When saving, if we cannot obtain a suitable memory segment there
is no point in continuing, so exit with an error.

When reading in the PCH, we have a situation that the read-in
data will replace the line tables used by the diagnostics output.
However, the state of the read-oin line tables is indeterminate
at some points where diagnostics might be needed.

To make this more robust, we save the existing line tables at
the start and, once we have read in the pointer to the new one,
put that to one side and restore the original table.  This
avoids compiler hangs if the read or memory acquisition code
issues an assert, fatal_error, segv etc.

Once the read is complete, we swap in the new line table that
came from the PCH.

If the read-in PCH is corrupted then we still have a broken
compilation w.r.t any future diagnostics - but there is little
that can be done about that without more careful validation of
the file.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>

gcc/ChangeLog:

	* ggc-common.c (gt_pch_save): If we cannot find a suitable
	memory segment for save, then error-out, do not try to
	continue.
	(gt_pch_restore): Save the existing line table, and when
	the replacement is being read, use that when constructing
	diagnostics.

PR102976 shows a test case where we generate wrong code when building
a vector pair from 2 vector registers.  The bug here is that with unlucky
register assignments, we can clobber one of the input operands before
we write both registers of the output operand.  The solution is to use
early-clobbers in the assemble pair and accumulator patterns.

2021-11-16  Peter Bergner  <bergner@linux.ibm.com>

gcc/
	PR target/102976
	* config/rs6000/mma.md (*vsx_assemble_pair): Add early-clobber for
	output operand.
	(*mma_assemble_acc): Likewise.

gcc/testsuite/
	PR target/102976
	* gcc.target/powerpc/pr102976.c: New test.

This provides a new function to get the name of a dummy argument,
so that identifying an argument can be made using just its name
instead of a mix of name matching (for keyword actual arguments)
and argument counting (for other actual arguments).

gcc/fortran/ChangeLog:
	* interface.c (gfc_dummy_arg_get_name): New function.
	* gfortran.h (gfc_dummy_arg_get_name): Declare it.
	* trans-array.c (arg_evaluated_for_scalarization): Pass a dummy
	argument wrapper as argument instead of an actual argument
	and an index number.  Check it’s non-NULL.  Use its name
	to identify it.
	(gfc_walk_elemental_function_args): Update call to
	arg_evaluated for scalarization.  Remove argument counting.

Now that we can get information about an actual arg's associated
dummy using the associated_dummy attribute, the field missing_arg_type
contains redundant information.
This removes it.

gcc/fortran/ChangeLog:
	* gfortran.h (gfc_actual_arglist::missing_arg_type): Remove.
	* interface.c (gfc_compare_actual_formal): Remove
	missing_arg_type initialization.
	* intrinsic.c (sort_actual): Ditto.
	* trans-expr.c (gfc_conv_procedure_call): Use associated_dummy
	and gfc_dummy_arg_get_typespec to get the dummy argument type.

This adds two functions working with the wrapper struct gfc_dummy_arg
and makes usage of them to simplify a bit the walking of elemental
procedure arguments for scalarization.  As information about dummy arguments
can be obtained from the actual argument through the just-introduced
associated_dummy field, there is no need to carry around the procedure
interface and walk dummy arguments manually together with actual arguments.

gcc/fortran/ChangeLog:
	* interface.c (gfc_dummy_arg_get_typespec,
	gfc_dummy_arg_is_optional): New functions.
	* gfortran.h (gfc_dummy_arg_get_typespec,
	gfc_dummy_arg_is_optional): Declare them.
	* trans.h (gfc_ss_info::dummy_arg): Use the wrapper type
	as declaration type.
	* trans-array.c (gfc_scalar_elemental_arg_saved_as_reference):
	use gfc_dummy_arg_get_typespec function to get the type.
	(gfc_walk_elemental_function_args): Remove proc_ifc argument.
	Get info about the dummy arg using the associated_dummy field.
	* trans-array.h (gfc_walk_elemental_function_args): Update declaration.
	* trans-intrinsic.c (gfc_walk_intrinsic_function):
	Update call to gfc_walk_elemental_function_args.
	* trans-stmt.c (gfc_trans_call): Ditto.
	(get_proc_ifc_for_call): Remove.

