[Natsheh]

Shouldn't it be equal to ~( 1 << 32 )

[fysiks]

Shifting by more than the size of the datatype is undefined in C and C++ (which likely applies to Pawn) so it's not a valid thing to do. So, effectively, 1<<32 is an invalid operation. See here.

[Natsheh]

Thanks helped alot.

[Natsheh]

so i am a bit confused how do i get a value of 32 bits of 1 is it like this ?

( 31 << 31 ) ?

since ~0 is invalid but it should work, returning a 32 bits of 1

[Bugsy]

What do you mean by 32 bits of 1? What are you trying to do?

31 << 31 is something like:

31 = 0001 1111

31 shifted left 31 (I may be slightly off)
1111 1000 0000 0000 0000 0000 0000 0000 0000

Bitwise-not on 0 should flip all bits to 1

[Natsheh]

what bit shifting will give me the following flip all of them to 1 ?

[Bugsy]

Bit shifting does not flip any bits, it moves bits.

1 << 3
0000 0001 (value of 1 in bits)
to
0000 1000 (1 moved 3 positions to the left)

3 << 3
0000 0011 (value of 3 in bits)
to
0001 1000 (3 moved 3 positions to the left)

Try it

PHP Code:

new iVal = -1;
new szBits[ 33 ];
    
for ( new i = 31 ; i >= 0 ; i-- )
{
    szBits[ 31 - i ] = iVal & ( 1 << i ) ? '1' : '0';
}
    
server_print( "Bits = %s" , szBits ); 


[Natsheh]

so you're saying that value ( -1 ) is equal to 0xFFFFFFFF or i misunderstood ?

i already solved my issue with 0xFFFFFFFF i just want to know if -1 is the same and how ?

Originally Posted by Bugsy Bitwise-not on 0 should flip all bits to 1

well that was unexpected fail, i tested it out and it didn't work quiet well.

[Bugsy]

Read up on bits, there are tutorials all over the net, they are not specific to AMX-X.

What didn't work in the code I posted? It worked for me

PHP Code:

public test() 
{
    new iVal = ~0;
    new szBits[ 40 ];
    new iStringPos = charsmax( szBits );
    
    szBits[ iStringPos ] = EOS;
    
    for ( new i = 31 ; i >= 0 ; i-- )
    {
        szBits[ charsmax( szBits ) - iStringPos-- ] = iVal & ( 1 << i ) ? '1' : '0';
        
        if ( !( iStringPos % 5 ) && ( iStringPos > 0 ) )
            szBits[ charsmax( szBits ) - iStringPos-- ] = ' ';    
    }
    
    server_print( "Value = %d" , iVal );
    server_print( "Bits = %s" , szBits );
} 


Output:

Value = -1
Bits = 1111 1111 1111 1111 1111 1111 1111 1111

[fysiks]

Originally Posted by Natsheh so you're saying that value ( -1 ) is equal to 0xFFFFFFFF or i misunderstood ?

See Two's Complement.