Retro68/gcc/libgo/go/math/abs.go

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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package math
// Abs returns the absolute value of x.
//
// Special cases are:
// Abs(±Inf) = +Inf
// Abs(NaN) = NaN
//extern fabs
func libc_fabs(float64) float64
func Abs(x float64) float64 {
return libc_fabs(x)
}
func abs(x float64) float64 {
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// TODO: once golang.org/issue/13095 is fixed, change this to:
// return Float64frombits(Float64bits(x) &^ (1 << 63))
// But for now, this generates better code and can also be inlined:
if x < 0 {
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return -x
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}
if x == 0 {
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return 0 // return correctly abs(-0)
}
return x
}