[LLVMdev] PHI nodes

Tanya Lattner lattner at apple.com
Tue Apr 20 10:46:18 PDT 2010


On Apr 20, 2010, at 2:46 AM, Orgoton Baberek wrote:

> Nick Lewycky <nicholas <at> mxc.ca> writes:
> 
>> 
>> Pedro Ferreira wrote:
>>> Hello,
>>> 
>>> I am trying to write a LLVM backend for a school project using only
>>> custom code (as with the CBackend) and I'm having difficulties
>>> handling the PHI nodes from LLVM asm code. Is there any pass we can do
>>> before my custom Module Pass to remove the PHI nodes?
>> 
>> Try the Reg2Mem pass. http://llvm.org/docs/Passes.html#reg2mem
>> 
>> Nick
>> 
> 
> 
> Interesting, didn't know about that one. That node however introduces wierd
> instructions on the code.

What do you mean by weird instructions?

> Although i think it might be easier if we could prevent the generation of such
> nodes. Is there any specific option we can use?
> 

No. If there was, it would look like the output of Reg2Mem anyways.

-Tanya






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