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From: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: [RFC/PATCH] Make powerpc64 use __thread for per-cpu variables
Date: Fri, 12 May 2006 01:41:32 +0200
To: Richard Henderson <rth@twiddle.net>
Cc: linux-arch@vger.kernel.org, linuxppc-dev@ozlabs.org,
	Paul Mackerras <paulus@samba.org>, "David S. Miller" <davem@davemloft.net>,
	linux-kernel@vger.kernel.org
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>> Would an asm clobber of GPR13 in the schedule routines (or a wrapper
>> for them, or whatever) work?
>
> No.  The address is cse'd symbolically long before the r13
> reference is exposed.

Current GCC won't ever do that over a (non-local, non-inlinable)
function call though.  _Current_ GCC.


Segher