0,0 → 1,59 |
/* 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)); |
} |
} |