xref: /freebsd/lib/msun/src/s_sinf.c (revision 952d112864d8008aa87278a30a539d888a8493cd)
1 /* s_sinf.c -- float version of s_sin.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
17 static char rcsid[] = "$Id$";
18 #endif
19 
20 #include "math.h"
21 #include "math_private.h"
22 
23 #ifdef __STDC__
24 	float sinf(float x)
25 #else
26 	float sinf(x)
27 	float x;
28 #endif
29 {
30 	float y[2],z=0.0;
31 	int32_t n, ix;
32 
33 	GET_FLOAT_WORD(ix,x);
34 
35     /* |x| ~< pi/4 */
36 	ix &= 0x7fffffff;
37 	if(ix <= 0x3f490fd8) return __kernel_sinf(x,z,0);
38 
39     /* sin(Inf or NaN) is NaN */
40 	else if (ix>=0x7f800000) return x-x;
41 
42     /* argument reduction needed */
43 	else {
44 	    n = __ieee754_rem_pio2f(x,y);
45 	    switch(n&3) {
46 		case 0: return  __kernel_sinf(y[0],y[1],1);
47 		case 1: return  __kernel_cosf(y[0],y[1]);
48 		case 2: return -__kernel_sinf(y[0],y[1],1);
49 		default:
50 			return -__kernel_cosf(y[0],y[1]);
51 	    }
52 	}
53 }
54