Commit e627cda5 ("IBM Z: Store long doubles in vector registers
when possible") introduced HAVE_TF macro which expands to a logical
"or" of HAVE_ constants.  Not all of these constants are available in
GENERATOR_FILE context, so a hack was used: simply expand to true in
this case, because the actual value matters only during compiler
runtime and not during generation.

However, one aspect of this value matters during generation after all:
whether or not it's a constant, which in this case it appears to be.
This results in incorrect values in insn-flags.h and broken bootstrap
for some configurations.

Fix by using a dummy value that is not a constant.

gcc/ChangeLog:

2020-11-10  Ilya Leoshkevich  <iii@linux.ibm.com>

	* config/s390/s390.h (HAVE_TF): Use opaque value when
	GENERATOR_FILE is defined.

For the --enable-clocale=generic configuration, the current code can
fail with a bad_alloc exception. This patch uses the nothrow version of
operator new and reports allocation failures by setting failbit in the
iostate variable.

	* config/locale/generic/c_locale.cc (__set_C_locale()): New function
	to set the "C" locale and return the name of the previous locale.
	(__convert_to_v<float>, __convert_to_v<double>)
	(__convert_to_v<long double>): Use __set_C_locale and set failbit on
	error.

Currently, when a static_assert fails, we only say "static assertion failed".
It would be more useful if we could also print the expression that
evaluated to false; this is especially useful when the condition uses
template parameters.  Consider the motivating example, in which we have
this line:

  static_assert(is_same<X, Y>::value);

if this fails, the user has to play dirty games to get the compiler to
print the template arguments.  With this patch, we say:

  error: static assertion failed
  note: 'is_same<int*, int>::value' evaluates to false

which I think is much better.  However, always printing the condition that
evaluated to 'false' wouldn't be very useful: e.g. noexcept(fn) is
always parsed to true/false, so we would say "'false' evaluates to false"
which doesn't help.  So I wound up only printing the condition when it was
instantiation-dependent, that is, we called finish_static_assert from
tsubst_expr.

Moreover, this patch also improves the diagnostic when the condition
consists of a logical AND.  Say you have something like this:

  static_assert(fn1() && fn2() && fn3() && fn4() && fn5());

where fn4() evaluates to false and the other ones to true.  Highlighting
the whole thing is not that helpful because it won't say which clause
evaluated to false.  With the find_failing_clause tweak in this patch
we emit:

  error: static assertion failed
    6 | static_assert(fn1() && fn2() && fn3() && fn4() && fn5());
      |                                          ~~~^~

so you know right away what's going on.  Unfortunately, when you combine
both things, that is, have an instantiation-dependent expr and && in
a static_assert, we can't yet quite point to the clause that failed.  It
is because when we tsubstitute something like is_same<X, Y>::value, we
generate a VAR_DECL that doesn't have any location.  It would be awesome
if we could wrap it with a location wrapper, but I didn't see anything
obvious.

In passing, I've cleaned up some things:
* use iloc_sentinel when appropriate,
* it's nicer to call contextual_conv_bool instead of the rather verbose
  perform_implicit_conversion_flags,
* no need to check for INTEGER_CST before calling integer_zerop.

gcc/cp/ChangeLog:

	PR c++/97518
	* cp-tree.h (finish_static_assert): Adjust declaration.
	* parser.c (cp_parser_static_assert): Pass false to
	finish_static_assert.
	* pt.c (tsubst_expr): Pass true to finish_static_assert.
	* semantics.c (find_failing_clause_r): New function.
	(find_failing_clause): New function.
	(finish_static_assert): Add a bool parameter.  Use
	iloc_sentinel.  Call contextual_conv_bool instead of
	perform_implicit_conversion_flags.  Don't check for INTEGER_CST before
	calling integer_zerop.  Call find_failing_clause and maybe use its
	location.  Print the original condition or the failing clause if
	SHOW_EXPR_P.

gcc/testsuite/ChangeLog:

	PR c++/97518
	* g++.dg/diagnostic/pr87386.C: Adjust expected output.
	* g++.dg/diagnostic/static_assert1.C: New test.
	* g++.dg/diagnostic/static_assert2.C: New test.

libcc1/ChangeLog:

	PR c++/97518
	* libcp1plugin.cc (plugin_add_static_assert): Pass false to
	finish_static_assert.

