Currently, goroutine switches are implemented with libc
    getcontext/setcontext functions, which saves/restores the machine
    register states and also the signal context. This does more than
    what we need, and performs an expensive syscall.
    
    This CL implements a simplified version of getcontext/setcontext,
    in assembly, that only saves/restores the necessary part, i.e.
    the callee-save registers, and the PC, SP. A simplified version
    of makecontext, written in C, is also added. Currently this is
    only implemented on Linux/AMD64.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/178298

From-SVN: r271818

2019-05-31  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* match.pd (~(vec?cst1:cst2)): New transformation.

gcc/testsuite/
	* g++.dg/tree-ssa/cprop-vcond.C: New file.

From-SVN: r271817

2019-05-31  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* match.pd (X/[ex]D<Y/[ex]D): Handle negative denominator.
	((size_t)(A /[ex] B) CMP C): New transformation.

gcc/testsuite/
	* gcc.dg/tree-ssa/cmpexactdiv-3.c: New file.
	* gcc.dg/tree-ssa/cmpexactdiv-4.c: New file.
	* gcc.dg/Walloca-13.c: Xfail.

From-SVN: r271816

Several SVE patterns need define_insn_and_splits that generate the
same insn_code, but with different operands.  That's probably a
niche requirement, but it's cropping up often enough on the ACLE
branch that I think it would be good to have a syntactic sugar for it.

This patch therefore adds a new construct called define_insn_and_rewrite.
It's basically a define_insn_and_split with an implicit split pattern,
obtained by copying the insn pattern and replacing match_operands with
match_dups and match_operators with match_op_dups.

2019-05-31  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* doc/md.texi: Document define_insn_and_rewrite.
	* rtl.def (DEFINE_INSN_AND_REWRITE): New rtx code.
	* gensupport.c (queue_elem): Update comment.
	(replace_operands_with_dups): New function.
	(gen_rewrite_sequence): Likewise.
	(process_rtx): Handle DEFINE_INSN_AND_REWRITE.
	* read-rtl.c (apply_subst_iterator): Likewise.
	(add_condition_to_rtx, named_rtx_p): Likewise.
	(rtx_reader::read_rtx_operand): Likewise.
	* config/aarch64/aarch64-sve.md
	(while_ult<GPI:mode><PRED_ALL:mode>_cc): Rename to...
	(*while_ult<GPI:mode><PRED_ALL:mode>_cc): ...this and use
	define_insn_and_rewrite.
	(*cond_<optab><mode>_any): Turn into define_insn_and_rewrites.
	Remove separate define_split.

From-SVN: r271815

	* include/std/tuple (tuple<>): Add noexcept to allocator-extended
	constructors.
	(tuple<T1, T2>::__nothrow_default_constructible()): New helper
	function.
	(tuple<T1, T2>::tuple(), explicit tuple<T1, T2>::tuple()): Use helper.

From-SVN: r271814

	* tree-ssa-alias.c (type_has_components_p): New function.
	(aliasing_component_refs_p): Use it.

From-SVN: r271813

Restore the using-declaration but locally in the source file, not in the
header.

	* src/c++98/bitmap_allocator.cc: Add using-declaration for size_t.

From-SVN: r271812

https://gcc.gnu.org/ml/gcc-patches/2019-05/msg02126.html
	* cp-tree.h (IDENTIFIER_LAMBDA_P): New.
	(TYPE_ANON_P): New.
	(LAMBDA_TYPE_P, TYPE_UNNAMED_P):  Likewise.
	(LAMBDANAME_PREFIX, LAMBDANAME_FORMAT): Delete.
	(make_lambda_name): Don't declare.
	* error.c (dump_aggr_type): Check for lambdas before other
	anonymous names.
	* lambda.c (begin_lambda_type): Use make_anon_name.
	* cp-lang.c (cxx_dwarf_name): Lambda names smell anonymous.
	* mangle.c (write_local_name): Likewise.
	* name-lookup.c (lambda_cnt, make_lambda_name): Delete.

