And again short post.
In this post I want to publish some tips about bit manipulation

WHOLE NUMBERS----------------------------------------------------

Setting the nth bit
x | (1<<n)

Clearing the nth bit
x & ~(1<<n)

Toggle nth bit
x ^ (1<<n)

Rounding to the next power of two
unsigned int v; //only works if v is 32 bit
v--;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
v++;

Getting the size of an integer
int maxInt = ~(1 << 31);
int maxInt = (1 << 31) - 1;
int maxInt = (1 << -1) - 1;

Getting the minimum integer
int minInt = 1 << 31;
int minInt = 1 << -1;

Getting the size of an long
long maxLong = ((long)1 << 127) - 1;

Multiplication by 2
n << 1;

Division by 2
n >> 1;

Multiplication by the mth power of 2
n << m;

Division by mth power 2
n >> m;

Equality check
(a^b) == 0; // a == b

Parity check
(n & 1) == 1;

Exchange of values
a ^= b;
b ^= a;
a ^= b;

The absolute value of a number
//version 1
x < 0 ? -x : x;

//version 2
(x ^ (x >> 31)) - (x >> 31);

Maximum of two numbers
b & ((a-b) >> 31) | a & (~(a-b) >> 31);

Minimum of two numbers
a & ((a-b) >> 31) | b & (~(a-b) >> 31);

Checking for the same sign
(x ^ y) >= 0;

Sign change
i = ~i + 1; // or
i = (i ^ -1) + 1; // i = -i

Calculating 2 ^ n
2 << (n-1);

Check for degree 2
n > 0 && (n & (n - 1)) == 0;

Remainder of 2 ^ n divided by m
m & (n - 1);

Average
(x + y) >> 1;
((x ^ y) >> 1) + (x & y);

Getting the mth bit n (from right to left)
(n >> (m-1)) & 1;

Setting the mth bit n (from right to left)
n & ~(1 << (m-1));

Checking the nth bit
if (x & (1<<n)) {
n-th bit is set
}
else {
n-th bit is not set
}

Selecting the rightmost 1
x & (-x)

Selecting the rightmost 0
~x & (x+1)

Change the rightmost 0 to 1
x | (x+1)

n+1
-~n

n-1
~-n

if (x==a) x=b; if (x==b) x=a;
x = a ^ b ^ x;

STRINGS---------------------------------------------------------

Convert letter to lowercase
(x | ' ')
//Result is always lowercase even if letter is already lowercase

Converting a letter to uppercase
(x & '_')
Result is always uppercase even if letter is already uppercase

Change the case of a letter
(x ^ ' ')
//eg. ('a' ^ ' ') => 'A' ; ('A' ^ ' ') => 'a'

Letter`s number in the alphabet
(x & "\x1F")
//Result is in 1..26 range, letter case is not important
//eg. ('a' & "\x1F") => 1 ; ('B' & "\x1F") => 2

Capital`s letter number in alphabet
(x & '?')
(x ^ '@')
//eg. ('C' & '?') => 3 ; ('Z' ^ '@') => 26

Lowercase letter number in alphabet
(x ^ ' ' ) //eg. ('d' ^ '') => 4 ; ('x' ^ '`') => 25

I hope it will useful ...