Re: [PATCH] inline: improve internal function costs

["Andre Vieira (lists)" <andre.simoesdiasvieira@arm.com>]

On 05/06/2023 04:04, Jan Hubicka wrote:
>> On Thu, 1 Jun 2023, Andre Vieira (lists) wrote:
>>
>>> Hi,
>>>
>>> This is a follow-up of the internal function patch to add widening and
>>> narrowing patterns.  This patch improves the inliner cost estimation for
>>> internal functions.
>>
>> I have no idea why calls are special in IPA analyze_function_body
>> and so I cannot say whether treating all internal fn calls as
>> non-calls is correct there.  Honza?
> 
> The reason is that normal statements are acconted as part of the
> function body, while calls have their costs attached to call edges
> (so it can be adjusted when call is inlined to otherwise optimized).
> 
> However since internal functions have no cgraph edges, this looks like
> a bug that we do not test it.  (the code was written before internal
> calls was introduced).
>

This sounds to me like you agree with my approach to treat internal 
calls different to regular calls.

> I wonder if we don't want to have is_noninternal_gimple_call that could
> be used by IPA code to test whether cgraph edge should exist for
> the statement.

I'm happy to add such a helper function @richi,rsandifo: you ok with that?
>>
>> The tree-inline.cc change is OK though (you can push that separately).
> The rest is OK too.
> Honza
>>
>> Thanks,
>> Richard.
>>
>>> Bootstrapped and regression tested on aarch64-unknown-linux-gnu.
>>>
>>> gcc/ChangeLog:
>>>
>>>          * ipa-fnsummary.cc (analyze_function_body): Correctly handle
>>>          non-zero costed internal functions.
>>>          * tree-inline.cc (estimate_num_insns): Improve costing for internal
>>>          functions.
>>>
>>
>> -- 
>> Richard Biener <rguenther@suse.de>
>> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg,
>> Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
>> HRB 36809 (AG Nuernberg)