This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: [PATCH] PR35371 GCSE loses track of REG_POINTER attribute

From: Jeff Law <law at redhat dot com>
To: Peter Bergner <bergner at vnet dot ibm dot com>
Cc: Richard Sandiford <rsandifo at nildram dot co dot uk>, gcc-patches <gcc-patches at gcc dot gnu dot org>, "H.J. Lu" <hjl at lucon dot org>
Date: Mon, 03 Mar 2008 12:15:25 -0700
Subject: Re: [PATCH] PR35371 GCSE loses track of REG_POINTER attribute
References: <20080225222624.GA26857@vervain.rchland.ibm.com> <87skzfzkvh.fsf@firetop.home> <1204052325.7014.2.camel@otta> <47C467BA.1090308@redhat.com> <1204240130.7376.16.camel@otta>

Peter Bergner wrote:

On Tue, 2008-02-26 at 12:25 -0700, Jeff Law wrote:

If someone wanted to get real ambitious they could revamp the
REG_POINTER propagation code as well.  It's amazingly simplistic
at the moment (see regclass.c:reg_scan_mark_refs).  Basically it
fails to propagate for any register destination that is set more
than once, even if all the sets are of the proper form for
propagating REG_POINTER.


Do you mean fix it up and then call it from more than just CSE?
Currently, the only call to reg_scan() isn't in a location that
will help me.

No.  I mean make it smarter.  If you read the code it's amazingly
simplistic and punts propagation of REG_POINTER for any pseudo
that is set more than once.

It shouldn't be terribly difficult to build a simple propagation
engine that handles multiple sets.

Jeff

Follow-Ups:
- Re: [PATCH] PR35371 GCSE loses track of REG_POINTER attribute
  - From: Peter Bergner

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]