[LLVMdev] IMPORTANT: Post-regalloc scheduling and JIT

[Evan Cheng]

Hi all,

I have turned on post- register allocation scheduling for x86 (Anton  
is investigating a problem on Linux, but it's *so far* working well on  
Darin). It's a very expensive codegen pass that can easily increase  
the codegen time by 10% or more. For this reason, I've added a new  
code generation optimization level CodeGenOpt::Less. If you are using  
the LLVM x86 JIT, you *should* initialize the with this optimization  
level to avoid running the pass (see  
LLVMTargetMachine::addPassesToEmitMachineCode).

Evan