github.com/euank/go@v0.0.0-20160829210321-495514729181/src/math/abs.go (about)

     1  // Copyright 2009 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  // Abs returns the absolute value of x.
     8  //
     9  // Special cases are:
    10  //	Abs(±Inf) = +Inf
    11  //	Abs(NaN) = NaN
    12  func Abs(x float64) float64 {
    13  	// TODO: once golang.org/issue/13095 is fixed, change this to:
    14  	// return Float64frombits(Float64bits(x) &^ (1 << 63))
    15  	// But for now, this generates better code and can also be inlined:
    16  	if x < 0 {
    17  		return -x
    18  	}
    19  	if x == 0 {
    20  		return 0 // return correctly abs(-0)
    21  	}
    22  	return x
    23  }