[LLVMdev] [patch] CodeEmitter Memory Foot Reduction

Chris Lattner clattner at apple.com
Thu Jul 16 11:34:30 PDT 2009


On Jul 16, 2009, at 10:04 AM, Aaron Gray wrote:

>
> I understand that you say that, but I can't bring myself to care at  
> this point.  Have you thought about how many cycles are already used  
> to produce the instructions that lead to the emission of those 10K  
> bytes?  The total percentage of time spent doing these virtual calls  
> will be tiny compared to the total time to generate the code.
>
> If you switch to using virtual functions, get the code working, and  
> we *measure* a performance problem, then we can fix it.  There are  
> much better ways to do this than templating the whole code emitter.
>
> That means JIT code also has the virtual function overhead too, this  
> will slow down existing JIT code. Templates are already there and  
> they work and they do not take up _too_ much memory.

As I said before, if you are compelled to, feel free to continue with  
your approach of premature optimization.  I will fix it later.

-Chris



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