AVR: Why doesn't my if statement yield TRUE?

Question

int i=0;
DDRD = 0xff;
PORTC = 0xff;  
while (1) 
{ 
    if(PINC5 == 1)
    {...}

I have been trying to figure out why the comparison of PC5 pin of PORTC with 1 yields False everytime. I have activated the "pull up" resistor for every pins of Port C. But still, when I compare the PC5 to 1, I don't get the expected result.

I know the proper way is to do the comparison using the bit-masking.

if((PORTC &(1<<PORTC5))==0).

But I can't figure out why the code presented above doesn't work.

I feel like I am missing some fundamentals in bit-wise operators but can't figure out what exactly. Thank you!!

The datasheet of Atmega 328P says the following:

All registers and bit references in this section are written in general form. A lower case “x” represents the numbering letter for the port, and a lower case “n” represents the bit number. However, when using the register or bit defines in a program, the precise form must be used. For example, PORTB3 for bit no. 3 in Port B, here documented generally as PORTxn.

Answer 1

PINC5 and PORTC5 are defines that equate to 5. So the code does not read status of pins of IO port C at all to get the status of the bits, it is just comparing if number 5 is number 1 and it never is. Also, PORTC is the output data register. If you want to read status of a pushbutton, you must read PINC register.