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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
func libc_sqrt(float64) float64 __asm__("sqrt")
// Sqrt returns the square root of x.
//
// Special cases are:
// Sqrt(+Inf) = +Inf
// Sqrt(±0) = ±0
// Sqrt(x < 0) = NaN
// Sqrt(NaN) = NaN
func Sqrt(x float64) float64 {
// special cases
// TODO(rsc): Remove manual inlining of IsNaN, IsInf
// when compiler does it for us
switch {
case x == 0 || x != x || x > MaxFloat64: // x == 0 || IsNaN(x) || IsInf(x, 1):
return x
case x < 0:
return NaN()
}
return libc_sqrt(x)
}
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