Fix a typo in an option name in documentation.

2020-12-20  Jakub Jelinek  <jakub@redhat.com>

	PR other/98400
	* doc/invoke.texi (-mbackchain): Fix a typo - -mmo-backchain ->
	-mno-backchain.

It seems we sometimes use DECL_ARTIFICIAL as choosing between
different code paths.  In order not to make -fdebug-aux-vars
do different things, set DECL_ARTIFICIAL on the variables to
avoid these different code paths (and the corresponding
regressions).

gcc/fortran/ChangeLog:

	* trans.c (create_var_debug_raw): Set DECL_ARTIFICIAL
	on variables.

gcc/testsuite/ChangeLog:

	* gfortran.dg/coarray/send_char_array_1.f90: Correct coarray
	indces.

constant_byte_string now uses a convert_to_bytes function, which doesn't
handle bitfields at all (don't punt on them, just puts them into wrong bits
or bytes).  Furthermore, I don't see a reason why that function should exist
at all, it duplicates native_encode_initializer functionality.
Except that native_encode_initializer punted on flexible array members and 2
tests in the testsuite relied on constant_byte_string handling those.
So, this patch throws away convert_to_bytes, uses native_encode_initializer
instead, but teaches it to handle flexible array members (only in the
non-mask mode with off == -1 for now), furthermore, it adds various corner
case checks that the old implementation was missing (like that STRING_CSTs
use int as length and therefore we shouldn't try to build larger than that
strings, or that native_encode*/native_interpret* APIs require sane
host and target bytes (8-bit on both).

2020-12-19  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/98366
	* fold-const.c (native_encode_initializer): Don't try to
	memset more than total_bytes with off == -1 even if len is large.
	Handle flexible array member initializers if off == -1 and mask is
	NULL.
	* expr.c (convert_to_bytes): Remove.
	(constant_byte_string): Use native_encode_initializer instead of
	convert_to_bytes.  Remove extraneous semicolon.  Punt on various
	corner-cases the APIs don't handle, like sizes > INT_MAX,
	BITS_PER_UNIT != 8, CHAR_BIT != 8.

	* gcc.c-torture/execute/pr98366.c: New test.

Manifest constants in D are represented as CONST_DECLs, which can be
imported from one module to another.  However, when compiling on strict
dwarf2 targets such as *-*-darwin10, importing CONST_DECLs cannot be
represented in debug as D did not exist as an AT_language until dwarf3,
and the only available fallback being DW_LANG_C.  As CONST_DECLs are
treated as enumerators in C, and not outputted individually in
gen_decl_die, this causes an internal error in force_decl_die to occur.

To handle this, similar to other places in dwarf2out, if a CONST_DECL is
seen in dwarf2out_imported_module_or_decl_1, then we simply return early
if the language is not one of Ada, D, or Fortran.

gcc/ChangeLog:

	PR d/98067
	* dwarf2out.c (dwarf2out_imported_module_or_decl_1): Handle
	  CONST_DECL only if is_fortran, is_ada, or is_dlang.

gcc/testsuite/ChangeLog:

	PR d/98067
	* gdc.dg/debug/debug.exp: New test.
	* gdc.dg/debug/dwarf2/dwarf2.exp: New test.
	* gdc.dg/debug/dwarf2/imports/pr98067.d: New test.
	* gdc.dg/debug/dwarf2/langdw2.d: New test.
	* gdc.dg/debug/dwarf2/langdw3.d: New test.
	* gdc.dg/debug/dwarf2/pr98067.d: New test.
	* gdc.dg/debug/trivial.d: New test.

The code I've added recently in find_bswap_or_nop for VECTOR CONSTRUCTORs
is missing punt on an important case - namely empty CONSTRUCTORs, because in that
case the loop will not initialize *n and the code after the loop will then
use the uninitialized structure.

2020-12-19  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/98378
	* gimple-ssa-store-merging.c (find_bswap_or_nop): Punt if CONSTRUCTOR
	has no elements.

Adjust mksysinfo and mkrsysinfo to strip out floating-point max numbers,
as they can trigger this error.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/278476

Adjust testcase to not actually check for an undefined warning since we
don't really care about it, or what line it is issued on.

	gcc/testsuite/
	* gcc.dg/pr97750.c: Remove check for warning.

