Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

Implementations of cexpl()

The change implements cexpl() for both ld80 and ld128 architectures.
Testing was done on x86_64 and aarch64 systems.

Along the way sincos[fl]() use an optimization that reduces the argument
to being done one rather than twice. This optimization actually pointed
to a bug in the ld128 version of sincosl(), which is now fixed. In
addition, the minmax polynomial coefficients for sincosl() have been
updated.

A concise log of the file-by-file changes follows.

* include/complex.h:
. Add a prototype for cexpl().

* lib/msun/Makefile:
. Add s_cexpl.c to the build.
. Setup a link for cexpl.3 to cexp.3.

* lib/msun/Symbol.map:
. Expose cexpl symbol in libm shared library.

* lib/msun/ld128/s_cexpl.c:
* Implementation of cexpl() for 128-bit long double architectures.
Tested on an aarch64 system.

* lib/msun/ld80/s_cexpl.c:
* Implementation of cexpl() for Intel 80-bit long double.

* lib/msun/man/cexp.3:
. Document cexpl().

* lib/msun/man/complex.3:
. Add a BUGS section about cpow[fl].

* lib/msun/src/s_cexp.c:
. Include float.h for weak references on 53-bit long double targets.
. Use sincos() to reduce argument reduction cost.

* lib/msun/src/s_cexpf.c:
. Use sincosf() to reduce argument reduction cost.

* lib/msun/src/k_sincosl.h:
. Catch up with the new minmax polynomial coefficients for the kernel for
the 128-bit cosl() implementation.
. BUG FIX: *cs was used where *sn should have been. This means that sinl()
was no computed correctly when iy != 0.

* lib/msun/src/s_cosl.c:
. Include fpmath.h to get access to IEEEl2bits.
. Replace M_PI_4 with pio4, a 64-bit or 113-bit approximation for pi / 4.

PR: 216862
MFC after: 1 week

Vendor import of stripped libc++ trunk r366426 (just before the release_90 branch
point):

https://llvm.org/svn/llvm-project/libcxx/trunk@366426

msun: add ld80/ld128 powl, cpow, cpowf, cpowl from openbsd

This corresponds to the latest status (hasn't changed in 9+
years) from openbsd of ld80/ld128 powl, and source cpowf, cpow,
cpowl (the complex power functions for float complex, double
complex, and long double complex) which are required for C99
compliance and were missing from FreeBSD. Also required for
some numerical codes using complex numbered Hamiltonians.

Thanks to jhb for tracking down the issue with making
weak_reference compile on powerpc.

When asked to review, bde said "I don't like it" - but
provided no actionable feedback or superior implementations.

Discussed with: jhb
Submitted by: jmd
Differential Revision: https://reviews.freebsd.org/D15919

Add implementations for clog(3), clogf(3), and clog(3).

PR: 216863
Submitted by: bde, Steven G. Kargl <sgk@troutmask.apl.washington.edu>
MFC after: 2 weeks

include: General further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Add new catrigl.c (r313761) APIs to include/complex.h

Reviewed by: bde, emaste
Approved by: bde, emaste (src committers)
Differential Revision: https://reviews.freebsd.org/D9615

Vendor import of libc++ trunk r256633:
https://llvm.org/svn/llvm-project/libcxx/trunk@256633

I'm happy to finally commit stephen@'s implementations of cacos,
cacosh, casin, casinh, catan, and catanh. Thanks to stephen@ and bde@
for working on these.

Submitted by: stephen@
Reviewed by: bde

Add C11 macros CMPLX(), CMPLXF() and CMPLXL().

Clang allows us to initialize complex numbers using an array
initializer, casted to a complex type. GCC has a builtin called
__builtin_complex().

Only use the static assertion when __generic is available.

Reported by: tijl

Remove redundant inclusion of <sys/cdefs.h>.

Mea culpa.

Make _Complex_I a proper float _Complex when using GCC 4.2.

It turns out our GCC has quite an interesting bug:

typeof(1.0fi) != float _Complex
typeof((float _Complex)1.0fi) != float _Complex
typeof((float _Complex)1.0i) == float _Complex

In other words: if casting to an equal size, GCC seems to take a
shortcut. By casting down from a double to a float, GCC doesn't take
this shortcut, yielding the proper type.

To prevent foot-shooting, add a _Static_assert() to guarantee that
_Complex_I is always a float _Complex. I'm not going to MFC this part of
the diff.

MFC after: 2 weeks

Import libcxxrt / libc++ into a vendor branch.

Approved by: dim (mentor)

Add c{cos,sin,tan}{,h}{,f} functions. This is joint work with
bde and kargl.

Add missing declarations that I intended to commit with r219359.
Not sure why we have math.h in lib/msun/ and complex.h in include/.

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.

Implement cproj{,f,l}().

Annotate creal(), cimag(), and conj() with __pure2.

Implement csqrtl().

Hook hypotl() and cabsl() up to the build.

Implement and document csqrt(3) and csqrtf(3).

Implement carg(3) and cargf(3).

Rotting in an old src tree since: March 2005

Stop defining '_Complex' in a C99 environment, it is supposed to be a keyword.

Use tabulators after '#define'.

Add implementations for cimag{,f,l}, creal{,f,l} and conj{,f,l}. They are
needed for cases where GCC's builtin functions cannot be used and for
compilers that don't know about them.

Approved by: das (mentor)

Remove the macros for creal{,f} and cimag{,f}. They failed to convert their
arguments to the needed type and so the result type depended on the argument
type. Fixing them isn't really worth the effort because GCC emits the same
assembler code with or without them.

Not minded by: ru
Approved by: das (mentor)

Breath deep and take __P out of the system include files.

# This appears to not break X11, but I'm having problems compiling the
# glide part of the server with or without this patch, so I can't tell
# for sure.

Added skeleton <complex.h> (aligned with the POSIX.1-200x), mostly
to fix the "-nostdinc WARNS=X" breakage caused by broken prototypes
for cabs() and cabsl() in <math.h>.

Reimplemented cabs() and cabsl() using new complex numbers types and
moved prototypes from <math.h> to <complex.h>.