Jonathan Wakely [Tue, 22 Mar 2022 21:29:56 +0000 (21:29 +0000)]
libstdc++: Fix feature test macros in <version> for freestanding
Some C++17 and C++20 feature test macros are only defined in <version>
for hosted builds, even though the features are supported for
freestanding.
libstdc++-v3/ChangeLog:
* include/std/version [!_GLIBCXX_HOSTED]
(__cpp_lib_bit_cast): Define for freestanding.
(__cpp_lib_string_contains): Do not define for freestanding.
(__cpp_lib_to_underlying): Likewise.
Jonathan Wakely [Mon, 22 Aug 2022 14:16:16 +0000 (15:16 +0100)]
libstdc++: Check for overflow in regex back-reference [PR106607]
Currently we fail to notice integer overflow when parsing a
back-reference expression, or when converting the parsed result from
long to int. This changes the result to be int, so no conversion is
needed, and uses the overflow-checking built-ins to detect an
out-of-range back-reference.
libstdc++-v3/ChangeLog:
PR libstdc++/106607
* include/bits/regex_compiler.tcc (_Compiler::_M_cur_int_value):
Use built-ins to check for integer overflow in back-reference
number.
* testsuite/28_regex/basic_regex/106607.cc: New test.
Jonathan Wakely [Mon, 22 Aug 2022 14:42:17 +0000 (15:42 +0100)]
libstdc++: Fix for explicit copy ctors in <thread> and <future> [PR106695]
When I changed std::thread and std::async to avoid unnecessary move
construction of temporaries, I introduced a regression where types with
an explicit copy constructor could not be passed to std::thread or
std::async. The fix is to add a constructor instead of using aggregate
initialization of an unnamed temporary.
libstdc++-v3/ChangeLog:
PR libstdc++/106695
* include/bits/std_thread.h (thread::_State_impl): Forward
individual arguments to _Invoker constructor.
(thread::_Invoker): Add constructor. Delete copies.
* include/std/future (__future_base::_Deferred_state): Forward
individual arguments to _Invoker constructor.
(__future_base::_Async_state_impl): Likewise.
* testsuite/30_threads/async/106695.cc: New test.
* testsuite/30_threads/thread/106695.cc: New test.
Jonathan Wakely [Tue, 12 Jul 2022 10:18:47 +0000 (11:18 +0100)]
libstdc++: Check for EOF if extraction avoids buffer overflow [PR106248]
In r11-2581-g17abcc77341584 (for LWG 2499) I added overflow checks to
the pre-C++20 operator>>(istream&, char*) overload. Those checks can
cause extraction to stop after filling the buffer, where previously it
would have tried to extract another character and stopped at EOF. When
that happens we no longer set eofbit in the stream state, which is
consistent with the behaviour of the new C++20 overload, but is an
observable and unexpected change in the C++17 behaviour. What makes it
worse is that the behaviour change is dependent on optimization, because
__builtin_object_size is used to detect the buffer size and that only
works when optimizing.
To avoid the unexpected and optimization-dependent change in behaviour,
set eofbit manually if we stopped extracting because of the buffer size
check, but had reached EOF anyway. If the stream's rdstate() != goodbit
or width() is non-zero and smaller than the buffer, there's nothing to
do. Otherwise, we filled the buffer and need to check for EOF, and maybe
set eofbit.
The new check is guarded by #ifdef __OPTIMIZE__ because otherwise
__builtin_object_size is useless. There's no point compiling and
emitting dead code that can't be eliminated because we're not
optimizing.
We could add extra checks that the next character in the buffer is not
whitespace, to detect the case where we stopped early and prevented a
buffer overflow that would have happened otherwise. That would allow us
to assert or set badbit in the stream state when undefined behaviour was
prevented. However, those extra checks would increase the size of the
function, potentially reducing the likelihood of it being inlined, and
so making the buffer size detection less reliable. It seems preferable
to prevent UB and silently truncate, rather than miss the UB and allow
the overflow to happen.
libstdc++-v3/ChangeLog:
PR libstdc++/106248
* include/std/istream [C++17] (operator>>(istream&, char*)):
Set eofbit if we stopped extracting at EOF.
* testsuite/27_io/basic_istream/extractors_character/char/pr106248.cc:
New test.
* testsuite/27_io/basic_istream/extractors_character/wchar_t/pr106248.cc:
New test.
