Common bit manipulation tips (Golang)

This is a creation in Article, where the information may have evolved or changed.

1, Judge parity

For I: = 0; I < 100; i++ {

If I% 2 = = 0 {    println (i)}if I & 0x1 = = 0 {    println (i)}

}
2, swap two numbers

Func Swap (A, b *int) {

If *a^*b! = 0 {    Temp: = *a    *a = *b    *b = temp}

}

Func Swap (A, b *int) {

If *a^*b! = 0 {    *a = *a + *b    *b = *a-*b    *a = *a-*b}

}

Func Swap (A, b *int) {

If *a^*b! = 0 {    *a ^= *b    *b ^= *a    *a ^= *b}

}
3, swap symbol

Func Excangesymbol (a int) (ret int) {

ret = ^a + 1return

}
4, Absolute value

Func calcabs (a int) (ret int) {

ret = (a ^ a>>31)-A>>31return

}
5, binary in reverse order

Func bytereverse (a int) int {

A = ((A & 0xAAAA) >> 1) | ((A & 0x5555) << 1) A = ((A & 0xCCCC) >> 2) | ((A & 0x3333) << 2) A = ((A & 0xf0f0) >> 4) | ((A & 0x0f0f) << 4) A = ((A & 0xff00) >> 8) | ((A & 0x00FF) << 8) return a

}
6, ask for the number of 1

Func calconenum (a int) int {

A = ((A & 0xAAAA) >> 1) + (A & 0x5555) A = ((A & 0xCCCC) >> 2) + (A & 0x3333) A = ((A & 0xF0 F0) >> 4) + (A & 0x0f0f) A = ((A & 0xff00) >> 8) + (A & 0x00FF) return a

}