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AW: [PATCH] SVN_UNALIGNED_ACCESS_IS_OK for ppc

From: Markus Schaber <m.schaber_at_codesys.com>
Date: Wed, 22 May 2013 07:58:35 +0000

Hi,

Von: Ben Reser [mailto:ben_at_reser.org]
> On Thu, May 16, 2013 at 2:27 PM, Branko Čibej <brane_at_wandisco.com> wrote:
> > On 16.05.2013 23:12, Mattias Engdegård wrote:
> >> [[[
> >> * subversion/include/svn_types.h:
> >> Set SVN_UNALIGNED_ACCESS_IS_OK for PowerPC.
> >> ]]]
> >
> > At first I thought, "that can't be right!" but it turns out that it is
> > ... somewhat. Only if we're sure that we use that macro for integer
> > access only. Which should be the case.
>
> Added documentation that this is for integer access and audited the existing
> uses of this macro, it's all integer accesses.

Hmm, when checking those places, I'm not sure whether modern compilers
with their auto-vectorizing optimizers really profit from the hand-optimized
code there, or whether that code might rather trouble the optimizer into
generating suboptimal code.

 
> For anyone that's interested on the PowerPC details see:
> http://www.ibm.com/developerworks/library/pa-dalign/

Best regards

Markus Schaber

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Received on 2013-05-22 09:59:19 CEST

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