History log of /freebsd-9.3-release/lib/msun/src/e_jnf.c
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# 267654 19-Jun-2014 gjb

Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

# 225736 22-Sep-2011 kensmith

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)


# 215237 13-Nov-2010 uqs

Fix bug in jn(3) and jnf(3) that led to -inf results

Explanation by Steve:
jn[f](n,x) for certain ranges of x uses downward recursion to compute
the value of the function. The recursion sequence that is generated is
proportional to the actual desired value, so a normalization step is
taken. This normalization is j0[f](x) divided by the zeroth sequence
member. As Bruce notes, near the zeros of j0[f](x) the computed value
can have giga-ULP inaccuracy. I found for the 1st zero of j0f(x) only
the leading decimal digit is correct. The solution to the issue is
fairly straight forward. The zeros of j0(x) and j1(x) never coincide,
so as j0(x) approaches a zero, the normalization constant switches to
j1[f](x) divided by the 2nd sequence member. The expectation is that
j1[f](x) is a more accurately computed value.

PR: bin/144306
Submitted by: Steven G. Kargl <kargl@troutmask.apl.washington.edu>
Reviewed by: bde
MFC after: 7 days


# 181405 07-Aug-2008 das

Remove some unused variables.

Reported by: Intel C Compiler


# 176451 22-Feb-2008 das

s/rcsid/__FBSDID/


# 97413 28-May-2002 alfred

Fix formatting, this is hard to explain, so I'll show one example.

- float ynf(int n, float x) /* wrapper ynf */
+float
+ynf(int n, float x) /* wrapper ynf */

This is because the __STDC__ stuff was indented.

Reviewed by: md5


# 97409 28-May-2002 alfred

Assume __STDC__, remove non-__STDC__ code.

Reviewed by: md5


# 50476 27-Aug-1999 peter

$Id$ -> $FreeBSD$


# 22993 22-Feb-1997 peter

Revert $FreeBSD$ to $Id$


# 21673 14-Jan-1997 jkh

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.


# 8870 30-May-1995 rgrimes

Remove trailing whitespace.


# 7658 07-Apr-1995 bde

Submitted by: J.T. Conklin <jtc@wimsey.com>

First part of update to fdlibm 5.2: fix jn(n, x) and jnf(n, x).
jn(-1, x) was too large by a factor of 3.


# 2117 19-Aug-1994 jkh

This commit was generated by cvs2svn to compensate for changes in r2116,
which included commits to RCS files with non-trunk default branches.


# 2116 19-Aug-1994 jkh

J.T. Conklin's latest version of the Sun math library.

-- Begin comments from J.T. Conklin:
The most significant improvement is the addition of "float" versions
of the math functions that take float arguments, return floats, and do
all operations in floating point. This doesn't help (performance)
much on the i386, but they are still nice to have.

The float versions were orginally done by Cygnus' Ian Taylor when
fdlibm was integrated into the libm we support for embedded systems.
I gave Ian a copy of my libm as a starting point since I had already
fixed a lot of bugs & problems in Sun's original code. After he was
done, I cleaned it up a bit and integrated the changes back into my
libm.
-- End comments

Reviewed by: jkh
Submitted by: jtc