From-SVN: r271811

2019-05-31  Bill Schmidt  <wschmidt@linux.ibm.com>
	    Michael Meissner  <meissner@linux.ibm.com>

	* gcc.target/powerpc/cpu-future.c: Require powerpc_future_ok.
	* gcc.target/powerpc/localentry-1.c: Likewise.
	* gcc.target/powerpc/localentry-direct-1.c: Likewise.
	* gcc.target/powerpc/notoc-direct-1.c: Likewise.
	* gcc.target/powerpc/pcrel-sibcall-1.c: Likewise.
	* lib/target-supports.exp (check_powerpc_future_hw_available): New.
	(check_effective_target_powerpc_future_ok): New.


Co-Authored-By: Michael Meissner <meissner@linux.ibm.com>

From-SVN: r271810

Make these functions restore the default handlers when passed a null
pointer. This is consistent with std::pmr::set_default_resource(0), and
also matches the current behaviour of libc++.

In order to avoid duplicating the preprocessor condition from
eh_term_handler.cc more that into a new eh_term_handler.h header and
define a macro that can be used in both eh_term_handler.cc and
eh_terminate.cc.

	PR libstdc++/90682
	* libsupc++/eh_term_handler.cc: Include eh_term_handler.h to get
	definition of _GLIBCXX_DEFAULT_TERM_HANDLER.
	* libsupc++/eh_term_handler.h: New header defining
	_GLIBCXX_DEFAULT_TERM_HANDLER.
	* libsupc++/eh_terminate.cc: Include eh_term_handler.h.
	(set_terminate): Restore default handler when argument is null.
	(set_unexpected): Likewise.
	* testsuite/18_support/set_terminate.cc: New test.
	* testsuite/18_support/set_unexpected.cc: New test.

From-SVN: r271808

These using-declarations appear to have been added for simplicity when
moving the non-standard extensions from namespace std to namespace
__gnu_cxx. Dumping all these names into namespace __gnu_cxx allows
unportable uses like __gnu_cxx::size_t and __gnu_cxx::pair, which serve
no useful purpose.

This patch removes most of the using-declarations from namespace scope,
then either qualifies names as needed or adds using-declarations at
block scope or typedefs at class scope.

	* include/backward/hashtable.h (size_t, ptrdiff_t)
	(forward_iterator_tag, input_iterator_tag, _Construct, _Destroy)
	(distance, vector, pair, __iterator_category): Remove
	using-declarations that add these names to namespace __gnu_cxx.
	* include/ext/bitmap_allocator.h (size_t, ptrdiff_t): Likewise.
	* include/ext/debug_allocator.h (size_t): Likewise.
	* include/ext/functional (size_t, unary_function, binary_function)
	(mem_fun1_t, const_mem_fun1_t, mem_fun1_ref_t, const_mem_fun1_ref_t):
	Likewise.
	* include/ext/malloc_allocator.h (size_t, ptrdiff_t): Likewise.
	* include/ext/memory (ptrdiff_t, pair, __iterator_category): Likewise.
	* include/ext/mt_allocator.h (size_t, ptrdiff_t): Likewise.
	* include/ext/new_allocator.h (size_t, ptrdiff_t): Likewise.
	* include/ext/numeric (iota): Fix outdated comment.
	* include/ext/pool_allocator.h (size_t, ptrdiff_t): Likewise.
	* include/ext/rb_tree (_Rb_tree, allocator): Likewise.
	* include/ext/rope (size_t, ptrdiff_t, allocator, _Destroy): Likewise.
	* include/ext/ropeimpl.h (size_t, printf, basic_ostream)
	(__throw_length_error, _Destroy, std::__uninitialized_fill_n_a):
	Likewise.
	* include/ext/slist (size_t, ptrdiff_t, _Construct, _Destroy)
	(allocator, __true_type, __false_type): Likewise.

From-SVN: r271807

This patch adds static asserts for type traits misuse with incomplete
classes and unions. This gives a nice readable error message instead
of an UB and odr-violations.

