Hello,
I'm having a problem trying to trying to store a local variable in my asm program. I push 3 parameters: nbrElts (number of elements in the array), nbrArray (the address of the array), and result1 (the average). I'm trying to divide by the number of elements that I push into the local variable space [ebp-4], but it locks up at that instruction and I can't figure out why. Any help would be greatly appreciated!
Main program:
.386
.MODEL FLAT
INCLUDE io.h
cr EQU 0dh ; carriage return character
LF EQU 0ah ; linefeed character
maxNbrs EQU 5 ; size of array
ExitProcess PROTO NEAR32 stdcall, dwExitCode:DWORD ; you need to declare your external routine
EXTERN Avg:near32 ; use this syntax to avoid mistakes
.STACK 4096 ; reserve 4096-byte stack
.DATA ; reserve storage for data
directions BYTE cr,Lf,Lf,"You may enter up to 5 numbers.",cr,Lf,Lf
BYTE "This program will find the average.",cr,Lf,Lf,0
prompt BYTE cr,Lf,"Number to insert into array? ",0
number DWORD ?
found BYTE cr,Lf,Lf,"The average is: ",0
result1 DWORD ?
remainder DWORD ?,cr,Lf,Lf,0
nbrArray DWORD maxNbrs DUP (?)
nbrElts DWORD ?
.CODE ; start of main program code
_start:
output directions ; display directions
mov nbrElts,0 ; number of elements = 0
mov result1,0 ; average starts at 0
lea ebx,nbrArray ; get address of nbrArray
looper:
output prompt ; prompt for number
input number,4 ; get number
atod number ; convert to integer
mov [ebx],eax ; store number in array
inc nbrElts ; add 1 to nbrElts
add ebx,4 ; get address of next item of array
inc ecx ; increase the ecx by 1
cmp ecx,5 ; is the ecx equal to 5?
je endlooper ; if ecx = 5, exit loop
jmp looper ; otherwise, repeat
endlooper:
push nbrElts ; push number of elements onto stack
lea eax,nbrArray ; push address of array onto stack
push eax
push result1 ; push the address of average onto stack
call Avg ; procedure call
dtoa result1,eax ; convert integer to ascii
dtoa remainder,edx ; convert remainder to ascii
output found ; output the average
INVOKE ExitProcess, 0 ; exit with return code 0
PUBLIC _start ; make entry point public
END ; end of source codeThe external call program:
.386
.MODEL FLAT
PUBLIC Avg
.CODE
Avg PROC NEAR32
push ebp ; store ebp
mov ebp,esp ; freeze stack pointer
sub esp,4 ; create space for one local dword
push ecx ; store ecx
push ebx ; store ebx
pushf ; store flags
mov ebx,[ebp+12] ; move array into ebx
mov ecx,[ebp+16] ; NbrElts in array into count
mov [ebp-4],ecx ; store number of elements
mov eax,[ebp+8] ; move result1 address into eax
forCount:
add eax,[ebx] ; load array integer
add ebx,4 ; get address for next item in array
loop forCount ; loop until count is 0
done:
div DWORD PTR [ebp-4] ; divide eax by nbrelts
popf ; restore flags
pop ecx ; restore ecx
pop ebx ; restore ebx
pop ebp ; restore ebp
ret ; return
Avg ENDP
PUBLIC AVG
END