The attached testcase is miscompiled, because we optimize shared clauses
to firstprivate when task body can't modify the variable even when the
task has depend clause.  That is wrong, because firstprivate means the
variable will be copied immediately when the task is created, while with
depend clause some other task might change it later before the dependencies
are satisfied and the task should observe the value only after the change.

2020-12-18  Jakub Jelinek  <jakub@redhat.com>

	* gimplify.c (struct gimplify_omp_ctx): Add has_depend member.
	(gimplify_scan_omp_clauses): Set it to true if OMP_CLAUSE_DEPEND
	appears on OMP_TASK.
	(gimplify_adjust_omp_clauses_1, gimplify_adjust_omp_clauses): Force
	GOVD_WRITTEN on shared variables if task construct has depend clause.

	* testsuite/libgomp.c/task-6.c: New test.

2020-12-18  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/testsuite/
	* g++.dg/gomp/declare-target-3.C: Only check .offload_var_table
	entries if offloading is enabled.

Either we should write test x$darwin_dynamic_lookup = xyes
or we should make sure the variable is always defined to non-empty string.

2020-12-18  Jakub Jelinek  <jakub@redhat.com>

	PR bootstrap/98380
	* configure.ac: Set darwin_dynamic_lookup=no instead to empty
	string.
	* configure: Regenerated.

Problem comes from using the wrong interface to get the index type for a
COND_REDUCTION. For fixed-length SVE we get a V2SI (a 64-bit Advanced
SIMD vector) instead of a VNx2SI (an SVE vector that stores SI elements
in DI containers).

Credits to Richard Sandiford for pointing out the issue's root cause.

Original PR snippet proposed to reproduce issue was only causing ICE for C++
compiler (see pr98177-1 test cases). I've slightly modified original
snippet in order to reproduce issue on both C and C++ compilers. These
are pr98177-2 test cases.

gcc/ChangeLog:

	PR target/98177
	* tree-vect-loop.c (vect_create_epilog_for_reduction): Use
	get_same_sized_vectype to obtain index type.
	(vectorizable_reduction): Likewise.

gcc/testsuite/ChangeLog:

	PR target/98177
	* g++.target/aarch64/sve/pr98177-1.C: New test.
	* g++.target/aarch64/sve/pr98177-2.C: New test.
	* gcc.target/aarch64/sve/pr98177-1.c: New test.
	* gcc.target/aarch64/sve/pr98177-2.c: New test.

The #ifdef RADIXCHAR directive should be moved one line up so that it
also guards the outer if statement, or else when RADIXCHAR is not
defined the outer if statement will end up nonsensically guarding the
declaration of output_length_upper_bound a few lines below it.

libstdc++-v3/ChangeLog:

	PR libstdc++/98377
	* src/c++17/floating_to_chars.cc (__floating_to_chars_precision):
	Fix mistake.

This should fix a build failure on AArch64 ILP32 due to int32_t mapping
to long int instead of int on this platform, which causes type deduction
to fail in the below call to std::max as reported in the PR.

libstdc++-v3/ChangeLog:

	PR libstdc++/98370
	* src/c++17/floating_to_chars.cc (__floating_to_chars_shortest):
	Provide explicit template arguments to the call to std::max.

This should fix a build failure on Windows which lacks <langinfo.h>,
from which we use nl_langinfo() to obtain the radix character of the
current locale.  (We can't use the more portable localeconv() from
<clocale> to obtain the radix character of the current locale here
because it's not thread-safe, unfortunately.)

This change means that on Windows and other such platforms, we'll just
always assume the radix character used by printf is '.' when formatting
a long double through it.

libstdc++-v3/ChangeLog:

	PR libstdc++/98374
	* src/c++17/floating_to_chars.cc: Guard include of <langinfo.h>
	with __has_include.
	(__floating_to_chars_precision) [!defined(RADIXCHAR)]: Don't
	attempt to obtain the radix character of the current locale,
	just assume it's '.'.

We need to test that FE_TONEAREST is defined before we may use it along
with fegetround/fesetround to adjust the floating-point rounding mode.
This fixes a build failure with older versions of newlib.

libstdc++-v3/ChangeLog:

	* src/c++17/floating_from_chars.cc (from_chars_impl)
	[!defined(FE_TONEAREST)]: Don't adjust the rounding mode.
	* src/c++17/floating_to_chars.cc (__floating_to_chars_precision):
	Likewise.

