// Copyright 2017 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 runtime

import 

var inf = float64frombits(0x7FF0000000000000)

// isNaN reports whether f is an IEEE 754 ``not-a-number'' value.
func isNaN( float64) ( bool) {
	// IEEE 754 says that only NaNs satisfy f != f.
	return  != 
}

// isFinite reports whether f is neither NaN nor an infinity.
func isFinite( float64) bool {
	return !isNaN( - )
}

// isInf reports whether f is an infinity.
func isInf( float64) bool {
	return !isNaN() && !isFinite()
}

// Abs returns the absolute value of x.
//
// Special cases are:
//	Abs(┬▒Inf) = +Inf
//	Abs(NaN) = NaN
func abs( float64) float64 {
	const  = 1 << 63
	return float64frombits(float64bits() &^ )
}

// copysign returns a value with the magnitude
// of x and the sign of y.
func copysign(,  float64) float64 {
	const  = 1 << 63
	return float64frombits(float64bits()&^ | float64bits()&)
}

// Float64bits returns the IEEE 754 binary representation of f.
func float64bits( float64) uint64 {
	return *(*uint64)(unsafe.Pointer(&))
}

// Float64frombits returns the floating point number corresponding
// the IEEE 754 binary representation b.
func float64frombits( uint64) float64 {
	return *(*float64)(unsafe.Pointer(&))
}