| 1 | /* k_sinf.c -- float version of k_sin.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 | #if defined(LIBM_SCCS) && !defined(lint) |
| 17 | static char rcsid[] = "$NetBSD: k_sinf.c,v 1.4 1995/05/10 20:46:33 jtc Exp $" ; |
| 18 | #endif |
| 19 | |
| 20 | #include <float.h> |
| 21 | #include <math.h> |
| 22 | #include <math_private.h> |
| 23 | |
| 24 | static const float |
| 25 | half = 5.0000000000e-01,/* 0x3f000000 */ |
| 26 | S1 = -1.6666667163e-01, /* 0xbe2aaaab */ |
| 27 | S2 = 8.3333337680e-03, /* 0x3c088889 */ |
| 28 | S3 = -1.9841270114e-04, /* 0xb9500d01 */ |
| 29 | S4 = 2.7557314297e-06, /* 0x3638ef1b */ |
| 30 | S5 = -2.5050759689e-08, /* 0xb2d72f34 */ |
| 31 | S6 = 1.5896910177e-10; /* 0x2f2ec9d3 */ |
| 32 | |
| 33 | float __kernel_sinf(float x, float y, int iy) |
| 34 | { |
| 35 | float z,r,v; |
| 36 | int32_t ix; |
| 37 | GET_FLOAT_WORD(ix,x); |
| 38 | ix &= 0x7fffffff; /* high word of x */ |
| 39 | if(ix<0x32000000) /* |x| < 2**-27 */ |
| 40 | { |
| 41 | math_check_force_underflow (x); |
| 42 | if ((int) x == 0) |
| 43 | return x; /* generate inexact */ |
| 44 | } |
| 45 | z = x*x; |
| 46 | v = z*x; |
| 47 | r = S2+z*(S3+z*(S4+z*(S5+z*S6))); |
| 48 | if(iy==0) return x+v*(S1+z*r); |
| 49 | else return x-((z*(half*y-v*r)-y)-v*S1); |
| 50 | } |
| 51 | |