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Date: Mon, 22 Aug 2005 16:30:00 -0000
From: Richard Henderson <rth@redhat.com>
To: Paolo Bonzini <paolo.bonzini@lu.unisi.ch>
Cc: Leehod Baruch <LEEHOD@il.ibm.com>, GCC Development <gcc@gcc.gnu.org>
Subject: Re: Question about merging two instructions.
Message-ID: <20050822163037.GA31598@redhat.com>
Mail-Followup-To: Richard Henderson <rth@redhat.com>,
	Paolo Bonzini <paolo.bonzini@lu.unisi.ch>,
	Leehod Baruch <LEEHOD@il.ibm.com>,
	GCC Development <gcc@gcc.gnu.org>
References: <OFA172C2D5.7846BC73-ONC2257065.00497D7B-C2257065.004A8FF3@il.ibm.com> <4309D517.7040106@lu.unisi.ch>
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On Mon, Aug 22, 2005 at 03:37:27PM +0200, Paolo Bonzini wrote:
> It may still make sense changing the default case of 
> simplify_replace_rtx to invoke replace_rtx rather than returning x.  But 
> this is unrelated, because nobody is currently passing a SET to 
> simplify_replace_rtx (only expressions), and you should do the same: 
> *you* said you want to replace on the RHS, so you really want to invoke 
> simplify_replace_rtx on the RHS.

Agreed.  If you're concerned about the LHS, use reg_overlap_mentioned_p
and abort the optimization.


r~