[polly] r256199 - Add option to assume single-loop scops with sufficient compute are profitable

Tobias Grosser via llvm-commits llvm-commits at lists.llvm.org
Tue Dec 22 05:51:40 PST 2015


On 12/22/2015 02:31 PM, Johannes Doerfert wrote:
> On 12/22, Tobias Grosser wrote:
>> On 12/22/2015 12:09 PM, Johannes Doerfert wrote:
>>> In this spirit I would like to change the default heuristic to:
>>>    #loops + #blocks > 2
>>> as that is the condition under which we can perform "by default enabled"
>>> optimizations.
>>
>> If this results in run-time benefits for at least one application we care
>> about and no run-time regressions, then I think this is fine.
>>
>> (I care a little less about compile-time regressions. The more we expose
>> them, the more visible they become and the more likely we are
>> to add improvements here).
> It will at least trigger distribution on Spec2006 hmmer. I think that's
> worth it.

Sure. Just would prefer to have a look at the performance data at least 
for LNT and SPEC. Most likely we are lucky and it is purely beneficial.

Best,
Tobias



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