This avoids having to instantiate a class template when we can detect
the true cases easily with a partial specialization.

libstdc++-v3/ChangeLog:

	* include/std/type_traits (is_lvalue_reference_v)
	(is_rvalue_reference_v, is_reference_v, is_const_v)
	(is_volatile_v): Define using partial specializations instead
	of instantiating class templates.

This avoids having to instantiate a class template that just uses the
same built-in anyway.

None of the corresponding class templates have any type-completeness
static assertions, so we're not losing any diagnostics by using the
built-ins directly.

libstdc++-v3/ChangeLog:

	* include/std/type_traits (is_enum_v, is_class_v, is_union_v)
	(is_empty_v, is_polymoprhic_v, is_abstract_v, is_final_v)
	(is_base_of_v, is_aggregate_v): Use built-in directly instead of
	instantiating class template.

C2x has completely removed unprototyped functions, so that () now
means the same as (void) in both function declarations and
definitions, where previously that change had been made for
definitions only.  Implement this accordingly.

This is a change where GNU/Linux distribution builders might wish to
try builds with a -std=gnu2x default to start early on getting old
code fixed that still has () declarations for functions taking
arguments, in advance of GCC moving to -std=gnu2x as default maybe in
GCC 14 or 15; I don't know how much such code is likely to be in
current use.

Bootstrapped with no regressions for x86_64-pc-linux-gnu.

gcc/c/
	* c-decl.cc (grokparms): Handle () in a function declaration the
	same as (void) for C2X.

gcc/testsuite/
	* gcc.dg/c11-unproto-3.c, gcc.dg/c2x-unproto-3.c,
	gcc.dg/c2x-unproto-4.c: New tests.
	* gcc.dg/c2x-old-style-definition-6.c, gcc.dg/c2x-unproto-1.c,
	gcc.dg/c2x-unproto-2.c: Update for removal of unprototyped
	functions.

This patch extends the SLP layout optimisation pass so that it
tries to remove layout changes that are brought about by permutes
of existing vectors.  This fixes the bb-slp-pr54400.c regression on
x86_64 and also means that we can remove the permutes in cases like:

typedef float v4sf __attribute__((vector_size(sizeof(float)*4)));

float __attribute__((noipa))
f(v4sf v0, v4sf v1)
{
  return v0[0]*v1[0]+v0[1]*v1[1]+v0[2]*v1[2]+v0[3]*v1[3];
}

The new test is a simple adaption of bb-slp-pr54400.c, with the
same style of markup.

gcc/
	* tree-vect-slp.cc (vect_build_slp_tree_2): When building a
	VEC_PERM_EXPR of an existing vector, set the SLP_TREE_LANES
	to the number of vector elements, if that's a known constant.
	(vect_optimize_slp_pass::is_compatible_layout): Remove associated
	comment about zero SLP_TREE_LANES.
	(vect_optimize_slp_pass::start_choosing_layouts): Iterate over
	all partition members when looking for potential layouts.
	Handle existing permutes of fixed-length vectors.

gcc/testsuite/
	* gcc.dg/vect/bb-slp-pr54400.c: Extend to aarch64.
	* gcc.dg/vect/bb-slp-layout-18.c: New test.

The conversion of a move pattern where both operands are AX_REG
should be prevented.

2022-09-01  Uroš Bizjak  <ubizjak@gmail.com>

gcc/ChangeLog:

	PR target/106707
	* config/i386/i386.md (moves to/from AX_REG into xchg peephole2):
	Do not convert a move pattern where both operands are AX_REG.

gcc/testsuite/ChangeLog:

	PR target/106707
	* gcc.target/i386/pr106707.c: New test.

gcc/ChangeLog:

	* range-op-float.cc (build_le): Convert to dconst*inf.
	(build_ge): Same.
	* value-range.cc (frange::set_signbit): Same.
	(frange::normalize_kind): Same.
	(range_tests_floats): Same.
	* value-range.h (vrp_val_max): Same.
	(vrp_val_min): Same.
	(frange::set_varying): Same.