There was originally no way from an actual argument to get
to the corresponding dummy argument, even if the job of sorting
and matching actual with dummy arguments was done.
The closest was a field named actual in gfc_intrinsic_arg that was
used as scratch data when sorting arguments of one specific call.
However that value was overwritten later on as arguments of another
call to the same procedure were sorted and matched.

This change removes that field from gfc_intrinsic_arg and adds instead
a new field associated_dummy in gfc_actual_arglist.

The new field has as type a new wrapper struct gfc_dummy_arg that provides
a common interface to both dummy arguments of user-defined procedures
(which have type gfc_formal_arglist) and dummy arguments of intrinsic procedures
(which have type gfc_intrinsic_arg).

As the removed field was used in the code sorting and matching arguments,
that code has to be updated.  Two local vectors with matching indices
are introduced for respectively dummy and actual arguments, and the
loops are modified to use indices and update those argument vectors.

gcc/fortran/ChangeLog:
	* gfortran.h (gfc_dummy_arg_kind, gfc_dummy_arg): New.
	(gfc_actual_arglist): New field associated_dummy.
	(gfc_intrinsic_arg): Remove field actual.
	* interface.c (get_nonintrinsic_dummy_arg): New.
	(gfc_compare_actual): Initialize associated_dummy.
	* intrinsic.c (get_intrinsic_dummy_arg): New.
	(sort_actual):  Add argument vectors.
	Use loops with indices on argument vectors.
	Initialize associated_dummy.

Preliminary refactoring to make further changes more obvious.
No functional change.

gcc/fortran/ChangeLog:
	* intrinsic.c (sort_actual): initialise variable and use it earlier.

libstdc++-v3/ChangeLog:

	* src/c++17/ryu/MERGE: Update the commit hash.
	* src/c++17/ryu/d2s_intrinsics.h: Merge from Ryu's master
	branch.

Signed-off-by: Patrick Palka <ppalka@redhat.com>

This is only supported for the cxx11 ABI, not for COW strings.

libstdc++-v3/ChangeLog:

	* include/bits/basic_string.h (basic_string, operator""s): Add
	constexpr for C++20.
	(basic_string::basic_string(basic_string&&)): Only copy
	initialized portion of the buffer.
	(basic_string::basic_string(basic_string&&, const Alloc&)):
	Likewise.
	* include/bits/basic_string.tcc (basic_string): Add constexpr
	for C++20.
	(basic_string::swap(basic_string&)): Only copy initialized
	portions of the buffers.
	(basic_string::_M_replace): Add constexpr implementation that
	doesn't depend on pointer comparisons.
	* include/bits/cow_string.h: Adjust comment.
	* include/ext/type_traits.h (__is_null_pointer): Add constexpr.
	* include/std/string (erase, erase_if): Add constexpr.
	* include/std/version (__cpp_lib_constexpr_string): Update
	value.
	* testsuite/21_strings/basic_string/cons/char/constexpr.cc:
	New test.
	* testsuite/21_strings/basic_string/cons/wchar_t/constexpr.cc:
	New test.
	* testsuite/21_strings/basic_string/literals/constexpr.cc:
	New test.
	* testsuite/21_strings/basic_string/modifiers/constexpr.cc: New test.
	* testsuite/21_strings/basic_string/modifiers/swap/char/constexpr.cc:
	New test.
	* testsuite/21_strings/basic_string/modifiers/swap/wchar_t/constexpr.cc:
	New test.
	* testsuite/21_strings/basic_string/version.cc: New test.

These swap overloads are non-standard, but are needed to make swap work
for vector<bool>::reference rvalues. They don't need to be called
explicitly, only via ADL, so hide them from normal lookup. This is what
I've proposed as the resolution to LWG 3638.

libstdc++-v3/ChangeLog:

	* include/bits/stl_bvector.h (swap(_Bit_reference, _Bit_reference))
	(swap(_Bit_reference, bool&), swap(bool&, _Bit_reference)):
	Define as hidden friends of _Bit_reference.

