Print out register values

flat assembler
Message board for the users of flat assembler.

Index > High Level Languages > Print out register values

Author

Thread

masterducky

Joined: 12 May 2010
Posts: 10

masterducky 14 May 2010, 16:04

Hi!

I would like to print out the values in registers in inline C.
What am i doing wrong?

Code:


#include <stdio.h>

int main()
{
    _asm
    {
       mov ecx, 5
       mov eax, ecx
       push eax
       call printf
       pop ebx
    }
    return 0;
}

14 May 2010, 16:04

edfed

Joined: 20 Feb 2006
Posts: 4353
Location: Now

edfed 14 May 2010, 16:12

http://www.cplusplus.com/reference/clibrary/cstdio/printf/

maybe you don't push enough parameters on the stack.

Code:

mov ecx,5
mov eax,ecx
push eax

Code:

push dword 5

is enough

14 May 2010, 16:12

masterducky

Joined: 12 May 2010
Posts: 10

masterducky 14 May 2010, 16:30

Yes of course, how could i forget it, it needs two arguments.

By the way it compiles rather this way:

Code:

 push dword ptr 5

Thank you Ed!

14 May 2010, 16:30

LocoDelAssembly
Your code has a bug

Joined: 06 May 2005
Posts: 4624
Location: Argentina

LocoDelAssembly 14 May 2010, 16:47

Quote:

By the way it compiles rather this way:

Code:
push dword ptr 5

That will be equivalent to "push dword [5]" which is an assured crash in Windows and probably in many others OSes that never allocate too low addresses.

14 May 2010, 16:47

masterducky

Joined: 12 May 2010
Posts: 10

masterducky 14 May 2010, 18:40

Thanks for letting me know that.

14 May 2010, 18:40

dosin

Joined: 24 Aug 2007
Posts: 337

dosin 14 May 2010, 23:36

depending on what you want ..
This works. if your using visual c++ ..

use the regs... to do the work ... then print with the standard lib outside the asm tags...

Code:

#include <stdio.h> 


int main() 
{ 

    int some_var=0;
    _asm 
    { 
       mov ecx, 5 
       mov eax, ecx 
       mov [some_var],eax
    } 

   printf("Value of some var: %i ",some_var);
    return 0; 
}

14 May 2010, 23:36

masterducky

Joined: 12 May 2010
Posts: 10

masterducky 15 May 2010, 04:09

Awesome, that's what i wanted to do.

Thank you Dosin!

15 May 2010, 04:09

< Last Thread | Next Thread >

Forum Rules:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum