执行除以10，我得到了一个"浮点异常"。当在GDB中单步执行代码时，我发现除除时ax = 23，bx = 10。

.686                                    ;
                                        ;
BSS SEGMENT                             ;
    BUF DB 0                            ;
BSS ENDS                                ;
                                        ;
DATA SEGMENT                            ;
    ASSUME DS:BSS                       ;
                                        ;
PUBLIC _start                           ;
_start PROC                             ;
    MOV cx, 230                         ;
    CALL prN                            ;
                                        ;
...
_start ENDP                             ;
                                        ;
;---------------------------------------;
; prNum                                 ;
; TOFIX: numbers are printed backwards  ;
;---------------------------------------;
; CX = number to print                  ;
;---------------------------------------;
prN PROC                                ;
    MOV ax, cx                          ; prepare first loop
    MOV bx, 10                          ; !! BX = 10
@@loop:                                 ;
    ;- PROBLEMATIC LINE vvvvvvvvvvvvvvvv;
    DIV bx                              ; Get rightmost decimal digit
    ;- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^;
    ADD dl, '0'                         ; convert to ASCII-numeral
    MOV BYTE PTR [BUF], dl              ;
    PUSHA                               ; Not ideal, this is a playground
    ;- print byte buffer                ;
...
    ;--                                 ;
    POPA                                ;
    OR ax, ax                           ; Is cx = 0?
    JNZ @@loop                          ; NO: loop for the next decimal part
    RET                                 ; YES: leave loop
prN ENDP                                ;
DATA ENDS
END

循环的示例（如我所想象的）：

MOV ax, cx ; ax = 230
MOV bx, 10 ; bx = 10
           ;
(@@loop)   ;
DIX bx     ; ax = 23 - dx = 0
;- print   ; STDOUT = 0
OR ax, ax  ; ZF = 0
JNZ @@loop ; continue looping with AX = 23

DIV bx     ; AX = 2 - DX = 3 --> THIS is where the SIGFPE occurs
;- print   ; STDOUT = 03
OR ax, ax  ; ZF = 0
JNZ @@loop ; continue looping with AX = 2
           ;
DIX bx     ; AX = 0 - DX = 2
;- print   ; STOUD = 032 (230 but backwards)
OR ax, ax  ; ZF = 1
JNZ @@loop ; not looping
RET        ; all done, we are returning

由于我是用23除以10，所以我希望这个运算不会有问题，特别是：

• 不被零除
• 无溢流
• 无下溢

我希望

AX = 2
DX = 3
BX = 10