The default implementation of the fenv.h methods return
-EOPNOTSUP. Some of these have implementations appropriate
for soft-float.
The intention of the new fenv.h is that it be portable
and that architectures provide their own implementation
of sys/fenv.h.
Applied changes from commit 8d98f95:
* arm/crt0.S: Initialise __heap_limit when ARM_RDI_MONITOR is defined.
* arm/syscalls.c: define __heap_limit global symbol.
* arm/syscalls.c (_sbrk): Honour __heap_limit.
Applied changes from commit 8d98f95:
Fixed semihosting for ARM when heapinfo not provided by debugger
Applied changes from the commit 9b11672:
When simulating arm code, the target program startup code (crt0) uses
semihosting invocations to get the command line from the simulator. The
simulator returns the command line and its size into the area passed in
parameter. (ARM 32-bit specifications :
http://infocenter.arm.com/help/topic/com.arm.doc.dui0058d/DUI0058.pdf
chapter "5.4.19 SYS_GET_CMDLINE").
The memory area pointed by the semihosting register argument is located
in .text section (usually not writtable (RX)).
If we run this code on a simulator that respects this rights properties
(qemu user-mode for instance), the command line will not be written to
the .text program memory, in particular the length of the string. The
program runs with an empty command line. This problem hasn't been seen
earlier probably because qemu user-mode is not so much used, but this can
happen with another simulator that refuse to write in a read-only segment.
With this modification, the command line can be correctly passed to the
target program.
Changes:
- newlib/libc/sys/arm/crt0.S : Arguments passed to the
AngelSWI_Reason_GetCmdLine semihosting invocation are placed into .data
section instead of .text
The Arm sys/param.h does not define anything differently to the
generic sys/param.h, but fails to define some things that that file
provides. There does not appear to be any reason to keep this version
and we should revert to using the common version.
_stat64 and _fstat64 are not exported from Cygwin. Use the
reentrant analogues, like everywhere else.
Signed-off-by: Corinna Vinschen <corinna-cygwin@cygwin.com>
SP initialization changes:
1. set default value in semihosting case as well
2. moved existing SP & SL init code for processor modes in separate routine and made it as "hook"
3. init SP for processor modes in Thumb mode as well
Add new macro FN_RETURN, FN_EH_START and FN_EH_END.
2019-07-09 Joern Rennecke <joern.rennecke@riscy-ip.com>
* libm/common/s_expm1.c ("math_config.h"): Include.
(expm1): Use __math_oflow to set errno.
* libm/common/s_log1p.c ("math_config.h"): Include.
(log1p): Use __math_divzero and __math_invalid to set errno.
* libm/common/sf_expm1.c ("math_config.h"): Include.
(expm1f): Use __math_oflow to set errno.
* libm/common/sf_log1p.c ("math_config.h"): Include.
(log1pf): Use __math_divzero and __math_invalid to set errno.
Update the offsets used to save registers into the stejmp jmp_buf
structure in order to:
* Avoid writing the supervision register outside the buffer and thus
clobbering something on the stack. Previously the supervision register
was written at offset 124 while the buffer was of length 124.
* Shrink the jmp_buf down to the size actually needed, by avoiding holes
at the locations of omitted registers.
Invert equality check instruction to correct the return value handling
in longjmp.
The return value should be the value of the second argument to longjmp,
unless the argument value was 0 in which case it should be 1.
Previously, longjmp would set return value 1 if the second argument was
non-zero, and 0 if it was 0, which was incorrect.
GCC r272640 modifies the MSP430 target to use "__int20__" for
PTRDIFF_TYPE (and therefore INTPTR_TYPE) instead of "__int20".
To support the calculation of pointer size in
newlib/libc/include/sys/_intsup.h, definitions for __int20__ need to be
added.
This patch set implements the Linux syscalls sched_getaffinity,
sched_setaffinity, pthread_getaffinity_np, and pthread_setaffinity_np.
Linux has a straightforward view of the cpu sets used in affinity masks.
They are simply long (1024-bit) bit masks. This code emulates that view
while internally dealing with Windows' distribution of available CPUs among
processor groups.
libX11 provides <X11/Xlocale.h>. The build of libX11 itself adds
include/X11 to the compiler's include path. This results in a name
collision with /usr/include/xlocale.h on case-insensitive filesystems.
Commit 90e35b1eb3 renamed sys/_locale.h to xlocale.h in March 2017 under
the assumption that we should provide the locale_t type in the same file
as on Linux, FreeBSD, and Darwin.
A few weeks later (June 2017), glibc removed the xlocale.h file in favor
of bits/types/locale_t.h, which shouldn't be included directly anyway.