We're starting to abuse the infinity endpoints in the frange code and
the associated range operators.  Building infinities are rather cheap,
and we could even inline them, but I think it's best to just not
recalculate them all the time.

I see about 20 uses of real_inf in the source code, not including the
backends.  And I'm about to add more :).

gcc/ChangeLog:

	* emit-rtl.cc (init_emit_once): Initialize dconstinf and
	dconstninf.
	* real.h: Add dconstinf and dconstninf.

PR c++/99968 is fixed since GCC 12.1 so we can remove the workaround.

libstdc++-v3/ChangeLog:

	* include/std/type_traits (is_scoped_enum): Remove workaround.

libstdc++-v3/ChangeLog:

	* include/std/ranges (__detail::__unarize): Define.
	(adjacent_view::_Iterator): Befriend adjacent_transform_view.
	(adjacent_transform_view): Define.
	(adjacent_transform_view::_Iterator): Define.
	(adjacent_transform_view::_Sentinel): Define.
	(views::__detail::__can_adjacent_transform_view): Define.
	(views::_AdjacentTransform): Define.
	(views::adjacent_transform): Define.
	(views::pairwise_transform): Define.
	* testsuite/std/ranges/adaptors/adjacent_transform/1.cc: New test.

Now that we have DFS_BACK_EDGE marks we can simply avoid walking
those instead of repeatedly looking for a cycle on the current chain.

	* gimple-predicate-analysis.cc (compute_control_dep_chain):
	Remove cycle detection, instead avoid walking backedges.

The following hides some internal details of compute_control_dep_chain.

	* gimple-predicate-analysis.cc (compute_control_dep_chain):
	New wrapping overload.
	(uninit_analysis::init_use_preds): Simplify.
	(uninit_analysis::init_from_phi_def): Likewise.

While looking at the DWARF handling of char8_t I wondered why we weren't
setting TREE_STRING_FLAG on it.  I hoped that setting that flag would be an
easy fix for PR102958, but it doesn't seem to be sufficicent.  But it still
seems correct.

I also tried setting the flag on char16_t and char32_t, but that broke
because braced_list_to_string assumes char-sized elements.  Since we don't
set the flag on wchar_t, I abandoned that idea.

gcc/c-family/ChangeLog:

	* c-common.cc (c_common_nodes_and_builtins): Set TREE_STRING_FLAG on
	char8_t.
	(braced_list_to_string): Check for char-sized elements.

Now that we keep track of the signbit, we can use it to fold __builtin_signbit.

I am assuming I don't have try too hard to get the actual signbit
number and 1 will do.  Especially, since we're inconsistent in trunk whether
we fold the builtin or whether we calculate it at runtime.

abulafia:~$ cat a.c
float nzero = -0.0;

main(){
    printf("0x%x\n", __builtin_signbit(-0.0));
    printf("0x%x\n", __builtin_signbit(nzero));
}
abulafia:~$ gcc a.c -w && ./a.out
0x1
0x80000000

It is amazing that we've been failing to fold something as simple as
this:

	if (x > 5.0)
	  num = __builtin_signbit (x);

It does the right thing now :-P.

gcc/ChangeLog:

	* gimple-range-fold.cc
	(fold_using_range::range_of_builtin_int_call): Add case for
	CFN_BUILT_IN_SIGNBIT.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/vrp-float-signbit-1.c: New test.

As discussed here:

	https://gcc.gnu.org/pipermail/gcc-patches/2022-August/600656.html

This adds an frange property to keep track of the sign bit.  We keep
it updated at all times, but we don't use it make any decisions when
!HONOR_SIGNED_ZEROS.

With this property we can now query the range for the appropriate sign
with frange::get_signbit ().  Possible values are yes, no, and unknown.

gcc/ChangeLog:

	* range-op-float.cc (foperator_equal::op1_range): Do not copy sign
	bit.
	(foperator_not_equal::op1_range): Same.
	* value-query.cc (range_query::get_tree_range): Set sign bit.
	* value-range-pretty-print.cc (vrange_printer::visit): Dump sign bit.
	* value-range.cc (frange::set_signbit): New.
	(frange::set): Adjust for sign bit.
	(frange::normalize_kind): Same.
	(frange::union_): Remove useless comment.
	(frange::intersect): Same.
	(frange::contains_p): Adjust for sign bit.
	(frange::singleton_p): Same.
	(frange::verify_range): Same.
	(range_tests_signbit): New tests.
	(range_tests_floats): Call range_tests_signbit.
	* value-range.h (class frange_props): Add signbit
	(class frange): Same.

