Reverse Bit Order

// Following function will reverse bits order (e.g.: 1101 -> 1011)
// in DWORD value (Integer, Cardinal).
function reverseBits(_EAX: Cardinal); assembler; register;
asm
xor edx, edx
mov ecx, 32
@Again:
shr eax, 1
rcl edx, 1
loop @Again
mov eax, edx
end;