Resolves:
PR tree-optimization/102960 - ICE: in sign_mask, at wide-int.h:855 in GCC 10.3.0

gcc/ChangeLog:

	PR tree-optimization/102960
	* gimple-fold.c (get_range_strlen): Take bitmap as an argument rather
	than a pointer to it.
	(get_range_strlen_tree): Same.  Remove bitmap allocation.  Use
	an auto_bitmap.
	(get_maxval_strlen): Use an auto_bitmap.
	* tree-ssa-strlen.c (get_range_strlen_dynamic): Factor out PHI
	handling...
	(get_range_strlen_phi): ...into this function.
	Avoid assuming maximum string length is constant
	(printf_strlen_execute): Dump pointer query cache contents when
	details are requisted.

gcc/testsuite/ChangeLog:

	PR tree-optimization/102960
	* gcc.dg/Wstringop-overflow-84.c: New test.

When the rshrn commit was reverted I missed this testcase.
This now updates it.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/shrn-combine-10.c: Use shrn.

This updates the signbit-2 test to check for
the scalar optimization if the target does not
support vectorization.

gcc/testsuite/ChangeLog:

	* gcc.dg/signbit-2.c: CHeck vect or scalar.

This was leading to an assertion failure ICE on a switch stmt when using
-fstrict-enums, due to erroneously reusing a range involving one enum
with a range involving a different enum.

gcc/analyzer/ChangeLog:
	PR analyzer/102662
	* constraint-manager.cc (bounded_range::operator==): Require the
	types to be the same for equality.

gcc/testsuite/ChangeLog:
	PR analyzer/102662
	* g++.dg/analyzer/pr102662.C: New test.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

It's been inconvenient that pretty-printing of PTRMEM_CST didn't display
what member the constant refers to.

Adding that is complicated by the absence of a langhook for CONSTANT_CLASS_P
nodes; the simplest fix for that is to use the tcc_exceptional hook for
tcc_constant as well.

gcc/cp/ChangeLog:

	* ptree.c (cxx_print_xnode): Handle PTRMEM_CST.

gcc/ChangeLog:

	* langhooks.h (struct lang_hooks): Adjust comment.
	* print-tree.c (print_node): Also call print_xnode hook for
	tcc_constant class.

This folds Fold ((type)(a<0)) << SIGNBITOFA into ((type)a) & signbit inside match.pd.
This was already handled in fold-cost by:
/* A < 0 ? <sign bit of A> : 0 is simply (A & <sign bit of A>).  */
I have not removed as we only simplify "a ? POW2 : 0" at the gimple level to "a << CST1"
and fold actually does the reverse of folding "(a<0)<<CST" into "(a<0) ? 1<<CST : 0".

OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

	PR tree-optimization/103218

gcc/ChangeLog:

	* match.pd: New pattern for "((type)(a<0)) << SIGNBITOFA".

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/pr103218-1.c: New test.

I fixed some undefined behaviour in string tests in r238609, but I only
fixed the narrow char versions. This applies the same fixes to the
wchar_t ones. These problems were found when testing a patch to make
std::basic_string usable in constexpr.

libstdc++-v3/ChangeLog:

	* testsuite/21_strings/basic_string/modifiers/append/wchar_t/1.cc:
	Fix reads past the end of strings.
	* testsuite/21_strings/basic_string/operations/compare/wchar_t/1.cc:
	Likewise.
	* testsuite/experimental/string_view/operations/compare/wchar_t/1.cc:
	Likewise.

libstdc++-v3/ChangeLog:

	* testsuite/21_strings/basic_string/allocator/71964.cc: Fix
	typo.
	* testsuite/23_containers/set/allocator/71964.cc: Likewise.

The (u)maddsihi4 patterns are using the ARC's VMAC2H(U)
instruction with null destination, however, VMAC2H(U) doesn't
rewrite the accumulator.  This patch solves the destination issue
of VMAC2H by replacing it with DMACH(U) instruction.

gcc/

	* config/arc/arc.md (maddhisi4): Use a single move to accumulator.
	(umaddhisi4): Likewise.
	(machi): Update pattern.
	(umachi): Likewise.

gcc/testsuite/

	* gcc.target/arc/tmac-4.c: New test.

Signed-off-by: Claudiu Zissulescu <claziss@synopsys.com>

The PR shows a missed control-dependent DCE caused by CFG cleanup
merging a forwarder resulting in a partially degenerate PHI node.
With control-dependent DCE we need to mark control dependences
of incoming edges into PHIs as necessary but that is unnecessarily
conservative for the case when two edges have the same value.
There is no easy way to mark only a subset of control dependences
of both edges necessary so the fix is to produce forwarder blocks
where then the control dependence captures the requirements more
precisely.

For gcc.dg/tree-ssa/ssa-dom-thread-7.c the number of edges in the
CFG decrease as we have commonized PHI arguments which in turn
results in different threadings.  The testcase is too complex
and the dump scanning too simple to do anything meaningful here
but to adjust the number of expected threads.

The same CFG massaging could be useful at RTL expansion time to
reduce the number of copies we need to insert on edges.

FAIL: gcc.dg/tree-ssa/ssa-hoist-4.c scan-tree-dump-times optimized "MAX_EXPR" 1

2021-11-12  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/102880
	* tree-ssa-dce.c (sort_phi_args): New function.
	(make_forwarders_with_degenerate_phis): Likewise.
	(perform_tree_ssa_dce): Call
	make_forwarders_with_degenerate_phis.

	* gcc.dg/tree-ssa/pr102880.c: New testcase.
	* gcc.dg/tree-ssa/pr69270-3.c: Robustify.
	* gcc.dg/tree-ssa/ssa-dom-thread-7.c: Change the number of
	expected threadings.

This allows extra edges into the middle BB for the PHI-OPT
transforms using replace_phi_edge_with_variable that do not
end up moving stmts from that middle BB.  This avoids regressing
gcc.dg/tree-ssa/ssa-hoist-4.c with the actual fix for PR102880
where CFG cleanup has the choice to remove two forwarders and
picks "the wrong" leading to

   if (a > b) /
       /\    /
      /  <BB>
     /    |
  # PHI <a, b>

rather than

   if (a > b)  |
       /\      |
    <BB> \     |
     /    \    |
  # PHI <a, b, b>

but it's relatively straight-forward to support extra edges
into the middle-BB in paths ending in replace_phi_edge_with_variable
and that do not require moving stmts.  That's because we really
only want to remove the edge from the condition to the middle BB.
Of course actually doing that means updating dominators in non-trival
ways which is why I kept the original code for the single edge
case and simply defer to CFG cleanup by adjusting the condition for
the complicated case.

The testcase needs to be a GIMPLE one since it's quite unreliable
to produce the desired CFG.

2021-11-15  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/102880
	* tree-ssa-phiopt.c (tree_ssa_phiopt_worker): Push
	single_pred (bb1) condition to places that really need it.
	(match_simplify_replacement): Likewise.
	(value_replacement): Likewise.
	(replace_phi_edge_with_variable): Deal with extra edges
	into the middle BB.

	* gcc.dg/tree-ssa/phi-opt-26.c: New testcase.

Update assembly output test pattern. Take into consideration also for
which platform we do execute the test (baremetal or linux).

gcc/testsuite/ChangeLog:

	* gcc.target/arc/add_n-combine.c: Update test patterns.
	* gcc.target/arc/builtin_eh.c: Update test for linux platforms.
	* gcc.target/arc/mul64-1.c: Disable this test while running on
	linux.
	* gcc.target/arc/tls-gd.c: Update matching patterns.
	* gcc.target/arc/tls-ie.c: Likewise.
	* gcc.target/arc/tls-ld.c: Likewise.
	* gcc.target/arc/uncached-8.c: Likewise.

Signed-off-by: Claudiu Zissulescu <claziss@synopsys.com>

As discussed on the mailing list, this patch replaces all but one
remaining open coded constructions of DEBUG_EXPR_DECL with calls to
build_debug_expr_decl, even if - in order not to introduce any
functional change - the mode of the constructed decl is then
overwritten.

It is not clear if changing the mode has any effect in practice and
therefore I have added a FIXME note to code which does it, as
requested.

