// See stackalloc.go's {new,put}StackAllocState.
	stackAllocState *stackAllocState

	scrPoset []*poset // scratch poset to be reused

	// Reusable regalloc state.
	regallocValues []valState

	ValueToProgAfter []*obj.Prog
	debugState       debugState

	Liveness interface{} // *gc.livenessFuncCache

	// Free "headers" for use by the allocators in allocators.go.
	// Used to put slices in sync.Pools without allocation.