github.com/liujq9674git/golang-src-1.7@v0.0.0-20230517174348-17f6ec47f3f8/src/math/copysign.go (about)

     1  // Copyright 2010 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package math
     6  
     7  // Copysign returns a value with the magnitude
     8  // of x and the sign of y.
     9  func Copysign(x, y float64) float64 {
    10  	const sign = 1 << 63
    11  	return Float64frombits(Float64bits(x)&^sign | Float64bits(y)&sign)
    12  }