Re: [PATCH, PR 54394] Compute loops when generating inline summaries

[Jan Hubicka <hubicka at ucw dot cz>]

> Hi,
> 
> the patch below fixes PR 54394.  The problem is that since revision
> 190346 we depend on bb->loop_father being non-NULL to get loop_depth.
> However, with loops not computed, the loop_father is NULL, loop_depth
> is thus considered zero and call graph edges out of such BB can be
> considered much cooler, leading to inlining regressions.
> 
> This patch fixes that by recomputing loops whenever optimizing, not
> only for loop bounds hints.  We might put the computation elsewhere or
> do it only under more restrictive circumstances, but I believe that
> after rev. 190346 we have to do it.  In particular, I am not sure
> whether we had (semi)correct loop_depths when doing early inlining or
> not, this patch re-calculates it for early inliner too.
> 
> Bootstrapped and tested on x86_64-linux, fixes fatigue run-time on
> an x86_64-linux and i686-linux for me.  What do you think?
> 
> Thanks,
> 
> Martin
> 
> 
> 2012-08-29  Martin Jambor  <mjambor@suse.cz>
> 
> 	PR middle-end/54394
> 	* ipa-inline-analysis.c (estimate_function_body_sizes): Compute
> 	dominance info and loops whenever optimizing.
> 
> 
> Index: src/gcc/ipa-inline-analysis.c
> ===================================================================
> --- src.orig/gcc/ipa-inline-analysis.c
> +++ src/gcc/ipa-inline-analysis.c
> @@ -2102,6 +2102,11 @@ estimate_function_body_sizes (struct cgr
>    info->conds = 0;
>    info->entry = 0;
>  
> +  if (optimize)

This is OK. I think you can also skip thi computation for early inlining
where we don't do any hints, so probably if (optimize && !early)

Honza