Efficient way to calculate the minimum power of 2 that is greater than or equal to the given integer

bit_ceil.go

package main

import (
	"fmt"
	"math/bits"
)

// BitCeil returns the minimum power of 2 that is greater than or equal to x.
// It returns 1 when x is 0.
func BitCeil(x uint) uint {
	if x < 2 {
		return 1
	}
	return 1 << (bits.UintSize - bits.LeadingZeros(x-1))
}

func main() {
	for i := range 30 {
		fmt.Printf("i = %d, BitCeil(i) = %d\n", i, BitCeil(uint(i)))
	}
}