A couple of dg-ice tests.

gcc/testsuite/ChangeLog:

	PR c++/52830
	PR c++/88982
	PR c++/90799
	PR c++/87765
	PR c++/89565
	* g++.dg/cpp0x/constexpr-52830.C: New test.
	* g++.dg/cpp0x/vt-88982.C: New test.
	* g++.dg/cpp1z/class-deduction76.C: New test.
	* g++.dg/cpp1z/constexpr-lambda26.C: New test.
	* g++.dg/cpp2a/nontype-class39.C: New test.

This groups all the constructors together, consistent with the synopses
in the C++20 standard.

libstdc++-v3/ChangeLog:

	* include/std/sstream (basic_stringbug, basic_istringstream)
	(basic_ostringstream, basic_stringstream): Reorder C++20
	constructors to be declared next to other constructors.

This adds the new overloads of basic_stringbuf::str, and the
corresponding overloads to basic_istringstream, basic_ostringstream and
basic_stringstream.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver (GLIBCXX_3.4.21): Tighten patterns.
	(GLIBCXX_3.4.29): Export new symbols.
	* include/bits/alloc_traits.h (__allocator_like): New concept.
	* include/std/sstream (basic_stringbuf::swap): Add exception
	specification.
	(basic_stringbuf::str() const): Add ref-qualifier. Use new
	_M_high_mark function.
	(basic_stringbuf::str(const SAlloc&) const): Define new function.
	(basic_stringbuf::str() &&): Likewise.
	(basic_stringbuf::str(const basic_string<C,T,SAlloc>&)):
	Likewise.
	(basic_stringbuf::str(basic_string<C,T,Alloc>&&)): Likewise.
	(basic_stringbuf::view() const): Use _M_high_mark.
	(basic_istringstream::str, basic_ostringstream::str)
	(basic_stringstream::str): Define new overloads.
	* src/c++20/sstream-inst.cc (basic_stringbuf::str)
	(basic_istringstream::str, basic_ostringstream::str)
	(basic_stringstream::str): Explicit instantiation definitions
	for new overloads.
	* testsuite/27_io/basic_istringstream/view/char/1.cc: Add more
	checks.
	* testsuite/27_io/basic_istringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_ostringstream/view/char/1.cc:
	Likewise.
	* testsuite/27_io/basic_ostringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_stringstream/view/char/1.cc:
	Likewise.
	* testsuite/27_io/basic_stringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_istringstream/str/char/2.cc: New test.
	* testsuite/27_io/basic_istringstream/str/wchar_t/2.cc: New test.
	* testsuite/27_io/basic_ostringstream/str/char/3.cc: New test.
	* testsuite/27_io/basic_ostringstream/str/wchar_t/3.cc: New test.
	* testsuite/27_io/basic_stringbuf/str/char/4.cc: New test.
	* testsuite/27_io/basic_stringbuf/str/wchar_t/4.cc: New test.
	* testsuite/27_io/basic_stringstream/str/char/5.cc: New test.
	* testsuite/27_io/basic_stringstream/str/wchar_t/5.cc.cc: New test.

This adds some more null checks to avoid a relational comparison with a
null pointer, similar to 78198b60.

libstdc++-v3/ChangeLog:

	PR libstdc++/97415
	* include/std/sstream (basic_stringbuf::_M_update_egptr)
	(basic_stringbuf::__xfer_bufptrs::__xfer_bufptrs): Check for
	null before comparing pointers.

gcc/

	* cgraph.h (symtab_node::get_section): Constify.
	(symtab_node::set_section): Declare new overload.
	* symtab.c (symtab_node::set_section): Define new overload.
	(symtab_node::copy_visibility_from): Use new overload of
	symtab_node::set_section.
	(symtab_node::resolve_alias): Same.
	* tree.h (set_decl_section_name): Declare new overload.
	* tree.c (set_decl_section_name): Define new overload.
	* tree-emutls.c (get_emutls_init_templ_addr): Same.
	* cgraphclones.c (cgraph_node::create_virtual_clone): Use new
	overload of symtab_node::set_section.
	(cgraph_node::create_version_clone_with_body): Same.
	* trans-mem.c (ipa_tm_create_version): Same.

gcc/c
	* c-decl.c (merge_decls): Use new overload of
	set_decl_section_name.

gcc/cp
	* decl.c (duplicate_decls): Use new overload of
	set_decl_section_name.
	* method.c (use_thunk): Same.
	* optimize.c (maybe_clone_body): Same.
	* coroutines.cc (act_des_fn): Same.

gcc/d
	* decl.cc (finish_thunk): Use new overload of
	set_decl_section_name

My previous cleanups to irange::set moved the early exit when
VARYING.  This caused poly int varyings to be created with
incorrect min/max.

We can just set varying and exit for all poly ints.

gcc/ChangeLog:

	* value-range.cc (irange::set): Early exit for poly ints.

gcc/analyzer/ChangeLog:

	* constraint-manager.cc (constraint_manager::merge): Remove
	unused code.
	* constraint-manager.h: Likewise.
	* program-state.cc (sm_state_map::sm_state_map): Likewise.
	(program_state::program_state): Likewise.
	(test_sm_state_map): Likewise.
	* program-state.h: Likewise.
	* region-model-reachability.cc (reachable_regions::reachable_regions): Likewise.
	* region-model-reachability.h: Likewise.
	* region-model.cc (region_model::handle_unrecognized_call): Likewise.
	(region_model::get_reachable_svalues): Likewise.
	(region_model::can_merge_with_p): Likewise.

gcc/fortran/ChangeLog:

	* dump-parse-tree.c (show_omp_clauses): Handle new reduction enums.
	* gfortran.h (OMP_LIST_REDUCTION_INSCAN, OMP_LIST_REDUCTION_TASK,
	OMP_LIST_IN_REDUCTION, OMP_LIST_TASK_REDUCTION): Add enums.
	* openmp.c (enum omp_mask1): Add OMP_CLAUSE_IN_REDUCTION
	and OMP_CLAUSE_TASK_REDUCTION.
	(gfc_match_omp_clause_reduction): Extend reduction handling;
	moved from ...
	(gfc_match_omp_clauses): ... here. Add calls to it.
	(OMP_TASK_CLAUSES, OMP_TARGET_CLAUSES, OMP_TASKLOOP_CLAUSES):
	Add OMP_CLAUSE_IN_REDUCTION.
	(gfc_match_omp_taskgroup): Add task_reduction matching.
	(resolve_omp_clauses): Update for new reduction clause changes;
	remove removed nonmonotonic-schedule restrictions.
	(gfc_resolve_omp_parallel_blocks): Add new enums to switch.
	* trans-openmp.c (gfc_omp_clause_default_ctor,
	gfc_trans_omp_reduction_list, gfc_trans_omp_clauses,
	gfc_split_omp_clauses): Handle updated reduction clause.

gcc/ChangeLog:

	* gimplify.c (gimplify_scan_omp_clauses, gimplify_omp_loop): Use 'do'
	instead of 'for' in error messages for Fortran.
	* omp-low.c (check_omp_nesting_restrictions): Likewise

gcc/testsuite/ChangeLog:

	* gfortran.dg/gomp/schedule-modifiers-2.f90: Remove some dg-error.
	* gfortran.dg/gomp/reduction4.f90: New test.
	* gfortran.dg/gomp/reduction5.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-1.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-2.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-3.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-4.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-5.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-6.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-7.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-8.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-9.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-10.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-11.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-12.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-13.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-14.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-15.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-16.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-17.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-18.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-19.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-20.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-21.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-22.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-23.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-24.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-25.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-26.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-27.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-28.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-29.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-30.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-31.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-32.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-33.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-34.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-35.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-36.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-37.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-38.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-39.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-40.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-41.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-42.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-43.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-44.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-45.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-46.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-47.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-48.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-49.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-50.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-51.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-52.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-53.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-54.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-55.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-56.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-57.f90: New test.
	* gfortran.dg/gomp/workshare-reduction-58.f90: New test.

