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Diffstat (limited to 'REORG.TODO/sysdeps/ieee754/dbl-64/e_sinh.c')
| -rw-r--r-- | REORG.TODO/sysdeps/ieee754/dbl-64/e_sinh.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/ieee754/dbl-64/e_sinh.c b/REORG.TODO/sysdeps/ieee754/dbl-64/e_sinh.c new file mode 100644 index 0000000000..8479bdd9b8 --- /dev/null +++ b/REORG.TODO/sysdeps/ieee754/dbl-64/e_sinh.c @@ -0,0 +1,90 @@ +/* @(#)e_sinh.c 5.1 93/09/24 */ +/* + * ==================================================== + * 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: e_sinh.c,v 1.7 1995/05/10 20:46:13 jtc Exp $"; +#endif + +/* __ieee754_sinh(x) + * Method : + * mathematically sinh(x) if defined to be (exp(x)-exp(-x))/2 + * 1. Replace x by |x| (sinh(-x) = -sinh(x)). + * 2. + * E + E/(E+1) + * 0 <= x <= 22 : sinh(x) := --------------, E=expm1(x) + * 2 + * + * 22 <= x <= lnovft : sinh(x) := exp(x)/2 + * lnovft <= x <= ln2ovft: sinh(x) := exp(x/2)/2 * exp(x/2) + * ln2ovft < x : sinh(x) := x*shuge (overflow) + * + * Special cases: + * sinh(x) is |x| if x is +INF, -INF, or NaN. + * only sinh(0)=0 is exact for finite x. + */ + +#include <float.h> +#include <math.h> +#include <math_private.h> + +static const double one = 1.0, shuge = 1.0e307; + +double +__ieee754_sinh (double x) +{ + double t, w, h; + int32_t ix, jx; + u_int32_t lx; + + /* High word of |x|. */ + GET_HIGH_WORD (jx, x); + ix = jx & 0x7fffffff; + + /* x is INF or NaN */ + if (__glibc_unlikely (ix >= 0x7ff00000)) + return x + x; + + h = 0.5; + if (jx < 0) + h = -h; + /* |x| in [0,22], return sign(x)*0.5*(E+E/(E+1))) */ + if (ix < 0x40360000) /* |x|<22 */ + { + if (__glibc_unlikely (ix < 0x3e300000)) { /* |x|<2**-28 */ + math_check_force_underflow (x); + if (shuge + x > one) + return x; + /* sinh(tiny) = tiny with inexact */ + } + t = __expm1 (fabs (x)); + if (ix < 0x3ff00000) + return h * (2.0 * t - t * t / (t + one)); + return h * (t + t / (t + one)); + } + + /* |x| in [22, log(maxdouble)] return 0.5*exp(|x|) */ + if (ix < 0x40862e42) + return h * __ieee754_exp (fabs (x)); + + /* |x| in [log(maxdouble), overflowthresold] */ + GET_LOW_WORD (lx, x); + if (ix < 0x408633ce || ((ix == 0x408633ce) && (lx <= (u_int32_t) 0x8fb9f87d))) + { + w = __ieee754_exp (0.5 * fabs (x)); + t = h * w; + return t * w; + } + + /* |x| > overflowthresold, sinh(x) overflow */ + return math_narrow_eval (x * shuge); +} +strong_alias (__ieee754_sinh, __sinh_finite) |