2020-12-18  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/
	* langhooks-def.h (lhd_get_decl_init): New.
	(lhd_finish_decl_inits): New.
	(LANG_HOOKS_GET_DECL_INIT): New.
	(LANG_HOOKS_OMP_FINISH_DECL_INITS): New.
	(LANG_HOOKS_DECLS): Add LANG_HOOKS_GET_DECL_INIT and
	LANG_HOOKS_OMP_FINISH_DECL_INITS.
	* langhooks.c (lhd_omp_get_decl_init): New.
	(lhd_omp_finish_decl_inits): New.
	* langhooks.h (struct lang_hooks_for_decls): Add omp_get_decl_init
	and omp_finish_decl_inits.
	* omp-offload.c (omp_discover_declare_target_var_r): Use
	get_decl_init langhook in place of DECL_INITIAL.  Call
	omp_finish_decl_inits langhook at end of function.

	gcc/cp/
	* cp-lang.c (cxx_get_decl_init): New.
	(cxx_omp_finish_decl_inits): New.
	(LANG_HOOKS_GET_DECL_INIT): New.
	(LANG_HOOKS_OMP_FINISH_DECL_INITS): New.
	* cp-tree.h (dynamic_initializers): New.
	* decl.c (dynamic_initializers): New.
	* decl2.c (c_parse_final_cleanups): Add initializer entries
	from vars to dynamic_initializers.

	gcc/testsuite/
	* g++.dg/gomp/declare-target-3.C: New.

When compiling with -msve-vector-bits=128, aarch64_preferred_simd_mode
would pass the same vector width to aarch64_simd_container_mode for
both SVE and Advanced SIMD, and so Advanced SIMD would always “win”.
This patch instead makes it choose directly between SVE and Advanced
SIMD modes, so that aarch64-autovec-preference==2 and
aarch64-autovec-preference==4 work for this configuration.

(aarch64-autovec-preference shouldn't affect aarch64_simd_container_mode
because that would have an ABI impact for things like GNU vectors.)

gcc/
	* config/aarch64/aarch64.c (aarch64_preferred_simd_mode): Use
	aarch64_full_sve_mode and aarch64_vq_mode directly, instead of
	going via aarch64_simd_container_mode.

Seems when I split the patch I forgot to include these into the rot iterator..
The uncommitted hunks were still in my local tree so didn't notice.

gcc/ChangeLog:

	* config/arm/iterators.md (rot): Add UNSPEC_VCMUL, UNSPEC_VCMUL90,
	UNSPEC_VCMUL180, UNSPEC_VCMUL270.

Windows has unique and special needs for open(2).

	gcc/cp/
	* module.cc (O_CLOEXEC, O_BINARY): Add window's support.
	(elf_in::defrost, module_state::do_import)
	(finish_module_processing): Use O_BINARY.

2020-12-18  Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran
	PR fortran/83118
	PR fortran/96012
	* resolve.c (resolve_ordinary_assign): Generate a vtable if
	necessary for scalar non-polymorphic rhs's to unlimited lhs's.
	* trans-array.c (get_class_info_from_ss): New function.
	(gfc_trans_allocate_array_storage): Defer obtaining class
	element type until all sources of class exprs are tried. Use
	class API rather than TREE_OPERAND. Look for class expressions
	in ss->info by calling get_class_info_from_ss. After, obtain
	the element size for class descriptors. Where the element type
	is unknown, cast the data as character(len=size) to overcome
	unlimited polymorphic problems.
	(gfc_conv_ss_descriptor): Do not fix class variable refs.
	(build_class_array_ref, structure_alloc_comps): Replace code
	replicating the new function gfc_resize_class_size_with_len.
	(gfc_alloc_allocatable_for_assignment): Obtain element size
	for lhs in cases of deferred characters and class enitities.
	Move code for the element size of rhs to start of block. Clean
	up extraction of class parameters throughout this function.
	After the shape check test whether or not the lhs and rhs
	element sizes are the same. Use earlier evaluation of
	'cond_null'. Reallocation of lhs only to happen if size changes
	or element size changes.
	* trans-expr.c (gfc_resize_class_size_with_len): New function.
	(gfc_get_class_from_expr): If a constant expression is
	encountered, return NULL_TREE;
	(trans_scalar_class_assign): New function.
	(gfc_conv_procedure_call): Ensure the vtable is present for
	passing a non-class actual to an unlimited formal.
	(trans_class_vptr_len_assignment): For expressions of type
	BT_CLASS, extract the class expression if necessary. Use a
	statement block outside the loop body. Ensure that 'rhs' is
	of the correct type. Obtain rhs vptr in all circumstances.
	(gfc_trans_scalar_assign): Call trans_scalar_class_assign to
	make maximum use of the vptr copy in place of assignment.
	(trans_class_assignment): Actually do reallocation if needed.
	(gfc_trans_assignment_1): Simplify some of the logic with
	'realloc_flag'. Set 'vptr_copy' for all array assignments to
	unlimited polymorphic lhs.
	* trans.c (gfc_build_array_ref): Call gfc_resize_class_size_
	with_len to correct span for unlimited polymorphic decls.
	* trans.h : Add prototype for gfc_resize_class_size_with_len.

