Go: math/bits Index | Examples | Files

package bits

import "math/bits"

Package bits implements bit counting and manipulation functions for the predeclared unsigned integer types.

Index

Examples

Package Files

bits.go bits_tables.go

Constants

const UintSize = uintSize

UintSize is the size of a uint in bits.

func Add Uses

func Add(x, y, carry uint) (sum, carryOut uint)

Add returns the sum with carry of x, y and carry: sum = x + y + carry. The carry input must be 0 or 1; otherwise the behavior is undefined. The carryOut output is guaranteed to be 0 or 1.

func Add32 Uses

func Add32(x, y, carry uint32) (sum, carryOut uint32)

Add32 returns the sum with carry of x, y and carry: sum = x + y + carry. The carry input must be 0 or 1; otherwise the behavior is undefined. The carryOut output is guaranteed to be 0 or 1.

func Add64 Uses

func Add64(x, y, carry uint64) (sum, carryOut uint64)

Add64 returns the sum with carry of x, y and carry: sum = x + y + carry. The carry input must be 0 or 1; otherwise the behavior is undefined. The carryOut output is guaranteed to be 0 or 1.

func Div Uses

func Div(hi, lo, y uint) (quo, rem uint)

Div returns the quotient and remainder of (hi, lo) divided by y: quo = (hi, lo)/y, rem = (hi, lo)%y with the dividend bits' upper half in parameter hi and the lower half in parameter lo. Div panics for y == 0 (division by zero) or y <= hi (quotient overflow).

func Div32 Uses

func Div32(hi, lo, y uint32) (quo, rem uint32)

Div32 returns the quotient and remainder of (hi, lo) divided by y: quo = (hi, lo)/y, rem = (hi, lo)%y with the dividend bits' upper half in parameter hi and the lower half in parameter lo. Div32 panics for y == 0 (division by zero) or y <= hi (quotient overflow).

func Div64 Uses

func Div64(hi, lo, y uint64) (quo, rem uint64)

Div64 returns the quotient and remainder of (hi, lo) divided by y: quo = (hi, lo)/y, rem = (hi, lo)%y with the dividend bits' upper half in parameter hi and the lower half in parameter lo. Div64 panics for y == 0 (division by zero) or y <= hi (quotient overflow).

func LeadingZeros Uses

func LeadingZeros(x uint) int

LeadingZeros returns the number of leading zero bits in x; the result is UintSize for x == 0.

func LeadingZeros16 Uses

func LeadingZeros16(x uint16) int

LeadingZeros16 returns the number of leading zero bits in x; the result is 16 for x == 0.

Code:play 

fmt.Printf("LeadingZeros16(%016b) = %d\n", 1, bits.LeadingZeros16(1))

Output:

LeadingZeros16(0000000000000001) = 15

func LeadingZeros32 Uses

func LeadingZeros32(x uint32) int

LeadingZeros32 returns the number of leading zero bits in x; the result is 32 for x == 0.

Code:play 

fmt.Printf("LeadingZeros32(%032b) = %d\n", 1, bits.LeadingZeros32(1))

Output:

LeadingZeros32(00000000000000000000000000000001) = 31

func LeadingZeros64 Uses

func LeadingZeros64(x uint64) int

LeadingZeros64 returns the number of leading zero bits in x; the result is 64 for x == 0.

Code:play 

fmt.Printf("LeadingZeros64(%064b) = %d\n", 1, bits.LeadingZeros64(1))

Output:

LeadingZeros64(0000000000000000000000000000000000000000000000000000000000000001) = 63

func LeadingZeros8 Uses

func LeadingZeros8(x uint8) int

LeadingZeros8 returns the number of leading zero bits in x; the result is 8 for x == 0.

Code:play 

fmt.Printf("LeadingZeros8(%08b) = %d\n", 1, bits.LeadingZeros8(1))

Output:

LeadingZeros8(00000001) = 7

func Len Uses

func Len(x uint) int

Len returns the minimum number of bits required to represent x; the result is 0 for x == 0.

func Len16 Uses

func Len16(x uint16) (n int)

Len16 returns the minimum number of bits required to represent x; the result is 0 for x == 0.

Code:play 

fmt.Printf("Len16(%016b) = %d\n", 8, bits.Len16(8))

Output:

Len16(0000000000001000) = 4

func Len32 Uses

func Len32(x uint32) (n int)

Len32 returns the minimum number of bits required to represent x; the result is 0 for x == 0.

Code:play 

fmt.Printf("Len32(%032b) = %d\n", 8, bits.Len32(8))

Output:

Len32(00000000000000000000000000001000) = 4

func Len64 Uses

func Len64(x uint64) (n int)

Len64 returns the minimum number of bits required to represent x; the result is 0 for x == 0.

Code:play 

fmt.Printf("Len64(%064b) = %d\n", 8, bits.Len64(8))

Output:

Len64(0000000000000000000000000000000000000000000000000000000000001000) = 4

func Len8 Uses

func Len8(x uint8) int

Len8 returns the minimum number of bits required to represent x; the result is 0 for x == 0.

