assembly block code Error ?

[Jackyquah]

Inside function :

TCHAR TStr[100];
TCHAR *TTStr=TStr;

*1)
__asm {
mov AL,[TStr];
}

*2)
__asm{
mov AL,[TTStr];
}


*1) is works.
*2) didn't work, It's said error C2443 : operand size conflict.

why *2) doesn't works ?

[MrViggy]

I don't use assembly much, but my guess is that the issue is that 'TStr' is actually "sizeof(TCHAR)*100" bytes, and 'TTStr' is only 4 bytes (on a 32 bit machine).

However, I don't know what AL is....

Viggy

[SuperKoko]

sizeof(TCHAR)==1 when compiling a non-unicode project, which means that a TCHAR contains 1 byte.
AL contains one byte.

mov AL,[TSTR]

Works, because it is equivalent to:

mov AL, byte ptr [(offset TStr)]

That is, it moves the first byte of the array into AL.

But:

mov AL,[TTStr]

requests for moving TTStr (which is a 4 bytes variable) to a one-byte register.
Thus, the compiler complains.
You may try something like:

mov EAX, [TTStr]

In that case, the whole pointer will be copied to the EAX register.
And the lowest byte is stored in AL.