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From: Segher Boessenkool <segher@kernel.crashing.org>
Subject: Re: Saving to 32 bits of GPRs in signal context
Date: Tue, 29 May 2007 16:31:57 +0200
To: Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
Cc: Steve Munroe <sjmunroe@us.ibm.com>,
	linuxppc-dev list <linuxppc-dev@ozlabs.org>,
	Paul Mackerras <paulus@samba.org>, Anton Blanchard <anton@samba.org>
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>  > We don't need another ABI change to powerpc32 (still recovering=20
> from the
>  > -msecure-plt ABI change) and WE DONT NEED a 3rd ABI.
>  >
>  > ABI changes ripple everywhere (not just GCC/GLIBC) including all=20
> debuggers
>  > and performance tools. Believe me you really don't want this.
>
> Fully agreed. =A0This may have gotten lost in the discussion thread, =
but=20
> what
> Ben originally proposed was *not* an ABI change, for exactly that=20
> reason.
> We simply want to allow strictly local use of 64-bit registers for
> performance optimization purposes, while still fully complying with
> the 32-bit ABI.

Some stuff gets added to the user version of the signal
frame; is that not an ABI change?  Quite possibly a
(supposedly) compatible change, but a change anyway.


Segher