Some features of the patch:
* each type trait has it's own static_assert inside. This gives better
diagnostics than the approach with putting the assert into a helper
structure and using it in each trait.
* the result of completeness check is not memorized by the compiler.
This gives no false positive after the first failed check.
* some of the compiler builtins already implement the check. But not
all of them! So the asserts are in all the type_traits that may
benefit from the check. This also makes the behavior of libstdc++ more
consistent across different (non GCC) compilers.
* std::is_base_of does not have the assert as it works well in many
cases with incomplete types

2019-05-31  Antony Polukhin  <antoshkka@gmail.com>

	PR libstdc++/71579
	* include/std/type_traits __type_identity, __is_complete_or_unbounded):
	New helpers for checking preconditions in traits.
	(is_trivial, is_trivially_copyable, is_standard_layout, is_pod)
	(is_literal_type, is_empty, is_polymorphic, is_final, is_abstract)
	(is_destructible, is_nothrow_destructible, is_constructible)
	(is_default_constructible, is_copy_constructible)
	(is_move_constructible, is_nothrow_default_constructible)
	(is_nothrow_constructible, is_nothrow_copy_constructible)
	(is_nothrow_move_constructible, is_copy_assignable, is_move_assignable)
	(is_nothrow_assignable, is_nothrow_copy_assignable)
	(is_nothrow_move_assignable, is_trivially_constructible)
	(is_trivially_copy_constructible, is_trivially_move_constructible)
	is_trivially_assignable, is_trivially_copy_assignable)
	(is_trivially_move_assignable, is_trivially_destructible)
	(alignment_of, is_swappable, is_nothrow_swappable, is_invocable)
	(is_invocable_r, is_nothrow_invocable)
	(has_unique_object_representations, is_aggregate): Add static_asserts
	to make sure that type traits are not misused with incomplete types.
	(__is_constructible_impl, __is_nothrow_default_constructible_impl)
	(__is_nothrow_constructible_impl, __is_nothrow_assignable_impl): New
	base characteristics without assertions that can be reused in other
	traits.
	* testsuite/20_util/is_complete_or_unbounded/memoization.cc: New test.
	* testsuite/20_util/is_complete_or_unbounded/memoization_neg.cc: New
	test.
	* testsuite/20_util/is_complete_or_unbounded/value.cc: New test.
	* testsuite/20_util/is_abstract/incomplete_neg.cc: New test.
	* testsuite/20_util/is_aggregate/incomplete_neg.cc: New test.
	* testsuite/20_util/is_class/value.cc: Check incomplete type.
	* testsuite/20_util/is_function/value.cc: Likewise.
	* testsuite/20_util/is_move_constructible/incomplete_neg.cc: New test.
	* testsuite/20_util/is_nothrow_move_assignable/incomplete_neg.cc: New
	test.
	* testsuite/20_util/is_polymorphic/incomplete_neg.cc: New test.
	* testsuite/20_util/is_reference/value.cc: Check incomplete types.
	* testsuite/20_util/is_unbounded_array/value.cc: Likewise.
	* testsuite/20_util/is_union/value.cc: Likewise.
	* testsuite/20_util/is_void/value.cc: Likewise.
	* testsuite/util/testsuite_tr1.h: Add incomplete union type.

From-SVN: r271806

Instead of duplicating the initialization functions that take string,
add a new member taking a raw pointer that can be used to convert the
constructor token from the old string to the new.

Also fix "mt19337" typos in a testcase.

	* include/bits/random.h (random_device::_M_init(const char*, size_t)):
	Add new private member function.
	* src/c++11/cow-string-inst.cc (random_device::_M_init(const string&))
	(random_device::_M_init_pretr1(const string&)): Call new private
	member with string data.
	* src/c++11/random.cc (random_device::_M_init(const char*, size_t)):
	Define.
	* testsuite/26_numerics/random/random_device/cons/default-cow.cc: New
	test using COW strings.
	* testsuite/26_numerics/random/random_device/cons/default.cc: Generate
	a value from the device.
	* testsuite/26_numerics/random/random_device/cons/token.cc: Likewise.
	Fix typo in token string.

