[llvm-dev] Open Project : Inter-procedural Register Allocation [GSoC 2016]

[C Bergström via llvm-dev]

>From the research and code I've seen - Doesn't this break regalloc
down into a global and location allocation strategy? (maybe I'm
remembering incorrectly)

On Wed, Mar 23, 2016 at 12:04 PM, Mehdi Amini via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
>
>> On Mar 22, 2016, at 6:04 PM, Matthias Braun via llvm-dev <llvm-dev at lists.llvm.org> wrote:
>>
>> No need to apologize this thread surely deserved some answers :)
>>
>> From my perspective this project sounds doable. I would expect the register allocation parts to be not too hard: I imagine this being just distilling a new clobber regmask after allocating a function. I would expect the challenging (or annoying) part to get a machine module pass (or a similar mechanism to influence the order in which functions are processed) and a callgraph in the backend.
>
> I have a very tiny patch that wrap the backend in a CGSCC pass manager, which will achieve what is needed here I believe: i.e. running CodeGen for every callee before any caller.
> I can rebase it if anyone is interested.
>
> --
> Mehdi
>
>
>
>> So this might end up being more pass manager / infrastructure work than register allocation.
>>
>> I'd be happy to answer detail questions or give guidance on the register allocation aspects.
>>
>> - Matthias
>>
>>> On Mar 22, 2016, at 5:27 PM, Sanjoy Das <sanjoy at playingwithpointers.com> wrote:
>>>
>>> Apologies: didn't notice how old this thread is before replying.
>>>
>>> On Tue, Mar 22, 2016 at 5:24 PM, Sanjoy Das
>>> <sanjoy at playingwithpointers.com> wrote:
>>>> Hi Vivek,
>>>>
>>>> [+CC Matthias, Quentin]
>>>>
>>>> Inter-procedural register allocation can be a big win, but my estimate
>>>> is that it will be challenging to complete within one summer unless
>>>> you're already familiar with LLVM's register allocator.
>>>>
>>>> I've CC'ed some people who can give you some more detailed information.
>>>>
>>>> -- Sanjoy
>>>>
>>>>
>>>> On Tue, Feb 9, 2016 at 9:17 PM, vivek pandya via llvm-dev
>>>> <llvm-dev at lists.llvm.org> wrote:
>>>>> Hello Community,
>>>>>
>>>>> I would like to know status of the project and also importance of it. If the
>>>>> project is still open I would like to work on GSoC 2016 proposal for
>>>>> Inter-procedural Register Allocation, in that case please also suggest
>>>>> possible mentor or let me know if anyone is willing to be mentor for this.
>>>>>
>>>>> Sincerely,
>>>>> Vivek Pandya
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> LLVM Developers mailing list
>>>>> llvm-dev at lists.llvm.org
>>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Sanjoy Das
>>>> http://playingwithpointers.com
>>>
>>>
>>>
>>> --
>>> Sanjoy Das
>>> http://playingwithpointers.com
>>
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