Q: Assembly return in 64 bits a sum of two numbers of 32 bits A + B (both of 32 bits).
The function will return a value of 64 bits
What i have to do ?

A: Assuming input on the stack and result in edx:eax as per the normal conventions:
xor edx, edx       ; high dword
mov eax, [esp + 4] ; 1st arg
add eax, [esp + 8] ; add 2nd arg
adc edx, 0         ; handle carry
ret

