History log of /freebsd-10.1-release/lib/msun/src/k_rem_pio2.c
Revision Date Author Comments
(<<< Hide modified files)
(Show modified files >>>)
# 272461 02-Oct-2014 gjb

Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

# 256281 10-Oct-2013 gjb

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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


# 242692 07-Nov-2012 kevlo

Fix typo; s/ouput/output


# 176550 25-Feb-2008 bde

Fix some off-by-1 errors.

e_rem_pio2.c:
Float and double precision didn't work because init_jk[] was 1 too small.
It needs to be 2 larger than you might expect, and 1 larger than it was
for these precisions, since its test for recomputing needs a margin of
47 bits (almost 2 24-bit units).

init_jk[] seems to be barely enough for extended and quad precisions.
This hasn't been completely verified. Callers now get about 24 bits
of extra precision for float, and about 19 for double, but only about
8 for extended and quad. 8 is not enough for callers that want to
produce extra-precision results, but current callers have rounding
errors of at least 0.8 ulps, so another 1/2**8 ulps of error from the
reduction won't affect them much.

Add a comment about some of the magic for init_jk[].

e_rem_pio2.c:
Double precision worked in practice because of a compensating off-by-1
error here. Extended precision was asked for, and it executed exactly
the same code as the unbroken double precision.

e_rem_pio2f.c:
Float precision worked in practice because of a compensating off-by-1
error here. Double precision was asked for, and was almost needed,
since the cosf() and sinf() callers want to produce extra-precision
results, at least internally so that their error is only 0.5009 ulps.
However, the extra precision provided by unbroken float precision is
enough, and the double-precision code has extra overheads, so the
off-by-1 error cost about 5% in efficiency on amd64 and i386.


# 176356 17-Feb-2008 das

Add more pi for long doubles. Also, avoid storing multiple copies
of the pi/2 array, as it is unlikely to vary, except in Indiana.


# 175507 20-Jan-2008 bde

Oops, when merging from the float version to the double versions, don't
forget to translate "float" to "double".

ucbtest didn't detect the bug, but exhaustive testing of the float
case relative to the double case eventually did. The bug only affects
args x with |x| ~> 2**19*(pi/2) on non-i386 (i386 is broken in a
different way for large args).


# 175499 19-Jan-2008 bde

Use STRICT_ASSIGN() for _kernel_rem_pio2f() and _kernel_rem_pio2f()
instead of a volatile cast hack for the float version only. The cast
hack broke with gcc-4, but this was harmless since the float version
hasn't been used for a few years. Merge from the float version so
that the double version has a chance of working on i386 with extra
precision.

See k_rem_pio2f.c rev.1.8 for the original hack.

Convert to _FBSDID().


# 141296 04-Feb-2005 das

Reduce diffs against vendor source (Sun fdlibm 5.3).


# 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.


# 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