u8rs086.asm

来自「开放源码的编译器open watcom 1.6.0版的源代码」· 汇编 代码 · 共 63 行

;*****************************************************************************
;*
;*                            Open Watcom Project
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;*  ========================================================================
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;*    This file contains Original Code and/or Modifications of Original
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;========================================================================
;==     Name:           U8RS                                           ==
;==     Operation:      integer eight byte right shift (unsigned)      ==
;==     Inputs:         AX:BX:CX:DX integer M1                         ==
;==                     SI          shift count                        ==
;==     Outputs:        AX:BX:CX:DX result                             ==
;========================================================================
include mdef.inc
include struct.inc

        modstart        u8rs086

        xdefp   __U8RS

        defp    __U8RS
        test    si,si                   ; shifting anything?
        _if     ne                      ; if so then
          _loop                         ; - top of loop
            shr ax,1                    ; - - shift one bit
            rcr bx,1                    ; - - ...
            rcr cx,1                    ; - - ...
            rcr dx,1                    ; - - ...
            dec si                      ; - - decrement shift count
          _until e                      ; - kick out if done
        _endif                          ; endif
        ret
        endproc __U8RS

        endmod
        end