strncpy.mac

来自「--- --- ---基于C语言的编译器的 简单实现」· MAC 代码 · 共 96 行

 INCLUDE PROLOG.H
_CC1:
 PUBLIC _strncpy
_strncpy:
 SUB SP,2
 MOV BX,0
 ADD BX,SP
 XCHG DX,BX
 MOV BX,08
 ADD BX,SP
 MOV BX,[BX]
 MOV SI,DX
 MOV [SI],BX
_CC3:
 MOV BX,4
 ADD BX,SP
 MOV DX,BX
 MOV BX,[BX]
 DEC BX
 MOV SI,DX
 MOV [SI],BX
 INC BX
 OR BX,BX
 JG $+5
 JMP _CC4
 MOV BX,0
 ADD BX,SP
 MOV DX,BX
 MOV BX,[BX]
 INC BX
 MOV SI,DX
 MOV [SI],BX
 DEC BX
 PUSH BX  ;
 MOV BX,8
 ADD BX,SP
 MOV DX,BX
 MOV BX,[BX]
 INC BX
 MOV SI,DX
 MOV [SI],BX
 DEC BX
 MOV AL,[BX]
 CBW
 MOV BX,AX
 POP DX
 MOV SI,DX
 MOV [SI],BL
 OR BX,BX
 JNZ $+5
 JMP _CC5
 JMP _CC3
_CC5:
_CC6:
 MOV BX,4
 ADD BX,SP
 MOV DX,BX
 MOV BX,[BX]
 DEC BX
 MOV SI,DX
 MOV [SI],BX
 INC BX
 OR BX,BX
 JG $+5
 JMP _CC7
 MOV BX,0
 ADD BX,SP
 MOV DX,BX
 MOV BX,[BX]
 INC BX
 MOV SI,DX
 MOV [SI],BX
 DEC BX
 XCHG DX,BX
 MOV BX,0
 MOV SI,DX
 MOV [SI],BL
 JMP _CC6
_CC7:
 JMP _CC3
_CC4:
 MOV BX,0
 ADD BX,SP
 MOV BX,[BX]
 XCHG DX,BX
 MOV BX,0
 MOV SI,DX
 MOV [SI],BL
 MOV BX,8
 ADD BX,SP
 MOV BX,[BX]
 ADD SP,2
 RET
 INCLUDE EPILOG.H
 END