/* e_asinhl.c -- long double version of e_asinh.c. * Conversion to long double by Ulrich Drepper, * Cygnus Support, drepper@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. * ==================================================== */ #if defined(LIBM_SCCS) && !defined(lint) static char rcsid[] = "$NetBSD: $"; #endif /* __ieee754_sinhl(x) * Method : * mathematically sinh(x) if defined to be (exp(x)-exp(-x))/2 * 1. Replace x by |x| (sinhl(-x) = -sinhl(x)). * 2. * E + E/(E+1) * 0 <= x <= 25 : sinhl(x) := --------------, E=expm1l(x) * 2 * * 25 <= x <= lnovft : sinhl(x) := expl(x)/2 * lnovft <= x <= ln2ovft: sinhl(x) := expl(x/2)/2 * expl(x/2) * ln2ovft < x : sinhl(x) := x*shuge (overflow) * * Special cases: * sinhl(x) is |x| if x is +INF, -INF, or NaN. * only sinhl(0)=0 is exact for finite x. */ #include #include #include static const long double one = 1.0, shuge = 1.0e4931L; long double __ieee754_sinhl(long double x) { long double t,w,h; u_int32_t jx,ix,i0,i1; /* Words of |x|. */ GET_LDOUBLE_WORDS(jx,i0,i1,x); ix = jx&0x7fff; /* x is INF or NaN */ if(__builtin_expect(ix==0x7fff, 0)) return x+x; h = 0.5; if (jx & 0x8000) h = -h; /* |x| in [0,25], return sign(x)*0.5*(E+E/(E+1))) */ if (ix < 0x4003 || (ix == 0x4003 && i0 <= 0xc8000000)) { /* |x|<25 */ if (ix<0x3fdf) { /* |x|<2**-32 */ if (fabsl (x) < LDBL_MIN) { long double force_underflow = x * x; math_force_eval (force_underflow); } if(shuge+x>one) return x;/* sinh(tiny) = tiny with inexact */ } t = __expm1l(fabsl(x)); if(ix<0x3fff) return h*(2.0*t-t*t/(t+one)); return h*(t+t/(t+one)); } /* |x| in [25, log(maxdouble)] return 0.5*exp(|x|) */ if (ix < 0x400c || (ix == 0x400c && i0 < 0xb17217f7)) return h*__ieee754_expl(fabsl(x)); /* |x| in [log(maxdouble), overflowthreshold] */ if (ix<0x400c || (ix == 0x400c && (i0 < 0xb174ddc0 || (i0 == 0xb174ddc0 && i1 <= 0x31aec0ea)))) { w = __ieee754_expl(0.5*fabsl(x)); t = h*w; return t*w; } /* |x| > overflowthreshold, sinhl(x) overflow */ return x*shuge; } strong_alias (__ieee754_sinhl, __sinhl_finite)