Re: Question about missing "cld" in x86 string assembly code

From: nai.xia
Date: Thu Dec 22 2011 - 10:52:44 EST




On 2011å12æ18æ 02:39, Linus Torvalds wrote:
On Sat, Dec 17, 2011 at 9:08 AM, Brian Gerst<brgerst@xxxxxxxxx> wrote:

The i386 ELF ABI states "The direction flag must be set to the
ââforwardââ (that is, zero) direction before entry and upon exit from
a function." Therefore it can be assumed to be clear, unless
explicitly set.

The exception, of course, being bootup, fault and interrupt handlers,
and after we've called out to foreign code (ie BIOS).

Yeah, I think I see these cld's now. Thanks for the answers!


Nai

So there *are* a few cld's sprinkled around, they are just fairly rare.

Linus
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