Re: Question about JUMP and LINK

[bill4carson <bill4carson at gmail dot com>]

On 2012å03æ16æ 23:23, Dave Hylands wrote:
> Hi Bill,
>
> On Thu, Mar 15, 2012 at 11:52 PM, bill4carson<bill4carson@gmail.com>  wrote:
> > Hi, All
> >
> > The question is simple.
> >
> > func_a {
> >
> >     call func_b
> > }
> >
> > func_b {
> >
> >     call func_c
> > }
> >
> > func_c {
> >
> >         return to func_a
> > }
> >
> >
> > The compiler I use let func_c to return func_a directly, IOW when func_b
> > calls func_c, it use JUMP, other JUMP and LINK, and it's definitely not
> > a question about inline or noinline.
> >
> > So can I ask why how to let the compiler use JUMP and LINK when func_b
> > calls func_c?
>
> This is called Tail Optimization. See
> http://c2.com/cgi/wiki?TailCallOptimization
>
> gcc (I'm using 4.4.4) with -O3 does this.
Thanks for the information.


> > If it's not the right place to post this, sorry for the noise.
>
> The kernel newbies list is probably not the right place (since this
> has nothing to do with the kernel). It also has nothing to do with
> binutils. It's a gcc optimization, so picking a gcc list would
> probably be more appropriate.

--
I am a slow learner
but I will keep trying to fight for my dreams!

--bill