gcc/testsuite/
	PR fortran/83118
	PR fortran/96012
	* gfortran.dg/dependency_60.f90: New test.
	* gfortran.dg/class_allocate_25.f90: New test.
	* gfortran.dg/class_assign_4.f90: New test.
	* gfortran.dg/unlimited_polymorphic_32.f03: New test.

Seems the ggc_remove ppc_nx 3 operand member relies on the hash tables to
contain pointers in the first element, which is not the case for
source_location_table* hash table, which has location_t and unsigned as
first two members and pointer somewhere else.
I've tried to change:
   static void
   pch_nx (T &p, gt_pointer_operator op, void *cookie)
   {
-    op (&p, cookie);
+    extern void gt_pch_nx (T *, gt_pointer_operator, void *);
+    gt_pch_nx (&p, op, cookie);
   }
in hash-traits.h, but that failed miserably.
So, this patch instead overrides the two pch_nx overloads (only the second
one is needed, the former one is identical to the ggc_remove one) but I need
to override both.

2020-12-18  Jakub Jelinek  <jakub@redhat.com>

	PR c++/98343
	* cp-gimplify.c (source_location_table_entry_hash::pch_nx): Override
	static member functions from ggc_remove.

	* g++.dg/pch/pr98343.C: New test.
	* g++.dg/pch/pr98343.Hs: New file.

Update the Go testsuite driver to handle +build lines as is done in
the upstream repo, and update some tests to the upstream repo copy
using +build lines with "gc" and "!gccgo" as appropriate.

	* go.test/go-test.exp (go-set-goos): New procedure.
	(go-gc-match): New procedure.
	(go-gc-tests): Call go-set-goos.  Use go-gc-match to handle +build
	lines.  Look for +build lines beyond first line of file.

The testcases are imported almost verbatim, with the only change being
to the -double_nan and -float_nan testcases.  We expect these values to
be formatted as "-nan" instead of "-nan(ind)".

libstdc++-v3/ChangeLog:

	* testsuite/20_util/to_chars/double.cc: New test, consisting of
	testcases imported from the MSVC STL testsuite.
	* testsuite/20_util/to_chars/float.cc: Likewise.

This implements the floating-point std::to_chars overloads for float,
double and long double.  We use the Ryu library to compute the shortest
round-trippable fixed and scientific forms for float, double and long
double.  We also use Ryu for performing explicit-precision fixed and
scientific formatting for float and double. For explicit-precision
formatting for long double we fall back to using printf.  Hexadecimal
formatting for float, double and long double is implemented from
scratch.

The supported long double binary formats are binary64, binary80 (x86
80-bit extended precision), binary128 and ibm128.

Much of the complexity of the implementation is in computing the exact
output length before handing it off to Ryu (which doesn't do bounds
checking).  In some cases it's hard to compute the output length
beforehand, so in these cases we instead compute an upper bound on the
output length and use a sufficiently-sized intermediate buffer only if
necessary.

Another source of complexity is in the general-with-precision formatting
mode, where we need to do zero-trimming of the string returned by Ryu,
and where we also take care to avoid having to format the number through
Ryu a second time when the general formatting mode resolves to fixed
(which we determine by doing a scientific formatting first and
inspecting the scientific exponent).  We avoid going through Ryu twice
by instead transforming the scientific form to the corresponding fixed
form via in-place string manipulation.

This implementation is non-conforming in a couple of ways:

1. For the shortest hexadecimal formatting, we currently follow the
   Microsoft implementation's decision to be consistent with the
   output of printf's '%a' specifier at the expense of sometimes not
   printing the shortest representation.  For example, the shortest hex
   form for the number 1.08p+0 is 2.1p-1, but we output the former
   instead of the latter, as does printf.

