lib/msun: Cleanup after $FreeBSD$ removal

Remove no longer needed explicit inclusion of sys/cdefs.h.

PR: 276669
MFC after: 1 week

lib: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Clean up libm use of the __ieee754_ prefix

This removes the __ieee754_ prefix from a number of the math functions.
msun/src/math_private.h contains the statement that

/*
* ieee style elementary functions
*
* We rename functions here to improve other sources' diffability
* against fdlibm.
*/
#define __ieee754_sqrt sqrt
...

Here, fdlibm refers to https://netlib.org/fdlibm. It is seen from
https://netlib.org/fdlibm/readme that this prefix was used to
differentiate between different standards:

Wrapper functions will twist the result of the ieee754
function to comply to the standard specified by the value
of _LIB_VERSION
if _LIB_VERSION = _IEEE_, return the ieee754 result;
if _LIB_VERSION = _SVID_, return SVID result;
if _LIB_VERSION = _XOPEN_, return XOPEN result;
if _LIB_VERSION = _POSIX_, return POSIX/ANSI result.
(These are macros, see fdlibm.h for their definition.)

AFAICT, FreeBSD has never supported these wrappers. In addition, as C99,
principally the long double, functions were added to libm, this
convention was not maintained. Given that only 148 of 324 files under
lib/msun contain a "Copyright (C) 1993 by Sun Microsystems" statement,
the removal of the __ieee754_ prefix provides consistency across all
source files.

The last time someone compared lib/msun to fdlibm appears to be

commit 3f70824172feb82ea3dcdb3866b54fe0eb7cd890
Author: David Schultz <das@FreeBSD.org>
Date: Fri Feb 4 18:26:06 2005 +0000

Reduce diffs against vendor source (Sun fdlibm 5.3).

The most recent fdlibm RCS string that appears in a Sun Microsystem
copyrighted file is date "95/01/18". With Oracle Corporation's
acquisition of Sun Microsystems in 2009, it is unlikely that fdlibm will
ever be updated. A search for fdlibm at https://opensource.oracle.com/
yields no hits.

Finally, OpenBSD removed the use of this prefix over 21 years ago. pSee
revision 1.6 of OpenBSD's math_private.h.

Note: this does not drop the __ieee754_ prefix from the trigonometric
argument reduction functions, e.g., __ieee754_rem_pio2. These functions
are internal to the libm and exported through Symbol.map; and thus,
reserved for the implementation.

PR: 272783
MFC after: 1 week

libm: Correct some typos in source code comments

- s/modfied/modified/
- s/minimun/minimum/

While here, fix some mandoc warnings:

- whitespace at end of input line
- unusual Xr punctuation
- missing comma before name

Obtained from: NetBSD
MFC after: 5 days

The value small=2**-(p+3), where p is the precision, can be determine from
lgamma(x) = -log(x) - log(1+x) + x*(1-g) + x**2*P(x) with g = 0.57...
being the Euler constant and P(x) a polynomial. Substitution of small
into the RHS shows that the last 3 terms are negligible in comparison to
the leading term. The choice of 3 may be conservative.

The value large=2**(p+3) is detemined from Stirling's approximation
lgamma(x) = x*(log(x)-1) - log(x)/2 + log(2*pi)/2 + P(1/x)/x
Again, substitution of large into the RHS reveals the last 3 terms
are negligible in comparison to the leading term.

Move the x=+-0 special case into the |x|<small block.

In the ld80 and ld128 implementaion, use fdlibm compatible comparisons
involving ix, lx, and llx. This replaces several floating point
comparisons (some involving fabsl()) and also fixes the special cases
x=1 and x=2.

While here
. Remove unnecessary parentheses.
. Fix/improve comments due to the above changes.
. Fix nearby whitespace.

* src/e_lgamma_r.c:
. Sort declaration.
. Remove unneeded explicit cast for type conversion.
. Replace a double literal constant by an integer literal constant.

