.NLIST	TOC,SYM
.TITLE	$DDIV
.SBTTL	ULBLIB 037	- Double Precision Divide
.IDENT	\V01.00\
.PSECT	.LIBC.
.ENABL	LC,GBL

; Copyright (c) 1998 by Mentec, Inc., Nashua, NH.
; All rights reserved
;
; This software is furnished under a license for use only on a
; single computer system and  may  be  copied  only  with  the
; inclusion of the above copyright notice.  This software,  or
; any other copies thereof, may not be provided  or  otherwise
; made available to any other person except for  use  on  such
; system and to one who agrees to these license  terms.  Title
; to  and  ownership of the software shall at all times remain
; in Mentec, Inc.
;
; The information in this document is subject to change without
; notice and should not be construed as a commitment by Digital
; Equipment Corporation, or Mentec, Inc.
;
; Digital and Mentec  assume  no  responsibility for the use or
; reliability of its software on equipment which is not supplied
; by Digital  or Mentec,  and listed  in the  Software  Product
; Description.
;+
; $DDIV
; This routine divides a double precision dividend by a single precision
; divisor yielding a double precision quotient and a single precision
; remainder.  All are unsigned.
;
;	R0	= single precision divisor
;	R1	= hi-order part of double precision dividend
;	R2	= lo-order part of double precision dividend
;
;	JSR	PC,$DDIV
;
;	R0	= single precision remainder
;	R1	= hi-order part of double precision quotient
;	R2	= lo-order part of double precision quotient
;-

$DDIV::
	MOV	R3,-(SP)	;Save R3
	MOV	#32.,R3		;Set iteration count in R3
	MOV	R0,-(SP)	;Put divisor on stack
	CLR	R0		;Set remainder to zero
1$:	ASL	R2		;Shift the entire dividend...
	ROL	R1		;... one bit to the left and ...
	ROL	R0		;... into the remainder
	CMP	R0,(SP)		;Is remainder .GE. divisor?
	BLO	2$		;No, skip to iteration control
	SUB	(SP),R0		;Yes, subtract divisor out
	INC	R2		; and increment the quotient
2$:	DEC	R3		;Repeat as long as necessary
	BGT	1$		;
	TST	(SP)+		;Purge divisor from stack
	MOV	(SP)+,R3	;Restore R3
	RETURN

.END