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Re: fold_builtin_memcpy cannot optimize <retval>?

From: Mark Mitchell <mark at codesourcery dot com>
To: law at redhat dot com
Cc: Jakub Jelinek <jakub at redhat dot com>, Richard Guenther <rguenth at tat dot physik dot uni-tuebingen dot de>, gcc at gcc dot gnu dot org
Date: Fri, 21 Jan 2005 10:03:53 -0800
Subject: Re: fold_builtin_memcpy cannot optimize <retval>?
Organization: CodeSourcery, LLC
References: <Pine.LNX.4.44.0501211136170.16464-100000@alwazn.tat.physik.uni-tuebingen.de> <20050121105158.GH4777@sunsite.mff.cuni.cz> <1106330271.30575.265.camel@localhost.localdomain>

Jeffrey A Law wrote:

I'm not an expert on the differences in the semantics of POINTER_TYPE
and REFERENCE_TYPE, but I do know that I've been treating them as
effectively the same.

The only difference is that a REFERENCE_TYPE object can never be NULL. Other than that, they are identical. (In C++, you cannot assign to a reference, but that is expressed by TREE_READONLY on the object.)

I think that it makes sense to use POINTER_TYPE_P almost everywhere in the middle-end. The other choices is to introduce explicit NOP_EXPRs to do the conversions -- but that's just a waste of memory, in my opinion.

--
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com
(916) 791-8304

Follow-Ups:
- Re: fold_builtin_memcpy cannot optimize <retval>?
  - From: Paul Brook

References:
- fold_builtin_memcpy cannot optimize <retval>?
  - From: Richard Guenther
- Re: fold_builtin_memcpy cannot optimize <retval>?
  - From: Jakub Jelinek
- Re: fold_builtin_memcpy cannot optimize <retval>?
  - From: Jeffrey A Law

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