Bitwise Operations
Go allows bit-wise operations in its language. This allows high-speed flag masking and low-level hardware interaction (if played nicely). In this section, we will look through the operations for bit manipulations. To know the basic of bits and math, you can visit the theory page.
Operators
For Go, however, the operators have some slight differences across various languages. They are:
& bitwise AND | bitwise OR ^ bitwise XOR&^ AND NOT<< left shift>> right shift^var NOTNOTE
- There is one extra:
AND NOT- This is for clearing bit with mask, a combined version of AND then NOT. Example:
- In C:
0xFF & ~0x0F = 0xF0 - In C:
0xAB & ~0x0F = 0xA0 - In Go:
0xFF &^ 0x0F = 0xF0 - In Go:
0xAB &^ 0x0F = 0xA0
- There is one special symbol:
NOT. Go doesn't support tilde (~) for bitwise operations.- In C:
~0x0F = 0xF0 - in Go:
^0x0F = 0xF0
- In C:
Basic Bit Operations
Now let's get into bit-wise operations. Here, we are looking at basic masking:
Selecting Bits
To select bits, you use the & operator.
0xAC & 0xF0 = 0xA00b10101100 & 0b11110000 = 0b10100000Clearing Bits
To clear bits, you use the &^ operator.
0xAC &^ 0xF0 = 0x0C0b10101100 &^ 0b11110000 = 0b00001100Set Bits
To set the bits, you use the | operator.
0xAC | 0xF0 = 0xFC0b10101100 | 0b11110000 = 0b11111100Flipping Bits
To flip the bits, you use the ^ (XOR) operator.
0xAC ^ 0xF0 = 0x5C0b10101100 ^ 0b11110000 = 0b01011100Shifting Operations
Now let's get into bit-wise shifting operations. You can either shift left or shift right by position numbers. Example:
0xAC & (1<<7) = 0x800b10101100 & 0b10000000 = 0b10000000Shift right will moves from the opposite side.
Bit Assignment
One thing to take note is that Go does not have binary literals (e.g. 0b00001010). Hence, the only best and easy way for you to set bit is to use shifting. Example:
0b00001010=(1 << 3) | (1 << 1)
That's all about bit-wise operations. Now you can switch 32 switches / 64 switches simultaneously depending on your processor, and save a lot of memory space too.