[LLVMdev] memory-to-memory instructions

Bagel bagel99 at gmail.com
Tue Aug 4 14:14:14 PDT 2009


On Tue Aug 4 13:53:16 CDT 2009, Evan Cheng wrote:
> The difficulty with matching these kind of patterns is to avoid cyclic  
> dag (tm). IsLegalAndProfitableToFold is probably checking for such  
> possibilities and rejected the match. X86 isel goes to great pain to  
> pre-process the dag to allow (store (op (load))) instructions to  
> match. You can take a look at it.

I will look at the x86 stuff.  However x86 doesn't have instructions that have 
dags (store (op (load), (load))) of the sort I'm trying to match. So I'm not 
too hopeful I'll find an easy fix.

thanks,
bagel



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