13a8617a8SJordan K. Hubbard /* k_tanf.c -- float version of k_tan.c 23a8617a8SJordan K. Hubbard * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 3960d3da0SBruce Evans * Optimized by Bruce D. Evans. 43a8617a8SJordan K. Hubbard */ 53a8617a8SJordan K. Hubbard 63a8617a8SJordan K. Hubbard /* 73a8617a8SJordan K. Hubbard * ==================================================== 873fbb89dSDavid Schultz * Copyright 2004 Sun Microsystems, Inc. All Rights Reserved. 93a8617a8SJordan K. Hubbard * 103a8617a8SJordan K. Hubbard * Permission to use, copy, modify, and distribute this 113a8617a8SJordan K. Hubbard * software is freely granted, provided that this notice 123a8617a8SJordan K. Hubbard * is preserved. 133a8617a8SJordan K. Hubbard * ==================================================== 143a8617a8SJordan K. Hubbard */ 153a8617a8SJordan K. Hubbard 16960d3da0SBruce Evans #ifndef INLINE_KERNEL_TANDF 173a8617a8SJordan K. Hubbard #ifndef lint 187f3dea24SPeter Wemm static char rcsid[] = "$FreeBSD$"; 193a8617a8SJordan K. Hubbard #endif 204ce51209SBruce Evans #endif 213a8617a8SJordan K. Hubbard 223a8617a8SJordan K. Hubbard #include "math.h" 233a8617a8SJordan K. Hubbard #include "math_private.h" 24e96c4fd9SBruce Evans 2516638b55SBruce Evans /* |tan(x)/x - t(x)| < 2**-25.5 (~[-2e-08, 2e-08]). */ 2694a5f9beSBruce Evans static const double 273a8617a8SJordan K. Hubbard T[] = { 2816638b55SBruce Evans 0x15554d3418c99f.0p-54, /* 0.333331395030791399758 */ 2916638b55SBruce Evans 0x1112fd38999f72.0p-55, /* 0.133392002712976742718 */ 3016638b55SBruce Evans 0x1b54c91d865afe.0p-57, /* 0.0533812378445670393523 */ 3116638b55SBruce Evans 0x191df3908c33ce.0p-58, /* 0.0245283181166547278873 */ 3216638b55SBruce Evans 0x185dadfcecf44e.0p-61, /* 0.00297435743359967304927 */ 3316638b55SBruce Evans 0x1362b9bf971bcd.0p-59, /* 0.00946564784943673166728 */ 343a8617a8SJordan K. Hubbard }; 353a8617a8SJordan K. Hubbard 36960d3da0SBruce Evans #ifdef INLINE_KERNEL_TANDF 374ce51209SBruce Evans extern inline 384ce51209SBruce Evans #endif 3959b19ff1SAlfred Perlstein float 4094a5f9beSBruce Evans __kernel_tandf(double x, int iy) 413a8617a8SJordan K. Hubbard { 42833f0e1aSBruce Evans double z,r,w,s; 43e96c4fd9SBruce Evans 443a8617a8SJordan K. Hubbard z = x*x; 453a8617a8SJordan K. Hubbard w = z*z; 463a8617a8SJordan K. Hubbard /* Break x^5*(T[1]+x^2*T[2]+...) into 47c01611e4SBruce Evans * x^5*(T[1]+x^4*T[3]+x^8*T[5]) + 48c01611e4SBruce Evans * x^5*(x^2*(T[2]+x^4*T[4])) 493a8617a8SJordan K. Hubbard */ 50960d3da0SBruce Evans r = (T[1]+w*(T[3]+w*T[5])) + z*(T[2]+w*T[4]); 513a8617a8SJordan K. Hubbard s = z*x; 52833f0e1aSBruce Evans r = (x+s*T[0])+(s*z)*r; 53833f0e1aSBruce Evans if(iy==1) return r; 54833f0e1aSBruce Evans else return -1.0/r; 553a8617a8SJordan K. Hubbard } 56