Hello,

In a recent review for one of the hwasan patches Richard S. noticed there are
quite a few errors of the form "%<someflag%> is incompatible with
<otherflag%>".
https://gcc.gnu.org/pipermail/gcc-patches/2020-October/556137.html

In order to avoid this creating extra work for translators we would like to
change these error messages to use the form "%qs is incompatible with %qs" and
pass the flag as format arguments.

This patch implements that change.
There is only one change in the output the compiler produces from this patch,
an error message of "-fsanitize=address and -fsanitize=kernel-address are
incompatible with -fsanitize=thread" has been changed to "-fsanitize=thread is
incompatible with -fsanitize=address|kernel-address".
This matches the similar error messages for live patching which use the
messages "-f<something> is incompatible with
-flive-patching=inline-only-static|inline-clone".

Ok for trunk?

gcc/ChangeLog:

	* opts.c (control_options_for_live_patching): Reform 'is incompatible
	with' error messages to use a standard message with differing format
	arguments.
	(finish_options): Likewise.

gcc/testsuite/ChangeLog:

	* c-c++-common/ubsan/sanitize-recover-7.c: Update testcase.

libgcc/

	* libgcc2.c: Fix whitespace issues in most recent change.

libgcc/

	* libgcc2.c (__addvSI3): Use overflow builtins.
	(__addvsi3, __addvDI3 ,__subvSI3, __subvsi3): Likewise.
	(__subvDI3 __mulvSI3, __mulvsi3, __negvSI2): Likewise.
	(__negvsi2, __negvDI2): Likewise.
	(__cmpdi2, __ucmpdi2): Adjust implementation to improve
	generated code.
	* libgcc2.h (__ucmpdi2): Adjust prototype.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/268177

The -Wunused-value warning in both C and C++ FEs (implemented
significantly differently between the two) sees the COMPLEX_EXPRs created
e.g. for complex pre/post increment and many other expressions as useless
and warns about it.

For the C warning implementation, on e.g.
COMPLEX_EXPR < ++REALPART_EXPR <x>, IMAGPART_EXPR <x>>;
would warn even on the IMAGPART_EXPR <x> there alone etc., so what works
is check if we'd warn about both operands of COMPLEX_EXPR and if yes,
warn on the whole COMPLEX_EXPR, otherwise don't warn.

The C++ warning implementation is significantly different and for that one
the only warn if both would be warned about doesn't really work,
we then miss warnings e.g. about
COMPLEX_EXPR <REALPART_EXPR <SAVE_EXPR <x>> + 1.0e+0, IMAGPART_EXPR <SAVE_EXPR <x>>> >>>>>
The patch replaces the warning_at call with call to the c-family
warn_if_unused_value function.

On the testcase which after the initial new tests contains pretty much
everything from gcc.dg/Wunused-value-1.c both approaches seem to work
nicely.

2020-11-10  Jakub Jelinek  <jakub@redhat.com>

	PR c/97748
gcc/c-family/
	* c-common.h (warn_if_unused_value): Add quiet argument defaulted
	to false.
	* c-warn.c (warn_if_unused_value): Likewise.  Pass it down
	recursively and just return true instead of warning if it is true.
	Handle COMPLEX_EXPR.
gcc/cp/
	* cvt.c (convert_to_void): Check (complain & tf_warning) in the outer
	if rather than twice times in the inner one.  Use warn_if_unused_value.
	Formatting fix.
gcc/testsuite/
	* c-c++-common/Wunused-value-1.c: New test.