After this patch, DEBUG_EXPR_DECLs are created only by
build_debug_expr_decl and make_debug_expr_from_rtl which looks like
it should be left alone.

gcc/ChangeLog:

2021-11-11  Martin Jambor  <mjambor@suse.cz>

	* cfgexpand.c (expand_gimple_basic_block): Use build_debug_expr_decl,
	add a fixme note about the mode assignment perhaps being unnecessary.
	* ipa-param-manipulation.c (ipa_param_adjustments::modify_call):
	Likewise.
	(ipa_param_body_adjustments::mark_dead_statements): Likewise.
	(ipa_param_body_adjustments::reset_debug_stmts): Likewise.
	* tree-inline.c (remap_ssa_name): Likewise.
	(tree_function_versioning): Likewise.
	* tree-into-ssa.c (rewrite_debug_stmt_uses): Likewise.
	* tree-ssa-loop-ivopts.c (remove_unused_ivs): Likewise.
	* tree-ssa.c (insert_debug_temp_for_var_def): Likewise.

Since we can now remove return values of functions with return_nonnull
type attribute, I'll feel a bit safer if we can test this does not ICE
when someone attempts to access a non-existent call LHS.  Eventually
we should probably drop the attribute when this happens.

gcc/testsuite/ChangeLog:

2021-11-15  Martin Jambor  <mjambor@suse.cz>

	* gcc.dg/ipa/ipa-sra-ret-nonull.c: New test.

After the Fortran changes we can mark it as implemented...

2021-11-16  Jakub Jelinek  <jakub@redhat.com>

	* libgomp.texi (OpenMP 5.1): Mark thread_limit clause to target
	construct as implemented.

As the testcase shows, the non-rectangular loop expansion code didn't
try to regimplify operands of GIMPLE_CONDs it built in some cases.
I have added a helper function which does that and used it in some places
that were regimplifying already to simplify those spots, plus added it
in a couple of other places where it was needed.

2021-11-16  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/103208
	* omp-expand.c (expand_omp_build_cond): New function.
	(expand_omp_for_init_counts, expand_omp_for_init_vars,
	expand_omp_for_static_nochunk, expand_omp_for_static_chunk): Use it.

	* c-c++-common/gomp/loop-11.c: New test.

This function punts if the builtins have no arguments, but as can be seen
on the testcase, even if it has some arguments but alloc_size attribute's
arguments point to arguments that aren't passed, we get a warning earlier
from the FE but should punt rather than ICE on it.
Other users of alloc_size attribute e.g. in
tree-object-size.c (alloc_object_size) punt similarly and similarly
even in the same TU maybe_warn_nonstring_arg correctly verifies calls have
enough arguments.

2021-11-16  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/102009
	* gimple-ssa-warn-access.cc (pass_waccess::check_alloc_size_call):
	Punt if any of alloc_size arguments is out of bounds vs. number of
	call arguments.

	* gcc.dg/pr102009.c: New test.

This patch teaches the i386 backend to avoid using BMI2's rorx
instructions when optimizing for size.  The benefits are shown
with the following example:

unsigned int ror1(unsigned int x) { return (x >> 1) | (x << 31); }
unsigned int ror2(unsigned int x) { return (x >> 2) | (x << 30); }
unsigned int rol2(unsigned int x) { return (x >> 30) | (x << 2); }
unsigned int rol1(unsigned int x) { return (x >> 31) | (x << 1); }

which currently with -Os -march=cascadelake generates:

ror1:	rorx    $1, %edi, %eax		// 6 bytes
        ret
ror2:	rorx    $2, %edi, %eax		// 6 bytes
        ret
rol2:	rorx    $30, %edi, %eax		// 6 bytes
        ret
rol1:	rorx    $31, %edi, %eax		// 6 bytes
        ret

but with this patch now generates:

ror1:	movl    %edi, %eax		// 2 bytes
        rorl    %eax			// 2 bytes
        ret
ror2:	movl    %edi, %eax		// 2 bytes
        rorl    $2, %eax		// 3 bytes
        ret
rol2:	movl    %edi, %eax		// 2 bytes
        roll    $2, %eax		// 3 bytes
        ret
rol1:	movl    %edi, %eax		// 2 bytes
        roll    %eax			// 2 bytes
        ret

I've confirmed that this patch is a win on the CSiBE benchmark,
even though rotations are rare, where for example libmspack/test/md5.o
shrinks from 5824 bytes to 5632 bytes.

