Update.
[glibc.git] / sysdeps / libm-ieee754 / s_cosf.c
blob86c59d440ca98be4eae0c63855acd4c459cb85d4
1 /* s_cosf.c -- float version of s_cos.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
5 /*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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 * ====================================================
16 #if defined(LIBM_SCCS) && !defined(lint)
17 static char rcsid[] = "$NetBSD: s_cosf.c,v 1.4 1995/05/10 20:47:03 jtc Exp $";
18 #endif
20 #include "math.h"
21 #include "math_private.h"
23 #ifdef __STDC__
24 static const float one=1.0;
25 #else
26 static float one=1.0;
27 #endif
29 #ifdef __STDC__
30 float __cosf(float x)
31 #else
32 float __cosf(x)
33 float x;
34 #endif
36 float y[2],z=0.0;
37 int32_t n,ix;
39 GET_FLOAT_WORD(ix,x);
41 /* |x| ~< pi/4 */
42 ix &= 0x7fffffff;
43 if(ix <= 0x3f490fd8) return __kernel_cosf(x,z);
45 /* cos(Inf or NaN) is NaN */
46 else if (ix>=0x7f800000) return x-x;
48 /* argument reduction needed */
49 else {
50 n = __ieee754_rem_pio2f(x,y);
51 switch(n&3) {
52 case 0: return __kernel_cosf(y[0],y[1]);
53 case 1: return -__kernel_sinf(y[0],y[1],1);
54 case 2: return -__kernel_cosf(y[0],y[1]);
55 default:
56 return __kernel_sinf(y[0],y[1],1);
60 weak_alias (__cosf, cosf)