Jonathan Wakely [Thu, 28 Jul 2022 19:55:51 +0000 (20:55 +0100)]
libstdc++: Tweak common_iterator::operator-> return type [PR104443]
This adjusts the return type to match the resolution of LWG 3672. There
is no functional difference, because decltype(auto) always deduced a
value anyway, but this makes it simpler and consistent with the working
draft.
libstdc++-v3/ChangeLog:
PR libstdc++/104443
* include/bits/stl_iterator.h (common_iterator::operator->):
Change return type to just auto.
cselib: add function to check if SET is redundant [PR106187]
A SET operation that writes memory may have the same value as an
earlier store but if the alias sets of the new and earlier store do
not conflict then the set is not truly redundant. This can happen,
for example, if objects of different types share a stack slot.
To fix this we define a new function in cselib that first checks for
equality and if that is successful then finds the earlier store in the
value history and checks the alias sets.
The routine is used in two places elsewhere in the compiler:
cfgcleanup and postreload.
gcc/ChangeLog:
PR rtl-optimization/106187
* alias.h (mems_same_for_tbaa_p): Declare.
* alias.c (mems_same_for_tbaa_p): New function.
* dse.c (record_store): Use it instead of open-coding
alias check.
* cselib.h (cselib_redundant_set_p): Declare.
* cselib.c: Include alias.h
(cselib_redundant_set_p): New function.
* cfgcleanup.c: (mark_effect): Use cselib_redundant_set_p instead
of rtx_equal_for_cselib_p.
* postreload.c (reload_cse_simplify): Use cselib_redundant_set_p.
(reload_cse_noop_set_p): Delete.
Richard Earnshaw [Wed, 11 May 2022 12:08:40 +0000 (13:08 +0100)]
arm: correctly handle misaligned MEMs on MVE [PR105463]
Vector operations in MVE must be aligned to the element size, so if we
are asked for a misaligned move in a wider mode we must recast it to a
form suitable for the known alignment (larger elements have better
address offset ranges, so there is some advantage to using wider
element sizes if possible). Whilst fixing this, also rework the
predicates used for validating operands - the Neon predicates are
not right for MVE.
gcc/ChangeLog:
PR target/105463
* config/arm/mve.md (*movmisalign<mode>_mve_store): Use
mve_memory_operand.
(*movmisalign<mode>_mve_load): Likewise.
* config/arm/vec-common.md (movmisalign<mode>): Convert to generator
form...
(@movmisalign<mode>): ... thus. Use generic predicates and then
rework operands if they are not valid. For MVE rework to a
narrower element size if the alignment is not high enough.
Peter Bergner [Sun, 28 Aug 2022 00:44:16 +0000 (19:44 -0500)]
rs6000: Allow conversions of MMA pointer types [PR106017]
GCC incorrectly disables conversions between MMA pointer types, which
are allowed with clang. The original intent was to disable conversions
between MMA types and other other types, but pointer conversions should
have been allowed. The fix is to just remove the MMA pointer conversion
handling code altogether.
Kewen.Lin [Tue, 16 Aug 2022 05:24:07 +0000 (00:24 -0500)]
rs6000: Adjust mov optabs for opaque modes [PR103353]
As PR103353 shows, we may want to continue to expand built-in
function __builtin_vsx_lxvp, even if we have already emitted
error messages about some missing required conditions. As
shown in that PR, without one explicit mov optab on OOmode
provided, it would call emit_move_insn recursively.
So this patch is to allow the mov pattern to be generated during
expanding phase if compiler has already seen errors.
PR target/103353
gcc/ChangeLog:
* config/rs6000/mma.md (define_expand movoo): Move TARGET_MMA condition
check to preparation statements and add handlings for !TARGET_MMA.
(define_expand movxo): Likewise.
This testcase does not generate anywhere near optimal code for 32-bit
code. For p10 it actually now fails this testcase, after the previous
patch. Let's xfail it.
RA now chooses GEN_OR_VSX_REGS in most cases. This is great in most
cases, but we often (or always?) use {l,st}{f,xs}iwzx now, which is
problematic because the integer load and store insns can use cheaper
addressing modes. We can fix that by putting a small penalty on the
instruction alternatives for those.
