[LLVMdev] Re: Why JITC?

Mike Hearn mike at plan99.net
Tue Aug 8 13:20:36 PDT 2006


On Mon, 07 Aug 2006 13:56:48 -0500, Andrew Lenharth wrote:
> Granted, LLVM currently doesn't really do much of this, but the
> infastructure is there to do so.

Right, but you can get this by doing profile directed optimisation during
development so end users/production systems don't have the overhead. Also
it seems to me that at some point the bookkeeping and analysis overhead
for these optimisations would reduce performance of the program by more
than they improve it. Eg keeping track of which calls are candidates for
inlining may increase memory usage, so increasing swapping or decreasing
cache utilisation, so losing you more performance than it gains.

thanks -mike




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