Re: [Chapel-gsoc] GSoC 2018 Compiling Chapel with LLVM/Polly

[Michael F. <mfe...@cr...>]

Hi -

Thanks for your interest in the Chapel+Polly GSoC project.

Chapel includes LLVM support but doesn't even build with Polly on master right now.

My initial experiments with Polly (which convinced me that the integration was nontrivial) relied on the commit here:

https://github.com/mppf/chapel/commit/3d95622aa5fcac506133f8fed893346a40a095eb

which might help with building and linking the Chapel compiler with a manually checked out Polly.

It might be more worth your time to learn about Polly and how to say apply it to file containing LLVM IR.
I think the project significantly involves figuring out why Polly wasn't identifying Chapel loops (at least it didn't when I tried it last). To do so will require some understanding of what Polly is doing.

I've attached a Chapel program that has loops we might like Polly to recognize. Of course it might make sense to start with a simpler program.
Anyway, with the program I attached, if you have a Chapel compiler built with CHPL_LLVM=llvm then you can run:

  chpl loop-opt-examples.chpl --llvm --llvm-print-ir=test10d --llvm-print-ir-stage=full > ir.ll

Here test10d is just the name of a function we're dumping to LLVM IR.

Then you should be able to perform other LLVM IR transformations (such as manually invoking Polly) on the resulting ir.ll file.

Cheers,

-michael
    
    My name is Sahil Yerawar. I am a third-year Computer Science Bachelor Student currently studying at IIT-Hyderabad. I have been working under Prof Ramakrishna Upadrasta[1] in the field of compilers since last summer.
    
    I have basic familiarity with LLVM infrastructure and took a course in our college( namely Introduction to Compiler Engineering).
    
    
    I am willing to apply for this year's GSoC under Polly Labs with the topic "Compiling Chapel with LLVM/Polly".
    
    
    I am wondering what is the appropriate starting point to initiate the analysis of this topic. More specifically which part of the Chapel codebase do you recommend to view to learn more about the current integration status of Polly with Chapel? I would deeply
     appreciate it.
    
    Thank You
    Sahil Yerawar
    Btech 3rd Year Undergraduate Student
    IIT-Hyderabad
    
    
    
    [1] https://www.iith.ac.in/~ramakrishna/
    
    ‌
    
    -- 
    Thanking you
    Sahil Yerawar
    Btech 3rd Year Undergraduate.