Improve compile times by avoiding unnecessary class template
instantiations.

__is_array_known_bounds and __is_array_unknown_bounds can be defined
without instantiating extent, by providing partial specializations for
the true cases.

std::extent can avoid recursing down through a multidimensional array,
so it stops after providing the result. Previously extent<T[n][m], 0>
would instantiate extent<T[n], -1u> and extent<T, -2u> as well.

std::is_array_v can use partial specializations to avoid instantiating
std::is_array, and similarly for std::rank_v and std::extent_v.

std::is_bounded_array_v and std::is_unbounded_array_v can also use
partial specializations, and then the class templates can be defined in
terms of the variable templates. This makes sense for these traits,
because they are new in C++20 and so the variable templates are always
available, which isn't true in general for C++11 and C++14 traits.

libstdc++-v3/ChangeLog:

	* include/std/type_traits (__is_array_known_bounds): Add partial
	specialization instead of using std::extent.
	(__is_array_unknown_bounds): Likewise.
	(extent): Add partial specializations to stop recursion after
	the result is found.
	(is_array_v): Add partial specializations instead of
	instantiating the class template.
	(rank_v, extent_v): Likewise.
	(is_bounded_array_v, is_unbounded_array_v): Likewise.
	(is_bounded_array, is_unbounded_array): Define in terms of the
	variable templates.

As discussed on IRC, the r13-2299-g68c61c2d bug only got missed
because dump_printf_loc had incorrect format attribute and therefore
almost no -Wformat=* checking was performed on it.
3, 0 are suitable for function with (whatever, whatever, const char *, va_list)
arguments, not for (whatever, whatever, const char *, ...), that one should
use 3, 4.

The following patch fixes that and adjusts all spots to fix warnings.
In many cases it is just through an ugly cast (for %G casts to gimple *
from gassign */gphi * and the like and for %p casts to void * from slp_node
etc.).
There are 3 spots where the mismatch was worse though, two using %u or %d
for unsigned HOST_WIDE_INT argument and one %T for enum argument (promoted
to int).

2022-09-01  Jakub Jelinek  <jakub@redhat.com>

	PR other/106782
	* dumpfile.h (dump_printf_loc): Use ATTRIBUTE_GCC_DUMP_PRINTF (3, 4)
	instead of ATTRIBUTE_GCC_DUMP_PRINTF (3, 0).
	* tree-parloops.cc (parloops_is_slp_reduction): Cast pointers to
	derived types of gimple to gimple * to avoid -Wformat warnings.
	* tree-vect-loop-manip.cc (vect_set_loop_condition,
	vect_update_ivs_after_vectorizer): Likewise.
	* tree-vect-stmts.cc (vectorizable_load): Likewise.
	* tree-vect-patterns.cc (vect_split_statement,
	vect_recog_mulhs_pattern, vect_recog_average_pattern,
	vect_determine_precisions_from_range,
	vect_determine_precisions_from_users): Likewise.
	* gimple-loop-versioning.cc
	(loop_versioning::analyze_term_using_scevs): Likewise.
	* tree-vect-slp.cc (vect_build_slp_tree_1): Likewise.
	(vect_build_slp_tree): Cast slp_tree to void * to avoid
	-Wformat warnings.
	(optimize_load_redistribution_1, vect_match_slp_patterns,
	vect_build_slp_instance, vect_optimize_slp_pass::materialize,
	vect_optimize_slp_pass::dump, vect_slp_convert_to_external,
	vect_slp_analyze_node_operations, vect_bb_partition_graph): Likewise.
	(vect_print_slp_tree): Likewise.  Also use
	HOST_WIDE_INT_PRINT_UNSIGNED instead of %u.
	* tree-vect-loop.cc (vect_determine_vectorization_factor,
	vect_analyze_scalar_cycles_1, vect_analyze_loop_operations,
	vectorizable_induction, vect_transform_loop): Cast pointers to derived
	types of gimple to gimple * to avoid -Wformat warnings.
	(vect_analyze_loop_2): Cast slp_tree to void * to avoid
	-Wformat warnings.
	(vect_estimate_min_profitable_iters): Use HOST_WIDE_INT_PRINT_UNSIGNED
	instead of %d.
	* tree-vect-slp-patterns.cc (vect_pattern_validate_optab): Use %G
	instead of %T and STMT_VINFO_STMT (SLP_TREE_REPRESENTATIVE (node))
	instead of SLP_TREE_DEF_TYPE (node).

