2008-03-28 14:56:47 -06:00
|
|
|
// 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.
|
|
|
|
|
2008-06-27 18:06:23 -06:00
|
|
|
package math
|
2008-03-28 14:56:47 -06:00
|
|
|
|
|
|
|
/*
|
2008-07-08 21:48:41 -06:00
|
|
|
* floating-point mod func without infinity or NaN checking
|
2008-03-28 14:56:47 -06:00
|
|
|
*/
|
|
|
|
|
2009-01-20 15:40:40 -07:00
|
|
|
func Fmod(x, y float64) float64 {
|
2008-03-28 14:56:47 -06:00
|
|
|
if y == 0 {
|
|
|
|
return x;
|
|
|
|
}
|
|
|
|
if y < 0 {
|
|
|
|
y = -y;
|
|
|
|
}
|
|
|
|
|
2009-01-16 15:58:14 -07:00
|
|
|
yfr, yexp := sys.Frexp(y);
|
2008-11-19 17:14:31 -07:00
|
|
|
sign := false;
|
|
|
|
r := x;
|
2008-03-28 14:56:47 -06:00
|
|
|
if x < 0 {
|
|
|
|
r = -x;
|
|
|
|
sign = true;
|
|
|
|
}
|
|
|
|
|
|
|
|
for r >= y {
|
2009-01-16 15:58:14 -07:00
|
|
|
rfr, rexp := sys.Frexp(r);
|
2008-03-28 14:56:47 -06:00
|
|
|
if rfr < yfr {
|
|
|
|
rexp = rexp - 1;
|
|
|
|
}
|
2009-01-16 15:58:14 -07:00
|
|
|
r = r - sys.Ldexp(y, rexp-yexp);
|
2008-03-28 14:56:47 -06:00
|
|
|
}
|
|
|
|
if sign {
|
|
|
|
r = -r;
|
|
|
|
}
|
|
|
|
return r;
|
|
|
|
}
|