For reference and the reasoning, see
https://sourceware.org/git/?p=glibc.git;a=commit;h=f0be25b6336d
Given the above, revert 90e35b1eb3 and
fix additional usage of xlocale.h.
From: Andrew Stubbs <ams@codesourcery.com>
Fix a bug in which the high-part of 64-bit values are being corrupted, leading
to erroneous stack overflow errors. The problem was only that the mixed-size
calculations are being treated as signed when they should be unsigned.
From: Kwok Cheung Yeung <kcy@codesourcery.com>
This patch adds enough support for constructors/destructors and OS functions
to be able to link and run gfortran programs on AMD GCN.
There's no actual ability to do I/O operations on this targets, besides
"write" to stdout and stderr, so most of the functions are just stubs.
prevents compiler warning when they end up being unused.
Reviewed by: kib
Obtained from: OpenBSD
MFC after: 2 weeks
Sponsored by: Klara Inc.
Differential Revision: https://reviews.freebsd.org/D20185
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
newlib's vfwscanf(3) (or specifically, __SVFWSCANF_R()) fails to correctly set
the assignment-suppressing character (`*') flag[1] which, when present in the
formatting string, results in undefined behaviour comprising retrieving and
dereferencing a pointer that was not supplied by the caller as such or at all.
When compared to the vfscanf(3) implementation, this would appear to be over
the missing goto match_failure statement preceded by the flags test seen below.
Hence, this patch (re)introduces it.
[1] <http://pubs.opengroup.org/onlinepubs/009695399/functions/fwscanf.html>
--
A commit from 2016 tried to address this GCC provided <stddef.h> issue
#if (defined (__FreeBSD__) && (__FreeBSD__ >= 5)) \
|| defined(__DragonFly__) \
|| defined(__FreeBSD_kernel__)
/* __size_t is a typedef on FreeBSD 5, must not trash it. */
#elif defined (__VMS__)
/* __size_t is also a typedef on VMS. */
#else
#define __size_t
#endif
with an include of <stddef.h> before <sys/_types.h> in <sys/types.h>.
Is is not robust enough. Do the include of <stddef.h> in <sys/_types.h>
directly and request only the necessary types.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
RTEMS uses a considerable part of FreeBSD kernel and user space sources.
These sources are compiled with a __FreeBSD__ define. On 2018-06-26
Gerald Pfeifer changed the GCC provided <stddef.h> so that it includes
<sys/_types.h> if __FreeBSD__ is defined. The Newlib <sys/_types.h>
included <sys/lock.h> which includes <sys/cdefs.h> on RTEMS which
includes <stddef.h>. To get rid of this cyclic dependency move the
optional _flock_t definition to <sys/reent.h>.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
This patch adds implementations of memcpy, memmove, memset and strcmp
optimized for size. The changes have been tested in
riscv/riscv-gnu-toolchain by riscv-dejagnu with
riscv-sim.exp/riscv-sim-nano.exp.
"tiny" printf is derived from _vfprintf_r in libc/stdio/nano-vfprintf.c.
"tiny" puts has been implemented so that it just calls write, without
any other processing.
Support for buffering, reentrancy and streams has been removed from
these functions to achieve reduced code size.
This reduced code size implementation of printf and puts can be enabled
in an application by passing "--wrap printf" and "--wrap puts" to the
GNU linker. This will replace references to "printf" and "puts" in user
code with "__wrap_printf" and "__wrap_puts" respectively.
If there is no implementation of these __wrap* functions in user code,
these "tiny" printf and puts implementations will be linked into the
final executable.
The wrapping mechanism is supposed to be invisible to the user:
- A GCC wrapper option such as "-mtiny-printf" will be added to alias
these wrap commands.
- If the user is unaware of the "tiny" implementation, and chooses to
implement their own __wrap_printf and __wrap_puts, their own
implementation will be automatically chosen over the "tiny" printf and
puts from the library.
Newlib must be configured with --enable-newlib-nano-formatted-io for
the "tiny" printf and puts functions to be built into the library.
Code size reduction examples:
printf("Hello World\n")
baseline - msp430-elf-gcc gcc-8_3_0-release
text data bss
5638 214 26
"tiny" puts enabled
text data bss
714 90 20
printf("Hello %d\n", a)
baseline - msp430-elf-gcc gcc-8_3_0-release
text data bss
10916 614 28
"tiny" printf enabled
text data bss
4632 280 20
The code in trap.S is to support the old APCS chunked stack variant,
which dates back to the Acorn days, so put it under #ifndef
__ARM_EABI__.
* libgloss/arm/trap.S: Use __ARM_EABI rather than PREFER_THUMB.
