Re: Status of CONFIG_FORCED_INLINING?

[Adrian Bunk <bunk@stusta.de>]

On Thu, May 24, 2007 at 11:32:07AM -0700, Roland Dreier wrote:
>  > The problem is that inline functions in headers are intended to be 
>  > called from different C files.
>  > 
>  > gcc might not inline it in the C files where it is called more than 
>  > once.
>  > 
>  > But it will always inline it if it's called only once.
>  > 
>  > One of both will be suboptimal, but from gcc's perspective it was 
>  > optimal.
> 
> Yes, we could probably get huge benefits from --combine and/or
> -fwhole-program to let gcc see more than one file at a time.
> 
> But I still don't see the issue with having gcc do the best it can on
> each file it compiles.  If you force the inlining, then that means
> that on files where not inlining was better, you've forced gcc to
> generate worse code.  (I don't see how not inlining could be locally
> better on a single file but globally worse, even though it generated
> better code on each compiled file)

Can you give examples where for one function it differs between 
different C files whether it should be inlined or not?

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