Like in r12-7519-g027e30414492d50feb2854aff38227b14300dc4b, I've done
git grep -v 'long long\|optab optab\|template template\|double double' | grep ' \([a-zA-Z]\+\) \1 '
This is just part of the changes, mostly for non-gcc directories.
I'll try to get to the rest soon. Obviously, the above command also
finds cases which are correct as is and shouldn't be changed, so one
needs to manually inspect everything.
I'd hope most of it is pretty obvious, but the config/ and libstdc++-v3/
hunks include a tweak in a license wording, though other copies of the
similar license have the wording right.
2024-04-02 Jakub Jelinek <jakub@redhat.com>
* Makefile.tpl: Fix duplicated words; returns returns ->
returns.
config/
* lcmessage.m4: Fix duplicated words; can can -> can,
package package -> package.
libdecnumber/
* decCommon.c (decFinalize): Fix duplicated words in
comment; the the -> the.
libgcc/
* unwind-dw2-fde.c (struct fde_accumulator): Fix duplicated
words in comment; is is -> is.
libgfortran/
* configure.host: Fix duplicated words; the the -> the.
libgm2/
* configure.host: Fix duplicated words; the the -> the.
libgomp/
* libgomp.texi (OpenMP 5.2): Fix duplicated words; with with ->
with.
(omp_target_associate_ptr): Fix duplicated words; either either ->
either.
(omp_init_allocator): Fix duplicated words; be be -> be.
(omp_realloc): Fix duplicated words; is is -> is.
(OMP_ALLOCATOR): Fix duplicated words; other other -> other.
* priority_queue.h (priority_queue_multi_p): Fix duplicated words;
to to -> to.
libiberty/
* regex.c (byte_re_match_2_internal): Fix duplicated words in comment;
next next -> next.
* dyn-string.c (dyn_string_init): Fix duplicated words in comment;
of of -> of.
libitm/
* beginend.cc (GTM::gtm_thread::begin_transaction): Fix duplicated
words in comment; not not -> not to.
libobjc/
* init.c (duplicate_classes): Fix duplicated words in comment; in in
-> in.
* sendmsg.c (__objc_prepare_dtable_for_class): Fix duplicated words
in comment; the the -> the.
* encoding.c (objc_layout_structure): Likewise.
libstdc++-v3/
* acinclude.m4: Fix duplicated words; file file -> file can.
* configure.host: Fix duplicated words; the the -> the.
libvtv/
* vtv_rts.cc (vtv_fail): Fix duplicated words; to to -> to.
* vtv_fail.cc (vtv_fail): Likewise.
Original bug report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111731
The unwinding mechanism registers both the code range and the unwind
table itself within a b-tree lookup structure. That data structure
assumes that is consists of non-overlappping intervals. This
becomes a problem if the unwinding table is embedded within the
code itself, as now the intervals do overlap.
To fix this problem we now keep the unwind tables in a separate
b-tree, which prevents the overlap.
libgcc/ChangeLog:
PR libgcc/111731
* unwind-dw2-fde.c: Split unwind ranges if they contain the
unwind table.
Original bug report: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110956
Rainer Orth successfully tested the patch on Solaris with a full bootstrap.
Some uncommon unwinding table encodings need to access the base pointer
for address computations. We do not have that information in calls to
__deregister_frame_info_bases, and previously simply used nullptr as
base pointer. That is usually fine, but for some Solaris i386 shared
libraries that results in wrong address computations.
To fix this problem we now associate the unwinding object with
the table pointer itself, which is always known, in addition to
the PC range. When deregistering a frame, we first locate the object
using the table pointer, and then use the base pointer stored within
the object to compute the PC range.
libgcc/ChangeLog:
PR libgcc/110956
* unwind-dw2-fde.c: Associate object with address of unwinding
table.
The radix sort uses two buffers, a1 for input and a2 for output.
After every digit the role of the two buffers is swapped.
When terminating the sort early the code made sure the output
was in a2. However, when we run out of bits, as can happen on
32bit platforms, the sorted result was in a1, as we had just
swapped a1 and a2.
This patch fixes the problem by unconditionally having a1 as
output after every loop iteration.
This bug manifested itself only on 32bit platforms and even then
only in some circumstances, as it needs frames where a swap
is required due to differences in the top-most byte, which is
affected by ASLR. The new logic was validated by exhaustive
search over 32bit input values.
libgcc/ChangeLog:
PR libgcc/109670
* unwind-dw2-fde.c: Fix radix sort buffer management.
The atomic fastpath bypasses the code that releases the sort
array which was lazily allocated during unwinding. We now
check after deregistering if there is an array to free.
libgcc/ChangeLog:
PR libgcc/109685
* unwind-dw2-fde.c: Free sort array in atomic fast path.
The non-atomic path does not have range information,
we have to adjust the assert handle that case, too.
libgcc/ChangeLog:
* unwind-dw2-fde.c: Fix assert in non-atomic path.
The assertion in __deregister_frame_info_bases assumes that for every
frame something was inserted into the lookup data structure by
__register_frame_info_bases. Unfortunately, this does not necessarily
hold true as the btree_insert call in __register_frame_info_bases will
not insert anything for empty ranges. Therefore, we need to explicitly
account for such empty ranges in the assertion as `ob` will be a null
pointer for such ranges, hence causing the assertion to fail.
Signed-off-by: Sören Tempel <soeren@soeren-tempel.net>
libgcc/ChangeLog:
* unwind-dw2-fde.c: Accept empty ranges when deregistering frames.
When registering an unwind frame with __register_frame_info_bases
we currently initialize that fde object eagerly. This has the
advantage that it is immutable afterwards and we can safely
access it from multiple threads, but it has the disadvantage
that we pay the initialization cost even if the application
never throws an exception.
