[LLVMdev] Questions about MachineScheduler

Tom Stellard tom at stellard.net
Mon Jul 22 11:50:53 PDT 2013


I'm working on defining a SchedMachineModel for the Southern Islands
family of GPUs, and I have two questions related to the

1. I have a resource that can process 15 instructions at the same time.
In the TableGen definitions, should I do:

def HWVMEM   : ProcResource<15>;


let BufferSize = 15 in {
def HWVMEM : ProcResource<1>;

2. Southern Islands has 256 registers, but there is a significant
performance penalty if you use more than a certain amount.  Do any of
the MachineSchedulers support switching into an 'optimize for register
pressure mode' once it detects register pressure above a certain limit?


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