Question

我在编写汇编程序结束时，故障区域是我的比较指令，它似乎没有工作，我做的任何事情似乎都没有工作，因此读入的所有输入都被发送到拒绝

代码：

loop_top:         
     input  string,40                  ; read ASCII characters
     atod  string                      ; convert to integer
     mov  number1, eax                 ; store in memory
     jz done

     cmp number1, 50                   ; number1>50?
     jg rejected
     cmp number1, -50                  ; number1<-50?
     jl rejected

rejected:
     dtoa number1ch,eax                ; convert to ASCII characters
     output number1ch                  ; print value and message to screen
     output reject 
     jmp loop_top

     mov eax, number1                  ; store in register
     cmp eax,0                         ; eax > 0?
     jnl isPositive

问题区域？：

         cmp number1, 50                  ; number1>50?
         jg rejected
         cmp number1, -50                 ; number1<-50?
         jl rejected

rejected:
         dtoa number1ch,eax               ; convert to ASCII characters
         output number1ch                 ; print value and message to screen
         output reject 
         jmp loop_top

所以任何数字ex：4,50,51，-3，-50，-51 ..都被发送到被拒绝。有人能解释一下为什么吗？谢谢！

Answer 1

即使rejected有效，您似乎只是“落到”number1：

     cmp number1, 50                   ; number1>50?
     jg rejected                       ; <<< jump to rejected if number1 > 50
     cmp number1, -50                  ; number1<-50?
     jl rejected                       ; <<< jump to rejected if number1 < -50

     ;; we get here if -50 <= number1 <= 50, i.e. if 
     ;; number1 is in the valid range...

     ;; but then we fall through to `rejected` anyway...

     ;; so code for processing `number1` needs to go here
     ;; (or you could just put a `jmp` here to the
     ;; relevant code)...

rejected:

Answer 2

         cmp number1, 50                  ; number1>50?
         jg rejected
         cmp number1, -50                 ; number1<-50?
         jl rejected

rejected:

好？

如果数字大于50，则由于jg而被拒绝如果该数字小于-50，则由于jl而被拒绝如果这些跳转都没有发生，执行将流向下一条指令（你填写）r_j_ct_d

装配 - 比较指令不起作用

2 个答案: