Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Merge the 386 and amd64 versions of the fenv.h, to make cc -m32
compilations which use fenv.h work.

Reviewed by: tjil
Sponsored by: The FreeBSD Foundation

Bugfix: feenableexcept() and fedisableexcept() should just return the
old exception mask, not mask | ~FE_ALL_EXCEPT.

MFC after: 2 weeks

Use #include "fenv.h" instead of #include <fenv.h>. This makes it
more convenient to compile the math library by itself.

Requested by: bde

Provide external definitions of all of the standardized functions in
fenv.h that are currently inlined.

The definitions are provided in fenv.c via 'extern inline'
declaractions. This assumes the compiler handles 'extern inline' as
specified in C99, which has been true under FreeBSD since 8.0.

The goal is to eventually remove the 'static' keyword from the inline
definitions in fenv.h, so that non-inlined references all wind up
pointing to the same external definition like they're supposed to.
I am deferring the second step to provide a window where
newly-compiled apps will still link against old math libraries.
(This isn't supported, but there's no need to cause undue breakage.)

Reviewed by: stefanf, bde

Remove duplicate .note.GNU-stack section declaration.

Reported by: arundel

Add section .note.GNU-stack for assembly files used by 386 and amd64.

Use __FBSDID() instead of RCSID() in most .S files under lib/msun/i386,
and one under lib/msun/amd64. This avoids adding the identifiers to the
.text section, and moves them to the .comment section instead.

Suggested by: bde
Approved by: rpaulo (mentor)

Placate new binutils, by using 16-bit %ax instead of 32-bit %eax as an
argument for fnstsw. Explicitely specify sizes for the XMM control and
status word and X87 control and status words.

Reviewed by: das
Tested by: avg
MFC after: 2 weeks

Use, in uncovered part, the END() macro in order to improve debugging.
In this specific case, Valgrind won't get confused when analyzing such
functions.

Sponsored by: Sandvine Incorporated
Tested by: emaste
MFC: 3 days

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

Hook up sqrtl() to the build.

MD implementations of sqrtl().

Use hardware remainder on amd64 since it is 5 to 10 times faster than
software remainder and is already used for remquo().

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

Translate from the i386 so that this compiles and runs.

I hope that this and the i386 version of it will not be needed, but
this is currently about 16 cycles or 36% faster than the C version,
and the i386 version is about 8 cycles or 19% faster than the C
version, due to poor optimization of the C version.

Add logbl(3) to libm.

Use C comments since we now preprocess these files with CPP.

Fix a problem relating to fesetenv() clobbering i387 register stack.

Details: As a side-effect of restoring a saved FP environment,
fesetenv() overwrites the tag word, which indicates which i387
registers are in use. Normally this isn't a problem because
the calling convention requires the register stack to be empty
on function entry and exit. However, fesetenv() is inlined, so we
need to tell gcc explicitly that the i387 registers get clobbered.

PR: 85101

Remove an unneeded fnstcw instruction.

Noticed by: bde

Add symbol versioning to libm.

Add a missing ldexpf() alias for amd64.

Noticed by: bz@, tjr@

More optimized math functions.

Implement and document remquo() and remquof().

Spell 'fedisableexcept' correctly.

Replace fegetmask() and fesetmask() with feenableexcept(),
fedisableexcept(), and fegetexcept(). These two sets of routines
provide the same functionality. I implemented the former as an
undocumented internal interface to make the regression test easier to
write. However, fe(enable|disable|get)except() is already part of
glibc, and I would like to avoid gratuitous differences. The only
major flaw in the glibc API is that there's no good way to report
errors on processors that don't support all the unmasked exceptions.

Define the LDBL_PREC to be the number of significant bits in a long
double's mantissa.

Move machine-dependent crud to its own makefile.

Remove wrappers and other cruft intended to support SVID, mistakes in
C90, and other arcana. Most of these features were never fully
supported or enabled by default.

Ok: bde, stefanf

amd64 assembly versions of sqrt(), lrint(), and llrint() using SSE2.

Mark all inline asms that read the floating-point control or status
registers as volatile. Instructions that *wrote* to FP state were
already marked volatile, but apparently gcc has license to move
non-volatile asms past volatile asms. This broke amd64's feupdateenv
at -O2 due to a WAR conflict between fnstsw and fldenv there.

Mark inline stmxcsr instructions as volatile, since this appears to be
the only way to convince gcc that they read the MXCSR. The volatile
annotation may be needed elsewhere as well.

Insert a missing '~' in feholdexcept(), so that it correctly clears
the exception flags in the mxcsr as well as the x87 FPU.

Add an fenv.h implementation for the amd64 port.

Reviewed by: standards@