Code:play 

fmt.Printf("Len8(%08b) = %d\n", 8, bits.Len8(8))

Output:

Len8(00001000) = 4

func Mul Uses

func Mul(x, y uint) (hi, lo uint)

Mul returns the full-width product of x and y: (hi, lo) = x * y with the product bits' upper half returned in hi and the lower half returned in lo.

func Mul32 Uses

func Mul32(x, y uint32) (hi, lo uint32)

Mul32 returns the 64-bit product of x and y: (hi, lo) = x * y with the product bits' upper half returned in hi and the lower half returned in lo.

func Mul64 Uses

func Mul64(x, y uint64) (hi, lo uint64)

Mul64 returns the 128-bit product of x and y: (hi, lo) = x * y with the product bits' upper half returned in hi and the lower half returned in lo.

func OnesCount Uses

func OnesCount(x uint) int

OnesCount returns the number of one bits ("population count") in x.

func OnesCount16 Uses

func OnesCount16(x uint16) int

OnesCount16 returns the number of one bits ("population count") in x.

Code:play 

fmt.Printf("OnesCount16(%016b) = %d\n", 14, bits.OnesCount16(14))

Output:

OnesCount16(0000000000001110) = 3

func OnesCount32 Uses

func OnesCount32(x uint32) int

OnesCount32 returns the number of one bits ("population count") in x.

Code:play 

fmt.Printf("OnesCount32(%032b) = %d\n", 14, bits.OnesCount32(14))

Output:

OnesCount32(00000000000000000000000000001110) = 3

func OnesCount64 Uses

func OnesCount64(x uint64) int

OnesCount64 returns the number of one bits ("population count") in x.

Code:play 

fmt.Printf("OnesCount64(%064b) = %d\n", 14, bits.OnesCount64(14))

Output:

OnesCount64(0000000000000000000000000000000000000000000000000000000000001110) = 3

func OnesCount8 Uses

func OnesCount8(x uint8) int

OnesCount8 returns the number of one bits ("population count") in x.

Code:play 

fmt.Printf("OnesCount8(%08b) = %d\n", 14, bits.OnesCount8(14))

Output:

OnesCount8(00001110) = 3

func Reverse Uses

func Reverse(x uint) uint

Reverse returns the value of x with its bits in reversed order.

func Reverse16 Uses

func Reverse16(x uint16) uint16

Reverse16 returns the value of x with its bits in reversed order.

Code:play 

fmt.Printf("%016b\n", 19)
fmt.Printf("%016b\n", bits.Reverse16(19))

Output:

0000000000010011
1100100000000000

func Reverse32 Uses

func Reverse32(x uint32) uint32

Reverse32 returns the value of x with its bits in reversed order.

Code:play 

fmt.Printf("%032b\n", 19)
fmt.Printf("%032b\n", bits.Reverse32(19))

Output:

00000000000000000000000000010011
11001000000000000000000000000000

func Reverse64 Uses

func Reverse64(x uint64) uint64

Reverse64 returns the value of x with its bits in reversed order.

Code:play 

fmt.Printf("%064b\n", 19)
fmt.Printf("%064b\n", bits.Reverse64(19))

Output:

0000000000000000000000000000000000000000000000000000000000010011
1100100000000000000000000000000000000000000000000000000000000000

func Reverse8 Uses

func Reverse8(x uint8) uint8

Reverse8 returns the value of x with its bits in reversed order.

Code:play 

fmt.Printf("%08b\n", 19)
fmt.Printf("%08b\n", bits.Reverse8(19))

Output:

00010011
11001000

func ReverseBytes Uses

func ReverseBytes(x uint) uint

ReverseBytes returns the value of x with its bytes in reversed order.

func ReverseBytes16 Uses

func ReverseBytes16(x uint16) uint16

ReverseBytes16 returns the value of x with its bytes in reversed order.

Code:play 

fmt.Printf("%016b\n", 15)
fmt.Printf("%016b\n", bits.ReverseBytes16(15))

Output:

0000000000001111
0000111100000000

func ReverseBytes32 Uses

func ReverseBytes32(x uint32) uint32

ReverseBytes32 returns the value of x with its bytes in reversed order.

Code:play 

fmt.Printf("%032b\n", 15)
fmt.Printf("%032b\n", bits.ReverseBytes32(15))

Output:

00000000000000000000000000001111
00001111000000000000000000000000

func ReverseBytes64 Uses

func ReverseBytes64(x uint64) uint64

ReverseBytes64 returns the value of x with its bytes in reversed order.

