[LLVMdev] LVLM runtime optimization during LLVM Analysis Passes.

[Philip Reames]

Doing this "in llvm-IR" is almost certainly the wrong approach. Decide 
on a profiling mechanism for your *source* language (instrumentation, 
sampling, etc..).  Modify your IR generation to include profiling 
information.  Modify your runtime to recompile/relink "hot" functions.

The only internal to LLVM parts are improving profile guided optimizations.

Philip

On 04/09/2014 06:15 PM, Sri wrote:
> Hi Philip
>            I understood what you have said here. Basically you are 
> saying , identifying the hot path during the runtime and compile those 
> section again would be hard in llvm-IR. I am currently looking forward 
> to do some analysis work on adaptive mechanism for llvm JIT so that , 
> we can see some improvement when we see that high frequent function 
> call during the run time. Do you have any idea , which approach would 
> be more convenient to start this work.
> Thanks.
>
> Regards
> Sri.
> On 04/09/2014 08:58 PM, Philip Reames wrote:
>> On the optimization side, profile guided opts are currently somewhat 
>> limited.  However, a couple of folks are actively working in this area.
>>
>> All of the runtime support (i.e. recompiling, linking, etc..) is out 
>> of scope for LLVM.  Since this is the majority of the work required 
>> to support PGO in a JIT, that's probably your answer.
>>
>> p.s. I'm answering what I *think* your question was.  If this doesn't 
>> help, you'll need to clarify your question.
>>
>> Philip
>>
>> On 04/07/2014 01:20 PM, Sri wrote:
>>> Hi
>>>        Does current llvm support dynamic optimization level for 
>>> generated llvm IR which means , is it possible to monitor some 
>>> function's execution pattern during the runtime and apply different 
>>> optimization level for particular function using LLVM Analysis Passes.
>>>
>>> Thanks
>>>
>>> Regards
>>> Sri.
>>>
>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
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>>
>

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