| /* k_cosf.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 <math.h> |
| #include "math_private.h" |
| |
| static const float |
| 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 */ |
| |
| float |
| __kernel_cosf(float x, float y) |
| { |
| 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)); |
| } |
| } |