60 lines
1.5 KiB
C
60 lines
1.5 KiB
C
|
/* kf_cos.c -- float version of k_cos.c
|
||
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* ====================================================
|
||
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||
|
|
*
|
||
|
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
||
|
|
* Permission to use, copy, modify, and distribute this
|
||
|
|
* software is freely granted, provided that this notice
|
||
|
|
* is preserved.
|
||
|
|
* ====================================================
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "fdlibm.h"
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
static const float
|
||
|
|
#else
|
||
|
|
static float
|
||
|
|
#endif
|
||
|
|
one = 1.0000000000e+00, /* 0x3f800000 */
|
||
|
|
C1 = 4.1666667908e-02, /* 0x3d2aaaab */
|
||
|
|
C2 = -1.3888889225e-03, /* 0xbab60b61 */
|
||
|
|
C3 = 2.4801587642e-05, /* 0x37d00d01 */
|
||
|
|
C4 = -2.7557314297e-07, /* 0xb493f27c */
|
||
|
|
C5 = 2.0875723372e-09, /* 0x310f74f6 */
|
||
|
|
C6 = -1.1359647598e-11; /* 0xad47d74e */
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
float __kernel_cosf(float x, float y)
|
||
|
|
#else
|
||
|
|
float __kernel_cosf(x, y)
|
||
|
|
float x,y;
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
float a,hz,z,r,qx;
|
||
|
|
__int32_t ix;
|
||
|
|
GET_FLOAT_WORD(ix,x);
|
||
|
|
ix &= 0x7fffffff; /* ix = |x|'s high word*/
|
||
|
|
if(ix<0x32000000) { /* if x < 2**27 */
|
||
|
|
if(((int)x)==0) return one; /* generate inexact */
|
||
|
|
}
|
||
|
|
z = x*x;
|
||
|
|
r = z*(C1+z*(C2+z*(C3+z*(C4+z*(C5+z*C6)))));
|
||
|
|
if(ix < 0x3e99999a) /* if |x| < 0.3 */
|
||
|
|
return one - ((float)0.5*z - (z*r - x*y));
|
||
|
|
else {
|
||
|
|
if(ix > 0x3f480000) { /* x > 0.78125 */
|
||
|
|
qx = (float)0.28125;
|
||
|
|
} else {
|
||
|
|
SET_FLOAT_WORD(qx,ix-0x01000000); /* x/4 */
|
||
|
|
}
|
||
|
|
hz = (float)0.5*z-qx;
|
||
|
|
a = one-qx;
|
||
|
|
return a - (hz - (z*r-x*y));
|
||
|
|
}
|
||
|
|
}
|