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.
7 // Frexp breaks f into a normalized fraction
8 // and an integral power of two.
9 // It returns frac and exp satisfying f == frac × 2**exp,
10 // with the absolute value of frac in the interval [½, 1).
14 // Frexp(±Inf) = ±Inf, 0
15 // Frexp(NaN) = NaN, 0
16 func Frexp(f
float64) (frac
float64, exp
int) {
20 func frexp(f
float64) (frac
float64, exp
int) {
24 return f
, 0 // correctly return -0
25 case IsInf(f
, 0) ||
IsNaN(f
):
30 exp
+= int((x
>>shift
)&mask
) - bias
+ 1
32 x |
= (-1 + bias
) << shift
33 frac
= Float64frombits(x
)