Synchronize most of libm with head as of r323004. This excludes a few
arch-specific updates for powerpcspe, mips and riscv, for which support
has not been merged yet.

Bump __FreeBSD_version for the addition of cacoshl, cacosl, casinhl,
casinl, catanl, catanhl, sincos, sincosf, and sincosl.

MFC r305382 (by bde):

Add asm versions of fmod(), fmodf() and fmodl() on amd64. Add asm
versions of fmodf() amd fmodl() on i387.

fmod is similar to remainder, and the C versions are 3 to 9 times
slower than the asm versions on x86 for both, but we had the strange
mixture of all 6 variants of remainder in asm and only 1 of 6
variants of fmod in asm.

MFC r305384 (by bde):

Disconnect the "optimized" asm variants of cos(), sin() and tan() from
the build on i386. Leave them in the source tree for regression tests.

The asm functions were always much less accurate (by a factor of more
than 10**18 in the worst case). They were faster on old CPUs. But
with each new generation of CPUs they get relatively slower. The
double precision C version's average advantage is about a factor of 2
on Haswell.

The asm functions were already intentionally avoided in float and long
double precision on i386 and in all precisions on amd64. Float
precision and amd64 give larger advantages to the C version. The long
double precision C code and compilers' understanding of long double
precision are not so good, so the i387 is still slightly faster for
long double precision, except for the unimportant subcase of huge args
where the sub-optimal C code now somehow beats the i387 by about a
factor of 2.

MFC r305385 (by bde):

Oops, the previous i386 version of e_fmodf.S and e_fmodl.S was
actually the amd64 version.

MFC r306409 (by emaste):

libm: fix some unused variable (rcsid) and dangling else warnings

s_{fabs,fmax,logb,scalb}{,f,l}.c may be built elsewhere with a higher
WARNS setting.

Reviewed by: ed
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D8061

MFC r306410 (by emaste):

libm: simplify i387 subdir logic with make's :S substitution

MFC r306527 (by emaste):

libm: remove unused variables for LDBL_MANT_DIG != 113

Sponsored by: The FreeBSD Foundation

MFC r306709 (by emaste):

libm: remove unused variables

Sponsored by: The FreeBSD Foundation

MFC r307066 (by br):

Don't use fmaxl/fminl on platforms with no long double support,
use fmax/fmin instead.

This fixes fmaxmin test failure on MIPS64.

Reviewed by: emaste
Sponsored by: DARPA, AFRL
Sponsored by: HEIF5
Differential Revision: https://reviews.freebsd.org/D8216

MFC r308172 (by emaste):

libm: add braces around initialization of subobjects

This cleans up a warning when building libm at higher WARNS levels and
makes the intent more clear. By the C standard the values are assigned
to subobject members in order so this change introduces no functional
change. (6.7.9 20)

Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D8333

MFC r313761 (by mmokhi):

Add casinl() cacosl() catanl() casinhl() cacoshl() catanhl() APIs to msun
to improve C11 conformance.

PR: 216850 216851 216852 216856 216857 216858
Submitted by: mmokhi
Reported by: sgk@troutmask.apl.washington.edu
Reviewed by: bde, mat, theraven
Approved by: bde (src committer), mat (mentor)
Differential Revision: https://reviews.freebsd.org/D9491

MFC r313863 (by mmokhi):

Fix building of r313761 on platforms that
`long double` is alias of `double` (MIPS, etc)

PR: 216850 216851 216852 216856 216857 216858
Reported by: emsate
Reviewed by: bde emaste hselasky
Approved by: bde emaste hselasky
Differential Revision: https://reviews.freebsd.org/D9491

MFC r313864 (by mmokhi):

Add documentations related to new APIs of r313761

PR: 216850 216851 216852 216856 216857 216858
Submitted by: sgk@troutmask.apl.washington.edu
Reported by: sgk@troutmask.apl.washington.edu
Reviewed by: bde emaste hselasky
Approved by: bde emaste hselasky
Differential Revision: https://reviews.freebsd.org/D9491

MFC r314950 (by ngie):

Don't expect :test_large_inputs to fail with i386 anymore

Recent changes (maybe a side-effect of the ATF-ification in r314649)
invalidate the failure expectation.

PR: 205446
Sponsored by: Dell EMC Isilon

MFC r317349 (by pfg):

msun: Remove trailing space in Sunsoft copyright statement.

Submittedby: kargl

MFC r319047 (by mmel):

Implement sincos, sincosf, and sincosl.
The primary benefit of these functions is that argument
reduction is done once instead of twice in independent
calls to sin() and cos().

* lib/msun/Makefile:
. Add s_sincos[fl].c to the build.
. Add sincos.3 documentation.
. Add appropriate MLINKS.

* lib/msun/Symbol.map:
. Expose sincos[fl] symbols in dynamic libm.so.

* lib/msun/man/sincos.3:
. Documentation for sincos[fl].

