- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

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

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

s/rcsid/__FBSDID/

Use STRICT_ASSIGN() instead of assorted direct volatile hacks to work
around assignments not working for gcc on i386. Now volatile hacks
for rint() and rintf() don't needlessly pessimize so many arches
and the remaining pessimizations (for arm and powerpc) can be avoided
centrally.

This cleans up after s_rint.c 1.3 and 1.13 and s_rintf.c 1.3 and 1.9:
- s_rint.c 1.13 broke 1.3 by only using a volatile cast hack in 1 place
when it was needed in 2 places, and the volatile cast hack stopped
working with gcc-4. These bugs only affected correctness tests on
i386 since i386 normally uses asm rint() and doesn't support the
extra precision mode that would break assignments of doubles.
- s_rintf.c 1.9 improved(?) on 1.3 by using a volatile variable hack
instead of an extra-precision variable hack, but it declared 2
variables as volatile when only 1 variable needed to be volatile.
This only affected speed tests on i386 since i386 uses asm rintf().

Restored removal of the special handling needed for a result of +-0.
It was lost in rev.1.9. The log message for rev.1.9 says that the
special case of +-0 is handled twice, but it was only handled once,
so it became unhandled, and this happened to break half of the cases
that return +-0:
- round-towards-minus-infinity: 0 < x < 1: result was -0 not 0
- round-to-nearest: -0.5 <= x < 0: result was 0 not -0
- round-towards-plus-infinity: -1 < x < 0: result was 0 not -0
- round-towards-zero: -1 < x < 0: result was 0 not -0

Fix a bug where rintf() rounded the wrong way in round-to-nearest mode
on all inputs of the form x.75, where x is an even integer and
log2(x) = 21. A similar problem occurred when rounding upward.
The bug involves the following snippet copied from rint():

i>>=1;
if((i0&i)!=0) i0 = (i0&(~i))|((0x100000)>>j0);

The constant 0x100000 should be 0x200000. Apparently this case was
never tested.

It turns out that the bit manipulation is completely superfluous
anyway, so remove it. (It tries to simulate 90% of the rounding
process that the FPU does anyway.) Also, the special case of +-0 is
handled twice (in different ways), so remove the second instance.

Throw in some related simplifications from bde:

- Work around a bug where gcc fails to clip to float precision by
declaring two float variables as volatile. Previously, we
tricked gcc into generating correct code by declaring some
float constants as doubles.

- Remove additional superfluous bit manipulation.

- Minor reorganization.

- Include <sys/types.h> explicitly.

Note that some of the equivalent lines in rint() also appear to be
unnecessary, but I'll defer to the numerical analysts who wrote it,
since I can't test all 2^64 cases.

Discussed with: bde

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

Assume __STDC__, remove non-__STDC__ code.

Reviewed by: md5

$Id$ -> $FreeBSD$

Revert $FreeBSD$ to $Id$

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.

Made rintf() actually work. It was completely broken (when s_rint.c
was compiled with -O) by the precision bug in the i386 version of
gcc (assignments and casts don't clip the precision). E.g.,
rintf(12.3456789) was 12.125.

Avoid the same bug in rint(). It was only broken for the unusual
case when the i387 precision is 64 bits. FreeBSD defaults to 53
bit precision to avoid problems like this, but the standard math
emulator always uses 64 bit precision.

Remove trailing whitespace.

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

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