2021-11-16  Roger Sayle  <roger@nextmovesoftware.com>

gcc/ChangeLog
	* config/i386/i386.md (*bmi2_rorx<mode3>_1): Make conditional
	on !optimize_function_for_size_p.
	(*<any_rotate><mode>3_1): Add preferred_for_size attribute.
	(define_splits): Conditionalize on !optimize_function_for_size_p.
	(*bmi2_rorxsi3_1_zext): Likewise.
	(*<any_rotate>si2_1_zext): Add preferred_for_size attribute.
	(define_splits): Conditionalize on !optimize_function_for_size_p.

gcc/ChangeLog:

	PR ipa/103262
	* ipa-modref.c (merge_call_side_effects): Fix uninitialized
	access.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/modref-dse-5.c: New test.

So while working on PR 103228 (and a few others), I noticed the testcase for PR 94785
was failing. The problem is that the nop_convert moved from being inside the IOR to be
outside of it. I also noticed the patch for PR 103228 was not needed to reproduce the
issue either.
This patch combines the two patterns together for the abs match when using multiplication
and adds a few places where nop_convert are optional.

OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

	PR tree-optimization/103245

gcc/ChangeLog:

	* match.pd: Combine the abs pattern matching using multiplication.
	Adding optional nop_convert too.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/pr103245-1.c: New test.

When failing to transform equivalent, but slighly different cases of
atomic bit test and operations to their canonical forms, return
immediately.

gcc/

	PR middle-end/103268
	* tree-ssa-ccp.c (optimize_atomic_bit_test_and): Add a missing
	return.

gcc/testsuite/

	PR middle-end/103268
	* gcc.dg/pr103268-1.c: New test.
	* gcc.dg/pr103268-2.c: Likewise.

	* MAINTAINERS: Update my address.

With each successive C++ standard the restrictions on the use of the
constexpr keyword for functions get weaker and weaker; it recently occurred
to me that it is heading toward the same fate as the C register keyword,
which was once useful for optimization but became obsolete.  Similarly, it
seems to me that we should be able to just treat inlines as constexpr
functions and not make people add the extra keyword everywhere.

There were a lot of testcase changes needed; many disabling errors about
non-constexpr functions that are now constexpr, and many disabling implicit
constexpr so that the tests can check the same thing as before, whether
that's mangling or whatever.

gcc/c-family/ChangeLog:

	* c.opt: Add -fimplicit-constexpr.
	* c-cppbuiltin.c: Define __cpp_implicit_constexpr.
	* c-opts.c (c_common_post_options): Disable below C++14.

gcc/cp/ChangeLog:

	* cp-tree.h (struct lang_decl_fn): Add implicit_constexpr.
	(decl_implicit_constexpr_p): New.
	* class.c (type_maybe_constexpr_destructor): Use
	TYPE_HAS_TRIVIAL_DESTRUCTOR and maybe_constexpr_fn.
	(finalize_literal_type_property): Simplify.
	* constexpr.c (is_valid_constexpr_fn): Check for dtor.
	(maybe_save_constexpr_fundef): Try to set DECL_DECLARED_CONSTEXPR_P
	on inlines.
	(cxx_eval_call_expression): Use maybe_constexpr_fn.
	(maybe_constexpr_fn): Handle flag_implicit_constexpr.
	(var_in_maybe_constexpr_fn): Use maybe_constexpr_fn.
	(potential_constant_expression_1): Likewise.
	(decl_implicit_constexpr_p): New.
	* decl.c (validate_constexpr_redeclaration): Allow change with
	-fimplicit-constexpr.
	(grok_special_member_properties): Use maybe_constexpr_fn.
	* error.c (dump_function_decl): Don't print 'constexpr'
	if it's implicit.
	* Make-lang.in (check-c++-all): Update.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/to_address/1_neg.cc: Adjust error.
	* testsuite/26_numerics/random/concept.cc: Adjust asserts.

gcc/testsuite/ChangeLog:

