> On 2 Jul 2026, at 09:00, Richard Biener <[email protected]> wrote:
> 
> On Wed, 1 Jul 2026, Jeffrey Law wrote:
> 
>> 
>> 
>> On 7/1/2026 9:43 AM, Kyrylo Tkachov wrote:
>>>> What I would suggest would be to look at the code we generate for the
>>>> split-paths tests before/after removal and make sure we're not missing
>>>> something.  The tests, more likely than not, test that split-paths
>>>> triggered rather than looking at the final assembly codes.
>>> So out of all split-path tests only one shows a difference with
>>> -fsplit-paths vs -fno-split-paths: split-paths-6.c where -fno-split-paths
>>> gives +3 aarch64 instructions, but this is a downstream artifact.
>>> In the source:
>>> void givehelp (int interactive)
>>> {
>>>   if (interactive)
>>>     while ((--((_impure_ptr->_stdin))->_r < 0
>>>                ? __srget_r (_impure_ptr, _impure_ptr->_stdin)
>>>                 : (int) (*((_impure_ptr->_stdin))->_p++)) != ' ‘);
>>> }
>>> 
>>> -fsplit-paths triggers once but the duplication is later remerged but the
>>> edge probabilities end up different and then loop rotation ends up making
>>> different layout decisions.
>>> So I don’t think it’s a very deliberate effect.
>> Yea, that's sounds more like a random downstream effect than something
>> intentional.  I don't really recall split-path-6, though a reasonable
>> assumption would be that I was playing around with the original patch and
>> included some tests I found when experimenting with the patch's behavior.
> 
> Can we preserve testcases as compile-only btw?  Some might have been
> introduced for ICEs, some for overall expected optimization (with
> no path splitting).
> 

You mean put them in the torture suite without the scans for expected 
dump/assembly?
Thanks,
Kyrill

> Richard.
> 
>> 
>> Jeff
>> 
>> 
> 
> -- 
> Richard Biener <[email protected]>
> SUSE Software Solutions Germany GmbH,
> Frankenstrasse 146, 90461 Nuernberg, Germany;
> GF: Jochen Jaser, Andrew McDonald; (HRB 36809, AG Nuernberg)


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