[LLVMdev] Specifying Additional Compilation Passes to lli

Evan Cheng evan.cheng at apple.com
Tue Sep 16 09:30:22 PDT 2008


On Sep 16, 2008, at 8:44 AM, Thomas B. Jablin wrote:

> Evan,
> So, if I understand you correctly, the design you have in mind is  
> to: create a PassManager, pass it to the JIT on construction, and  
> modify runJITOnFunction to run the second PassManager on the  
> Function being jit'd before running the codegen PassManager. Thanks.

Optimiztions should be done before JIT, right? Why not run the  
optimizations (using the second PM) on the function that's scheduled  
for JIT before? Perhaps I am not understanding what you are trying to  
do.

Evan

>
> Tom
>
> ----- Original Message -----
> From: "Evan Cheng" <evan.cheng at apple.com>
> To: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>
> Sent: Tuesday, September 16, 2008 2:38:30 AM GMT -05:00 US/Canada  
> Eastern
> Subject: Re: [LLVMdev] Specifying Additional Compilation Passes to lli
>
>
> On Sep 15, 2008, at 9:56 AM, Thomas B. Jablin wrote:
>
>> Evan,
>> My overall goal is to support dynamic optimization in LLVM.  In
>> order to do so, I must gather profiling information at runtime, then
>> recompile the profiled functions. Currently, I'm just adding and
>> removing calls into my profiler in a custom pass.  What is the
>> advantage of giving the JIT a second profile manager over my current
>> implementation? Thanks.
>> Tom
>
> It's just a cleaner design. There are well defined pass manager,
> executionengine, and JIT api's. We don't want to unnecessarily extend
> them. JITState PM controls the codegen passes. If you want to add LLVM
> level optimization passes, you can simple use a separate PM to run  
> them.
>
> Evan
>
>>
>>
>> ----- Original Message -----
>> From: "Evan Cheng" <evan.cheng at apple.com>
>> To: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>
>> Sent: Monday, September 15, 2008 12:46:16 PM GMT -05:00 US/Canada
>> Eastern
>> Subject: Re: [LLVMdev] Specifying Additional Compilation Passes to  
>> lli
>>
>> Hi Tom,
>>
>> I don't think this is the right approach. May I ask you what passes
>> you are trying to add? If you just want to run a number of llvm level
>> optimization passes, the right approach is to add your own pass
>> manager instead.
>>
>> Evan
>>
>> On Sep 11, 2008, at 10:30 AM, Thomas B. Jablin wrote:
>>
>>> Hi,
>>>
>>> I'm interested in specifying some additional passes to the JIT via
>>> the command-line. The enclosed patch allows lli to take compiler
>>> passes as command-line arguments in the same way opt does. This is
>>> my first submission, so any comments, criticisms, or observations
>>> would be very welcome. Thanks.
>>>
>>> Tom
>>> Jablin
>>> <
>>> PassArgumentsForLLI
>>> .diff>_______________________________________________
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>>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>
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