	* lib/g++-dg.exp: Handle "impcx".
	* lib/target-supports.exp
	(check_effective_target_implicit_constexpr): New.
	* g++.dg/abi/abi-tag16.C:
	* g++.dg/abi/abi-tag18a.C:
	* g++.dg/abi/guard4.C:
	* g++.dg/abi/lambda-defarg1.C:
	* g++.dg/abi/mangle26.C:
	* g++.dg/cpp0x/constexpr-diag3.C:
	* g++.dg/cpp0x/constexpr-ex1.C:
	* g++.dg/cpp0x/constexpr-ice5.C:
	* g++.dg/cpp0x/constexpr-incomplete2.C:
	* g++.dg/cpp0x/constexpr-memfn1.C:
	* g++.dg/cpp0x/constexpr-neg3.C:
	* g++.dg/cpp0x/constexpr-specialization.C:
	* g++.dg/cpp0x/inh-ctor19.C:
	* g++.dg/cpp0x/inh-ctor30.C:
	* g++.dg/cpp0x/lambda/lambda-mangle3.C:
	* g++.dg/cpp0x/lambda/lambda-mangle5.C:
	* g++.dg/cpp1y/auto-fn12.C:
	* g++.dg/cpp1y/constexpr-loop5.C:
	* g++.dg/cpp1z/constexpr-lambda7.C:
	* g++.dg/cpp2a/constexpr-dtor3.C:
	* g++.dg/cpp2a/constexpr-new13.C:
	* g++.dg/cpp2a/constinit11.C:
	* g++.dg/cpp2a/constinit12.C:
	* g++.dg/cpp2a/constinit14.C:
	* g++.dg/cpp2a/constinit15.C:
	* g++.dg/cpp2a/spaceship-constexpr1.C:
	* g++.dg/cpp2a/spaceship-eq3.C:
	* g++.dg/cpp2a/udlit-class-nttp-neg2.C:
	* g++.dg/debug/dwarf2/auto1.C:
	* g++.dg/debug/dwarf2/cdtor-1.C:
	* g++.dg/debug/dwarf2/lambda1.C:
	* g++.dg/debug/dwarf2/pr54508.C:
	* g++.dg/debug/dwarf2/pubnames-2.C:
	* g++.dg/debug/dwarf2/pubnames-3.C:
	* g++.dg/ext/is_literal_type3.C:
	* g++.dg/ext/visibility/template7.C:
	* g++.dg/gcov/gcov-12.C:
	* g++.dg/gcov/gcov-2.C:
	* g++.dg/ipa/devirt-35.C:
	* g++.dg/ipa/devirt-36.C:
	* g++.dg/ipa/devirt-37.C:
	* g++.dg/ipa/devirt-44.C:
	* g++.dg/ipa/imm-devirt-1.C:
	* g++.dg/lookup/builtin5.C:
	* g++.dg/lto/inline-crossmodule-1_0.C:
	* g++.dg/modules/enum-1_a.C:
	* g++.dg/modules/fn-inline-1_c.C:
	* g++.dg/modules/pmf-1_b.C:
	* g++.dg/modules/used-1_c.C:
	* g++.dg/tls/thread_local11.C:
	* g++.dg/tls/thread_local11a.C:
	* g++.dg/tm/pr46653.C:
	* g++.dg/ubsan/pr70035.C:
	* g++.old-deja/g++.other/delete6.C:
	* g++.dg/modules/pmf-1_a.H:
	Adjust for implicit constexpr.

split_nonconstant_init was doing the wrong thing for both the initialization
and cleanup here; we know the size from the initializer, and we can pass it
along.  This doesn't make the testcase work, since the y destructor is still
broken, but it removes the wrong error for the aggregate initialization.

gcc/cp/ChangeLog:

	* typeck2.c (split_nonconstant_init_1): Handle flexarrays better.

gcc/testsuite/ChangeLog:

	* g++.dg/ext/flexary37.C: Remove expected error.

