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