From: Andrew Cagney <ac131313@cygnus.com>
To: Richard.Earnshaw@arm.com
Cc: twall@oculustech.com, gdb@sources.redhat.com
Subject: Re: packing/unpacking 4-octet longs
Date: Wed, 05 Dec 2001 10:42:00 -0000 [thread overview]
Message-ID: <3C0E6A8C.9040306@cygnus.com> (raw)
In-Reply-To: <200112051645.QAA06737@cam-mail2.cambridge.arm.com>
> I'm not aware of this affecting the ARM (except in that FPA format doubles
> and long doubles always have the word with the exponent at the lowest
> address, but there's nothing in the IEEE FP specs that says this is
> invalid). In particular, storing a word, or multi-word, at an unaligned
> address does not change the order of bytes in memory, so
> memcpy(unaligned_address, aligned_address, sizeof(some_word))
> does not require diddling with the internal order (or have I misunderstood
> the problem?)
That was a useful manual :-) See 5-21 where it explains that a
misaligned 32bit access gets rotated before it is stored :-/
enjoy,
Andrew
next prev parent reply other threads:[~2001-12-05 18:42 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-12-04 5:44 Timothy Wall
2001-12-05 8:26 ` Andrew Cagney
2001-12-05 8:46 ` Richard Earnshaw
2001-12-05 10:11 ` Lars Brinkhoff
2001-12-05 10:42 ` Andrew Cagney [this message]
2001-12-06 2:03 ` Richard Earnshaw
2001-12-05 9:31 ` Timothy Wall
2001-12-05 10:03 ` Andrew Cagney
2001-12-05 10:20 ` Timothy Wall
2001-12-05 10:49 ` Andrew Cagney
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