1/* k_tanf.c -- float version of k_tan.c
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
| 1/* k_tanf.c -- float version of k_tan.c
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
| 3 * Optimized by Bruce D. Evans.
|
3 */
4
5/*
6 * ====================================================
7 * Copyright 2004 Sun Microsystems, Inc. All Rights Reserved.
8 *
9 * Permission to use, copy, modify, and distribute this
10 * software is freely granted, provided that this notice
11 * is preserved.
12 * ====================================================
13 */
14
| 4 */
5
6/*
7 * ====================================================
8 * Copyright 2004 Sun Microsystems, Inc. All Rights Reserved.
9 *
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
|
15#ifndef INLINE_KERNEL_TANF
| 16#ifndef INLINE_KERNEL_TANDF
|
16#ifndef lint
| 17#ifndef lint
|
17static char rcsid[] = "$FreeBSD: head/lib/msun/src/k_tanf.c 152766 2005-11-24 13:48:40Z bde $";
| 18static char rcsid[] = "$FreeBSD: head/lib/msun/src/k_tanf.c 152870 2005-11-28 05:35:32Z bde $";
|
18#endif
19#endif
20
21#include "math.h"
22#include "math_private.h"
23
24/* |tan(x)/x - t(x)| < 2**-25.5 (~[-2e-08, 2e-08]). */
25static const double
26T[] = {
27 0x15554d3418c99f.0p-54, /* 0.333331395030791399758 */
28 0x1112fd38999f72.0p-55, /* 0.133392002712976742718 */
29 0x1b54c91d865afe.0p-57, /* 0.0533812378445670393523 */
30 0x191df3908c33ce.0p-58, /* 0.0245283181166547278873 */
31 0x185dadfcecf44e.0p-61, /* 0.00297435743359967304927 */
32 0x1362b9bf971bcd.0p-59, /* 0.00946564784943673166728 */
33};
34
| 19#endif
20#endif
21
22#include "math.h"
23#include "math_private.h"
24
25/* |tan(x)/x - t(x)| < 2**-25.5 (~[-2e-08, 2e-08]). */
26static const double
27T[] = {
28 0x15554d3418c99f.0p-54, /* 0.333331395030791399758 */
29 0x1112fd38999f72.0p-55, /* 0.133392002712976742718 */
30 0x1b54c91d865afe.0p-57, /* 0.0533812378445670393523 */
31 0x191df3908c33ce.0p-58, /* 0.0245283181166547278873 */
32 0x185dadfcecf44e.0p-61, /* 0.00297435743359967304927 */
33 0x1362b9bf971bcd.0p-59, /* 0.00946564784943673166728 */
34};
35
|
35#ifdef INLINE_KERNEL_TANF
| 36#ifdef INLINE_KERNEL_TANDF
|
36extern inline
37#endif
38float
39__kernel_tandf(double x, int iy)
40{
41 double z,r,w,s;
42
43 z = x*x;
44 w = z*z;
45 /* Break x^5*(T[1]+x^2*T[2]+...) into
46 * x^5*(T[1]+x^4*T[3]+x^8*T[5]) +
47 * x^5*(x^2*(T[2]+x^4*T[4]))
48 */
| 37extern inline
38#endif
39float
40__kernel_tandf(double x, int iy)
41{
42 double z,r,w,s;
43
44 z = x*x;
45 w = z*z;
46 /* Break x^5*(T[1]+x^2*T[2]+...) into
47 * x^5*(T[1]+x^4*T[3]+x^8*T[5]) +
48 * x^5*(x^2*(T[2]+x^4*T[4]))
49 */
|
49 r = T[1]+w*(T[3]+w*T[5]) + z*(T[2]+w*T[4]);
| 50 r = (T[1]+w*(T[3]+w*T[5])) + z*(T[2]+w*T[4]);
|
50 s = z*x;
51 r = (x+s*T[0])+(s*z)*r;
52 if(iy==1) return r;
53 else return -1.0/r;
54}
| 51 s = z*x;
52 r = (x+s*T[0])+(s*z)*r;
53 if(iy==1) return r;
54 else return -1.0/r;
55}
|