* src/e_lgammaf_r.c:
. Sort declaration.

* ld128/e_lgammal_r.c:
. Replace a long double literal constant by a double literal constant.

* ld80/e_lgammal_r.c:
. Remove unused '#include float.h'
. Replace a long double literal constant by a double literal constant.

Requested by: bde

Remove whitespace and 2 blank lines.

* Whitespace.

For targets that have a signed zero, lgamma_r(-0, &signgamp) should
set signgamp = -1.

Submitted by: enh at google dot com (e_lgamma[f]_r.c)

* Makefile:
. Hook e_lgammal[_r].c to the build.
. Create man page links for lgammal[-r].3.

* Symbol.map:
. Sort lgammal to its rightful place.
. Add FBSD_1.4 section for the new lgamal_r symbol.

* ld128/e_lgammal_r.c:
. 128-bit implementataion of lgammal_r().

* ld80/e_lgammal_r.c:
. Intel 80-bit format implementation of lgammal_r().

* src/e_lgamma.c:
. Expose lgammal as a weak reference to lgamma for platforms
where long double is mapped to double.

* src/e_lgamma_r.c:
. Use integer literal constants instead of real literal constants.
Let compiler(s) do the job of conversion to the appropriate type.
. Expose lgammal_r as a weak reference to lgamma_r for platforms
where long double is mapped to double.

* src/e_lgammaf_r.c:
. Fixed the Cygnus Support conversion of e_lgamma_r.c to float.
This includes the generation of new polynomial and rational
approximations with fewer terms. For each approximation, include
a comment on an estimate of the accuracy over the relevant domain.
. Use integer literal constants instead of real literal constants.
Let compiler(s) do the job of conversion to the appropriate type.
This allows the removal of several explicit casts of double values
to float.

* src/e_lgammal.c:
. Wrapper for lgammal() about lgammal_r().

* src/imprecise.c:
. Remove the lgamma.

* src/math.h:
. Add a prototype for lgammal_r().

* man/lgamma.3:
. Document the new functions.

Reviewed by: bde

Remove an initialized, but otherwise, unused variable.

According to the ISO C standard, lgamma(-integer) returns
inf and raises the divided-by-zero exception. Compilers
constant fold one/zero to inf but do not raise the exception.
Introduce a volatile vzero to prevent the constant folding.

Move the declaration of zero into the main declaration block.

While here, fix a nearby disordering of 'lx,ix'

Discussed with: bde

Fix a tab that somehow became 8 spaces.

Remove parentheses in a return statement to be consistent with the
rest of the file.

Rename sin_pi() in the float version to sin_pif().

Remove large comment that precedes sin_pif(). The comment
duplicates a comment in e_lgamma_r.c where the algorithm
is documented.

Requested by: bde

Compute sin(pi*x) without actually doing the pi*x multiplication.
sin_pi(x) is only called for x < 0 and |x| < 2**(p-1) where p is
the precision of x. The new argument reduction is an optimization
compared to the old code, and it removes a chunk of dead code.
Accuracy tests in the intervals (-21,-20), (-20,-19), ... (-1,0)
show no differences between the old and new code.

Obtained from: bde

Remove some unnecessary initializations.

Obtained from: DragonFlyBSD

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

- Import the HEAD csup code which is the basis for the cvsmode work.

s/rcsid/__FBSDID/

Don't assume that int is signed 32-bits in one place. Keep assuming
that ints have >= 31 value bits elsewhere. s/int/int32_t/ seems to
have been done too globally for all other files in msun/src before
msun/ was imported into FreeBSD.

Minor fixes in comments.

e_lgamma_r.c:
Describe special cases in more detail:
- exception for lgamma(0) and lgamma(neg.integer)
- lgamma(-Inf) = Inf. This is wrong but is required by C99 Annex F. I
hope to change this.

Reduce diffs against vendor source (Sun fdlibm 5.3).

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.

Remove trailing whitespace.

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