2. The Ryu routine generic_binary_to_decimal that we use for performing
   shortest formatting for large floating point types is implemented
   using the __int128 type, but some targets with a large long double
   type lack __int128 (e.g. i686), so we can't perform shortest
   formatting of long double on such targets through Ryu.  As a
   temporary stopgap this patch makes the long double to_chars overloads
   just dispatch to the double overloads on these targets, which means
   we lose precision in the output.  (We could potentially fix this by
   writing a specialized version of Ryu's generic_binary_to_decimal
   routine that uses uint64_t instead of __int128.)  [Though I wonder if
   there's a better way to work around the lack of __int128 on i686
   specifically?]

3. Our shortest formatting for __ibm128 doesn't guarantee the round-trip
   property if the difference between the high- and low-order exponent
   is large.  This is because we treat __ibm128 as if it has a
   contiguous 105-bit mantissa by merging the mantissas of the high-
   and low-order parts (using code extracted from glibc), so we
   potentially lose precision from the low-order part.  This seems to be
   consistent with how glibc printf formats __ibm128.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver: Add new exports.
	* include/std/charconv (to_chars): Declare the floating-point
	overloads for float, double and long double.
	* src/c++17/Makefile.am (sources): Add floating_to_chars.cc.
	* src/c++17/Makefile.in: Regenerate.
	* src/c++17/floating_to_chars.cc: New file.
	(to_chars): Define for float, double and long double.
	* testsuite/20_util/to_chars/long_double.cc: New test.

This performs the following modifications to our local copy of Ryu in
order to make it more readily usable for our std::to_chars
implementation:

  * Remove all #includes
  * Remove copy_special_str routines
  * Adjust the exponent formatting to match printf
  * Remove some functions we're not going to use
  * Add an out-parameter to d2exp_buffered_n for the scientific exponent
  * Store the sign bit inside struct floating_decimal_[32|64]
  * Rename [df]2s_buffered_n and change their return type
  * Make generic_binary_to_decimal take the bit representation in parts

libstdc++-v3/ChangeLog:

	* src/c++17/ryu/common.h, src/c++17/ryu/d2fixed.c,
	src/c++17/ryu/d2fixed_full_table.h, src/c++17/ryu/d2s.c,
	src/c++17/ryu/d2s_intrinsics.h, src/c++17/ryu/f2s.c,
	src/c++17/ryu/f2s_intrinsics.h, src/c++17/ryu/generic_128.c:
	Apply local modifications.

This imports the source files from the Ryu library that define
d2s_buffered_n, f2s_buffered_n, d2fixed_buffered_n, d2exp_buffered_n and
generic_binary_to_decimal, which we're going to use as the base of our
std::to_chars implementation.

libstdc++-v3/ChangeLog:

	* src/c++17/ryu/MERGE: New file.
	* src/c++17/ryu/common.h, src/c++17/ryu/d2fixed.c,
	src/c++17/ryu/d2fixed_full_table.h, src/c++17/ryu/d2s.c,
	src/c++17/ryu/d2s_full_table.h, src/c++17/ryu/d2s_intrinsics.h,
	src/c++17/ryu/digit_table.h, src/c++17/ryu/f2s.c,
	src/c++17/ryu/f2s_intrinsics.h, src/c++17/ryu/generic_128.c,
	src/c++17/ryu/generic_128.h, src/c++17/ryu/ryu_generic_128.h:
	Import these files from the Ryu library.

This makes tracking of potentially unstable satisfaction results more
precise by recording the specific types for which completion failed
during satisfaction.  We now recompute a satisfaction result only if one
of these types has been completed since the last time we computed the
satisfaction result.  Thus the number of times that we recompute a
satisfaction result is now bounded by the number of such incomplete
types, rather than being effectively unbounded.  This allows us to
remove the invalid assumption in note_ftc_for_satisfaction that was
added to avoid a compile time performance regression in cmcstl2 due to
repeated recomputation of a satisfaction result that depended on
completion of a permanently incomplete class template specialization.