From-SVN: r271805

2019-05-31  Martin Liska  <mliska@suse.cz>

	* gdbhooks.py: Add const_tree to TreePrinter.

From-SVN: r271804

2019-05-31  Thomas De Schampheleire  <thomas.de_schampheleire@nokia.com>

	PR debug/86964
	* common.opt (feliminate-unused-debug-symbols): Enable by default.
	* doc/invoke.texi (Debugging Options): Document new default of
	-feliminate-unused-debug-symbols and remove restriction to 'stabs'.

	* g++.dg/debug/dwarf2/fesd-any.C: Use
	-fno-eliminate-unused-debug-symbols.
	* g++.dg/debug/dwarf2/fesd-baseonly.C: Likewise.
	* g++.dg/debug/dwarf2/fesd-none.C: Likewise.
	* g++.dg/debug/dwarf2/fesd-reduced.C: Likewise.
	* g++.dg/debug/dwarf2/fesd-sys.C: Likewise.
	* g++.dg/debug/dwarf2/inline-var-1.C: Likewise.
	* g++.dg/debug/enum-2.C: Likewise.
	* gcc.dg/debug/dwarf2/fesd-any.c: Likewise.
	* gcc.dg/debug/dwarf2/fesd-baseonly.c: Likewise.
	* gcc.dg/debug/dwarf2/fesd-none.c: Likewise.
	* gcc.dg/debug/dwarf2/fesd-reduced.c: Likewise.
	* gcc.dg/debug/dwarf2/fesd-sys.c: Likewise.

From-SVN: r271803

re PR tree-optimization/90671 (ICE on valid code at -Os and above with -g enabled in gsi_split_seq_after, at gimple-iterator.c:345)

	PR tree-optimization/90671
	* tree-ssa-threadupdate.c (ssa_create_duplicates): If
	template_block used to be empty on the first call, don't use
	gsi_split_seq_after and gsi_insert_seq_after, but remember whole
	seq with bb_seq and set it with set_bb_seq.

	* gcc.dg/torture/pr90671.c: New test.

From-SVN: r271802

The test for pr84497 uses a facility that requires alias support from
the target, and therefore fails on targets without.  Add a suitable 
dg-require statement.

2019-05-31  Iain Sandoe  <iain@sandoe.co.uk>

	* g++.dg/cpp0x/pr84497.C: Require alias support.

From-SVN: r271801

Darwin has a .align taking a power of 2 by default, so that some
tests expecting a byte count are failing, fixed thus.

gcc/testsuite/

2019-05-31  Iain Sandoe  <iain@sandoe.co.uk>

	* gcc.target/i386/falign-functions-3.c: Adjust align syntax
	and label for Darwin.
	* gcc.target/i386/attr-aligned-2.c: Adjust align syntax for
	Darwin.

From-SVN: r271800

.p2align support is present in all x86 assemblers on released
Darwin systems.

gcc/

2019-05-29  Iain Sandoe  <iain@sandoe.co.uk>

	* config/i386/darwin.h (ASM_OUTPUT_MAX_SKIP_ALIGN): New.

From-SVN: r271799

2019-05-30  Bill Schmidt  <wschmidt@linux.ibm.com>
	    Michael Meissner  <meissner@linux.ibm.com>

	* config/rs6000/predicates.md (pcrel_address): New define_predicate.
	(prefixed_mem_operand): Likewise.
	(non_prefixed_mem_operand): Likewise.
	* config/rs6000/rs6000-protos.h (rs6000_prefixed_address): New
	prototype.
	* config/rs6000/rs6000.c (print_operand_address): Handle
	PC-relative addresses.
	(mode_supports_prefixed_address_p): New function.
	(rs6000_prefixed_address): New function.
	* config/rs6000/rs6000.h (SYMBOL_FLAG_PCREL): New #define.
	(SYMBOL_REF_PCREL_P): Likewise.


