1 /* s_sinf.c -- float version of s_sin.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 * Optimized by Bruce D. Evans.
4 */
5
6 /*
7 * ====================================================
8 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9 *
10 * Developed at SunPro, a Sun Microsystems, Inc. business.
11 * Permission to use, copy, modify, and distribute this
12 * software is freely granted, provided that this notice
13 * is preserved.
14 * ====================================================
15 */
16
17 #ifndef lint
18 static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_sinf.c,v 1.14 2005/11/28 06:15:10 bde Exp $";
19 #endif
20
21 #include "math.h"
22 #define INLINE_KERNEL_COSDF
23 #define INLINE_KERNEL_SINDF
24 #include "math_private.h"
25 #include "k_cosf.c"
26 #include "k_sinf.c"
27
28 /* Small multiples of pi/2 rounded to double precision. */
29 static const double
30 s1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */
31 s2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */
32 s3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */
33 s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
34
35 float
sinf(float x)36 sinf(float x)
37 {
38 float y[2];
39 int32_t n, hx, ix;
40
41 GET_FLOAT_WORD(hx,x);
42 ix = hx & 0x7fffffff;
43
44 if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
45 if(ix<0x39800000) /* |x| < 2**-12 */
46 if(((int)x)==0) return x; /* x with inexact if x != 0 */
47 return __kernel_sindf(x);
48 }
49 if(ix<=0x407b53d1) { /* |x| ~<= 5*pi/4 */
50 if(ix<=0x4016cbe3) { /* |x| ~<= 3pi/4 */
51 if(hx>0)
52 return __kernel_cosdf(x - s1pio2);
53 else
54 return -__kernel_cosdf(x + s1pio2);
55 } else
56 return __kernel_sindf((hx > 0 ? s2pio2 : -s2pio2) - x);
57 }
58 if(ix<=0x40e231d5) { /* |x| ~<= 9*pi/4 */
59 if(ix<=0x40afeddf) { /* |x| ~<= 7*pi/4 */
60 if(hx>0)
61 return -__kernel_cosdf(x - s3pio2);
62 else
63 return __kernel_cosdf(x + s3pio2);
64 } else
65 return __kernel_sindf(x + (hx > 0 ? -s4pio2 : s4pio2));
66 }
67
68 /* sin(Inf or NaN) is NaN */
69 else if (ix>=0x7f800000) return x-x;
70
71 /* general argument reduction needed */
72 else {
73 n = __ieee754_rem_pio2f(x,y);
74 switch(n&3) {
75 case 0: return __kernel_sindf((double)y[0]+y[1]);
76 case 1: return __kernel_cosdf((double)y[0]+y[1]);
77 case 2: return __kernel_sindf(-(double)y[0]-y[1]);
78 default:
79 return -__kernel_cosdf((double)y[0]+y[1]);
80 }
81 }
82 }
83