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From: David Edelsohn <dje@watson.ibm.com>
To: Andrew Haley <aph@redhat.com>
Cc: Gabriel Paubert <paubert@iram.es>,
	        Sergei Poselenov <sposelenov@emcraft.com>,
	gcc@gcc.gnu.org,         "'rt'" <rt@emcraft.com>
Subject: Re: powercp-linux cross GCC 4.2 vs GCC 4.0.0: -Os code size regression? [Emcraft #11717]
Date: Sat, 19 Jan 2008 16:35:00 -0000	[thread overview]
Message-ID: <200801191624.m0JGOvlM024140@makai.watson.ibm.com> (raw)
In-Reply-To: <4791F924.6020603@redhat.com>

>>>>> Andrew Haley writes:

Andrew> I suspect that the real reason for the change in save/restore is because
Andrew> not using lmw/stmw is faster.  That's just a guess though.  gcc could probably
Andrew> be fixed to use ldmw/stmw if -Os is used.

Andrew> Anyway, now we've found something specific this is for the ppc maintainer to comment.

	GCC does use load/store multiple and load/store string
instructions if -Os is used, but not when the sequence is broken up by a
fixed register.

David

  reply	other threads:[~2008-01-19 16:26 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-16 11:24 powercp-linux cross GCC 4.2 vs GCC 4.0.0: -Os code size regression? Sergei Poselenov
2008-01-16 12:15 ` Duncan Sands
2008-01-16 12:19   ` Sergei Poselenov
2008-01-16 12:35     ` Duncan Sands
2008-01-16 13:20     ` Andrew Haley
2008-01-16 13:17 ` Andrew Haley
2008-01-16 15:59   ` Sergei Poselenov
2008-01-16 17:10     ` Andrew Haley
2008-01-16 17:14       ` Sergei Poselenov
2008-01-16 19:36         ` Andrew Haley
2008-01-17 14:52           ` powercp-linux cross GCC 4.2 vs GCC 4.0.0: -Os code size regression? [Emcraft #11717] Sergei Poselenov
2008-01-17 15:11             ` Richard Guenther
2008-01-17 18:27             ` Gabriel Paubert
2008-01-19 16:26               ` Andrew Haley
2008-01-19 16:35                 ` David Edelsohn [this message]
2008-01-19 16:51                   ` Andrew Haley
2008-01-19 19:10                     ` David Edelsohn
2008-01-21 17:25                     ` powercp-linux cross GCC 4.2 vs GCC 4.0.0: -Os code size regression? (filed bug 34903)[Emcraft #11717] Sergei Poselenov
2008-01-17 12:14     ` powercp-linux cross GCC 4.2 vs GCC 4.0.0: -Os code size regression? Gabriel Paubert
2008-01-17 12:47       ` Sergei Poselenov
2008-01-17 13:10         ` Gabriel Paubert

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