Co-Authored-By: Michael Meissner <meissner@linux.ibm.com>

From-SVN: r271798

From-SVN: r271796

From-SVN: r271795

	* gimplify.c (enum gimplify_omp_var_data): Add GOVD_CONDTEMP.
	(gimplify_adjust_omp_clauses_1): Handle GOVD_CONDTEMP.
	(gimplify_omp_for): If worksharing loop with lastprivate conditional
	is nested inside of parallel region, add _condtemp_ clause to both.
	* tree-nested.c (convert_nonlocal_omp_clauses,
	convert_local_omp_clauses): Ignore OMP_CLAUSE__CONDTEMP_ instead of
	assertion failure.
	* omp-general.h (struct omp_for_data): Add have_pointer_condtemp
	member.
	* omp-general.c (omp_extract_for_data): Compute it.
	* omp-low.c (scan_sharing_clauses): Handle OMP_CLAUSE__CONDTEMP_.
	(lower_rec_input_clauses): Likewise.
	(lower_lastprivate_conditional_clauses): If OMP_CLAUSE__CONDTEMP_
	clause is already present, just add one further one after it.
	(lower_lastprivate_clauses): Handle cond_ptr with array type.
	(lower_send_shared_vars): Clear _condtemp_ vars.
	(lower_omp_1) <case GIMPLE_ASSIGN>: Handle target data like critical
	or section or taskgroup.
	* omp-expand.c (determine_parallel_type): Disallow combining only if
	first OMP_CLAUSE__CONDTEMP_ has pointer type.  Disallow combining
	of parallel sections if OMP_CLAUSE__CONDTEMP_ is present.
	(expand_omp_for_generic, expand_omp_for_static_nochunk,
	expand_omp_for_static_chunk, expand_omp_for): Use
	fd->have_pointer_condtemp instead of fd->lastprivate_conditional to
	determine if a special set of API routines are needed and if condtemp
	needs to be initialized, while always initialize cond_var if
	fd->lastprivate_conditional is non-zero.

From-SVN: r271791

	gcc/go/
	* go-gcc.cc (Gcc_backend::Gcc_backend): Add BUILT_IN_ATOMIC_FETCH_AND_1
	and BUILT_IN_ATOMIC_FETCH_OR_1.

From-SVN: r271790

This only change the cxx11 basic_string, because COW strings don't
correctly propagate allocators anyway.

2019-05-30  Nina Dinka Ranns  <dinka.ranns@gmail.com>

	LWG2788 basic_string spurious use of a default constructible allocator
	* include/bits/basic_string.tcc [_GLIBCXX_USE_CXX11_ABI]
	(basic_string::_M_replace_dispatch): Construct temporary string with
	the current allocator.
	* testsuite/21_strings/basic_string/allocator/char/lwg2788.cc: New.
	* testsuite/21_strings/basic_string/allocator/wchar_t/lwg2788.cc: New.

From-SVN: r271789

From-SVN: r271788

2019-05-30  Bill Schmidt  <wschmidt@linux.ibm.com>
	    Michael Meissner  <meissner@linux.ibm.com>

	* config/rs6000/constraints.md (eI): New constraint.
	* config/rs6000/predicates.md (cint34_operand): New predicate.
	* config/rs6000/rs6000.h (SIGNED_16BIT_OFFSET_P): New #define.
	(SIGNED_34BIT_OFFSET_P): Likewise.
	* doc/md.texi (eI): Document constraint.


Co-Authored-By: Michael Meissner <meissner@linux.ibm.com>

From-SVN: r271787

2019-05-30  Thomas Koenig  <tkoenig@gcc.gnu.org>

    * gfc-internals.texi (Translating to GENERIC): New chapter.