Code:play 

fmt.Printf("%064b\n", 15)
fmt.Printf("%064b\n", bits.ReverseBytes64(15))

Output:

0000000000000000000000000000000000000000000000000000000000001111
0000111100000000000000000000000000000000000000000000000000000000

func RotateLeft Uses

func RotateLeft(x uint, k int) uint

RotateLeft returns the value of x rotated left by (k mod UintSize) bits. To rotate x right by k bits, call RotateLeft(x, -k).

func RotateLeft16 Uses

func RotateLeft16(x uint16, k int) uint16

RotateLeft16 returns the value of x rotated left by (k mod 16) bits. To rotate x right by k bits, call RotateLeft16(x, -k).

Code:play 

fmt.Printf("%016b\n", 15)
fmt.Printf("%016b\n", bits.RotateLeft16(15, 2))
fmt.Printf("%016b\n", bits.RotateLeft16(15, -2))

Output:

0000000000001111
0000000000111100
1100000000000011

func RotateLeft32 Uses

func RotateLeft32(x uint32, k int) uint32

RotateLeft32 returns the value of x rotated left by (k mod 32) bits. To rotate x right by k bits, call RotateLeft32(x, -k).

Code:play 

fmt.Printf("%032b\n", 15)
fmt.Printf("%032b\n", bits.RotateLeft32(15, 2))
fmt.Printf("%032b\n", bits.RotateLeft32(15, -2))

Output:

00000000000000000000000000001111
00000000000000000000000000111100
11000000000000000000000000000011

func RotateLeft64 Uses

func RotateLeft64(x uint64, k int) uint64

RotateLeft64 returns the value of x rotated left by (k mod 64) bits. To rotate x right by k bits, call RotateLeft64(x, -k).

Code:play 

fmt.Printf("%064b\n", 15)
fmt.Printf("%064b\n", bits.RotateLeft64(15, 2))
fmt.Printf("%064b\n", bits.RotateLeft64(15, -2))

Output:

0000000000000000000000000000000000000000000000000000000000001111
0000000000000000000000000000000000000000000000000000000000111100
1100000000000000000000000000000000000000000000000000000000000011

func RotateLeft8 Uses

func RotateLeft8(x uint8, k int) uint8

RotateLeft8 returns the value of x rotated left by (k mod 8) bits. To rotate x right by k bits, call RotateLeft8(x, -k).

Code:play 

fmt.Printf("%08b\n", 15)
fmt.Printf("%08b\n", bits.RotateLeft8(15, 2))
fmt.Printf("%08b\n", bits.RotateLeft8(15, -2))

Output:

00001111
00111100
11000011

func Sub Uses

func Sub(x, y, borrow uint) (diff, borrowOut uint)

Sub returns the difference of x, y and borrow: diff = x - y - borrow. The borrow input must be 0 or 1; otherwise the behavior is undefined. The borrowOut output is guaranteed to be 0 or 1.

func Sub32 Uses

func Sub32(x, y, borrow uint32) (diff, borrowOut uint32)

Sub32 returns the difference of x, y and borrow, diff = x - y - borrow. The borrow input must be 0 or 1; otherwise the behavior is undefined. The borrowOut output is guaranteed to be 0 or 1.

func Sub64 Uses

func Sub64(x, y, borrow uint64) (diff, borrowOut uint64)

Sub64 returns the difference of x, y and borrow: diff = x - y - borrow. The borrow input must be 0 or 1; otherwise the behavior is undefined. The borrowOut output is guaranteed to be 0 or 1.

func TrailingZeros Uses

func TrailingZeros(x uint) int

TrailingZeros returns the number of trailing zero bits in x; the result is UintSize for x == 0.

func TrailingZeros16 Uses

func TrailingZeros16(x uint16) int

TrailingZeros16 returns the number of trailing zero bits in x; the result is 16 for x == 0.

Code:play 

fmt.Printf("TrailingZeros16(%016b) = %d\n", 14, bits.TrailingZeros16(14))

Output:

TrailingZeros16(0000000000001110) = 1

func TrailingZeros32 Uses

func TrailingZeros32(x uint32) int

TrailingZeros32 returns the number of trailing zero bits in x; the result is 32 for x == 0.

Code:play 

fmt.Printf("TrailingZeros32(%032b) = %d\n", 14, bits.TrailingZeros32(14))

Output:

TrailingZeros32(00000000000000000000000000001110) = 1

func TrailingZeros64 Uses

func TrailingZeros64(x uint64) int

TrailingZeros64 returns the number of trailing zero bits in x; the result is 64 for x == 0.

Code:play 

fmt.Printf("TrailingZeros64(%064b) = %d\n", 14, bits.TrailingZeros64(14))

Output:

TrailingZeros64(0000000000000000000000000000000000000000000000000000000000001110) = 1

func TrailingZeros8 Uses

func TrailingZeros8(x uint8) int

TrailingZeros8 returns the number of trailing zero bits in x; the result is 8 for x == 0.

Code:play 

fmt.Printf("TrailingZeros8(%08b) = %d\n", 14, bits.TrailingZeros8(14))

Output:

TrailingZeros8(00001110) = 1

Package bits imports 1 packages (graph) and is imported by 846 packages. Updated 2019-07-09. Refresh now. Tools for package owners.