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Date: Tue, 31 Jan 1995 07:30:22 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199501302030.HAA09887@godzilla.zeta.org.au>
To: jc@irbs.com, mtaylor@gateway.cybernet.com
Subject: Re: disable structure packing with gcc?
Cc: freebsd-hackers@freefall.cdrom.com
Sender: hackers-owner@FreeBSD.org
Precedence: bulk

>> I'm writing a byte-swapping routine for structures in gcc 2.4.5 (FreeBSD
>> 1.1.5.1).  gcc insists on packing structures, and I do not fully understand
>> the packing method it uses.
>> 
>> How can I turn off structure packing (to get to single byte alignment)?

s/packing/padding/.

>gcc 2.X  supports #pragma pack() directives if it is compiled with
>-DHANDLE_SYSV_PRAGMA.  I have several cross-compilers with this option
>enabled and they DTRT.

gcc.2.[4-5] supports __attribute__ ((packed)) declarations in all
configurations.  This feature is even more unportable than #praga pack.

Bruce