diff options
Diffstat (limited to 'src/math/sinhl.c')
| -rw-r--r-- | src/math/sinhl.c | 87 |
1 files changed, 23 insertions, 64 deletions
diff --git a/src/math/sinhl.c b/src/math/sinhl.c index 8a54677e..14e3371b 100644 --- a/src/math/sinhl.c +++ b/src/math/sinhl.c @@ -1,32 +1,3 @@ -/* origin: OpenBSD /usr/src/lib/libm/src/ld80/e_sinhl.c */ -/* - * ==================================================== - * 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. - * ==================================================== - */ -/* 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*huge (overflow) - * - * Special cases: - * sinhl(x) is |x| if x is +INF, -INF, or NaN. - * only sinhl(0)=0 is exact for finite x. - */ - #include "libm.h" #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 @@ -35,47 +6,35 @@ long double sinhl(long double x) return sinh(x); } #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 -static const long double huge = 1.0e4931L; - long double sinhl(long double x) { - long double t,w,h; - uint32_t jx,ix,i0,i1; - - /* Words of |x|. */ - GET_LDOUBLE_WORDS(jx, i0, i1, x); - ix = jx & 0x7fff; - - /* x is INF or NaN */ - if (ix == 0x7fff) return x + x; + union { + long double f; + struct{uint64_t m; uint16_t se; uint16_t pad;} i; + } u = {.f = x}; + unsigned ex = u.i.se & 0x7fff; + long double h, t, absx; h = 0.5; - if (jx & 0x8000) + if (u.i.se & 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 (huge + x > 1.0) - return x;/* sinh(tiny) = tiny with inexact */ - t = expm1l(fabsl(x)); - if (ix < 0x3fff) - return h*(2.0*t - t*t/(t + 1.0)); - return h*(t + t/(t + 1.0)); - } - - /* |x| in [25, log(maxdouble)] return 0.5*exp(|x|) */ - if (ix < 0x400c || (ix == 0x400c && i0 < 0xb17217f7)) - return h*expl(fabsl(x)); - - /* |x| in [log(maxdouble), overflowthreshold] */ - if (ix < 0x400c || (ix == 0x400c && (i0 < 0xb174ddc0 || - (i0 == 0xb174ddc0 && i1 <= 0x31aec0ea)))) { - w = expl(0.5*fabsl(x)); - t = h*w; - return t*w; + /* |x| */ + u.i.se = ex; + absx = u.f; + + /* |x| < log(LDBL_MAX) */ + if (ex < 0x3fff+13 || (ex == 0x3fff+13 && u.i.m>>32 < 0xb17217f7)) { + t = expm1l(absx); + if (ex < 0x3fff) { + if (ex < 0x3fff-32) + return x; + return h*(2*t - t*t/(1+t)); + } + return h*(t + t/(t+1)); } - /* |x| > overflowthreshold, sinhl(x) overflow */ - return x*huge; + /* |x| > log(LDBL_MAX) or nan */ + t = expl(0.5*absx); + return h*t*t; } #endif |