[LLVMdev] Question to Chris

[Tanya Lattner]

Ok, here are a few suggestions and comments:

1) LLVM has the capabilities to do everything that you are trying to  
re-implement.
2) Have you looked at the C backend? It recreates loops. It may not  
create "for" loops but you can hack on it to do that.
3) The way you are converting out of SSA is wrong. You will suffer  
from lost copies. You should look at using demotePHI(). see include/ 
llvm/Transforms/Utils/Local.h
4) LLVM will  compute your trip counts for you, use LoopInfo. You  
need to be in SSA form to do this.

-Tanya

On Feb 1, 2008, at 11:51 PM, Seung Jae Lee wrote:

> Dear Prof.Adve and Bill,
>
> I deeply appreciate your comments and concerns.
> (Please forgive my late response. I've tried some more cases to  
> make this issue)
>
> As Prof.Adve mentioned, I need to explain exactly what my problem  
> is, but I have no good ability that I can explain it in this plain  
> text space.
>
> For this reason, I made a .pdf file and linked it as follows:
>
> https://netfiles.uiuc.edu/lee225/www/MakingLoops.pdf
>
> Would you please explain to me how I can access to this problem in  
> a better way if you can figure out?
>
> Once again, I really appreciate your time and favor, Bill and  
> Prof.Adve.
>
> Truly yours,
> Seung J. Lee
>
>
> ---- Original message ----
>> Date: Mon, 28 Jan 2008 09:39:52 -0600
>> From: "Vikram S. Adve" <vadve at uiuc.edu>
>> Subject: Re: [LLVMdev] Question to Chris
>> To: LLVM Developers Mailing List <llvmdev at cs.uiuc.edu>
>>
>> Bill,
>>
>> Depending on what Seung's problem is, converting *out* of SSA form  
>> may
>> actually be the wrong thing to do.  Seung needs to explain exactly
>> problem he is unable solve using SSA form.
>>
>> --Vikram
>> http://www.cs.uiuc.edu/~vadve
>> http://llvm.org/
>>
>>
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