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 | } |