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Date: Thu, 17 Jan 2008 16:18:42 -0600
From: Scott Wood <scottwood@freescale.com>
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To: Bruce_Leonard@selinc.com
Subject: Re: Endian problem when accessing internel regs on 8347
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Bruce_Leonard@selinc.com wrote:
>>> __asm__ __volatile__("lwz%U1%X1 %0,%1; twi 0,%0,0; isync" : "=r" (ret) 
> : 
>>> "m" (*addr));
>> They allow the compiler to use update and/or index mode for the memory 
>> operand.
> 
> Well that makes sense, U for update and X for index, but I'm not sure 
> they're applicable to this particular instruction and I'm not sure that 
> the memory operand makes sense for PowerPC.

Why not?

> However, before I post 
> anything that makes me look like I've got hoof-n-mouth disease I'm going 
> to do some more digging.  Is the GCC manual the only "official" 
> documentation on this (I've found a couple of web sites but none of them 
> gun.org)

I believe so... other than the sources, of course. :-)

-Scott