循環不斷循環

Question

我一直試圖創建一個循環來打印一個字符的次數取決於用戶的輸入，但是，循環不停止，而是無限地進行。

mov esi, [items]   //Esi points to the first item - Calling data from the C code and assigning it to the esi source indexer, in this case being the users inputted number. 



    loop1: mov eax, [esi]  // moves the first number which is in esi to the eax register 
      push eax    // pushes it onto the stack so it can be used 
      call printInt  // Prints the integer in the eax register 



      push ','    // Prints a comma after the number inputted 
      call printChar 

      push ' '    // Prints a space 
      call printChar 

      mov cx, 0   // assigning the value of 0 to counter 
      loop2: 
        push '*'  // pushing the required character onto the stack 
        call printChar // printing the character 
        inc cx   // incrementing the counter by 1 
        cmp cx, [esi] // comparing the program counter with the users inputted number 
        jne loop2  // jumping back to the beginning of the loop if cx is not equal to the users input thus printing the character the same number of times as the users inputted number 

      call printNewLine 

      mov eax, [esi] 
      add esi, 4   // Now that's odd. Esi is pointing at an integer, and that's 4 bytes in size. 
      cmp eax, 0 

      jnz loop1 



     jmp finish   // We need to jump past the subroutine(s) that follow 
           // else the CPU will just carry on going. 

該程序的輸入和輸出由C控制，這就是我爲帖子標記C的原因。

程序中不工作的部分應該是從loop2開始到jne loop2結束。

非常感謝您的幫助。

Answer 1

內環（始於loop2一）被告知，如果[esi] == 0運行65000次，因爲在第一次迭代cx已經比0

更大的沒錯，外部功能可能會破壞它，以及。這裏需要了解的一個主要問題是他們的calling convention。從它的外觀（通過堆棧傳遞第一個參數），您的CX內容在返回時幾乎註定要失敗：幾乎所有通過堆棧傳遞所有內容的約定都假定CX被調用者保存。