1/* s_tanf.c -- float version of s_tan.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5/*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16#ifndef lint
| 1/* s_tanf.c -- float version of s_tan.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5/*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16#ifndef lint
|
17static char rcsid[] = "$FreeBSD: head/lib/msun/src/s_tanf.c 152540 2005-11-17 03:53:22Z bde $";
| 17static char rcsid[] = "$FreeBSD: head/lib/msun/src/s_tanf.c 152596 2005-11-19 02:38:27Z bde $";
|
18#endif
19
20#include "math.h"
21#include "math_private.h"
22
| 18#endif
19
20#include "math.h"
21#include "math_private.h"
22
|
| 23/* Small multiples of pi/2 rounded to double precision. */
24static const double
25t1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */
26t2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */
27t3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */
28t4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
29
30static inline float
31__kernel_tandf(double x, int iy)
32{
33 return __kernel_tanf((float)x, x - (float)x, iy);
34}
35
|
23float
24tanf(float x)
25{
| 36float
37tanf(float x)
38{
|
26 float y[2];
27 int32_t n, ix;
| 39 float y[2],z=0.0;
40 int32_t n, hx, ix;
|
28
| 41
|
29 GET_FLOAT_WORD(ix,x);
30 ix &= 0x7fffffff;
| 42 GET_FLOAT_WORD(hx,x);
43 ix = hx & 0x7fffffff;
|
31
32 if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
33 if(ix<0x39800000) /* |x| < 2**-12 */
34 if(((int)x)==0) return x; /* x with inexact if x != 0 */
| 44
45 if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
46 if(ix<0x39800000) /* |x| < 2**-12 */
47 if(((int)x)==0) return x; /* x with inexact if x != 0 */
|
35 return __kernel_tanf(x,0.0,1);
| 48 return __kernel_tanf(x,z,1);
|
36 }
| 49 }
|
| 50 if(ix<=0x407b53d1) { /* |x| ~<= 5*pi/4 */
51 if(ix<=0x4016cbe3) /* |x| ~<= 3pi/4 */
52 return __kernel_tandf(x + (hx>0 ? -t1pio2 : t1pio2), -1);
53 else
54 return __kernel_tandf(x + (hx>0 ? -t2pio2 : t2pio2), 1);
55 }
56 if(ix<=0x40e231d5) { /* |x| ~<= 9*pi/4 */
57 if(ix<=0x40afeddf) /* |x| ~<= 7*pi/4 */
58 return __kernel_tandf(x + (hx>0 ? -t3pio2 : t3pio2), -1);
59 else
60 return __kernel_tandf(x + (hx>0 ? -t4pio2 : t4pio2), 1);
61 }
|
37
38 /* tan(Inf or NaN) is NaN */
39 else if (ix>=0x7f800000) return x-x;
40
| 62
63 /* tan(Inf or NaN) is NaN */
64 else if (ix>=0x7f800000) return x-x;
65
|
41 /* argument reduction needed */
| 66 /* general argument reduction needed */
|
42 else {
43 n = __ieee754_rem_pio2f(x,y);
44 /* integer parameter: 1 -- n even; -1 -- n odd */
45 return __kernel_tanf(y[0],y[1],1-((n&1)<<1));
46 }
47}
| 67 else {
68 n = __ieee754_rem_pio2f(x,y);
69 /* integer parameter: 1 -- n even; -1 -- n odd */
70 return __kernel_tanf(y[0],y[1],1-((n&1)<<1));
71 }
72}
|