[LLVMdev] Supporting Complex Register Allocation Constraints (PBQP Allocator Status Update)

[Jakob Stoklund Olesen]

On Sep 20, 2010, at 7:53 AM, Lang Hames wrote:

> I've just committed some changes to the PBQP allocator which are designed to make it easier to implement custom register allocation constraints. This is a quick summary of those changes, and of the status of the PBQP allocator in general.

Thanks, Lang!

Out of curiosity, how are you dealing with live range splitting and coalescing in PBQP? I know you added the LoopSplitter pass.

For linear scan in LLVM we are going in the direction of aggressive coalescing before allocation, and on-demand splitting during allocation.

I know that other allocators use no early coalescing, and coalesce during allocation.

/jakob