diff options
Diffstat (limited to 'lib/libm/noieee_src/n_asinh.c')
| -rw-r--r-- | lib/libm/noieee_src/n_asinh.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/lib/libm/noieee_src/n_asinh.c b/lib/libm/noieee_src/n_asinh.c index c5e7f867922..55e8bd9b53e 100644 --- a/lib/libm/noieee_src/n_asinh.c +++ b/lib/libm/noieee_src/n_asinh.c @@ -1,3 +1,4 @@ +/* $OpenBSD: n_asinh.c,v 1.6 2008/06/12 22:43:36 martynas Exp $ */ /* $NetBSD: n_asinh.c,v 1.1 1995/10/10 23:36:35 ragge Exp $ */ /* * Copyright (c) 1985, 1993 @@ -46,16 +47,16 @@ static char sccsid[] = "@(#)asinh.c 8.1 (Berkeley) 6/4/93"; * log1p(x) ...return log(1+x) * * Method : - * Based on + * Based on * asinh(x) = sign(x) * log [ |x| + sqrt(x*x+1) ] * we have * asinh(x) := x if 1+x*x=1, * := sign(x)*(log1p(x)+ln2)) if sqrt(1+x*x)=x, else - * := sign(x)*log1p(|x| + |x|/(1/|x| + sqrt(1+(1/|x|)^2)) ) + * := sign(x)*log1p(|x| + |x|/(1/|x| + sqrt(1+(1/|x|)^2)) ) * * Accuracy: * asinh(x) returns the exact inverse hyperbolic sine of x nearly rounded. - * In a test run with 52,000 random arguments on a VAX, the maximum + * In a test run with 52,000 random arguments on a VAX, the maximum * observed error was 1.58 ulps (units in the last place). * * Constants: @@ -81,16 +82,16 @@ ic(ln2lo, 1.9082149292705877000E-10, -33, 1.A39EF35793C76) double asinh(x) double x; -{ +{ double t,s; const static double small=1.0E-10, /* fl(1+small*small) == 1 */ big =1.0E20, /* fl(1+big) == big */ - one =1.0 ; + one =1.0 ; if (isnan(x)) return (x); - if((t=copysign(x,one))>small) + if((t=copysign(x,one))>small) if(t<big) { s=one/t; return(copysign(log1p(t+t/(s+sqrt(one+s*s))),x)); } else /* if |x| > big */ |