[gameprogrammer] Re: Pushing on stack in assembly
- From: "Ed Sinjiashvili" <ed.sinjiashvili@xxxxxxxxx>
- To: gameprogrammer@xxxxxxxxxxxxx
- Date: Sun, 23 Mar 2008 11:18:07 +0300
On 3/22/08, Kevin Jenkins <gameprogrammer@xxxxxxxxxx> wrote:
>
> Almost got my variadic RPC working. But pushing on the stack isn't
> working for me. If anyone knows assembly, can they tell me what I'm
> doing wrong?
>
> // Load variable source address for movsd instruction.
> lea esi,stack
Assuming that your 'stack' variable is just a pointer to where you
store parameters for next call,
you should use 'mov esi, stack', instead of 'lea esi, stack'. The latter
will grab the pointer to your pointer.
Anyway, I've
tried to emulate what you are doing and it works fine for me. Here's the code:
#include <malloc.h>
void _cdecl func(char b, unsigned long long a)
{
printf("Int: %lli, Char %c\n", a, b);
}
void call_with_asm(unsigned long long a, char b)
{
int stack_size = sizeof(unsigned long long) + sizeof(int);
int loop_count = stack_size / 4;
char *stack = (char *) _alloca(stack_size);
int *p = (int *) stack;
*p ++ = (int) b;
*p ++ = (int) (a);
*p = (int) (a >> 32);
__asm {
push esi
push edi
push ecx
sub esp, stack_size
mov esi, stack
mov edi, esp
mov ecx, loop_count
cld
rep movsd
call func
add esp, stack_size
pop ecx
pop edi
pop esi
}
}
int _tmain(int argc, _TCHAR* argv[])
{
unsigned long long d = 100000000000;
func('J', d);
call_with_asm(d, 'Y');
return 0;
}
-- Ed
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