This commit changes the logic to initialize the objects lazily.
The objects themselves are inserted into the b-tree when
registering the frame, but the sorted fde_vector is
not constructed yet. Only on the first time that an
exception tries to pass through the registered code the
object is initialized. We notice that with a double checking,
first doing a relaxed load of the sorted bit and then re-checking
under a mutex when the object was not initialized yet.
Note that the check must implicitly be safe concering a concurrent
frame deregistration, as trying the deregister a frame that is
on the unwinding path of a concurrent exception is inherently racy.
libgcc/ChangeLog:
* unwind-dw2-fde.c: Initialize fde object lazily when
the first exception tries to pass through.
When registering a dynamic unwinding frame the fde list is sorted.
Previously, we split the list into a sorted and an unsorted part,
sorted the later using heap sort, and merged both. That can be
quite slow due to the large number of (expensive) comparisons.
This patch replaces that logic with a radix sort instead. The
radix sort uses the same amount of memory as the old logic,
using the second list as auxiliary space, and it includes two
techniques to speed up sorting: First, it computes the pointer
addresses for blocks of values, reducing the decoding overhead.
And it recognizes when the data has reached a sorted state,
allowing for early termination. When running out of memory
we fall back to pure heap sort, as before.
For this test program
\#include <cstdio>
int main(int argc, char** argv) {
return 0;
}
compiled with g++ -O -o hello -static hello.c we get with
perf stat -r 200 on a 5950X the following performance numbers:
old logic:
0,20 msec task-clock
930.834 cycles
3.079.765 instructions
0,00030478 +- 0,00000237 seconds time elapsed
new logic:
0,10 msec task-clock
473.269 cycles
1.239.077 instructions
0,00021119 +- 0,00000168 seconds time elapsed
libgcc/ChangeLog:
* unwind-dw2-fde.c: Use radix sort instead of split+sort+merge.
When using the atomic fast path deregistering can fail during
program shutdown if the lookup structures are already destroyed.
The assert in __deregister_frame_info_bases takes that into
account. In the non-fast-path case however is not aware of
program shutdown, which caused a compiler error on such platforms.
We fix that by introducing a constant for in_shutdown in
non-fast-path builds.
We also drop the destructor priority, as it is not supported on
all platforms and we no longer rely upon the priority anyway.
libgcc/ChangeLog:
* unwind-dw2-fde.c: Introduce a constant for in_shutdown
for the non-fast-path case. Drop destructor priority.
In some scenarios (e.g., when mixing gcc and clang code), it can
happen that frames are deregistered after the lookup structure
has already been destroyed. That in itself would be fine, but
it triggers an assert in __deregister_frame_info_bases that
expects to find the frame.
To avoid that, we now remember that the btree as already been
destroyed and disable the assert in that case.
libgcc/ChangeLog:
* unwind-dw2-fde.c: (release_register_frames) Remember
when the btree has been destroyed.
(__deregister_frame_info_bases) Disable the assert when
shutting down.
uintptr_t is no available for all targets, use __UINTPTR_TYPE__
instead.
libgcc/ChangeLog:
* unwind-dw2-fde.c: Replace uintptr_t with typedef
for __UINTPTR_TYPE__.
* unwind-dw2-btree.h: Likewise.
The __register_frame/__deregister_frame functions are used to register
unwinding frames from JITed code in a sorted list. That list itself
is protected by object_mutex, which leads to terrible performance
in multi-threaded code and is somewhat expensive even if single-threaded.
There was already a fast-path that avoided taking the mutex if no
frame was registered at all.
This commit eliminates both the mutex and the sorted list from
the atomic fast path, and replaces it with a btree that uses
optimistic lock coupling during lookup. This allows for fully parallel
unwinding and is essential to scale exception handling to large
core counts.
libgcc/ChangeLog:
* unwind-dw2-fde.c (release_registered_frames): Cleanup at shutdown.
(__register_frame_info_table_bases): Use btree in atomic fast path.
(__deregister_frame_info_bases): Likewise.
(_Unwind_Find_FDE): Likewise.
(base_from_object): Make parameter const.
(classify_object_over_fdes): Add query-only mode.
(get_pc_range): Compute PC range for lookup.
* unwind-dw2-fde.h (last_fde): Make parameter const.
* unwind-dw2-btree.h: New file.
PR libgcc/71744
* unwind-dw2-fde.c (ATOMIC_FDE_FAST_PATH): Define if __register_frame*
is not the primary registry and atomics are available.
(any_objects_registered): New variable.
(__register_frame_info_bases, __register_frame_info_table_bases):
Atomically store 1 to any_objects_registered after registering first
unwind info.
(_Unwind_Find_FDE): Return early if any_objects_registered is 0.
From-SVN: r240193
2012-03-12 Richard Guenther <rguenther@suse.de>
* gthr.h (__GTHREAD_MUTEX_INIT_FUNCTION): Adjust specification.
* gthr-posix.h (__GTHREAD_MUTEX_INIT_FUNCTION): Define.
(__gthread_mutex_init_function): New function.
* gthr-single.h (__GTHREAD_MUTEX_INIT_FUNCTION): Define.
PR gcov/49484
* libgcov.c: Include gthr.h.
(__gcov_flush_mx): New global variable.
(init_mx, init_mx_once): New functions.
(__gcov_flush): Protect self with a mutex.
(__gcov_fork): Re-initialize mutex after forking.
* unwind-dw2-fde.c: Change condition under which to use
__GTHREAD_MUTEX_INIT_FUNCTION.
From-SVN: r185231
