Re: [PATCH] x86: add missed clobber for 32-bit memmove

[Jike Song]

On Sat, Oct 18, 2008 at 12:35 AM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> Jike Song wrote:
>>
>> memmove() is implemented by inline assembly. It calls std at first
>> and cld at last, but EFLAGS still should be clobbered.
>
> gcc always treats EFLAGS as clobbered on x86.  The "cc" clobber is needed on
> some platforms, but is a noop on x86.

No wonder there are inline asms that clobbered eflags/rflags but
without declaring them as clobbered. Thanks for your information.

It turns out that I need to read through the gcc x86 back-end as long
as I want to be a Linux/x86 developer, right? That sounds
discouraging:)

-- 
Thanks,
Jike
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