Use ranges for lengths and object sizes in strncat and snprintf to
determine if they can be transformed into simpler operations.

gcc/ChangeLog:

	* gimple-fold.c (gimple_fold_builtin_strncat): Use ranges to
	determine if it is safe to transform to strcat.
	(gimple_fold_builtin_snprintf): Likewise.

gcc/testsuite/ChangeLog:

	* gcc.dg/fold-stringops-2.c: Define size_t.
	(safe1): Adjust.
	(safe4): New test.
	* gcc.dg/fold-stringops-3.c: New test.

Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>

Instead of comparing LEN and SIZE only if they are constants, use their
ranges to decide if LEN will always be lower than or same as SIZE.

This change ends up putting the stringop-overflow warning line number
against the strcpy implementation, so adjust the warning check to be
line number agnostic.

gcc/ChangeLog:

	* gimple-fold.c (known_lower): New function.
	(gimple_fold_builtin_strncat_chk,
	gimple_fold_builtin_memory_chk, gimple_fold_builtin_stxcpy_chk,
	gimple_fold_builtin_stxncpy_chk,
	gimple_fold_builtin_snprintf_chk,
	gimple_fold_builtin_sprintf_chk): Use it.

gcc/testsuite/ChangeLog:

	* gcc.dg/Wobjsize-1.c: Make warning change line agnostic.
	* gcc.dg/fold-stringops-2.c: New test.

Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>

Avoid going through another folding cycle and use the ignore flag to
directly transform BUILT_IN_STPCPY_CHK to BUILT_IN_STRCPY when set,
likewise for BUILT_IN_STPNCPY_CHK to BUILT_IN_STPNCPY.

Dump the transformation in dump_file so that we can verify in tests that
the direct transformation actually happened.

gcc/ChangeLog:

	* gimple-fold.c (dump_transformation): New function.
	(gimple_fold_builtin_stxcpy_chk,
	gimple_fold_builtin_stxncpy_chk): Use it.  Simplify to
	BUILT_IN_STRNCPY if return value is not used.

gcc/testsuite/ChangeLog:

	* gcc.dg/fold-stringops-1.c: New test.

Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>

Check optab before transforming equivalent, but slighly different cases
of atomic bit test and operations to their canonical forms.

gcc/

	PR middle-end/103184
	* tree-ssa-ccp.c (optimize_atomic_bit_test_and): Check optab
	before transforming equivalent, but slighly different cases to
	their canonical forms.

gcc/testsuite/

	PR middle-end/103184
	* gcc.dg/pr103184-1.c: New test.
	* gcc.dg/pr103184-2.c: Likewise.

For at least one target (Darwin) the platform convention is to
register static destructors (i.e. __attribute__((destructor)))
with __cxa_atexit rather than placing them into a list that is
run by some other mechanism.

This patch provides a target hook that allows a target to opt
into this and handling for the process in ipa_cdtor_merge ().

When the mode is enabled (dtors_from_cxa_atexit is set) we:

 * Generate new CTORs to register static destructors with
   __cxa_atexit and add them to the existing list of CTORs;
   we then process the revised CTORs list.

 * We sort the DTORs into priority and then TU order, this
   means that they are registered in that order with
   __cxa_atexit () and therefore will be run in the reverse
   order.

 * Likewise, CTORs are sorted into priority and then TU order,
   which means that they will run in that order.

This matches the behavior of using init/fini (or
mod_init_func/mod_term_func) sections.

This also fixes a bug where Fortran needs a DTOR to be run to
close IO.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>

	PR fortran/102992

gcc/ChangeLog:

	* config/darwin.h (TARGET_DTORS_FROM_CXA_ATEXIT): New.
	* doc/tm.texi: Regenerated.
	* doc/tm.texi.in: Add TARGET_DTORS_FROM_CXA_ATEXIT hook.
	* ipa.c (cgraph_build_static_cdtor_1): Return the built
	function decl.
	(build_cxa_atexit_decl): New.
	(build_dso_handle_decl): New.
	(build_cxa_dtor_registrations): New.
	(compare_cdtor_tu_order): New.
	(build_cxa_atexit_fns): New.
	(ipa_cdtor_merge): If dtors_from_cxa_atexit is set,
	process the DTORs/CTORs accordingly.
	(pass_ipa_cdtor_merge::gate): Also run if
	dtors_from_cxa_atexit is set.
	* target.def (dtors_from_cxa_atexit): New hook.