* newlib/libc/sys/arm/trap.S: Use __ARM_EABI rather than
__thumb2__.
Commit 69f4c40291 improved most
macro checks to be ARMv8-M baseline proof, but missed a few
occurrences which otherwise fail to build when using a CPU setting
such as cortex-m0 or cortex-m23. This patch brings the same
changes as the ones that were committed to libgloss at that time.
newlib:
* libc/sys/arm/crt0.S: Use THUMB1_ONLY rather than
__ARM_ARCH_6M__.
These missing includes were causing build warnings, but also a real bug in
which the "size" parameter to "write" was being passed in 32-bit, whereas it
ought to be 64-bit. This led to intermittent bad behaviour.
The GCN port outputs stdout and stderr via a shared-memory interface.
Previously the buffer was limited to 1000 write operations, which was enough
for testing purposes, but easy to exhaust.
This patch implements a new circular buffering system allowing a greater
amount of output. The interface must allow hundreds of hardware threads to
output simultaneously. The new limit is UINT32_MAX write operations.
Unfortunately, there's no way to tell if the host side has also been updated.
This code will misbehave unless the gcn-run from GCC is also updated (although
it's fine the other way around), but that patch has already been committed.
OK?
Andrew Stubbs
Mentor Graphics / CodeSourcery
as POSIX 2008 requires. It also matches now how our 'ls' works for years.
b) Remove comment expressed 2 fears:
1) One just simple describe how strcoll() works in _any_ context,
not for directories only. Are we plan to remove strcoll() from everything
just because it is little more complex than strcmp()? I doubt, and
directories give nothing different here. Moreover, strcoll() used
in 'ls' for years and nobody complaints yet.
2) Plain wrong statement about undefined strcoll() behaviour. strcoll()
always gives predictable results, falling back to strcmp() on any
trouble, see strcoll(3).
No objections from -current list discussion.
to obtain an initial estimate of the array length needed to store all
the directory entries. Although BSD has historically guaranteed that
st_size is the size of the directory file, POSIX does not, and more to
the point, some recent filesystems such as ZFS use st_size to mean
something else.
The fix is to not stat the directory at all, set the initial
array size to 32 entries, and realloc it in powers of 2 if that
proves insufficient.
PR: 113668
in libc's gen/ directory.
- Move CSRG IDs into __SCCSID().
- When a file has been copied, consistently use 'From: <tag>' for strings
referencing the version of the source file copied from in the license
block comment.
- Some of the 'From:' tags were using $FreeBSD$ that was being expanded on
each checkout. Fix those to hardcode the FreeBSD tag from the file that
was copied at the time of the copy.
- When multiple strings are present list them in "chronological" order,
so CSRG (__SCCSID) before FreeBSD (__FBSDID). If a file came from
OtherBSD and contains a CSRG ID from the OtherBSD file, use the order
CSRG -> OtherBSD -> FreeBSD.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D15831
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
Mainly focus on files that use BSD 3-Clause license.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
This patch removes the definitions of HUGE_VAL from some of the float math
functions. HUGE_VAL is defined in newlib/libc/include/math.h, so it is not
necessary to have a further definition in the math functions.
Add support for the AMD GCN GPU architecture. This is primarily intended for
use with OpenMP and OpenACC offloading. It can also be used for stand-alone
programs, but this is intended mostly for testing the compiler and is not
expected to be useful in general.
The GPU architecture is highly parallel, and therefore Newlib must be
configured to use dynamic re-entrancy, and thread-safe malloc.
The only I/O available is a via a shared-memory interface provided by libgomp
and the gcn-run tool included with GCC. At this time this is limited to
stdout, argc/argv, and the return code.
This patch significantly improves performance of memmem using a novel
modified Horspool algorithm. Needles up to size 256 use a bad-character
table indexed by hashed pairs of characters to quickly skip past mismatches.
Long needles use a self-adapting filtering step to avoid comparing the whole
needle repeatedly.
By limiting the needle length to 256, the shift table only requires 8 bits
per entry, lowering preprocessing overhead and minimizing cache effects.
This limit also implies worst-case performance is linear.
Small needles up to size 2 use a dedicated linear search. Very long needles
use the Two-Way algorithm (to avoid increasing stack size inlining is now disabled).
The performance gain is 6.6 times on English text on AArch64 using random
needles with average size 8 (this is even faster than the recently improved strstr
algorithm, so I'll update that in the near future).
The size-optimized memmem has also been rewritten from scratch to get a
2.7x performance gain.
