Re: [PATCH] Fix PR78306

[Jeff Law <law@redhat.com>]

On 11/15/2016 07:58 AM, Richard Biener wrote:
>
> Appearantly for some unknown reason we refuse to inline anything into
> functions calling cilk_spawn.  That breaks fortified headers and
> all other always-inline function calls (intrinsics come to my mind as
> well).
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu, ok for trunk?
>
> Thanks,
> Richard.
>
> 2016-11-15  Richard Biener  <rguenther@suse.de>
>
> 	PR tree-optimization/78306
> 	* ipa-inline-analysis.c (initialize_inline_failed): Do not
> 	inhibit inlining if function calls cilk_spawn.
> 	(can_inline_edge_p): Likewise.
>
> 	* gcc.dg/cilk-plus/pr78306.c: New testcase.
Balaji added this check explicitly. There should be tests in the 
testsuite (spawnee_inline, spawner_inline) which exercise that code.

I suspect those bits were taken into the trunk as-is and were missed 
during the review cycle.  The actual tests look to only verify that we 
don't crash at runtime -- they do nothing to verify we get the correct 
results.

My understanding of Cilk is that it should be possible to literally 
define away the Cilk keywords and the resulting program should "just 
work".  It would seem that if we must avoid inlining to get proper 
behavior around a cilk_spawn then cilk_spawn is perhaps more fragile 
than it ought to be.


Jeff