Source file src/pkg/math/modf.go
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.
4
5 package math
6
7 // Modf returns integer and fractional floating-point numbers
8 // that sum to f. Both values have the same sign as f.
9 //
10 // Special cases are:
11 // Modf(±Inf) = ±Inf, NaN
12 // Modf(NaN) = NaN, NaN
13 func Modf(f float64) (int float64, frac float64)
14
15 func modf(f float64) (int float64, frac float64) {
16 if f < 1 {
17 if f < 0 {
18 int, frac = Modf(-f)
19 return -int, -frac
20 }
21 return 0, f
22 }
23
24 x := Float64bits(f)
25 e := uint(x>>shift)&mask - bias
26
27 // Keep the top 12+e bits, the integer part; clear the rest.
28 if e < 64-12 {
29 x &^= 1<<(64-12-e) - 1
30 }
31 int = Float64frombits(x)
32 frac = f - int
33 return
34 }