Iain Buclaw [Tue, 16 Aug 2022 10:22:10 +0000 (12:22 +0200)]
d: Update DIP links in gdc documentation to point at upstream repository
The wiki links probably worked at some point in the distant past, but
now the official location of tracking all D Improvement Proposals is on
the upstream dlang/DIPs GitHub repository.
PR d/106638
gcc/d/ChangeLog:
* gdc.texi: Update DIP links to point at upstream dlang/DIPs
repository.
Peter Bergner [Sat, 18 Jun 2022 04:43:23 +0000 (23:43 -0500)]
c: Handle initializations of opaque types [PR106016]
The initial commit that added opaque types thought that there couldn't
be any valid initializations for variables of these types, but the test
case in the bug report shows that isn't true. The solution is to handle
OPAQUE_TYPE initializations like the other scalar types.
Testing has shown that using the load vector pair and store vector pair
instructions for block moves has some performance issues on power10.
A patch on June 11th modified the code so that GCC would not set
-mblock-ops-vector-pair by default if we are tuning for power10, but it would
set the option if we were tuning for a different machine and have load and store
vector pair instructions enabled.
This patch eliminates the code setting -mblock-ops-vector-pair. If you want to
generate load vector pair and store vector pair instructions for block moves,
you must use -mblock-ops-vector-pair.
2022-08-08 Michael Meissner <meissner@linux.ibm.com>
gcc/
* config/rs6000/rs6000.c (rs6000_option_override_internal): Remove code
setting -mblock-ops-vector-pair. Patch back ported from trunk, August
3rd, 2022.
Peter Bergner [Fri, 25 Mar 2022 22:59:07 +0000 (17:59 -0500)]
rs6000: Update testsuite to use -mdejagnu-cpu= and -mdejagnu-tune= options
This patch updates the POWER testsuite test cases using -mcpu= and -mtune=
to use the preferred -mdejagnu-cpu= and -mdejagnu-tune= options. This also
obviates the need for the dg-skip-if directive, since the user cannot
override the -mcpu= value being used to compile the test case.
Lewis Hyatt [Sat, 9 Jul 2022 20:12:21 +0000 (16:12 -0400)]
c: Fix location for _Pragma tokens [PR97498]
The handling of #pragma GCC diagnostic uses input_location, which is not always
as precise as needed; in particular the relative location of some tokens and a
_Pragma directive will crucially determine whether a given diagnostic is enabled
or suppressed in the desired way. PR97498 shows how the C frontend ends up with
input_location pointing to the beginning of the line containing a _Pragma()
directive, resulting in the wrong behavior if the diagnostic to be modified
pertains to some tokens found earlier on the same line. This patch fixes that by
addressing two issues:
a) libcpp was not assigning a valid location to the CPP_PRAGMA token
generated by the _Pragma directive.
b) C frontend was not setting input_location to something reasonable.
With this change, the C frontend is able to change input_location to point to
the _Pragma token as needed.
This is just a two-line fix (one for each of a) and b)), the testsuite changes
were needed only because the location on the tested warnings has been somewhat
improved, so the tests need to look for the new locations.
gcc/c/ChangeLog:
PR preprocessor/97498
* c-parser.c (c_parser_pragma): Set input_location to the
location of the pragma, rather than the start of the line.
libcpp/ChangeLog:
PR preprocessor/97498
* directives.c (destringize_and_run): Override the location of
the CPP_PRAGMA token from a _Pragma directive to the location of
the expansion point, as is done for the tokens lexed from it.
gcc/testsuite/ChangeLog:
PR preprocessor/97498
* c-c++-common/pr97498.c: New test.
* gcc.dg/pragma-message.c: Adapt for improved warning locations.
Peter Bergner [Mon, 25 Jul 2022 05:51:44 +0000 (00:51 -0500)]
rs6000: Adjust -mdejagnu-cpu to filter out -mtune [PR106345]
As PR106345 shows, when configuring compiler with an explicit
option --with-tune=<value>, it would cause some test cases to
fail if their test points are sensitive to tune setting, such
as: group_ending_nop, loop align etc. It doesn't help that
even to specify one explicit -mcpu=.
This patch is to adjust the behavior of -mdejagnu-cpu by
filtering out all -mcpu= and -mtune= options, then test cases
would use <cpu> as tune as the one specified by -mdejagnu-cpu.
