Re: [Dev-C++] Offset problems in assembly

[Daniel K. O. <dan...@ya...>]

First: GCC uses AT&T syntax by default, but it accepts Intel as well.

You can set which syntax you want to use by default, with the "-masm=x" 
compiler option, where "x" can be:
    "att" -> for AT&T syntax
    "intel" -> for Intel syntax (d'oh....)

So, with -masm=intel you can write:

---
char hello[] = "Hello";

__asm(
    "mov ebx, _hello \n"
    "more intel asm here... \n"
);
---

And with -masm=att (the default) you can do:

---
char hello[] = "Hello";

__asm(
    "mov $_hello, %ebx \n"
    "more at&t asm here... \n"
);
---


If you want to mix ASM code, you can use ".intel_syntax" and 
".att_syntax" to change the syntax for the next lines. Just don't 
forget  to change it back to the default syntax:

Option -> -masm=att
---
char hello[] = "Hello";

__asm(
                ".intel_syntax \n"
                "mov ebx, _hello \n"
                "more intel asm here... \n"

                ".att_syntax \n" // back to default syntax
);
---


Also, check:
http://www.codeproject.com/useritems/gccasm.asp
And also the Dev-Cpp's FAQ.


And please, learn how to use Google, I found all this in the first 
results page. ;)


Daniel K. O.


Bjorn Terelius wrote:

> I'm using visual studio for this project, so it may be the wrong place 
> for the question.
> Anyway, when I try compile code like:
>
>
> char hello[] = "Hello";
> __asm
>     {
>     mov ebx, offset hello
>     ...
>     }
>
> the compiler fail and respond "error C2415: improper operand type"
> This only occur when I'm trying to use offset
>
> Does anyone recognize this?
> I havn't found any helpful information on MSDN or by searching with 
> Google
>
> Thanks
> Bjorn Terelius