linux-mips
[Top] [All Lists]

Re: Disabling lwl and lwr instruction generation

To: Richard Hodges <rh@matriplex.com>
Subject: Re: Disabling lwl and lwr instruction generation
From: Zhang Fuxin <fxzhang@ict.ac.cn>
Date: Thu, 13 Mar 2003 10:07:46 -0500
Cc: Ralf Baechle <ralf@linux-mips.org>, Ranjan Parthasarathy <ranjanp@efi.com>, "'linux-mips@linux-mips.org'" <linux-mips@linux-mips.org>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <D9F6B9DABA4CAE4B92850252C52383AB0796823C@ex-eng-corp.efi.com> <20030313014338.C29568@linux-mips.org> <Pine.BSF.4.50.0303121647400.95890-100000@mail.matriplex.com>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.1) Gecko/20020809


Richard Hodges wrote:

On Thu, 13 Mar 2003, Ralf Baechle wrote:

On Wed, Mar 12, 2003 at 10:05:20AM -0800, Ranjan Parthasarathy wrote:

Is there a way to tell gcc to not generate the lwl, lwr instructions?
Gcc will only ever generate these instructions when __attribute__((unaligned))
is used.

I got lwl and lwr from a memcpy() with two void pointers...

I quickly changed those to the (aligned) structure pointers instead, and
then memcpy() changed to ordinary word loads and stores.

So, is somebody starting a toolchain for that new Chinese CPU? :-)

I don't hear about it,but it will happen soon or later:)

We work around lwl/lwr problem by modifying toolchain from H.J. Lu's rh port.

it seems that gcc will explicitly output lwl/lwr for unaligned block copy,in other cases it will generate
ulW macros for gas to handle.





-Richard






<Prev in Thread] Current Thread [Next in Thread>