; void _HalveUnsArr(a,n)
 ;
 ; ARGUMENT
 ;      unsigned *a[];
 ;      unsigned n;
 ;
 ; DESCRIPTION
 ;      Halves the number a (taken as one number of 'n' 16-bit unsigneds).
 ;
 ; SIDE EFFECTS
 ;      If number is odd, discards low-order bit.
 ;
 ; RETURNS
 ;      None.
 ;
 ; AUTHOR
 ;  Andy Anderson   31-JAN-1987  13:30
 ;   Copyright (C) 1987-90 Greenleaf Software Inc.  All Rights Reserved.
 ;
 ; MODIFICATIONS
 ;      aa      08-JUL-87       80-bit
 ;
 ;

        include model.h
        include prologue.h
        include gm.equ

        pseg    gmath
;
;  if large memory model then:
;
;       parm1_ = ptr to source 1
;       parm3_ = number of words to shift right (divide by 2)
;
;  for if small model then
;       parm1_ = ptr to source1
;       parm2_ = number of words to shift right (divide by 2)
;
;

        cproc   _HalveUnsArr,,_hmi

if      _LDATA
        push    ds
        lds     si,parm1_       ; ptr to a
        mov     cx,parm3_       ; get number of words to shift
else
        mov     si,parm1_
        mov     cx,parm2_       ; ditto for small model
endif
        xor     bx,bx           ; clear flags
        mov     bx,cx           ; then convert number of word to
        dec     bx              ;  index for loop
        rcl     bx,1            ; change byte to word offset
        xor     ax,ax           ; clear flags
lp:
        rcr     Word Ptr [bx+si],1      ; word and divide it by 2
        dec     bx              ; and decrease the index (offset)
        dec     bx
        loop    lp              ;  for next until done

; no return values
if      _LDATA
        pop     ds
endif
        cproce
        endps
        END