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.
7 // Copysign returns a value with the magnitude of f
8 // and the sign of sign.
9 func Copysign(f, sign float64) float64 {
10 const signBit = 1 << 63
11 return Float64frombits(Float64bits(f)&^signBit | Float64bits(sign)&signBit)