* lib/msun/src/k_sincos.h:
. Kernel for sincos() function. This merges the individual kernels
for sin() and cos(). The merger offered an opportunity to re-arrange
the individual kernels for better performance.

* lib/msun/src/k_sincosf.h:
. Kernel for sincosf() function. This merges the individual kernels
for sinf() and cosf(). The merger offered an opportunity to re-arrange
the individual kernels for better performance.

* lib/msun/src/k_sincosl.h:
. Kernel for sincosl() function. This merges the individual kernels
for sinl() and cosl(). The merger offered an opportunity to re-arrange
the individual kernels for better performance.

* lib/msun/src/math.h:
. Add prototytpes for sincos[fl]().

* lib/msun/src/math_private.h:
. Add RETURNV macros. This is needed to reset fpsetprec on I386
hardware for a function with type void.

* lib/msun/src/s_sincos.c:
. Implementation of sincos() where sin() and cos() were merged into
one routine and possibly re-arranged for better performance.

* lib/msun/src/s_sincosf.c:
. Implementation of sincosf() where sinf() and cosf() were merged into
one routine and possibly re-arranged for better performance.

* lib/msun/src/s_sincosl.c:
. Implementation of sincosl() where sinl() and cosl() were merged into
one routine and possibly re-arranged for better performance.

PR: 215977, 218300
Submitted by: Steven G. Kargl <sgk@troutmask.apl.washington.edu>
Differential Revision: https://reviews.freebsd.org/D10765

MFC r321457 (by ngie):

Mark :reduction as an expected failure

It fails with clang 5.0+.

PR: 220989
Reported by: Jenkins

MFC r322418 (by rlibby):

lib/msun: avoid referring to broken LDBL_MAX

LDBL_MAX is broken on i386:
https://lists.freebsd.org/pipermail/freebsd-numerics/2012-September/000288.html

Gcc has produced +Infinity for LDBL_MAX on i386 and amd64 with -m32
for some time, and newer versions of gcc are now warning that the
"floating constant exceeds range of 'long double'". Avoid this by
referring to half the value of LDBL_MAX instead.

Reviewed by: bde
Approved by: markj (mentor)
Sponsored by: Dell EMC Isilon

MFC r322435 (by rlibby):

Revert r322418, LDBL_MAX_EXP unsuitable for macro pasting on some arches

Either need a different way to spell HALF_LDBL_MAX, or a different way
to spell LDBL_MAX_EXP, or a different approach.

Reported by: ian

MFC r322921 (by ngie):

Revert r321457

It doesn't fail after ^/head@r322855 (the releng_50 clang merge).

PR: 220989

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Add assembly versions of remquol() and remainderl().

Hook up sqrtl() to the build.

Implement rintl(), nearbyintl(), lrintl(), and llrintl().
Thanks to bde@ for feedback and testing of rintl().

Add logbl(3) to libm.

Removed the optimized asm versions of scalb() and scalbf(). These
functions are only for compatibility with obsolete standards. They
shouldn't be used, so they shouldn't be optimized. Use the generic
versions instead.

This fixes scalbf() as a side effect. The optimized asm version left
garbage on the FP stack. I fixed the corresponding bug in the optimized
asm scalb() and scalbn() in 1996. NetBSD fixed it in scalb(), scalbn()
and scalbnf() in 1999 but missed fixing it in scalbf(). Then in 2005
the bug was reimplemented in FreeBSD by importing NetBSD's scalbf().

The generic versions have slightly different error handling:
- the asm versions blindly round the second parameter to a (floating
point) integer and proceed, while the generic versions return NaN
if this rounding changes the value. POSIX permits both behaviours
(these functions are XSI extensions and the behaviour for a bogus
non-integral second parameter is unspecified). Apart from this
and the bug in scalbf(), the behaviour of the generic versions seems
to be identical. (I only exhusatively tested
generic_scalbf(1.0F, anyfloat) == asm_scalb(1.0F, anyfloat). This
covers many representative corner cases involving NaNs and Infs but
doesn't test exception flags. The brokenness of scalbf() showed up
as weird behaviour after testing just 7 integer cases sequentially.)

Add symbol versioning to libm.

More optimized math functions.

Implement and document remquo() and remquof().

- Define the LDBL_PREC to be the number of significant bits in a long
double's mantissa.
- Add an assembly version of scalbnl.

Remove the i387 versions of atan(), atan2(), and atan2f().
They are slower than the MI routines on modern hardware,
except for degenerate cases such as the Pentium 4.

PR: 67469

Remove i387 versions of asin() and acos(). Although the hardware
instruction was faster on the 486, it's slower than our MD version on
modern processors.

Determined by: bde
PR: 67469

Remove the float versions of the i387 trig functions obtained from
NetBSD. They're buggy, giving particularly for inputs larger in
magnitude than 2**63.

Noticed by: bde
PR: 67469

Move machine-dependent crud to its own makefile.