Subversion Repositories shark

Rev

Rev 1618 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 pj 1
/* s_cosf.c -- float version of s_cos.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: s_cosf.c,v 1.2 1995/05/30 05:49:30 rgrimes Exp $";
18
#endif
19
 
20
#include "math.h"
21
#include "math_private.h"
22
 
23
#ifdef __STDC__
24
static const float one=1.0;
25
#else
26
static float one=1.0;
27
#endif
28
 
29
#ifdef __STDC__
30
        float cosf(float x)
31
#else
32
        float cosf(x)
33
        float x;
34
#endif
35
{
36
        float y[2],z=0.0;
37
        int32_t n,ix;
38
 
39
        GET_FLOAT_WORD(ix,x);
40
 
41
    /* |x| ~< pi/4 */
42
        ix &= 0x7fffffff;
43
        if(ix <= 0x3f490fd8) return __kernel_cosf(x,z);
44
 
45
    /* cos(Inf or NaN) is NaN */
46
        else if (ix>=0x7f800000) return x-x;
47
 
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);
57
            }
58
        }
59
}