Re: [uml-devel] arch/um/sys-i386/setjmp.S: useless #ifdef _REGPARM's?

From: Adrian Bunk
Date: Tue Aug 22 2006 - 15:25:54 EST


On Tue, Aug 22, 2006 at 01:42:33PM -0400, Jeff Dike wrote:
> On Tue, Aug 22, 2006 at 06:07:41PM +0200, Adrian Bunk wrote:
> > I didn't find a corresponding open bug in the gcc Bugzilla.
> >
> > Can someone verify whether it's still present, and if yes, open a gcc
> > bug?
>
> Yup, it's easy enough to check.

Thanks.

> > It's set globally in arch/i386/Makefile:
> > cflags-$(CONFIG_REGPARM) += -mregparm=3
>
> IIRC, there used to be functions explicitly declared as __regparam or
> something, and that's what I was grepping for. Does this turn every
> function with three or fewer parameters into a regparam function?
>...

With -mregparm=3, the first up to three parameters that aren't bigger
than an integer are passed in registers instead of on the stack.

> Jeff

cu
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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