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SubjectRe: [RFC 0/6] x86 tip asm ENTRY,ENDPROC cleanup
Date
On Fri, 13 Feb 2009 16:34:00 -0800, "H. Peter Anvin" <hpa@zytor.com>
said:
> Alexander van Heukelum wrote:
> >
> > Hi Cyrill,
> >
> > I like this direction. If I understand correctly:
> >
> > ENTRY/END or GLOBAL/END for data.
> > ENTRY/ENDPROC or GLOBAL/ENDPROC for functions.
> >
>
> Fine for functions, but it's really not okay to use the same macros for
> data. Furthermore, we need to consider special entry points that don't
> behave like normal functions -- like system call or interrupt entry.
>
> Why? Because if we're compiling with frame pointers, we would like the
> wrapper macros for functions to handle setting up and tearing down the
> frame pointer, at least in the common case.

Hi Peter,

I see. But that would be new behaviour. I would propose to use
completely separate macro's to handle frame-setup code generation,
and keep ENTRY/GLOBAL/END/ENDPROC only for setting metadata and
alignment. I think it's worth it to spell out code-generating
macro's explicitly: there are not that many asm functions, and
quite a few of them would need special handling. I think noone
wants to see an ENDPROC_NOFRAMETEARDOWN ;).

The common-case example would look like this.

GLOBAL(c_callable_function)
ENTER
[asm-code]
LEAVE
ret
ENDPROC(c_callable_function)

Greetings,
Alexander

> -hpa
--
Alexander van Heukelum
heukelum@fastmail.fm

--
http://www.fastmail.fm - I mean, what is it about a decent email service?



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