.NLIST	TOC,SYM
.TITLE	$MUL
.SBTTL	ULBLIB 039	- Integer multiply magnitude numbers
.IDENT	\V03.02\
.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.
;+
; $MUL
; This routine multiplies two unsigned integers.
;
;	R0	= multiplier
;	R1	= multiplicand
;
;	CALL	$MUL
;
;	R0	= high order result
;	R1	= low order result
;-

.PSECT	.LIBC.

$MUL::
	MOV	R0,-(SP)	;Save R0 for adds
	MOV	#21,-(SP)	;Set repeat count
	CLR	R0		;Clear high part
1$:	ROR	R0		;Double right shift
	ROR	R1		;
	BCC	2$		;If C-bit = 0, do not add
	ADD	2(SP),R0	;
2$:	DEC	(SP)		;Decrement repeat count
	BGT	1$		;If GT, more to go
3$:	CMP	(SP)+,(SP)+	;Clean stack
	RETURN

.END