shell.esm

来自「开放源码的编译器open watcom 1.6.0版的源代码」· ESM 代码 · 共 80 行

.387
		PUBLIC	multiply_
DGROUP		GROUP	CONST,CONST2,_DATA
_TEXT		SEGMENT	BYTE PUBLIC USE16 'CODE'
		ASSUME CS:_TEXT, DS:DGROUP, SS:DGROUP
multiply_:
    mov       ax,3
    push      ax
    xor       ax,ax
L$1:
    test      word ptr 2[di],8000H
    jne       L$2
    shl       word ptr [di],1
    rcl       word ptr 2[di],1
    shl       word ptr [si],1
    rcl       word ptr 2[si],1
    rcl       word ptr 4[si],1
    rcl       word ptr 6[si],1
    rcl       ax,1
    jmp       L$1
L$2:
    mov       bx,ax
    mov       cx,0ffffH
    mul       cx
    add       ax,bx
    adc       dx,0
    add       ax,word ptr 6[si]
    adc       dx,0
    mov       cx,dx
    mov       bx,ax
    div       word ptr 2[di]
    push      ax
    mul       word ptr 2[di]
    sub       bx,ax
    sbb       cx,dx
    pop       ax
    mov       word ptr 6[si],ax
    mul       word ptr [di]
    test      cx,cx
    jne       L$5
L$3:
    cmp       dx,bx
    jb        L$5
    ja        L$4
    cmp       ax,word ptr 4[si]
    jbe       L$5
L$4:
    dec       word ptr 6[si]
    sub       ax,word ptr [di]
    sbb       dx,0
    add       bx,word ptr 2[di]
    adc       cx,0
    jmp       L$3
L$5:
    sub       word ptr 4[si],ax
    sbb       bx,dx
    mov       word ptr 6[si],bx
    sbb       cx,0
    pop       dx
    dec       dx
    cmp       dx,2
    je        L$6
    mov       word ptr 8[si],cx
    test      dx,dx
    je        L$7
L$6:
    sub       si,2
    mov       ax,bx
    push      dx
    jmp       L$2
L$7:
_TEXT		ENDS
CONST		SEGMENT	WORD PUBLIC USE16 'DATA'
CONST		ENDS
CONST2		SEGMENT	WORD PUBLIC USE16 'DATA'
CONST2		ENDS
_DATA		SEGMENT	WORD PUBLIC USE16 'DATA'
_DATA		ENDS
		END