In order to continue to detect the instability in concepts-complete3.C,
we also need to explicitly keep track of return type deduction failure
alongside type completion failure.  So this patch also adds a call to
note_ftc_for_satisfaction in require_deduced_type.

gcc/cp/ChangeLog:

	* constraint.cc (satisfying_constraint): Move up definition
	and give it bool type.
	(failed_type_completion_count): Replace with ...
	(failed_type_completions): ... this.
	(note_failed_type_completion_for_satisfaction): Append the
	supplied argument to failed_type_completions.
	(some_type_complete_p): Define.
	(sat_entry::maybe_unstable): Replace with ...
	(sat_entry::ftc_begin, sat_entry::ftc_end): ... these.
	(satisfaction_cache::ftc_count): Replace with ...
	(satisfaction_cache::ftc_begin): ... this.
	(satisfaction_cache::satisfaction_cache): Adjust accordingly.
	(satisfaction_cache::get): Adjust accordingly, using
	some_type_complete_p.
	(satisfaction_cache::save): Adjust accordingly.
	(satisfying_constraint_p): Remove unused function.
	(satisfy_constraint): Set satisfying_constraint.
	(satisfy_declaration_constraints): Likewise.
	* decl.c (require_deduced_type): Call
	note_failed_type_completion_for_satisfaction.

This patch further extends the satisfaction_cache class to diagnose
self-recursive satisfaction.

gcc/cp/ChangeLog:

	* constraint.cc (sat_entry::evaluating): New member.
	(satisfaction_cache::get): If entry->evaluating, diagnose
	self-recursive satisfaction.  Otherwise, set entry->evaluating
	if we're not reusing a cached satisfaction result.
	(satisfaction_cache::save): Clear entry->evaluating.
	(satisfy_atom): Set up diagnosing_failed_constraint before the
	first call to get().

gcc/testsuite/ChangeLog:

	PR c++/96840
	* g++.dg/cpp2a/concepts-pr88395.C: Adjust to expect the
	self-recursive satisfaction to get directly diagnosed.
	* g++.dg/cpp2a/concepts-recursive-sat2.C: Likewise.
	* g++.dg/cpp2a/concepts-recursive-sat4.C: New test.

This implements lightweight heuristical detection and diagnosing of
satisfaction whose result changes at different points in the program,
which renders the program ill-formed NDR as of P2104.  We've recently
started to more aggressively cache satisfaction results, and so the goal
with this patch is to make this caching behavior more transparent to
the user.

A satisfaction result is flagged as "potentially unstable" (at the atom
granularity) if during its computation, some type completion failure
occurs.  This is detected by making complete_type_or_maybe_complain
increment a counter upon failure and comparing the value of the counter
before and after satisfaction.  (We don't instrument complete_type
directly because it's used "opportunistically" in many spots where type
completion failure doesn't necessary lead to substitution failure.)

Such flagged satisfaction results are always recomputed from scratch,
even when performing satisfaction quietly.  When saving a satisfaction
result, we now compare the computed result with the cached result, and
if they differ, proceed with diagnosing the instability.

Most of the implementation is confined to the satisfaction_cache class,
which has been completely rewritten.

gcc/cp/ChangeLog:

	* constraint.cc (failed_type_completion_count): New.
	(note_failed_type_completion_for_satisfaction): New.
	(sat_entry::constr): Rename to ...
	(sat_entry::atom): ... this.
	(sat_entry::location): New member.
	(sat_entry::maybe_unstable): New member.
	(sat_entry::diagnose_instability): New member.
	(struct sat_hasher): Adjust after the above renaming.
	(get_satisfaction, save_satisfaction): Remove.
	(satisfaction_cache): Rewrite completely.
	(satisfy_atom): When instantiation of the parameter mapping
	fails, set diagnose_instability.  Propagate location from
	inst_cache.entry to cache.entry if the secondary lookup
	succeeded.
	(satisfy_declaration_constraints): When
	failed_type_completion_count differs before and after
	satisfaction, then don't cache the satisfaction result.
	* cp-tree.h (note_failed_type_completion_for_satisfaction):
	Declare.
	* pt.c (tsubst) <case TYPENAME_TYPE>: Use
	complete_type_or_maybe_complain instead of open-coding it.
	* typeck.c (complete_type_or_maybe_complain): Call
	note_failed_type_completion_for_satisfaction when type
	completion fails.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp2a/concepts-complete1.C: New test.
	* g++.dg/cpp2a/concepts-complete2.C: New test.
	* g++.dg/cpp2a/concepts-complete3.C: New test.

