MODULE COROUT(ZIP)=
BEGIN

	%<  The BLISS-11 out-of-line create and exchange jump routines  >%

    EXTERNAL $BREG;
    GLOBAL $PREV;

    GLOBAL ROUTINE $CREAT(NUMPARMS,ROUTNAME,STKBEGIN,STKLEN,RTRN)=
	!
	! NUMPARMS - the number of parameters passed to the routine, doubled.
	! 	     These are below NUMPARMS on the stack ("above" it,
	!	     in terms of actual addresses).
	! ROUTNAME - a pointer to the beginning of the routine code.
	! STKBEGIN - not the base of the stack, but the lowest address
	!	     of the block allocated for the stack (i.e. the
	!	     number after "AT" in the user's program).
	! STKLEN   - the size of the allocated block in bytes.
	! RTRN	   - a pointer to the routine to be executed if the
	!	   - new process tries to do a RETURN.
	!
	BEGIN
	REGISTER A,BASE;
	MACRO PUSH(EXP)=(A_.A-2; .A_(EXP))$;

	A_BASE_.STKBEGIN+.STKLEN-2;
	DECR I FROM .NUMPARMS TO 1 BY 2
		DO PUSH(.(NUMPARMS+.I));	! Push each argument
	PUSH(.RTRN);				! Push the return address
	PUSH(.ROUTNAME);			! Push the Starting Adress
	A_.A-5*2;				! Save Room for R$1 through R$5
	.BASE_.A;
	.BASE
	END;

    GLOBAL ROUTINE EXCHJ(STKBASE)=
	!
	!    The call on EXCHJ pushes the stackbase pointer, and puts
	! the value passed in R$0.  Since EXCHJ itself doesn't
	! fiddle with R$0, the routine is not declared with any
	! special linkage type.
	!    The user may wish to decrease the overhead involved in
	! an exchange jump by passing the stackbase pointer in a
	! register.  This has not been done here, in order to achieve
	! full generality--that is, the user who wishes to reserve
	! one of the registers need only put the RESERVE declaration
	! at the head of the module, and need not rewrite this
	! routine.
	!
	BEGIN
	MACRO SAV[REG]=(REG_.REG+1; REG_.REG-1)$,
	      RST[REG]=$;

	SAV(R1,R2,R3,R4,R5);
	$PREV_.$BREG;
	.$BREG_.SP;
	$BREG_.STKBASE;
	SP_..STKBASE;
	RST(R5,R4,R3,R2,R1);
	.VREG
	END;

END ELUDOM