// a[1] is a register number expressed as a constant or register value
			target = &a[2]
			prog.From = a[0]
			if a[0].Type != obj.TYPE_CONST {
				// Legacy code may use a plain constant, accept it, and coerce
				// into a constant. E.g:
				//   BC 4,...
				// into
				//   BC $4,...
				prog.From = obj.Addr{
					Type:   obj.TYPE_CONST,
					Offset: p.getConstant(prog, op, &a[0]),
				}

			}