From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-patches-return-76058-listarch-gcc-patches=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 3422 invoked by alias); 17 Jan 2003 18:25:34 -0000
Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Archive: <http://gcc.gnu.org/ml/gcc-patches/>
List-Post: <mailto:gcc-patches@gcc.gnu.org>
List-Help: <mailto:gcc-patches-help@gcc.gnu.org>
Sender: gcc-patches-owner@gcc.gnu.org
Received: (qmail 3410 invoked from network); 17 Jan 2003 18:25:31 -0000
Received: from unknown (HELO atrey.karlin.mff.cuni.cz) (195.113.31.123)
  by sources.redhat.com with SMTP; 17 Jan 2003 18:25:31 -0000
Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 4018)
	id E5BD24F9AC; Fri, 17 Jan 2003 19:25:30 +0100 (CET)
Date: Fri, 17 Jan 2003 18:25:00 -0000
From: Jan Hubicka <jh@suse.cz>
To: law@redhat.com
Cc: John David Anglin <dave@hiauly1.hia.nrc.ca>,
	roger@www.eyesopen.com, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Fix RTL sharing problem in CSE
Message-ID: <20030117182530.GB20846@atrey.karlin.mff.cuni.cz>
References: <200301171715.h0HHFOL0006221@hiauly1.hia.nrc.ca> <200301171727.h0HHQqIo014525@localhost.redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <200301171727.h0HHQqIo014525@localhost.redhat.com>
User-Agent: Mutt/1.3.28i
X-SW-Source: 2003-01/txt/msg01241.txt.bz2

> In message <200301171715.h0HHFOL0006221@hiauly1.hia.nrc.ca>, "John David Anglin
> " writes:
>  >> > 2003-01-16  Roger Sayle  <roger@eyesopen.com>
>  >> > 
>  >> > 	* cse.c (cse_insn): Avoid RTL sharing when updating the RETVAL
>  >> > 	insn's notes following a substitution inside a libcall.
>  >> 
>  >> This doesn't fix the hppa64 problem.  I will try to investigate further.
>  >
>  >This is the insn that causes the ICE:
>  >
>  >regclass.i.12.loop:
>  >(insn 599 598 600 0000000000000000 (set (reg:DI 263)
>  >        (mult:DI (zero_extend:DI (subreg:SI (reg:DI 262) 4))
>  >	    (zero_extend:DI (subreg:SI (reg/v:DI 157) 4)))) -1 (nil)
>  >	(nil))
>  >
>  >regclass.i.13.bypass:
>  >(insn 599 598 600 21 0000000000000000 (set (reg:DI 263)
>  >        (mult:DI (zero_extend:DI (subreg:SI (const_int -44 [0xffffffffffffffd
>  >4]) 4))
>  >	    (zero_extend:DI (subreg:SI (reg/v:DI 157) 4)))) -1 (nil)
>  >	(nil))
>  >
>  >regclass.i.19.life:
>  >(insn 599 598 600 18 0000000000000000 (set (reg:DI 263)
>  >        (mult:DI (zero_extend:DI (subreg:SI (const_int -44 [0xffffffffffffffd
>  >4]) 4))
>  >	    (zero_extend:DI (subreg:SI (reg/v:DI 157) 4)))) -1 (nil)
>  >    (expr_list:REG_DEAD (reg/v:DI 157)
>  >	(nil)))
>  >
>  >The ICE occurs because combine tries to simplify it and it can't because
>  >of the constant substitution in the regclass.i.13.bypass pass.  It would
>  >seem to me that the subreg should be simplified when the substitution for
>  >DI 262 is made.  After that, the mode information is lost.
> Agreed.
When replacement is made by validate_replace_reg, this is done
automatically.  I think bypass pass should use it consistently...

Honza
> 
> jeff