[llvm-dev] [Newbie Question] Compute a schedule region's scheduled cycles.

[陳韋任 via llvm-dev]

+Matthias.

2017-06-10 5:06 GMT+08:00 陳韋任 <chenwj.cs97g at g2.nctu.edu.tw>:

> Also you might need to check use PostRASchedulerList or
> PostMachineScheduler,
> PostRASchedulerList is considered deprecated as mentioned in [1].
>
> [1] http://lists.llvm.org/pipermail/llvm-dev/2017-April/112348.html
>
> HTH,
> chenwj
>
>
> 2017-06-10 4:03 GMT+08:00 陳韋任 <chenwj.cs97g at g2.nctu.edu.tw>:
>
>> Not saying I am totally understand how thing works, but I think you're
>> misleading
>> by the DAG in the class name ScheduleDAGInstrs. I only see MachineInstrs
>> there, no SDNode. And the comment of ScheduleDAGInstrs says,
>>
>>   /// A ScheduleDAG for scheduling lists of MachineInstr.
>>
>> One place mentioning DAG is relate to constructing the dependency of
>> SUnit,
>> i.e., Value2SUsMap.
>>
>> Regards,
>> chenwj
>>
>>
>>
>> 2017-06-09 23:34 GMT+08:00 Xunhao Li (Alan, CRC) via llvm-dev <
>> llvm-dev at lists.llvm.org>:
>>
>>> Hi All,
>>>
>>>
>>>
>>> I am trying to construct a small optimization based on ScheduleDAGInstrs
>>> that does the following:
>>>
>>> 1.      Find candidate nodes in the DAG, and speculatively modify the
>>> node (nodes).
>>>
>>> 2.      After modification, try to compute the scheduled cycles of the
>>> region.
>>>
>>> 3.      If the cycle number improves, go back to 1. to find the next
>>> candidate node.
>>>
>>>
>>>
>>> I am thinking using SchedulePostRATDList’s top-down algorithm to
>>> calculate the cycles needed for the region’s execution. However, it
>>> decomposes the schedule DAG while calculating the cycles --- In my case I
>>> want to keep the DAG so that we don’t need to construct it again in the
>>> following steps.
>>>
>>>
>>>
>>> So my question is: is there a way (or API) to calculate the scheduled
>>> cycles needed for the region, without touching the DAG? Or is there a
>>> better way to do so in a ScheduleDAG? Did I missed something?
>>>
>>>
>>>
>>> Thanks in advance. Much appreciated.
>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>>>
>>
>>
>> --
>> Wei-Ren Chen (陳韋任)
>> Homepage: https://people.cs.nctu.edu.tw/~chenwj
>>
>
>
>
> --
> Wei-Ren Chen (陳韋任)
> Homepage: https://people.cs.nctu.edu.tw/~chenwj
>



-- 
Wei-Ren Chen (陳韋任)
Homepage: https://people.cs.nctu.edu.tw/~chenwj
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