Common bit manipulation tips (Golang)

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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>>31 return}

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 & 0xf0f0) >> 4) + (A & 0x0f0f) A = ((A & 0xff00) >> 8) + (A & 0x00FF) return a}