This patch adds support for -mcpu=cortex-a78c command line option.
For more information about this processor, see [0]:

[0] https://developer.arm.com/ip-products/processors/cortex-a/cortex-a78c

gcc/ChangeLog:

	* config/arm/arm-cpus.in: Add Cortex-A78C core.
	* config/arm/arm-tables.opt: Regenerate.
	* config/arm/arm-tune.md: Regenerate.
	* doc/invoke.texi: Update docs.

I'd used reg_raw_mode[regno] for general registers, even though
the array is only valid for hard registers.  This patch uses
regno_reg_rtx instead.

gcc/
	PR rtl-optimization/98347
	* rtl-ssa/access-utils.h (full_register): Use regno_reg_rtx
	instead of reg_raw_mode.

commit 64432b68
Author: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date:   Thu Dec 17 18:02:37 2020 +0000

    vect, aarch64: Extend SVE vs Advanced SIMD costing decisions in vect_better_loop_vinfo_p

changed default_estimated_poly_value to

HOST_WIDE_INT
default_estimated_poly_value (poly_int64 x, poly_value_estimate_kind)
{
  return x.coeffs[0];
}

Update default_estimated_poly_value prototype in targhooks.h to match it.

	* targhooks.h (default_estimated_poly_value): Updated.

It seems users are confused by the lack of standard library header
units.

	gcc/
	* doc/invoke.texi (C++ Modules): Document lack of std
	library header units.

While experimenting with some backend costs for Advanced SIMD and SVE I
hit many cases where GCC would pick SVE for VLA auto-vectorisation even when
the backend very clearly presented cheaper costs for Advanced SIMD.
For a simple float addition loop the SVE costs were:

vec.c:9:21: note:  Cost model analysis:
  Vector inside of loop cost: 28
  Vector prologue cost: 2
  Vector epilogue cost: 0
  Scalar iteration cost: 10
  Scalar outside cost: 0
  Vector outside cost: 2
  prologue iterations: 0
  epilogue iterations: 0
  Minimum number of vector iterations: 1
  Calculated minimum iters for profitability: 4

and for Advanced SIMD (Neon) they're:

vec.c:9:21: note:  Cost model analysis:
  Vector inside of loop cost: 11
  Vector prologue cost: 0
  Vector epilogue cost: 0
  Scalar iteration cost: 10
  Scalar outside cost: 0
  Vector outside cost: 0
  prologue iterations: 0
  epilogue iterations: 0
  Calculated minimum iters for profitability: 0
vec.c:9:21: note:    Runtime profitability threshold = 4

yet the SVE one was always picked. With guidance from Richard this seems
to be due to the vinfo comparisons in vect_better_loop_vinfo_p, in
particular the part with the big comment explaining the
estimated_rel_new * 2 <= estimated_rel_old heuristic.

This patch extends the comparisons by introducing a three-way estimate
kind for poly_int values that the backend can distinguish.
This allows vect_better_loop_vinfo_p to ask for minimum, maximum and
likely estimates and pick Advanced SIMD overs SVE when it is clearly cheaper.

gcc/
	* target.h (enum poly_value_estimate_kind): Define.
	(estimated_poly_value): Take an estimate kind argument.
	* target.def (estimated_poly_value): Update definition for the
	above.
	* doc/tm.texi: Regenerate.
	* targhooks.c (estimated_poly_value): Update prototype.
	* tree-vect-loop.c (vect_better_loop_vinfo_p): Use min, max and
	likely estimates of VF to pick between vinfos.
	* config/aarch64/aarch64.c (aarch64_cmp_autovec_modes): Use
	estimated_poly_value instead of aarch64_estimated_poly_value.
	(aarch64_estimated_poly_value): Take a kind argument and handle
	it.

Clang didn't like sizeot (uintset::value) in a templated context.  Not sure
where the problem lies -- ambiguous std, gcc erroneous accept or clang erroneous
reject.  Anyway, this avoids that construct.

	PR c++/98340
	gcc/cp/
	* module.cc (uintset<T>::hash::add): Use uintset (0u).MEMBER,
	rather than uintset::MEMBER.

While this doesn't fix 98324, it was an omission.  Cribbed code from
libcpp to build libcody as PIC.

	libcody/
	* configure.ac: Add --enable-host-shared.
	* Makefile.in: Add FLAGPIC.
	* configure: Regenerated.