1b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 2b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project/* @(#)e_sinh.c 1.3 95/01/18 */ 3b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project/* 4b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * ==================================================== 5b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 6b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * 7b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * Developed at SunSoft, a Sun Microsystems, Inc. business. 8b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * Permission to use, copy, modify, and distribute this 9b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * software is freely granted, provided that this notice 10b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * is preserved. 11b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * ==================================================== 12b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project */ 13b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 14b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project/* __ieee754_sinh(x) 15b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * Method : 16b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * mathematically ieee_sinh(x) if defined to be (ieee_exp(x)-ieee_exp(-x))/2 17b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * 1. Replace x by |x| (ieee_sinh(-x) = -ieee_sinh(x)). 18b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * 2. 19b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * E + E/(E+1) 20b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * 0 <= x <= 22 : ieee_sinh(x) := --------------, E=ieee_expm1(x) 21b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * 2 22b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * 23b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * 22 <= x <= lnovft : ieee_sinh(x) := ieee_exp(x)/2 24b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * lnovft <= x <= ln2ovft: ieee_sinh(x) := ieee_exp(x/2)/2 * ieee_exp(x/2) 25b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * ln2ovft < x : ieee_sinh(x) := x*shuge (overflow) 26b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * 27b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * Special cases: 28b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * sinh(x) is |x| if x is +INF, -INF, or NaN. 29b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project * only ieee_sinh(0)=0 is exact for finite x. 30b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project */ 31b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 32b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project#include "fdlibm.h" 33b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 34b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project#ifdef __STDC__ 35b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Projectstatic const double one = 1.0, shuge = 1.0e307; 36b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project#else 37b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Projectstatic double one = 1.0, shuge = 1.0e307; 38b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project#endif 39b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 40b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project#ifdef __STDC__ 41b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project double __ieee754_sinh(double x) 42b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project#else 43b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project double __ieee754_sinh(x) 44b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project double x; 45b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project#endif 46b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project{ 47b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project double t,w,h; 48b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project int ix,jx; 49b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project unsigned lx; 50b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 51b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project /* High word of |x|. */ 52b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project jx = __HI(x); 53b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project ix = jx&0x7fffffff; 54b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 55b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project /* x is INF or NaN */ 56b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project if(ix>=0x7ff00000) return x+x; 57b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 58b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project h = 0.5; 59b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project if (jx<0) h = -h; 60b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */ 61b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project if (ix < 0x40360000) { /* |x|<22 */ 62b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project if (ix<0x3e300000) /* |x|<2**-28 */ 63b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project if(shuge+x>one) return x;/* ieee_sinh(tiny) = tiny with inexact */ 64b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project t = ieee_expm1(ieee_fabs(x)); 65b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project if(ix<0x3ff00000) return h*(2.0*t-t*t/(t+one)); 66b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project return h*(t+t/(t+one)); 67b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project } 68b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 69b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project /* |x| in [22, ieee_log(maxdouble)] return 0.5*ieee_exp(|x|) */ 70b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project if (ix < 0x40862E42) return h*__ieee754_exp(ieee_fabs(x)); 71b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 72b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project /* |x| in [log(maxdouble), overflowthresold] */ 73b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project lx = *( (((*(unsigned*)&one)>>29)) + (unsigned*)&x); 74b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project if (ix<0x408633CE || (ix==0x408633ce)&&(lx<=(unsigned)0x8fb9f87d)) { 75b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project w = __ieee754_exp(0.5*ieee_fabs(x)); 76b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project t = h*w; 77b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project return t*w; 78b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project } 79b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project 80b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project /* |x| > overflowthresold, ieee_sinh(x) overflow */ 81b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project return x*shuge; 82b07e1d9fd8d9e4e03698e0bd9bf77154c5390326The Android Open Source Project} 83