The following patch introduces a new warning - -Winvalid-utf8 similarly
to what clang now has - to diagnose invalid UTF-8 byte sequences in
comments, but not just in those, but also in string/character literals
and outside of them.

The warning is on by default when explicit -finput-charset=UTF-8 is
used and C++23 compilation is requested and if -{,W}pedantic or
-pedantic-errors it is actually a pedwarn.

The reason it is on by default only for -finput-charset=UTF-8 is
that the sources often are UTF-8, but sometimes could be some ASCII
compatible single byte encoding where non-ASCII characters only
appear in comments.  So having the warning off by default
is IMO desirable.  The C++23 pedantic mode for when the source code
is UTF-8 is -std=c++23 -pedantic-errors -finput-charset=UTF-8.

2022-09-01  Jakub Jelinek  <jakub@redhat.com>

	PR c++/106655
libcpp/
	* include/cpplib.h (struct cpp_options): Implement C++23
	P2295R6 - Support for UTF-8 as a portable source ...

I'm just shuffling the FP self tests here, with no change to existing
functionality.

If we agree that explicit NANs in the source code with !HONOR_NANS
should behave any differently, I'm happy to address whatever needs
fixing, but for now I'd like to unblock the !HONOR_NANS build systems.

I have added an adaptation of a test Jakub suggested we handle in the PR:

void funk(int cond)
{
  float x;

  if (cond)
    x = __builtin_nan ("");
  else
    x = 1.24;

  bar(x);
}

For !HONOR_NANS, the range for the PHI of x_1 is the union of 1.24 and
NAN which is really 1.24 with a maybe NAN.  This reflects the IL-- the
presence of the actual NAN.  However, VRP will propagate this because
it sees the 1.24 and ignores the possibility of a NAN, per
!HONOR_NANS.  IMO, this is correct.  OTOH, for HONOR_NANS the unknown
NAN property keeps us from propagating the value.

Is there a reason we don't warn for calls to __builtin_nan when
!HONOR_NANS?  That makes no sense to me.

	PR tree-optimization/106785

gcc/ChangeLog:

	* value-range.cc (range_tests_nan): Adjust tests for !HONOR_NANS.
	(range_tests_floats): Same.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/vrp-float-nan-1.c: New test.

gcc/ChangeLog:

	* tree-if-conv.cc (is_cond_scalar_reduction): Add MULT_EXPR
	recognition.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/gen-vect-34.c: New test.
	* gcc.dg/vect/vect-ifcvt-18.c: New test.

Commit r12-2266 updated the scanned assembly content from

  "{\mlvx\M|\mlxv\M|\mlxvd2x\M}"

to

  "{\mp?lxv\M|\mlxv\M|\mlxvd2x\M}"

for the test case pr86731-fwrapv-longlong.c unexpectedly.

It's meant to update "lxv" to "p?lxv", should leave the
"lvx" unchanged.  So fix the typo accordingly.

	PR testsuite/106682

gcc/testsuite/ChangeLog:

	* gcc.target/powerpc/pr86731-fwrapv-longlong.c: Fix typo.

When we expand an MMA disassemble built-in with C++ using a pointer that
is cast to a valid MMA type, the type isn't passed down to the expand
machinery and we end up using the base type of the pointer which leads to
an ICE.  This patch enforces we always use the correct MMA type regardless
of the pointer type being used.

