blob: e99f2348c00dff6b6e00dda51ea5b22343f06a6f (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
|
/* origin: FreeBSD /usr/src/lib/msun/src/k_cosf.c */
/*
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
* Debugged and optimized by Bruce D. Evans.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/* |cos(x) - c(x)| < 2**-34.1 (~[-5.37e-11, 5.295e-11]). */
const C0: f64 = -0.499999997251031003120; /* -0x1ffffffd0c5e81.0p-54 */
const C1: f64 = 0.0416666233237390631894; /* 0x155553e1053a42.0p-57 */
const C2: f64 = -0.00138867637746099294692; /* -0x16c087e80f1e27.0p-62 */
const C3: f64 = 0.0000243904487962774090654; /* 0x199342e0ee5069.0p-68 */
#[cfg_attr(all(test, assert_no_panic), no_panic::no_panic)]
pub(crate) fn k_cosf(x: f64) -> f32 {
let z = x * x;
let w = z * z;
let r = C2 + z * C3;
(((1.0 + z * C0) + w * C1) + (w * z) * r) as f32
}
|
