From 92ec5b31c6336fda16656c3dda5e267707eefcad Mon Sep 17 00:00:00 2001 From: Andreas Jaeger Date: Mon, 11 Jun 2001 12:32:56 +0000 Subject: Update. 2001-06-11 Andreas Jaeger * sysdeps/ieee754/ldbl-128/e_coshl.c: New file. Contributed by Stephen L Moshier . * aclocal.m4: Quote AC_FD_MSG and AC_FD_CC. * sysdeps/powerpc/fpu/libm-test-ulps: Add ULPs for tanh (-0.7). * sysdeps/s390/fpu/libm-test-ulps: Likewise. --- sysdeps/ieee754/ldbl-128/e_coshl.c | 103 +++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) create mode 100644 sysdeps/ieee754/ldbl-128/e_coshl.c (limited to 'sysdeps/ieee754/ldbl-128') diff --git a/sysdeps/ieee754/ldbl-128/e_coshl.c b/sysdeps/ieee754/ldbl-128/e_coshl.c new file mode 100644 index 0000000000..7ffc4d5159 --- /dev/null +++ b/sysdeps/ieee754/ldbl-128/e_coshl.c @@ -0,0 +1,103 @@ +/* + * ==================================================== + * 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. + * ==================================================== + */ + +/* Changes for 128-bit long double contributed by + Stephen L. Moshier */ + +/* __ieee754_coshl(x) + * Method : + * mathematically coshl(x) if defined to be (exp(x)+exp(-x))/2 + * 1. Replace x by |x| (coshl(x) = coshl(-x)). + * 2. + * [ exp(x) - 1 ]^2 + * 0 <= x <= ln2/2 : coshl(x) := 1 + ------------------- + * 2*exp(x) + * + * exp(x) + 1/exp(x) + * ln2/2 <= x <= 22 : coshl(x) := ------------------- + * 2 + * 22 <= x <= lnovft : coshl(x) := expl(x)/2 + * lnovft <= x <= ln2ovft: coshl(x) := expl(x/2)/2 * expl(x/2) + * ln2ovft < x : coshl(x) := huge*huge (overflow) + * + * Special cases: + * coshl(x) is |x| if x is +INF, -INF, or NaN. + * only coshl(0)=1 is exact for finite x. + */ + +#include "math.h" +#include "math_private.h" + +#ifdef __STDC__ +static const long double one = 1.0, half = 0.5, huge = 1.0e4900L, +ovf_thresh = 1.1357216553474703894801348310092223067821E4L; +#else +static long double one = 1.0, half = 0.5, huge = 1.0e4900L, +ovf_thresh = 1.1357216553474703894801348310092223067821E4L; +#endif + +#ifdef __STDC__ +long double +__ieee754_coshl (long double x) +#else +long double +__ieee754_coshl (x) + long double x; +#endif +{ + long double t, w; + int32_t ex; + u_int32_t mx, lx; + ieee854_long_double_shape_type u; + + u.value = x; + ex = u.parts32.w0 & 0x7fffffff; + + /* Absolute value of x. */ + u.parts32.w0 = ex; + + /* x is INF or NaN */ + if (ex >= 0x7fff0000) + return x * x; + + /* |x| in [0,0.5*ln2], return 1+expm1l(|x|)^2/(2*expl(|x|)) */ + if (ex < 0x3ffd62e4) /* 0.3465728759765625 */ + { + t = __expm1l (u.value); + w = one + t; + if (ex < 0x3fc60000) /* |x| < 2^-57 */ + return w; /* cosh(tiny) = 1 */ + + return one + (t * t) / (w + w); + } + + /* |x| in [0.5*ln2,40], return (exp(|x|)+1/exp(|x|)/2; */ + if (ex < 0x40044000) + { + t = __ieee754_expl (u.value); + return half * t + half / t; + } + + /* |x| in [22, ln(maxdouble)] return half*exp(|x|) */ + if (ex <= 0x400c62e3) /* 11356.375 */ + return half * __ieee754_expl (u.value); + + /* |x| in [log(maxdouble), overflowthresold] */ + if (u.value <= ovf_thresh) + { + w = __ieee754_expl (half * u.value); + t = half * w; + return t * w; + } + + /* |x| > overflowthresold, cosh(x) overflow */ + return huge * huge; +} -- cgit 1.4.1