github.com/mattn/go@v0.0.0-20171011075504-07f7db3ea99f/src/math/signbit.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  // Signbit returns true if x is negative or negative zero.
     8  func Signbit(x float64) bool {
     9  	return Float64bits(x)&(1<<63) != 0
    10  }