浮点数中断的程序

Question

; Author:
; Date:
; This is the Visual Studio 2012 version

; Preprocessor directives
.586        ; use the 80586 set of instructions
.MODEL FLAT ; use the flat memory model (only 32 bit addresses, no segment:offset)

; External source files
INCLUDE io.h   ; header file for input/output
INCLUDE fio.h  ; header file for floating point conversions to and from ASCII

; Stack configuration
.STACK 4096    ; allocate 4096 bytes for the stack

; Named memory allocation and initialization
; Use REAL4 for floating point values
.DATA
    prompt1     BYTE    "Enter circumference: ", 0 ; Basic prompt
    string      BYTE    40 DUP (?)
    BoxLabel1   BYTE    "The radius is "
    radius      BYTE    12 DUP (?), 0

    msg1        BYTE    "The circle circumference is: ", 0ah
    circumf2    BYTE    12 DUP (?), 0ah
    msg2        BYTE    "The circle area is: ", 0ah
    area2       BYTE    12 DUP (?), 0

radiusInput REAL4   1.0
pi          REAL4   3.14
two         REAL4   2.0
areA        REAL4   1.0
circumf     REAL4   1.0

; procedure definitions
.CODE
_MainProc PROC
;************ INPUT *************
    input   prompt1, string, 40         ; read ASCII characters
    atof    radiusInput, string         ; Convert (ASCII TO FLOAT) macro
;********************************   
    finit   
    push    radiusInput
    call    findCircumf ; BREAKS HERE!!!!


;   call    findArea

;done:

;************ OUTPUT ************
    ftoa    radius, radiusInput
    ftoa    area2, areA
    ftoa    circumf2, circumf
    output  BoxLabel1, msg1
;********************************

;*********** CLEAN-UP ***********
    mov     EAX, 0  ; exit with return code 0
    ret
;********************************
_MainProc ENDP

;##################### findCircumf PROCEDURE ##################
findCircumf PROC
; ******** CIRCUMFERENCE ********
; Formula 2*Pi*R
    fld     two             ; ST(0) has 2.0
    fld     pi              ; ST(0) has 3.14 ST(1) 2.0
    fmul    st(0), st(1)    ; ST(0) has 6.28    2*Pi
    fld     radiusInput     ; ST(0) has radius input (3.5) ST(1) has 6.28
    fmul    ST(0), ST(1)    ; ST(0) has 21.98   2*Pi*R
    fst     circumf
;********************************
findCircumf ENDP

;###################### findArea PROCEDURE #####################
findArea PROC
;************ AREA **************
; Forumla R*R*Pi
    fld     radiusInput     ; ST(0) has radius input (3.5) 
    fmul    st(0), st(0)    ; ST(0) has 12.25   R*R (or R^2)
    fld     pi              ; ST(0) has 3.14    ST(1) has 12.25
    fmul    st(0), st(1)    ; ST(0) has 38.465  R*R*Pi
    fstp    areA            ; areA has 38.465 
;********************************
findArea ENDP
END   ; end of source code

在调用 findCircumf 时中断并显示错误列表

windows32.exe has triggered a breakpoint.
The thread 0x1570 has exited with code 0 (0x0).
The program '[628] windows32.exe' has exited with code 0 (0x0).

我知道我做错了什么。我假设这与我的回归有关。 在该过程中，reurn 值在 ST(0) 中。我不确定我做错了什么，我使用的是浮点数。

Answer 1

1.) 首先，过程结束时没有返回语句。

2.) 因为我使用浮点和堆栈，所以我在每个过程调用之前都放了 finit。

3.) 我需要在每个过程的开头建立一个堆栈帧

push    ebp             ; save base pointer
mov     ebp, esp        ; establish stack frame
push    ebx             ; save EBX

4.) 在每个过程返回之前从堆栈帧中弹出寄存器

pop     ebx             ; restore EBX
pop     ebp             ; restore EBP
ret                     ; return  

这些东西解决了我的问题。