[LLVMdev] LiveVariables/LiveInterval on huge functions

Evan Cheng evan.cheng at apple.com
Mon Apr 14 15:09:46 PDT 2008

Sure, it makes sense. I'll take a look at it.


On Apr 14, 2008, at 3:09 PM, Chris Lattner wrote:

> On Mon, 14 Apr 2008, Evan Cheng wrote:
>>> This sounds like unanticipated fallout from Evan's recent tweaks  
>>> of the  inliner.  Evan, thoughts?
>> Previously the inliner assign each basic block cost of 20. So this  
>> line is simply estimating the number of caller basic blocks. My  
>> tweak simply removed the number of basic blocks from the equation  
>> so the cost of a callee is simply number of instructions * 5. I  
>> don't think it should / would impact this case. Edwin, can you  
>> revert 49061 and 48725 to see if they have any impact?
>> The -30000 cost reduction for internal function does seem excessive  
>> though.
> Right, so now the cost estimate of the function is much lower than  
> it was before.  This isn't itself a problem, but it means that the  
> 30000 bonus for being called at one callsite should also be reduced  
> to match, seem reasonable?
> -Chris
> -- 
> http://nondot.org/sabre/
> http://llvm.org/

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