[src/trunk]: src/lib/libm/man Improve and update. Also note again the lack of...

[jruoho <jruoho%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/bab65e64d687
branches:  trunk
changeset: 769502:bab65e64d687
user:      jruoho <jruoho%NetBSD.org@localhost>
date:      Mon Sep 12 16:08:42 2011 +0000

description:
Improve and update. Also note again the lack of tanhl() in NetBSD.

diffstat:

 lib/libm/man/tanh.3 |  44 ++++++++++++++++++++++++++++++++++++--------
 1 files changed, 36 insertions(+), 8 deletions(-)

diffs (67 lines):

diff -r bd989cf18e38 -r bab65e64d687 lib/libm/man/tanh.3
--- a/lib/libm/man/tanh.3       Mon Sep 12 16:00:56 2011 +0000
+++ b/lib/libm/man/tanh.3       Mon Sep 12 16:08:42 2011 +0000
@@ -26,9 +26,9 @@
 .\" SUCH DAMAGE.
 .\"
 .\"     from: @(#)tanh.3       5.1 (Berkeley) 5/2/91
-.\"    $NetBSD: tanh.3,v 1.12 2003/08/07 16:44:49 agc Exp $
+.\"    $NetBSD: tanh.3,v 1.13 2011/09/12 16:08:42 jruoho Exp $
 .\"
-.Dd May 2, 1991
+.Dd September 12, 2011
 .Dt TANH 3
 .Os
 .Sh NAME
@@ -53,9 +53,34 @@
 For a discussion of error due to roundoff, see
 .Xr math 3 .
 .Sh RETURN VALUES
-The
-.Fn tanh
-function returns the hyperbolic tangent value.
+Upon successful completion,
+these functions return the hyperbolic tangent value.
+The following may also occur:
+.Bl -enum -offset indent
+.It
+If
+.Fa x
+is \*(Pm\* 0,
+.Fa x
+is returned.
+.It
+If
+.Fa x
+is \*(Na, a \*(Na is returned.
+.It
+If
+.Fa x
+is positive infinity, a value 1 is returned;
+if
+.Fa x
+is negative infinity, -1 is returned.
+.It
+If
+.Fa x
+is subnormal, a range error can occur and
+.Fa x
+is returned.
+.El
 .Sh SEE ALSO
 .Xr acos 3 ,
 .Xr asin 3 ,
@@ -68,7 +93,10 @@
 .Xr sinh 3 ,
 .Xr tan 3
 .Sh STANDARDS
+The described functions conform to
+.St -isoC-99 .
+.Sh BUGS
 The
-.Fn tanh
-function conforms to
-.St -ansiC .
+.Vt long double
+variant is not supported in
+.Nx .