2022-08-31  Peter Bergner  <bergner@linux.ibm.com>

gcc/
	PR target/101322
	* config/rs6000/rs6000-builtin.cc (rs6000_gimple_fold_mma_builtin):
	Enforce the use of a valid MMA pointer type.

gcc/testsuite/
	PR target/101322
	* g++.target/powerpc/pr101322.C: New test.

gcc/ChangeLog:

	* config/riscv/riscv.cc (riscv_conditional_register_usage): Add vector
	registers.

gcc/ChangeLog:

	* config/riscv/riscv.cc (riscv_const_insns): Add cost of poly_int.
	(riscv_output_move): Add csrr vlenb assembly.
	* config/riscv/riscv.md (move_type): Add csrr vlenb type.
	(ext): New attribute.
	(ext_enabled): Ditto.
	(enabled): Ditto.

gcc/ChangeLog:

	* config/riscv/constraints.md (TARGET_VECTOR ? V_REGS : NO_REGS): Add
	"vr" constraint.
	(TARGET_VECTOR ? VD_REGS : NO_REGS): Add "vd" constraint.
	(TARGET_VECTOR ? VM_REGS : NO_REGS): Add "vm" constraint.
	(vp): Add poly constraint.

gcc/ChangeLog:

	* config/riscv/riscv.h (enum reg_class): Change vype to vtype.

gcc/ChangeLog:

	* config/riscv/riscv.cc (riscv_convert_vector_bits): Change
	configuration according to TARGET_MIN_VLEN.
	* config/riscv/riscv.h (UNITS_PER_FP_REG): Fix comment.

Implement some changes to the currently supported C2x standard
attributes that have been made to the specification since they were
first implemented in GCC, and some consequent changes:

* maybe_unused is now supported on labels.  In fact that was already
  accidentally supported in GCC as a result of sharing the
  implementation with __attribute__ ((unused)), but needed to be
  covered in the tests.

* As part of the support for maybe_unused on labels, its
  __has_c_attribute value changed.

* The issue of maybe_unused accidentally being already supported on
  labels showed up the lack of tests for other standard attributes
  being incorrectly applied to labels; add such tests.

* Use of fallthrough or nodiscard attributes on labels already
  properly resulted in a pedwarn.  For the deprecated attribute,
  however, there was only a warning, and the wording "'deprecated'
  attribute ignored for 'void'" included an unhelpful "for 'void'".
  Arrange for the case of the deprecated attribute on a label to be
  checked for separately and result in a pedwarn.  As with
  inappropriate uses of fallthrough (see commit
  6c80b1b5), it seems reasonable for
  this pedwarn to apply regardless of whether [[]] or __attribute__
  was used and regardless of whether C or C++ is being compiled.

* Attributes on case or default labels (the standard syntax supports
  attributes on all kinds of labels) were quietly ignored, whether or
  not appropriate for use in such a context, because they weren't
  passed to decl_attributes at all.  (Note where I'm changing the
  do_case prototype that such a function is actually only defined in
  the C front end, not for C++, despite the declaration being in
  c-common.h.)

* A recent change as part of the editorial review in preparation for
  the C2x CD ballot has changed the __has_c_attribute value for
  fallthrough to 201910 to reflect when that attribute was actually
  voted into the working draft.

Bootstrapped with no regressions for x86_64-pc-linux-gnu.

gcc/c-family/
	* c-attribs.cc (handle_deprecated_attribute): Check and pedwarn
	for LABEL_DECL.
	* c-common.cc (c_add_case_label): Add argument ATTRS.  Call
	decl_attributes.
	* c-common.h (do_case, c_add_case_label): Update declarations.
	* c-lex.cc (c_common_has_attribute): For C, produce a result of
	201910 for fallthrough and 202106 for maybe_unused.

gcc/c/
	* c-parser.cc (c_parser_label): Pass attributes to do_case.
	* c-typeck.cc (do_case): Add argument ATTRS.  Pass it to
	c_add_case_label.