2022-07-25 Peter Bergner <bergner@linux.ibm.com>
Kewen Lin <linkw@linux.ibm.com>
PR testsuite/106345
gcc/ChangeLog:
* config/rs6000/rs6000.h (DRIVER_SELF_SPECS): Adjust -mdejagnu-cpu
to filter out all -mtune options.
Kewen Lin [Tue, 26 Jul 2022 02:29:14 +0000 (21:29 -0500)]
rs6000: Preserve REG_EH_REGION when replacing load/store [PR106091]
As test case in PR106091 shows, rs6000 specific pass swaps
doesn't preserve the reg_note REG_EH_REGION when replacing
some load insn at the end of basic block, it causes the
flow info verification to fail unexpectedly. Since memory
reference rtx may trap, this patch is to ensure we copy
REG_EH_REGION reg_note while replacing swapped aligned load
or store.
PR target/106091
gcc/ChangeLog:
* config/rs6000/rs6000-p8swap.c (replace_swapped_aligned_store): Copy
REG_EH_REGION when replacing one store insn having it.
(replace_swapped_aligned_load): Likewise.
Patrick Palka [Fri, 22 Jul 2022 16:52:03 +0000 (12:52 -0400)]
libstdc++: Fix backward compatibility of P2325R3 backport [PR106320]
The 11 and 10 partial backports of P2325R3, r11-9555-g92d612cccc1eec and r10-10808-g22b86cdc4d7fdd, unnecessarily preserved some changes from the
paper that made certain view specializations no longer default
constructible, changes which aren't required to reap the overall benefits
of the paper and which are backward incompatible with pre-P2325R3 code in
practice.
This patch reverts the problematic changes, specifically it relaxes the
constraints on various views' default constructors added by the paper
so that we keep only the constraints that were already implicitly
imposed by the NSDMIs of the view. Thus for example this patch retains
the default_initializable<_Vp> constraint on transform_view's default
constructor since its '_Vp _M_base = _Vp()' NSDMI already requires this
constraint, and it removes the default_initializable<_Fp> constraint
since the corresponding member '__detail::__box<_Fp> _M_fun' doesn't
require default constructibility (specializations of __box are always
default constructible).
After reverting these changes, all static_asserts from p2325.cc that
verify lack of default constructibility now fail as expected, matching
the pre-P2325R3 behavior.
PR libstdc++/106320
libstdc++-v3/ChangeLog:
* include/std/ranges (single_view): Relax constraints on
default constructor so as to preserve pre-P2325R3 behavior.
(filter_view): Likewise.
(transform_view): Likewise.
(take_while_view): Likewise.
(drop_while_view): Likewise.
* testsuite/std/ranges/adaptors/join.cc (test13): New test.
* testsuite/std/ranges/p2325.cc: Fix S to be only non default
constructible and not also non copy constructible. XFAIL the
tests that verify a non default constructible functor makes a
view non default constructible (lines 94, 97 and 98). XFAIL
the test that effectively verifies a non default constructible
element type makes single_view non default constructible (line
114).
Richard Biener [Wed, 4 May 2022 08:43:07 +0000 (10:43 +0200)]
tree-optimization/103116 - SLP permutes and peeling for gaps
The testcase shows that we can end up with a contiguous access across
loop iterations but by means of permutations the elements accessed
might only cover parts of a vector. In this case we end up with
GROUP_GAP == 0 but still need to avoid accessing excess elements
in the last loop iterations. Peeling for gaps is designed to cover
this but a single scalar iteration might not cover all of the excess
elements. The following ensures peeling for gaps is done in this
situation and when that isn't sufficient because we need to peel
more than one iteration (gcc.dg/vect/pr103116-2.c), fail the SLP
vectorization.
2022-05-04 Richard Biener <rguenther@suse.de>
PR tree-optimization/103116
* tree-vect-stmts.c (get_group_load_store_type): Handle the
case we need peeling for gaps even though GROUP_GAP is zero.
* gcc.dg/vect/pr103116-1.c: New testcase.
* gcc.dg/vect/pr103116-2.c: Likewise.
This fixes the following conformance problems reported in the PR:
- Move constructor and move assignment should be defined.
- Copy assignment from a valueless object should be allowed.
Assignment is completely rewritten by this patch, as the previous
version had a number of problems. The converting assignment failed to
handle the case of assigning a new value to a valueless object, which
should work. It only accepted lvalue arguments, so wasn't usable to
implement the move assignment operator. Finally, it enforced the
precondition that the argument is not valueless, which is correct for
the converting assignment but not for the copy assignment.