Tested against GLIBC testsuite and randomized tests.
Message-Id: <DB5PR08MB1030649D051FA8532A4512C883B20@DB5PR08MB1030.eurprd08.prod.outlook.com>
FreeBSD uses a 64-bit ino_t since 2017-05-23. We need this for the
pipe() support in libbsd.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Various structures exported by sysctl_rtsock() contain padding fields
which were not being zeroed.
Reported by: Thomas Barabosch, Fraunhofer FKIE
Reviewed by: ae
MFC after: 3 days
Security: kernel memory disclosure
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18333
The threshold value at which powf overflows depends on the rounding mode
and the current check did not take this into account. So when the result
was rounded away from zero it could become infinity without setting
errno to ERANGE.
Example: pow(0x1.7ac7cp+5, 23) is 0x1.fffffep+127 + 0.1633ulp
If the result goes above 0x1.fffffep+127 + 0.5ulp then errno is set,
which is fine in nearest rounding mode, but
powf(0x1.7ac7cp+5, 23) is inf in upward rounding mode
powf(-0x1.7ac7cp+5, 23) is -inf in downward rounding mode
and the previous implementation did not set errno in these cases.
The fix tries to avoid affecting the common code path or calling a
function that may introduce a stack frame, so float arithmetics is used
to check the rounding mode and the threshold is selected accordingly.
for {n,u,m}stosbt
Integer overflows and wrong constants limited the accuracy of these
functions and created situatiosn where sbttoXs(Xstosbt(Y)) != Y. This
was especailly true in the ns case where we had millions of values
that were wrong.
Instead, used fixed constants because there's no way to say ceil(X)
for integer math. Document what these crazy constants are.
Also, use a shift one fewer left to avoid integer overflow causing
incorrect results, and adjust the equasion accordingly. Document this.
Allow times >= 1s to be well defined for these conversion functions
(at least the Xstosbt). There's too many users in the tree that they
work for >= 1s.
This fixes a failure on boot to program firmware on the mlx4
NIC. There was a msleep(1000) in the code. Prior to my recent rounding
changes, msleep(1000) worked, but msleep(1001) did not because the old
code rounded to just below 2^64 and the new code rounds to just above
it (overflowing, causing the msleep(1000) to really sleep 1ms).
A test program to test all cases will be committed shortly. The test
exaustively tries every value (thanks to bde for the test).
Sponsored by: Netflix, Inc
Differential Revision: https://reviews.freebsd.org/D18051
of the result rather than the floor(). Returning the floor means that
sbttoX(Xtosbt(y)) != y for almost all values of y. In practice, this
results in a difference of at most 1 in the lsb of the sbintime_t. This
difference is meaningless for all current users of these functions, but
is important for the newly introduced sysctl conversion routines which
implicitly rely on the transformation being idempotent.
Sponsored by: Netflix, Inc
Mainly focus on files that use BSD 3-Clause license.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
and decimal time units. Use them in some existing code that is
vulnerable to roundoff errors.
The existing constant SBT_1NS is a honeypot, luring unsuspecting folks into
writing code such as long_timeout_ns*SBT_1NS to generate the argument for a
sleep call. The actual value of 1ns in sbt units is ~4.3, leading to a
large roundoff error giving a shorter sleep than expected when multiplying
by the trucated value of 4 in SBT_1NS. (The evil honeypot aspect becomes
clear after you waste a whole day figuring out why your sleeps return early.)
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
- Add CLOCK_REALTIME_COARSE, CLOCK_MONOTONIC_RAW,
CLOCK_MONOTONIC_COARSE and CLOCK_BOOTTIME
- Guard new values with __GNU_VISIBLE
- Add CLOCK_REALTIME_COARSE as (clockid_t) 0 for simplicity
(It allows to have all values < 8 and so be used as array
index into an array of clocks)
- Fix macro bracketing
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
A previous commit introduced the ability to use the semi-hosting
SYS_EXIT_EXTENDED operation to libgloss, this commit adds the same
ability to the sys/arm/ backend so that building newlib only will
provide the same capabilities.
This patch fixes an issue in the previous memset loop change. If the
zva size is >= 256 and there are more than 64 bytes left in the
tail, we could enter the loop and thus need to rebias dst by 32 as
well.
Since no known CPUs use this size this can't be tested natively, so I've
tested it on a simulator initialized with a large zva size.
--
Do not define __ATTRIBUTE_IMPURE_PTR__ for RTMES on the v850 target.
