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From: Jan Hubicka <jh@suse.cz>
To: Richard Henderson <rth@redhat.com>,
	David Edelsohn <dje@watson.ibm.com>,
	Bernd Schmidt <bernds@redhat.co.uk>, Jan Hubicka <jh@suse.cz>,
	gcc@gcc.gnu.org, degger@fhm.edu
Subject: Re: cant_combine_insn_p hard_reg->reg moves
Date: Wed, 26 Dec 2001 04:13:00 -0000	[thread overview]
Message-ID: <20011226131056.A29813@atrey.karlin.mff.cuni.cz> (raw)
In-Reply-To: <20011225231251.A6306@redhat.com>

> On Tue, Dec 25, 2001 at 09:02:42PM -0500, David Edelsohn wrote:
> > Could cant_combine_insn_p test for hard regs with either REG_EQUIV
> > involving computations of ARG_POINTER_REGNUM or FUNCTION_VALUE_REGNO_P?
> 
> No.  IIRC, this was introduced specifically to cure problems with
> argument registers.  x86 regparm is the biggest offender here.
> 
> The only solutions are a new register allocator, or post-reload
> cleanup optimizations such as -fcprop-registers.  Anything else
> risks keeping a hard register live too long.

BTW what is the situation of cprop-registers? Will it get enabled for 3.1
once the bugs are tracked down. Are the problems serisous.

Honza
> 
> 
> r~

  reply	other threads:[~2001-12-26 12:11 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-12-17 10:30 rs6000: Trivial code generation stupidity degger
2001-12-17 10:31 ` David Edelsohn
2001-12-17 12:54   ` degger
2001-12-17 13:12     ` David Edelsohn
2001-12-17 13:21     ` David Edelsohn
2001-12-18  3:53       ` Analysis try (was: Re: rs6000: Trivial code generation stupidity) degger
2001-12-25 23:13         ` cant_combine_insn_p hard_reg->reg moves David Edelsohn
2001-12-26  1:18           ` Richard Henderson
2001-12-26  4:13             ` Jan Hubicka [this message]
2001-12-26 11:25               ` Richard Henderson

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