Rather than open coding the masks, add helper macros to do the magic.
This makes code easier to read.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Check wheter the compiler has the option -fno-tree-loop-distribute-patterns
to inhibit loop transformation to library calls and uses it on memset
and memmove default implementation to avoid recursive calls.
The most common use case of math functions is with default rounding
mode, i.e. rounding to nearest. Setting and restoring rounding mode
is an unnecessary overhead for this, so I've added support for a
context, which does the set/restore only if the FP status needs a
change. The code is written such that only x86 uses these. Other
architectures should be unaffected by it, but would definitely benefit
if the set/restore has as much overhead relative to the rest of the
code, as the x86 bits do.
Here's a summary of the performance improvement due to these
improvements; I've only mentioned functions that use the set/restore
and have benchmark inputs for x86_64:
Before:
cos(): ITERS:4.69335e+08: TOTAL:28884.6Mcy, MAX:4080.28cy, MIN:57.562cy, 16248.6 calls/Mcy
exp(): ITERS:4.47604e+08: TOTAL:28796.2Mcy, MAX:207.721cy, MIN:62.385cy, 15543.9 calls/Mcy
pow(): ITERS:1.63485e+08: TOTAL:28879.9Mcy, MAX:362.255cy, MIN:172.469cy, 5660.86 calls/Mcy
sin(): ITERS:3.89578e+08: TOTAL:28900Mcy, MAX:704.859cy, MIN:47.583cy, 13480.2 calls/Mcy
tan(): ITERS:7.0971e+07: TOTAL:28902.2Mcy, MAX:1357.79cy, MIN:388.58cy, 2455.55 calls/Mcy
After:
cos(): ITERS:6.0014e+08: TOTAL:28875.9Mcy, MAX:364.283cy, MIN:45.716cy, 20783.4 calls/Mcy
exp(): ITERS:5.48578e+08: TOTAL:28764.9Mcy, MAX:191.617cy, MIN:51.011cy, 19071.1 calls/Mcy
pow(): ITERS:1.70013e+08: TOTAL:28873.6Mcy, MAX:689.522cy, MIN:163.989cy, 5888.18 calls/Mcy
sin(): ITERS:4.64079e+08: TOTAL:28891.5Mcy, MAX:6959.3cy, MIN:36.189cy, 16062.8 calls/Mcy
tan(): ITERS:7.2354e+07: TOTAL:28898.9Mcy, MAX:1295.57cy, MIN:380.698cy, 2503.7 calls/Mcy
So the improvements are:
cos: 27.9089%
exp: 22.6919%
pow: 4.01564%
sin: 19.1585%
tan: 1.96086%
The downside of the change is that it will have an adverse performance
impact on non-default rounding modes, but I think the tradeoff is
justified.
__clock_gettime and other __clock_* functions could result in an extra
PLT reference within libc.so if it actually gets used. None of the
code currently uses them, which is why this probably went unnoticed.
Since we want to use this in installed headers, move it to the installed
sys/cdefs.h. This requires a slight tweaking of the name (add trailing
underscores).
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
These prototypes are duplicated in many places. Add a dedicated
header for holding prototypes for program-specific functions to
avoid that.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This feature is specifically for the C++ compiler to offload calling
thread_local object destructors on thread program exit, to glibc.
This is to overcome the possible complication of destructors of
thread_local objects getting called after the DSO in which they're
defined is unloaded by the dynamic linker. The DSO is marked as
'unloadable' if it has a constructed thread_local object and marked as
'unloadable' again when all the constructed thread_local objects
defined in it are destroyed.
These internal knobs are not exposed as part of the public ABI, so mark
them hidden to avoid generating relocations against them.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We can't assume sock_cloexec and pipe2 are bound together as the former
defines are found in glibc only while the latter are a combo of kernel
headers and glibc. So if we do a runtime detection of SOCK_CLOEXEC, but
pipe2() is a stub inside of glibc, we hit a problem. For example:
main()
{
getgrnam("portage");
if (!popen("ls", "r"))
perror("popen()");
}
getgrnam() will detect that the kernel supports SOCK_CLOEXEC and then set
both __have_sock_cloexec and __have_pipe2 to true. But if glibc was built
against older kernel headers where __NR_pipe2 does not exist, glibc will
have a ENOSYS stub for it. So popen() will always fail as glibc assumes
pipe2() works.