The previous definition lead to the following linker error in
combination with -fdata-sections:
relocation truncated to fit: R_V810_GPWLO_1 against symbol
`_global_impure_ptr' defined in .rodata._global_impure_ptr section in
libc.a(lib_a-impure.o)
relocation truncated to fit: R_V810_GPWLO_1 against symbol `_impure_ptr'
defined in .data._impure_ptr section in libc.a(lib_a-impure.o)
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
The <machine/param.h> header file exposes some unrelated stuff not
covered by C or POSIX. Avoid its use in <sys/_cpuset.h> since it is
included in <rtems.h>.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
This fixes an ineffiency in the non-zero memset. Delaying the writeback
until the end of the loop is slightly faster on some cores - this shows
~5% performance gain on Cortex-A53 when doing large non-zero memsets.
Tested against the GLIBC testsuite.
The new GCC port for OpenRISC will use the init_fini_array only and not
provide the init() and fini() functions. Disable the function usage by
default as its no longer needed.
Signed-off-by: Stafford Horne <shorne@gmail.com>
The malloc, alloc_size and alloc_aligned attributes must be only used in
case the function returns the pointer to the allocated memory.
See also:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87683
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
The following FreeBSD kernel methods are not in any standard and
prototypes/definitions were leaking into application space:
+ round_page()
+ trunc_page()
+ atop()
+ ptoa()
+ pgtok()
v3: Add support for read ahead using strnlen, giving an additional 25% speedup
on large inputs (both short and long needles).
This patch significantly improves performance of strstr by using Sunday's
Quick-Search algorithm. Due to its simplicity it has the best average
performance of string matching algorithms on almost all inputs. It uses a
bad-character shift table to skip past mismatches.
The needle length is limited to 254 - this reduces the shift table memory
4 to 8 times, lowering preprocessing overhead and minimizing cache effects.
The limit also implies its worst-case performance is linear.
Larger needles are processed by the Two-Way algorithm. The macro AVAILABLE
has been improved to use strnlen to read the input in chunks. This results
in a 2.5 times speedup for large needles, reducing the performance drop when
the Quick-Search algorithm can't be used.
The code for 1-4 byte needles has been simplified and now uses unsigned
char. Since the optimized code relies on 8-bit chars, we defer to the
size-optimized implementation if CHAR_BIT > 8.
The performance gain of finding a set of randomly chosen words of size 8 in
256 bytes of English text is 14 times on AArch64. For longer haystacks the
gain is well over 20 times.
The size-optimized strstr has also been rewritten from scratch to improve
performance. On the same test the performance gain is 69%.
Tested against GLIBC testsuite, randomized tests and the GNULIB strstr test
(https://git.savannah.gnu.org/cgit/gnulib.git/tree/tests/test-strstr.c).
--
Use existing HAVE_OPENDIR define to determine if a generic
implementation should be provided. Cygwin for example has its own
implementation of opendir() and dirfd().
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
This is used by the file system support of libstdc++ for example. Use
content from latest FreeBSD <sys/dirent.h>
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Move common content of the various <sys/dirent.h> and the latest FreeBSD
<dirent.h> to <dirent.h>.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Use O_RDONLY since you are not supposed to write to a directory.
Use O_DIRECTORY as mandated by POSIX (The Open Group Base Specifications
Issue 7, 2018 edition IEEE Std 1003.1-2017):
"If the type DIR is implemented using a file descriptor, the descriptor
shall be obtained as if the O_DIRECTORY flag was passed to open()."
Use O_CLOEXEC as mandated by POSIX:
"When a file descriptor is used to implement the directory stream, it
behaves as if the FD_CLOEXEC had been set for the file descriptor."
Drop the fcntl() call in favour of O_CLOEXEC.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Make the POSIX O_CLOEXEC, O_NOFOLLOW, O_DIRECTORY, O_EXEC, and O_SEARCH
open() flags available also to non-Cygwin systems.
Make the BSD/glibc O_DIRECT open() flag available also to non-Cygwin
systems.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Commit fbace81684
("Import correctly working strtold from David M. Gay.")
introduced two new files, strtorx.c and strtodg.c. The functions
are only called from strtold.c. However, while strtold.c is only
built if HAVE_LONG_DOUBLE is defined, the patch erroneously added
the two new files to GENERAL_SOURCES unconditionally.
Fix this by building both files only if HAVE_LONG_DOUBLE has been
defined.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Commit 6c212a8b78
("Fix strtod ("nan") and strtold ("nan") returns wrong negative NaN")
introduced an unconditional dependency to nanl and, in turn, to libm.
Rather than including nanl in libc as well, just call __builtin_nanl
from here. Requires GCC 3.3 or later.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>