Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Fix fpset*() to not trap if there is a currently unmasked exception.
Unmasked exceptions (which can be fixed up using fpset*() before they
trap) are very rare, especially on amd64 since SSE exceptions trap
synchronously, but I want to merge the faster amd64 implementations of
fpset*() back to i386 without introducing the bug on i386.

The i386 implementation has always avoided the trap automatically by
changing things using load/store of the FP environment, but this is
very slow. Most changes only affect the control word, so they can
usually be done much more efficiently, and amd64 has always done this,
but loading the control word can trap.

This version use the fast method only in the usual case where it will
not trap. This only costs a couple of integer instructions (including
one branch which I haven't optimized carefully yet) in the usual case,
but bloats the inlines a lot. The inlines were already a bit too large
to handle both the FPU and SSE.

Fix some style bugs:
- fix a previous style fix: shifts should be in the correct direction even
if they are null.
- restore a comment about namespace pollution from floatingpoint.h 1.12 and
update it.
- remove unused namespace pollution FP_*REG.
- improve some comments.
- sort macro definitions for entry points.
- don't use underscores for macro args.

Simplify the ifdefs:
- fix this to compile with C++ by casting ints to enums in a few places
and by using the correct parameter type for _fpsetprec(). Remove
__cplusplus ifdefs which disabled the buggy code.
- remove __CC_SUPPORTS___INLINE ifdefs. `__inline' vs `inline', and either
of these #defined away, are supposed to be handled by very old ifdefs
in <sys/cdefs.h>. Thus the __CC_SUPPORTS___INLINE macro is not needed
here (or anywhere else that it used). It is less needed here than in
most places, since this file is userland-only and userland is far from
supporting INTEL_COMPILER. The __CC_SUPPORTS___INLINE__ macro which
was used here is even less needed. It is to support spelling `inline'
as `__inline__' instead of the usual spelling `__inline'.

Fix some style bugs that I missed in the previous commit (remove unused
asms and sort more variables).

Fix some style bugs (mainly, use explicit shifts when accessing bit-fields
even if the shift count happens to be 0, sort declarations, and spell
__inline normally).

Improve some comments.

The memory operands to fldcw and ldmxcsr are inputs, not outputs.

Remove fpsetsticky(). This was added for SysV compatibility, but due
to mistakes from day 1, it has always had semantics inconsistent with
SVR4 and its successors. In particular, given argument M:

- On Solaris and FreeBSD/{alpha,sparc64}, it clobbers the old flags
and *sets* the new flag word to M. (NetBSD, too?)
- On FreeBSD/{amd64,i386}, it *clears* the flags that are specified in M
and leaves the remaining flags unchanged (modulo a small bug on amd64.)
- On FreeBSD/ia64, it is not implemented.

There is no way to fix fpsetsticky() to DTRT for both old FreeBSD apps
and apps ported from other operating systems, so the best approach
seems to be to kill the function and fix any apps that break. I
couldn't find any ports that use it, and any such ports would already
be broken on FreeBSD/ia64 and Linux anyway.

By the way, the routine has always been undocumented in FreeBSD,
except for an MLINK to a manpage that doesn't describe it. This
manpage has stated since 5.3-RELEASE that the functions it describes
are deprecated, so that must mean that functions that it is *supposed*
to describe but doesn't are even *more* deprecated. ;-)

Note that fpresetsticky() has been retained on FreeBSD/i386. As far
as I can tell, no other operating systems or ports of FreeBSD
implement it, so there's nothing for it to be inconsistent with.

PR: 75862
Suggested by: bde

netchild's mega-patch to isolate compiler dependencies into a central
place.

This moves the dependency on GCC's and other compiler's features into
the central sys/cdefs.h file, while the individual source files can
then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to
refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42.

By now, GCC and ICC (the Intel compiler) have been actively tested on
IA32 platforms by netchild. Extension to other compilers is supposed
to be possible, of course.

Submitted by: netchild
Reviewed by: various developers on arch@, some time ago

Update the graffiti.

Fix a dumbass mistake. I had the 'set' and 'get' reversed in the
fpsetround/fpgetround macro pairs.

Extend the machine/ieeefp.h that was inherited from i386 to support
the SSE mxcsr register as well. Since gcc will intermix SSE2 and x87
FP code, the fpsetround() etc mode had better be the same.

There are hooks to enable these inlines to be instantiated inside libc
for non-gcc or C++ callers. (g++ doesn't like the inlines that tried
to extract an integer and convert it to an enum).

o Move the contents of <machine/floatingpoint.h> over to
<machine/ieeefp.h> where it belongs.
o Remove the i386 specific inclusion of <machine/floatingpoint.h>
from <ieeefp.h>, now that including <machine/ieeefp.h> is enough
for all architectures.
o Allow <machine/ieeefp.h> to inline the functions exposed by the
headers by checking for _IEEEFP_INLINED_ in the MI header. When
defined, prototypes are not given and it is assumed that the MD
headers, when inlining only a subset of the functions provide
prototypes for the functions not being inlined.

Based on patch from: Terry Lambert <tlambert2@mindspring.com>
Tested with: make release.

$Id$ -> $FreeBSD$

On FPU exceptions, pass a useful error code (one of the FPE_...
macros) to the signal handler, for old-style BSD signal handlers as
the second (int) argument, for SA_SIGINFO signal handlers as
siginfo_t->si_code. This is source-compatible with Solaris, except
that we have no <siginfo.h> (which isn't even mentioned in POSIX
1003.1b).

An rather complete example program is at
http://www3.cons.org/cracauer/freebsd-signal.c
This will be added to the regression tests in src/.

This commit also adds code to disable the (hardware) FPU from
userconfig, so that you can use a software FP emulator on a machine
that has hardware floating point. See LINT.

Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.

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.

Fix a bunch of spelling errors in the comment fields of
a bunch of system include files.

Delete redundant #ifdef __i386__, be consistent about idempotency
protection.

Submitted by: Bruce Evans

Move ieeefp.h over, and put it in the correct subdirectory this time.

Submitted by: Andrew Moore