MFC r327400 (by eadler):

cacos(3): correct spelling of 'I'

In some cases we had 'i' instead of 'I'.

PR: 195517
Submitted by: stephen

MFC r329259 (by eadler):

msun: signed overflow in atan2

As a component of atan2(y, x), the case of x == 1.0 is farmed out to
atan(y). The current implementation of this comparison is vulnerable
to signed integer underflow (that is, undefined behavior), and it's
performed in a somewhat more complicated way than it need be. Change
it to not be quite so cute, rather directly comparing the high/low
bits of x to the specific IEEE-754 bit pattern that encodes 1.0.

Note that while there are three different e_atan* files in the
relevant directory, only this one needs fixing. e_atan2f.c already
compares against the full bit pattern encoding 1.0f, while
e_atan2l.cuses bitwise-ands/ors/nots and so doesn't require a change.

Closes #130

Submitted by: Jeff Walden (@jswalden github PR #130)
Reviewed by: bde

MFC r334721 (by cem):

clog.3, complex.3: Fix typos and igor style issues

PR: 228783
Reported by: Karsten <freebsd-bugzilla AT kkoenig.net>

MFC r336299 (by mmacy):

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

MFC r336563:

Recommit r336497: Fix powl, cpow, cpowf, and cpowl imports from OpenBSD

This is a follow-up to r336299.

* lib/msun/Makefile:
. Remove polevll.c

* lib/msun/ld80/e_powl.c:
. Copy contents of polevll.c to here. This is the only consumer of
these functions. Make functions 'static inline'.
. Make reducl a 'static inline' function.

* lib/msun/man/exp.3:
. Remove BUGS section that no longer applies.

* lib/msun/src/math_private.h:
. Remove prototypes of __p1evll() and __polevll()

* lib/msun/src/s_cpow.c:
* lib/msun/src/s_cpowf.c:
* lib/msun/src/s_cpowl.c
. Include math_private.h.
. Use the CMPLX macro from either C99 or math_private.h (depends on
compiler support) instead of the problematic use of complex I.

Submitted by: Steve Kargl <sgk@troutmask.apl.washington.edu>
PR: 229876

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

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

* 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

* Makefile:
. Add s_erfl.c to building libm.
. Add MLINKS for erfl.3 and erfcl.3.

* Symbol.map:
. Move erfl and erfcl to their proper location.

* ld128/s_erfl.c:
. Implementations of erfl and erfcl in the IEEE 754 128-bit format.

* ld80/s_erfl.c:
. Implementations of erfl and erfcl in the Intel 80-bit format.

* man/erf.3:
. Document the new functions.
. While here, remove an incomplete sentence.

* src/imprecise.c:
. Remove the stupidity of mapping erfl and erfcl to erf and erfc.

* src/math.h:
. Move the declarations of erfl and erfcl to their proper place.

* src/s_erf.c:
. For architectures where double and long double are the same
floating point format, use weak references to map erfl to
erf and ercl to erfc.

Reviewed by: bde (many earlier versions)

* Makefile:
. Hook coshl, sinhl, and tanhl into libm.
. Create symbolic links for corresponding manpages.
. While here remove a nearby extraneous space.

* Symbol.map:
* src/math.h:
. Move coshl, sinhl, and tanhl to their proper locations.

* man/cosh.3:
* man/sinh.3:
* man/tanh.3:
. Update the manpages.

* src/e_cosh.c:
* src/e_sinh.c:
* src/s_tanh.c:
. Add weak reference for LBDL_MANT_DIG==53 targets.

* src/imprecise.c:
. Remove the coshl, sinhl, and tanhl kludge.

* src/e_coshl.c:
. ld80 and ld128 implementation of coshl().

* src/e_sinhl.c:
. ld80 and ld128 implementation of sinhl().

* src/s_tanhl.c:
. ld80 and ld128 implementation of tanhl().

Obtained from: bde (mostly), das and kargl

Add stub implementations of the missing C++11 math functions.
These are weak and so can be replaced by other versions in applications
that choose to do so, and will give a linker warning when used so that
applications that rely on the extra precision can avoid them.

Note that since the C/C++ specs only guarantee that long double has
precision equal to double, code that actually relies on these functions
having greater precision is unportable at best and broken at worst.