[LLVMdev] CostModelAnalysis for 3.0 release

[Nadav Rotem]

On Feb 7, 2013, at 3:17 PM, ryan <stdstack at gmail.com> wrote:

> Thanks a lot for the reply, Nadav!
> I see that using the cost model in target-independent analysis is not good. But I really like the idea of having instruction 
> cost estimation available. Also the reason I can't directly move to 3.2 code base is that it fails to compile(produce bc files) big 
> project like MySQL, where 3.0 has no problem.
> 

Is this a known problem ? Can you please file a bugzilla ? LLVM should be able to compiler MySQL … 


> Right now, I'm trying to hard code a particular target, and copy part of the TargetTransformInfo and X86TargetTransformInfo 
> to a simple LLVM 3.0 project to try out. So far I'm stuck in instantiating X86TargetMachine and wondering whether it can be 
> created from instances of TargetMachine or TargetData.
> 

Look at tools/opt/opt.cpp  or tools/llc/llc.cpp. They both initialize the target machine using the target data.