Ad:

C++ Discussion Thread
Unsolved
Views: 3668

Dec 7th, 2005

C++ to ASM

Expand Post »

I have a problem i have a fully operational C++ code that works but when i convert it to ASM (assembly) code it doesnt work I dont know where I am going wrong but here are both codes..

C++ Syntax (Toggle Plain Text)
 
#include <iostream>
using namespace std;
 
int main()
{
       int n, tmpA, tmpB
       int CO[0] = { 0 };
cin >> n;
CO[0] = 1;
 
for( int = 2; i < (n + 3); i++)
{
     tmpB = CO[k] + CO[k + 1];
     CO[k] = tmpA;
     cout << " " << tmpA;
     tmpA = tmpB;
}
cout  << endl;
}
return 0;
}
 
#include <iostream>
using namespace std;

int main()
{
       int n, tmpA, tmpB
       int CO[0] = { 0 };
cin >> n;
CO[0] = 1;

for( int = 2; i < (n + 3); i++)
{
     tmpB = CO[k] + CO[k + 1];
     CO[k] = tmpA;
     cout << " " << tmpA;
     tmpA = tmpB;
}
cout  << endl;
}
return 0;
}

And here is the ASM code I hope this is the right place where people know how to program in ASM??

C++ Syntax (Toggle Plain Text)
TITLE Combinatorial Coefficents
INCLUDE Irvine32.inc
 
.data
CO DWORD 40 DUP(0)
mystr1 BYTE "Please enter a positive number from 1 to 40: ", 0
 
i DWORD ?
k DWORD ?
n DWORD ?
tmpA DWORD ?
tmpB DWORD ?
.code 
main PROC
mov edx, OFFSET mystr1
call WriteString
call CrLf
 
call ReadInt
mov n, eax
mov ebx, CO[0] 
mov ebx, 1
 
 
 
LL:  
    mov  edx, 2  ; i = 2
    add  n, 3  ; n + 3 
    cmp edx, n
    jae QX
 
 
    mov tmpA, 1 ; tmpA = 1
 
 
 
LX: 
     mov k, 0
                                    ;mov edx, i
    dec edx ; i - 1
    cmp k, edx
    jae QX
 
    mov esi, OFFSET CO
    shl esi, 2
 
    mov ebx, CO[esi]
    add ebx, CO[esi + 4]
    mov eax, tmpA
    mov eax, CO[esi]
                                     ;mov tmpA, eax
                                     ;mov eax, tmpA 
    call WriteDec
    call CrLf
    mov eax, ebx
                                     ; mov tmpA, eax
    inc k
    inc edx
    jmp LL
 
 
 
 
 
 
 
 
 
 
 
QX:
 
exit
main ENDP
END main
TITLE Combinatorial Coefficents
INCLUDE Irvine32.inc

.data
CO DWORD 40 DUP(0)
mystr1 BYTE "Please enter a positive number from 1 to 40: ", 0

i DWORD ?
k DWORD ?
n DWORD ?
tmpA DWORD ?
tmpB DWORD ?
.code 
main PROC
mov edx, OFFSET mystr1
call WriteString
call CrLf

call ReadInt
mov n, eax
mov ebx, CO[0] 
mov ebx, 1

    
 
LL:  
    mov  edx, 2  ; i = 2
    add  n, 3  ; n + 3 
    cmp edx, n
    jae QX
          
    
    mov tmpA, 1 ; tmpA = 1
    
    
       
LX: 
     mov k, 0
                                    ;mov edx, i
    dec edx ; i - 1
    cmp k, edx
    jae QX
    
    mov esi, OFFSET CO
    shl esi, 2
    
    mov ebx, CO[esi]
    add ebx, CO[esi + 4]
    mov eax, tmpA
    mov eax, CO[esi]
                                     ;mov tmpA, eax
                                     ;mov eax, tmpA 
    call WriteDec
    call CrLf
    mov eax, ebx
                                     ; mov tmpA, eax
    inc k
    inc edx
    jmp LL
    


    
    
   
    



   
QX:

exit
main ENDP
END main

Similar Threads

intergrating ASM to C++ in C++
ASM Game Coding Problem/Question in Assembly
Starting ASM in Assembly
My Sample ASM Code in Assembly
asm in C in C++

heavyc

Reputation Points: 10

Solved Threads: 0

Newbie Poster

Offline

15 posts
since Sep 2005

Permalink

Dec 7th, 2005

Re: C++ to ASM

IANAAP (I Am Not An Assember Programmer) but, some thoughts:
Feels like there is as many ways to write assembler as there are assemblers thought... What is the problem ?

Argh, whats up with the k variable in the c++ example (not declared) ? and counting goes in different directions (down in asm, up in c++)
What you do seem to be doing is to set edx to 2 and count down to zero, that cant be right... (Edit seems you are counting both edx and k up at the end, first edx - 1 + 1 each round, and k = 0 + 1 each round... I got a head ache right now so now I'll stop reading this)
Even worse you loop through the loop initation all the time (LL)...
(this looks odd)

C++ Syntax (Toggle Plain Text)

    mov eax, tmpA
    mov eax, CO[esi]

And where did the swap/save between tmpA and tmpB go ?

And I have no idea about the included functions, do they preserv all registers, what arguments do they take, and so on...

perniciosus

Reputation Points: 29

Solved Threads: 4

Junior Poster in Training

Offline

78 posts
since Nov 2005

Permalink

Dec 7th, 2005

Re: C++ to ASM

C++ Syntax (Toggle Plain Text)
      int CO[0] = { 0 };
      int CO[0] = { 0 };

The above is not a valid array -- its an array of 0 elements. that means "CO[0] = 1;" will produce undefined behavior because CO[0] does not exist.

Ancient Dragon

Sponsor

Team Colleague

Featured Poster

Reputation Points: 5608

Solved Threads: 2283

Retired and Enjoying Life

Offline

21,961 posts
since Aug 2005

Permalink

Dec 8th, 2005

Re: C++ to ASM

thanks for taking an intrest in the code, but i went to my teacher and i actually figured it out again thank you for taking an intrest

heavyc

Reputation Points: 10

Solved Threads: 0

Newbie Poster

Offline

15 posts
since Sep 2005

This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.

Previous Thread in C++ Forum Timeline: Easy Polymorphism Q Part 2 :)

Next Thread in C++ Forum Timeline: I guess it's a question about a loop

DaniWeb Message

Cancel Changes

User Name
Password