[LLVMdev] LiveVariables/LiveInterval on huge functions

Chris Lattner sabre at nondot.org
Mon Apr 14 15:09:35 PDT 2008

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 



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