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Date: Thu, 10 Aug 2006 10:05:14 -0400
From: Chuck Swiger <cswiger@mac.com>
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To: =?ISO-8859-1?Q?Dag-Erling_Sm=F8rgrav?= <des@des.no>
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Cc: freebsd-fs@FreeBSD.org, freebsd-current@FreeBSD.org,
	freebsd-geom@FreeBSD.org
Subject: Re: GJournal (hopefully) final patches.
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Dag-Erling Smørgrav wrote:
> Markus Trippelsdorf <markus@trippelsdorf.de> writes:
>> Adding -fno-strict-aliasing to the CFLAGS of sbin/fsck_ffs/Makefile
>> solved the problem for now.
> 
> -fno-strict-aliasing does not solve anything, it just prevents the
> compiler from telling you about bugs in your code.

It also prevents the compiler's optimizer from assuming that a pointer 
dereference may impact datatypes of other sizes.

Since there exists C code that changes, say, int16_t's or int32_t's one byte 
at a time, using that flag prevents the compiler from generating buggy 
executables from C sources which do not adhere to the assumptions made by 
"strict aliasing".

-- 
-Chuck