From-SVN: r271786

This patch adds support in SVE to combine:
- fsub and fabs into fabd

fsub    z0.s, z0.s, z1.s
fabs    z0.s, p1/m, z0.s
---
fabd    z0.s, p1/m, z0.s, z1.s

2019-05-30  Sylvia Taylor  <sylvia.taylor@arm.com>

gcc/
	* config/aarch64/aarch64-sve.md (*fabd<mode>3): New.

gcc/testsuite/
	* gcc.target/aarch64/sve/fabd_1.c: New.

From-SVN: r271785

    
    Let the Go frontend recognize sync/atomic functions and turn them
    into intrinsics.
    
    Also make sure not to intrinsify calls in go or defer statements.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/178937

From-SVN: r271784

	PR c++/90598
	* tree.c (lvalue_kind): Return clk_none for expressions with
	with VOID_TYPE_P.

	* g++.dg/cpp0x/pr90598.C: New test.

From-SVN: r271783

	* doc/xml/manual/diagnostics.xml: Update list of headers that define
	exception classes.
	* doc/xml/manual/support.xml: Rewrite advice around NULL. Rewrite
	section about new/delete overloads. Improve section on verbose
	terminate handler.
	* doc/html/*: Regenerate.

From-SVN: r271782

2019-05-30  Bill Schmidt  <wschmidt@linux.ibm.com>
	    Michael Meissner  <meissner@linux.ibm.com>

	* rs6000-cpus.def (OTHER_FUSION_MASKS): New #define.
	(ISA_3_0_MASKS_SERVER): Mask off OTHER_FUSION_MASKS.
	(ISA_3_0_MASKS_IEEE): Remove OPTION_MASK_DIRECT_MOVE.
	(ISA_FUTURE_MASKS_SERVER): Add OPTION_MASK_PREFIXED_ADDR.
	(OTHER_FUTURE_MASKS): Likewise.
	(POWERPC_MASKS): Likewise.
	* rs6000.c (rs6000_option_override_internal): Error if -mpcrel is
	specified without -mprefixed-addr or -mcpu=future.  Error if
	-mprefixed-addr is specified without -mcpu=future.
	(rs6000_opt_masks): Add entry for prefixed-addr.
	* rs6000.opt (mprefixed-addr): New option.


Co-Authored-By: Michael Meissner <meissner@linux.ibm.com>

From-SVN: r271781

	gcc/ChangeLog
	* aarch64/aarch64.c (aarch64_post_cfi_startproc): Add
	cfun->is_thunk check.

From-SVN: r271780

From-SVN: r271777

The status of P1353R0 was "Partial" because we don't define the
__cpp_lib_three_way_comparison macro, but that's because we don't
support the feature. So the paper can be marked as done.

	* doc/xml/manual/status_cxx2020.xml: Add feature-test macro for
	P0811R3. Change status of P1353R0.
	* doc/html/*: Regenerate.

From-SVN: r271774

	* doc/xml/manual/status_cxx2011.xml: Use <variablelist> for
	documentation of implementation-defined types for [thread.req.native].
	* doc/xml/manual/status_cxx2017.xml: Update documentation of
	implementation-defined strings for [variant.bad.access]. Fix typo in
	documentation of implementation-defined support for [fs.conform.9945].
	* doc/html/*: Regenerate.

From-SVN: r271773

	* tree-predcom.c (is_inv_store_elimination_chain): Fix a typo - lenght
	to length.

	* lang.opt (ftail-call-workaround=): Fix a typo - lenghts to lengths.

From-SVN: r271770

	libgomp:
	* configure.ac: Call AX_COUNT_CPUS.
	Substitute CPU_COUNT.
	* testsuite/Makefile.am (check-am): Use CPU_COUNT as processor
	count fallback.
	* aclocal.m4: Regenerate.
	* configure: Regenerate.
	* Makefile.in, testsuite/Makefile.in: Regenerate.

	config:
	* ax_count_cpus.m4: New file.

From-SVN: r271769

gcc/testsuite/

2019-05-30  Iain Sandoe  <iain@sandoe.co.uk>

	* gcc.target/i386/pr86257.c: Require native TLS support.
	* gcc.target/i386/stack-prot-sym.c: Likewise.

From-SVN: r271768