gcc/testsuite/
	* gcc.dg/c2x-attr-deprecated-2.c, gcc.dg/c2x-attr-fallthrough-2.c,
	gcc.dg/c2x-attr-maybe_unused-1.c, gcc.dg/c2x-attr-nodiscard-2.c:
	Add tests of attributes on labels.
	* gcc.dg/c2x-has-c-attribute-2.c: Update expected results for
	maybe_unused and fallthrough.

libstdc++-v3/ChangeLog:

	* include/bits/ranges_base.h (__advance_fn::operator()): Add
	parentheses in assert condition to avoid -Wparentheses warning.
	* include/std/ranges: (take_view::take_view): Uglify 'base'.
	(take_while_view::take_while_view): Likewise.
	(elements_view::elements_view): Likewise.
	(views::_Zip::operator()): Adjust position of [[nodiscard]] for
	compatibility with -fconcepts-ts.
	(zip_transform_view::_Sentinel): Uglify 'OtherConst'.
	(views::_ZipTransform::operator()): Adjust position of
	[[nodiscard]] for compatibilty with -fconcepts-ts.

fixincludes/ChangeLog:

	* configure: Regenerate.

libitm/ChangeLog:

	* configure: Regenerate.

ChangeLog:

	* configure: Regenerate.
	* configure.ac: Delete hpux9 and hpux10.

config/ChangeLog:

	* mh-pa-hpux10: Removed.

contrib/ChangeLog:

	* config-list.mk: Remove deprecated ports.

contrib/header-tools/ChangeLog:

	* README: Remove deprecated ports.
	* reduce-headers: Likewise.

gcc/ChangeLog:

	* config.build: Remove deprecated ports.
	* config.gcc: Likewise.
	* config.host: Likewise.
	* configure.ac: Likewise.
	* configure: Regenerate.
	* config/pa/pa-hpux10.h: Removed.
	* config/pa/pa-hpux10.opt: Removed.
	* config/pa/t-dce-thr: Removed.

gnattools/ChangeLog:

	* configure.ac: Remove deprecated ports.
	* configure: Regenerate.

libstdc++-v3/ChangeLog:

	* configure: Regenerate.
	* crossconfig.m4: Remove deprecated ports.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/lambda/lambda-conv.C: Remove useless test.
	* gcc.c-torture/execute/ieee/hugeval.x: Likewise.
	* gcc.dg/torture/pr47917.c: Likewise.
	* lib/target-supports.exp: Likewise.

libgcc/ChangeLog:

	* config.host: Remove hppa.

libitm/ChangeLog:

	* configure: Regenerate.

fixincludes/ChangeLog:

	* configure: Regenerate.

std::string now has [[nodiscard]] attributes on most members, causing
-Wunused-result warnings for this test.

gcc/testsuite/ChangeLog:

	PR testsuite/106795
	* g++.dg/tree-ssa/empty-loop.C: Use -Wno-unused-result.

Always install limits.h and syslimits.h header files
to include folder.

When --disable-fixincludes is used, then no system header files
are fixed by the tools in fixincludes. Moreover, the fixincludes
tools are not built any longer.

gcc/ChangeLog:

	* Makefile.in: Always install limits.h and syslimits.h to
	include folder.
	* configure.ac: Assign STMP_FIXINC blank if
	--disable-fixincludes is used.
	* configure: Regenerate.

Review null string checks to show:
_String != nullptr

rather than:
_String != 0

libstdc++-v3/ChangeLog:

	* include/debug/debug.h: Use nullptr rather than '0' in checks in post-C++11.
	* include/debug/string: Likewise.
	* testsuite/21_strings/basic_string/operations/ends_with/char.cc: Use __gnu_test::string.
	* testsuite/21_strings/basic_string/operations/ends_with/nonnull.cc: Likewise.
	* testsuite/21_strings/basic_string/operations/ends_with/wchar_t.cc: Likewise.
	* testsuite/21_strings/basic_string/operations/starts_with/wchar_t.cc: Likewise.
	* testsuite/21_strings/basic_string/operations/starts_with/nonnull.cc: Likewise.
	* testsuite/21_strings/basic_string/operations/starts_with/char.cc: Likewise..

