ASM Community

It's my personal belief that, when combining assembly and HLLs, you should only shell out to assembly when you have a fairly "costly" routine - when there's enough speed gained that pushing a couple of variables and doing a call won't be a burden.

If you find yourself in need of a lot of small-and-fast routines, a refactor of your source is probably in order; ie, rather than building a "DrawSprite" with a super-fast PutPixel routine... you should drop the putpixel mentality, and do direct pixel manipulation in DrawSprite.

Last time I tried, I couldn't come up with better ways of accessing member variables than what you have posted - vc2003 seems to turn "mov eax, m_blah" into a "mov eax, 0". Your "this + 0" and "this + 4" is extremely unmanagable, and doing copies back and forth via temps is a bit annoying...

So you'd rather see me do a call like "asm_transformvertices(m_transformedVertList, m_blueprintVertList, m_xformMatrix);" instead of implementing it with inline assembly.

http://www.ultranos.com/asm
See "ATC" there  - C++ wrapper for MASM (sorry, no inline asm). Only doesn't support inheritance of 2 or more classes at once.
You'll need to use "EnterHostedClass" and "LeaveHostedClass" - to make ATC not build constructors.
Your above code would need the following asm:

EnterHostedClass

class TClass,,C++ compatible
	long m_dwVar1
	long m_dwVar2
	void Whatever
endclass

LeaveHostedClass


asm_TClass_Whatever proc ; usually would be TClass_Whatever
	assume ecx:ptr TClass
	
	mov eax,.dwVar1
	mov eax,.dwVar2
	
	assume ecx:nothing
	ret
asm_TClass_Whatever endp

You could rename asm_TClass_Whatever to the mangled name your C++ compiler makes (the ??TClass????Whatever@0AOZD) , for it to get recognized by the linker immediately...

No no, just define the class definition, even less - only the data-members.
It's mostly copy-paste work :)
If your class has no virtual funcs, I forgot to say, it has to be "non-virtual" instead of "C++ compatible"
But classes are mostly with virtual funcs (otherwise they're usually useless).

Anyway, it's recommended to know your compiler's output, and conform to it - then you'll be perfectly sure in what you're doing with that class data in asm.

Maybe a fourth solution will be to continue in C++, but have your code like this:

#define TClass__m_dwVar1	
#define TClass__m_dwVar2	

class TClass{
  public:
    dword m_dwVar1;
    dword m_dwVar2;
   
    void Whatever();
}

void TClass::Whatever() {
    __asm
    {
        mov ecx, this // btw, isn't this line useless??

        mov eax,TClass__m_dwVar1
        mov eax,TClass__m_dwVar2
     }
}

//-------- class CVirtual ---------------------
#define CVirtual__var1		
#define CVirtual__var2		

class CVirtual{
	virtual ~CVirtual();
  public:
    dword m_dwVar1;
    dword m_dwVar2;
   
    void DoIt();	
}

void CVirtual::DoIt() {
    __asm
    {
        mov eax,CVirtual__var1
        add eax,CVirtual__var2
     }
}

Then later, just modify the defines if necessary