While this isn't too much of an issue for some arches as they added the
functionality to the kernel at the same time, not all arches are that
lucky.
Since the code already has dedicated names for each feature, delete the
defines wiring these three features together and make each one a proper
dedicated knob.
We've been carrying this in Gentoo since glibc-2.9.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
[BZ #13579] Do not free l_initfini and allow it to be reused
on subsequent dl_open calls for the same library. This fixes
the invalid memory access in do_lookup_x when the previously
free'd l_initfini was accessed through l_searchlist when a
library had been opened for the second time.
New configure option --enable-obsolete-rpc makes the deprecated RPC
headers and functions available at compile time as they were before
version 2.14. This option will be removed at some time in the future
after the TI-RPC library becomes fully sufficient for the needs of
existing applications.
Whenever getaddrinfo needed network interface information it used the
netlink interface to read the information every single time. The
problem is that this information can change at any time.
The patch implements monitoring of the network interfaces through
nscd. If no change is detected the previously read information can
be reused (which is the norm). This timestamp information is also
made available to other processes using the shared memory segment
between nscd and those processes.
fopen should set the FD_CLOEXEC flag if requested evenif the kernel does
not support an aotmic operation.
freopen should reuse the file descriptor for the stream. This is
especially important for calls to change the standard streams (stin,
stdout, stderr).
The getcwd syscall (so far?) can only handle path up to one page
in size. There is no limit about directory hierarchy depth, though,
and the POSIX getcwd is supposed to handle this. In that case fall
back to the generic getcwd.
Additionally, optimize the generic getcwd to use openat when possible
to change the asymptotic performance from O(N^2) to O(n).
Like the real header, the libc-internal wrapper for wchar.h needs to
undefine the macros so that if the header was already included before
the macros don't stay defined and cause problems later.
The old implementation uses fd 0 to determine the login TTY. This
was needed because using /dev/tty it is not possible to deduce the
login TTY. For some time now there is the pseudo-file
/proc/self/loginuid which directly helps us to find the user. Prefer
using this file. It also works if stdin is closed, redirected, or
re-opened.
On some architectures the update of the l_used field in the lookup
functions races with setting the other bits in the bitfield. Simply
avoid this and optimize use of l_used in general.
grantpt was performing two consecutive calls to stat with the same
file name. Avoid this by creating a special version of the ptsname
function which allows to pass the stat result back to the caller.
We use a callback function into libc.so to get access to the data
structure with the information and have special versions of the test
macros which automatically use this function.
The following patch fixes catomic_compare_and_exchange_*_rel definitions
(which were never used and weren't correct) and uses
catomic_compare_and_exchange_val_rel in _int_free. Comparing to the
pre-2009-07-02 --enable-experimental-malloc state the generated code should
be identical on all arches other than ppc/ppc64 and on ppc/ppc64 should use
lwsync instead of isync barrier.
The terminal output etc is not visible in a core file. The new
libc-internal variable __abort_msg will point to a string with the
message which has been printed before the abort in case abort is
called from inside libc. BZ #10217
If longjmp restores the stack frame to an address which is beyond
the stack frame at the time of the longjmp call it would install
an uninitialized stack frame. If compiled with _FORTIFY_SOURCE
defined, longjmp will now bail out in this situation.
Roland McGrath
David S. Miller
Mike Frysinger
Adhemerval Zanella
Siddhesh Poyarekar
Joseph Myers
Ondrej Bilka
Ryan S. Arnold
Thomas Schwinge
Andreas Schwab
Jan Kratochvil
Andreas Schwab
H.J. Lu
Maxim Kuvyrkov
Marek Polacek
Florian Weimer
Carlos O'Donell
Andreas Schwab
Andreas Jaeger
Thomas Schwinge
Andreas Jaeger
Petr Baudis
Richard Henderson
Ulrich Drepper
Paul Eggert
Chris Metcalf
Ulrich Drepper
Jakub Jelinek
Ulrich Drepper
Duncan Simpson