libstdc++-v3/ChangeLog:

	* include/std/ranges (adjacent_view): Define.
	(enable_borrowed_range<adjacent_view>): Define.
	(__detail::__repeated_tuple): Define.
	(adjacent_view::_Iterator): Define.
	(adjacent_view::_Sentinel): Define.
	(views::__detail::__can_adjacent_view): Define.
	(views::_Adjacent): Define.
	(views::adjacent): Define.
	(views::pairwise): Define.
	* testsuite/std/ranges/adaptors/adjacent/1.cc: New test.

  Add _GLIBCXX_DEBUG_BACKTRACE macro to activate backtrace generation on
_GLIBCXX_DEBUG assertions. Prerequisite is to have configure the lib with:

--enable-libstdcxx-backtrace=yes

libstdc++-v3/ChangeLog:

	* include/debug/formatter.h
	[_GLIBCXX_HAVE_STACKTRACE](__glibcxx_backtrace_state): Declare.
	[_GLIBCXX_HAVE_STACKTRACE](__glibcxx_backtrace_create_state): Declare.
	[_GLIBCXX_HAVE_STACKTRACE](__glibcxx_backtrace_full_callback): Define.
	[_GLIBCXX_HAVE_STACKTRACE](__glibcxx_backtrace_error_callback): Define.
	[_GLIBCXX_HAVE_STACKTRACE](__glibcxx_backtrace_full_func): Define.
	[_GLIBCXX_HAVE_STACKTRACE](__glibcxx_backtrace_full): Declare.
	[_GLIBCXX_HAVE_STACKTRACE](_Error_formatter::_M_backtrace_state): New.
	[_GLIBCXX_HAVE_STACKTRACE](_Error_formatter::_M_backtrace_full): New.
	* src/c++11/debug.cc [_GLIBCXX_HAVE_STACKTRACE](print_backtrace): New.
	(_Error_formatter::_M_error()): Adapt.
	* src/libbacktrace/Makefile.am: Add backtrace.c.
	* src/libbacktrace/Makefile.in: Regenerate.
	* src/libbacktrace/backtrace-rename.h (backtrace_full): New.
	* testsuite/23_containers/vector/debug/assign4_backtrace_neg.cc: New test.
	* doc/xml/manual/debug_mode.xml: Document _GLIBCXX_DEBUG_BACKTRACE.
	* doc/xml/manual/using.xml: Likewise.

The tests for sizeless SVE types include checks that the types
are handled for initialisation purposes in the same way as scalars.
GNU C and C2x now allow scalars to be initialised using empty braces,
so this patch updates the SVE tests to match.

gcc/testsuite/
	* gcc.target/aarch64/sve/acle/general-c/gnu_vectors_1.c: Update
	tests for empty initializers.
	* gcc.target/aarch64/sve/acle/general-c/gnu_vectors_2.c: Likewise.
	* gcc.target/aarch64/sve/acle/general-c/sizeless-1.c: Likewise.
	* gcc.target/aarch64/sve/acle/general-c/sizeless-2.c: Likewise.

When processing USE predicates we can drop from the AND chain,
when procsssing DEF predicates we can drop from the OR chain.  Do
that instead of giving up completely.  This also removes cases
that should never trigger.

	* gimple-predicate-analysis.cc (predicate::init_from_control_deps):
	Assert the guard_bb isn't empty and has more than one successor.
	Drop appropriate parts of the predicate when an edge fails to
	register a predicate.
	(predicate::dump): Dump empty predicate as TRUE.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/logical_traits/requirements/short_circuit.cc: New test.

This isn't required by the standard, but there's an LWG issue suggesting
to add it.

Also use __invoke_result instead of result_of, to match the spec in
recent standards.

libstdc++-v3/ChangeLog:

	* include/bits/refwrap.h (reference_wrapper::operator()): Add
	noexcept-specifier and use __invoke_result instead of result_of.
	* testsuite/20_util/reference_wrapper/invoke-noexcept.cc: New test.