A new _M_assign member is added to handle all cases of assignment
(copying from an lvalue, moving from an rvalue, and converting from a
different type). The not valueless precondition is checked in the
converting assignment before calling _M_assign, so isn't enforced for
copy and move assignment. The new function no longer uses a switch, so
handles valueless objects as the LHS or RHS of the assignment.
libstdc++-v3/ChangeLog:
PR libstdc++/100823
* include/bits/stl_iterator.h (common_iterator): Define move
constructor and move assignment operator.
(common_iterator::_M_assign): New function implementing
assignment.
(common_iterator::operator=): Use _M_assign.
(common_iterator::_S_valueless): New constant.
* testsuite/24_iterators/common_iterator/100823.cc: New test.
Jonathan Wakely [Wed, 20 Jul 2022 11:49:28 +0000 (12:49 +0100)]
libstdc++: Fix minor bugs in std::common_iterator
The noexcept-specifier for some std::common_iterator constructors was
incorrectly using an rvalue as the first argument of
std::is_nothrow_assignable_v. This gave the wrong answer for some types,
e.g. std::common_iterator<int*, S>, because an rvalue of scalar type
cannot be assigned to.
Also fix the friend declaration to use the same constraints as on the
definition of the class template. G++ fails to diagnose this error, due
to PR c++/96830.
Finally, the copy constructor was using std::move for its argument
in some cases, which should be removed.
libstdc++-v3/ChangeLog:
* include/bits/stl_iterator.h (common_iterator): Fix incorrect
uses of is_nothrow_assignable_v. Fix inconsistent constraints on
friend declaration. Do not move argument in copy constructor.
* testsuite/24_iterators/common_iterator/1.cc: Check for
noexcept constructibnle/assignable.
Jonathan Wakely [Wed, 12 Jan 2022 16:58:18 +0000 (16:58 +0000)]
libstdc++: Use std::construct_at in std::common_iterator [PR103992]
This should have been done as part of the LWG 3574 changes.
libstdc++-v3/ChangeLog:
PR libstdc++/103992
* include/bits/stl_iterator.h (common_iterator): Use
std::construct_at instead of placement new.
* testsuite/24_iterators/common_iterator/1.cc: Check copy
construction is usable in constant expressions.
Jonathan Wakely [Mon, 10 Jan 2022 16:51:49 +0000 (16:51 +0000)]
libstdc++: Make std::common_iterator completely constexpr-able (LWG 3574)
This library issue was approved in the October 2021 plenary.
This backport for gcc-11 also includes some [[nodiscard]] attributes
from earlier commits on trunk.
libstdc++-v3/ChangeLog:
* include/bits/stl_iterator.h (common_iterator): Add constexpr
to all member functions (LWG 3574).
* testsuite/24_iterators/common_iterator/1.cc: Evaluate some
tests as constant expressions.
* testsuite/24_iterators/common_iterator/2.cc: Likewise.
Jonathan Wakely [Tue, 28 Jun 2022 14:56:30 +0000 (15:56 +0100)]
libstdc++: Fix experimental::filesystem::status on Windows [PR88881]
Although the Filesystem TS isn't properly supported on Windows (unlike
the C++17 Filesystem lib), most tests do pass. Two of the failures are
due to PR 88881 which was only fixed for std::filesystem not the TS.
This applies the fix to the TS implementation too.
libstdc++-v3/ChangeLog:
PR libstdc++/88881
* src/filesystem/ops.cc (has_trailing_slash): New helper
function.
(fs::status): Strip trailing slashes.
(fs::symlink_status): Likewise.
* testsuite/experimental/filesystem/operations/temp_directory_path.cc:
Clean the environment before each test and use TMP instead of
TMPDIR so the test passes on Windows.
regrename: Fix -fcompare-debug issue in check_new_reg_p [PR105041]
In check_new_reg_p, the nregs of a du chain is computed by obtaining the
MODE of the first element in the chain, and then calling
hard_regno_nregs() with the MODE. But the first element of the chain can
be a DEBUG_INSN whose mode need not be the same as the rest of the
elements in the du chain. This was resulting in fcompare-debug failure
as check_new_reg_p was returning a different result with -g for the same
candidate register. We can instead obtain nregs from the du chain
itself.