[LLVMdev] New JIT APIs

[Caldarale, Charles R]

From: Lang Hames [mailto:lhames at gmail.com] 
Subject: Re: [LLVMdev] New JIT APIs

> > We're currently using LLVM 3.3 in production (due to performance regressions in newer 
> > versions), so I don't know if some other scheme is appropriate for current levels.

> Do you have any insight into what regressed?

The differences were noted using our standard in-house benchmarks, and we haven't really had the time to do much EMON- and instruction-level research into the differences (the product isn't out the door yet).  One of the problems may be in register allocation, since there seemed to be more spills and reloads; there's no evidence that MCJIT itself was an issue.  We'll be able to start checking out 3.6 (or 3.7) in detail in June or thereabouts.

 - Chuck