25:00 -0000	[thread overview]
Message-ID: <20090211192507.357.qmail@sourceware.org> (raw)
In-Reply-To: <bug-38306-6642@http.gcc.gnu.org/bugzilla/>



------- Comment #13 from jv244 at cam dot ac dot uk  2009-02-11 19:25 -------
(In reply to comment #12)
>   /* For -O2 and beyond, turn off -fschedule-insns by default.  It tends to
>      make the problem with not enough registers even worse.  */
> 
> As risky as this may be (for performance, not correctness), what about changing
> "if (level > 1)" to "if (level == 2)"?  And what about enabling it on x86-64?

But even on x86-64 this seems to lead to ICEs (see PR38403). 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38306


  parent reply	other threads:[~2009-02-11 19:25 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-28 16:02 [Bug target/38306] New: [4.4 Regression] 15% slowdown of computational kernel jv244 at cam dot ac dot uk
2008-11-28 16:03 ` [Bug target/38306] " jv244 at cam dot ac dot uk
2008-11-28 16:25 ` pinskia at gcc dot gnu dot org
2008-11-30 11:40 ` rguenth at gcc dot gnu dot org
2008-11-30 11:49 ` rguenth at gcc dot gnu dot org
2008-11-30 16:18 ` jv244 at cam dot ac dot uk
2008-11-30 16:27 ` jv244 at cam dot ac dot uk
2008-11-30 16:40 ` rguenth at gcc dot gnu dot org
2008-12-03 19:04 ` [Bug target/38306] [4.4 Regression] 15% slowdown w.r.t. 4.3 of computational kernel on some architectures steven at gcc dot gnu dot org
2008-12-03 21:29 ` hjl dot tools at gmail dot com
2008-12-04 16:12 ` jv244 at cam dot ac dot uk
2008-12-05 12:18 ` rguenth at gcc dot gnu dot org
2008-12-06 15:38 ` steven at gcc dot gnu dot org
2008-12-06 18:56 ` jv244 at cam dot ac dot uk
2009-02-11 19:00 ` bonzini at gnu dot org
2009-02-11 19:25 ` jv244 at cam dot ac dot uk [this message]
2009-04-21 15:59 ` [Bug target/38306] [4.4/4.5 " jakub at gcc dot gnu dot org
2009-07-22 10:35 ` jakub at gcc dot gnu dot org
2009-09-01  6:56 ` jv244 at cam dot ac dot uk
2009-09-01  8:54 ` bonzini at gnu dot org
2009-09-01  9:13 ` jv244 at cam dot ac dot uk
2009-09-01  9:18 ` jv244 at cam dot ac dot uk
2009-10-15 12:50 ` jakub at gcc dot gnu dot org
2010-01-21 13:19 ` jakub at gcc dot gnu dot org
2010-04-30  9:00 ` [Bug target/38306] [4.4/4.5/4.6 " jakub at gcc dot gnu dot org

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