github.com/coyove/sdss@v0.0.0-20231129015646-c2ec58cca6a2/contrib/roaring/popcnt.go (about)

     1  //go:build go1.9
     2  // +build go1.9
     3  
     4  // "go1.9", from Go version 1.9 onward
     5  // See https://golang.org/pkg/go/build/#hdr-Build_Constraints
     6  
     7  package roaring
     8  
     9  import "math/bits"
    10  
    11  func popcount(x uint64) uint64 {
    12  	return uint64(bits.OnesCount64(x))
    13  }