[LLVMdev] llvm register reload/spilling around calls

[Dan Gohman]

On Oct 19, 2010, at 8:00 PM, Jakob Stoklund Olesen wrote:
> 
> 
> One problem is that calling conventions are handled while building the selection DAG, and the DAG doesn't really know to represent clobbered registers.
> 
> Perhaps X86TargetLowering::LowerCall() could decorate the X86ISD::CALL node with the calling convention somehow?
> 
> Dan, do you have any thoughts on how to communicate the calling convention and call clobbered registers to the eventual CALL MachineInstr?

The simplest way would probably be to add separate X86ISD opcodes for
each desired set of call-clobbered registers.

Dan