MFC r297790:
r297790 (by pfg):

libc: replace 0 with NULL for pointers.

While here also cleanup some surrounding code; particularly
drop some malloc() casts.

Found with devel/coccinelle.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Conditionalize the __floatunsisf and __floatunsidf functions, added in
NetBSD's rev 1.6 of this file, on !defined(SOFTFLOAT_FOR_GCC). These
functions are provided by libgcc, so we don't need them. This should
unbreak mips.

Merge in the latest SoftFloat changes from NetBSD. (NetBSD isn't the
original vendor, but we're using their heavily modified version.)
This brings in functions for long double emulation (both extended and
quad formats), which may be useful for testing, and also for replacing
libc/sparc64/fpu/.

Remove functions from softfloat's Symbol.map that don't need to be exported.
Also use the proper number of underscores for internal names. (Changing
the names should be fine, since apparently the symbols are currently
unused.)

Convert softfloat to use the standard exception flag and rounding macros
in fenv.h instead of the non-standard and incomplete ones in ieeefp.h.

Thanks to Ian Lepore for testing this patch.

Powerpc is special here. powerpc and powerpc64 use different ABIs, so
their implementations aren't in the same files. Introduce LIBC_ARCH
and use that in preference to MACHINE_CPUARCH. Tested by amd64 and
powerpc64 builds (thanks nathanw@)

MFtbemd:

Prefer MACHNE_CPUARCH to MACHINE_ARCH in most contexts where you want
to test of all the CPUs of a given family conform.

Add #endif missed in r206490.

While SPARC V9 allows tininess to be detected either before or after
rounding (impl. dep. #55), the SPARC JPS1 responsible for SPARC64 and
UltraSPARC processors defines that in all cases tininess is detected
before rounding therefore rounding up to the smallest normalized number
should set the underflow flag. This change is needed for using SoftFloat
on sparc64 for reference purposes.

PR: 144900
Submitted by: Peter Jeremy

Reflect license change from NetBSD.

Obtained from: NetBSD

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

Add each directory's symbol map file to SYM_MAPS.

Add symbol maps and initial symbol version definitions to libc.

Reviewed by: davidxu

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

Oooops I forgot to commit that.
Use fp_rnd_t, not fp_rnd.

Reported by: Jia-Shiun Li (jiashiun at gmail dot com)

Import the softfloat emulation library, needed for FreeBSD/arm right now.
It should become useless when gcc 3.4 will be imported, as libgcc from
gcc 3.4 contains this bits for arm.