The following removes an assert that can not easily be adjusted to
cover the additional cases we now handle after the removal of
the same-align DRs vector.

2020-11-10  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/97769
	* tree-vect-data-refs.c (vect_update_misalignment_for_peel):
	Remove assert.

	* gcc.dg/vect/pr97769.c: New testcase.

This deals with blocks elimination added.

2020-11-10  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/97780
	* tree-ssa-pre.c (fini_pre): Deal with added basic blocks
	when freeing PHI_TRANS_TABLE.

2020-11-10  Zhiheng Xie  <xiezhiheng@huawei.com>
	    Nannan Zheng  <zhengnannan@huawei.com>

gcc/ChangeLog:

	* config/aarch64/aarch64-simd-builtins.def: Add proper FLAG
	for tbl/tbx intrinsics.

This patch implements some parts of the target variable mapping changes
specified in OpenMP 5.0, including base-pointer attachment/detachment
behavior for array section list-items in map clauses, and ordering of
map clauses according to map kind.

2020-11-10  Chung-Lin Tang  <cltang@codesourcery.com>

gcc/c-family/ChangeLog:

	* c-common.h (c_omp_adjust_map_clauses): New declaration.
	* c-omp.c (struct map_clause): Helper type for c_omp_adjust_map_clauses.
	(c_omp_adjust_map_clauses): New function.

gcc/c/ChangeLog:

	* c-parser.c (c_parser_omp_target_data): Add use of
	new c_omp_adjust_map_clauses function. Add GOMP_MAP_ATTACH_DETACH as
	handled map clause kind.
	(c_parser_omp_target_enter_data): Likewise.
	(c_parser_omp_target_exit_data): Likewise.
	(c_parser_omp_target): Likewise.
	* c-typeck.c (handle_omp_array_sections): Adjust COMPONENT_REF case to
	use GOMP_MAP_ATTACH_DETACH map kind for C_ORT_OMP region type.
	(c_finish_omp_clauses): Adjust bitmap checks to allow struct decl and
	same struct field access to co-exist on OpenMP construct.

gcc/cp/ChangeLog:

	* parser.c (cp_parser_omp_target_data): Add use of
	new c_omp_adjust_map_clauses function. Add GOMP_MAP_ATTACH_DETACH as
	handled map clause kind.
	(cp_parser_omp_target_enter_data): Likewise.
	(cp_parser_omp_target_exit_data): Likewise.
	(cp_parser_omp_target): Likewise.
	* semantics.c (handle_omp_array_sections): Adjust COMPONENT_REF case to
	use GOMP_MAP_ATTACH_DETACH map kind for C_ORT_OMP region type. Fix
	interaction between reference case and attach/detach.
	(finish_omp_clauses): Adjust bitmap checks to allow struct decl and
	same struct field access to co-exist on OpenMP construct.

gcc/ChangeLog:

	* gimplify.c (is_or_contains_p): New static helper function.
	(omp_target_reorder_clauses): New function.
	(gimplify_scan_omp_clauses): Add use of omp_target_reorder_clauses to
	reorder clause list according to OpenMP 5.0 rules. Add handling of
	GOMP_MAP_ATTACH_DETACH for OpenMP cases.
	* omp-low.c (is_omp_target): New static helper function.
	(scan_sharing_clauses): Add scan phase handling of GOMP_MAP_ATTACH/DETACH
	for OpenMP cases.
	(lower_omp_target): Add lowering handling of GOMP_MAP_ATTACH/DETACH for
	OpenMP cases.

gcc/testsuite/ChangeLog:

	* c-c++-common/gomp/clauses-2.c: Remove dg-error cases now valid.
	* gfortran.dg/gomp/map-2.f90: Likewise.
	* c-c++-common/gomp/map-5.c: New testcase.

libgomp/ChangeLog:

	* libgomp.h (enum gomp_map_vars_kind): Adjust enum values to be bit-flag
	usable.
	* oacc-mem.c (acc_map_data): Adjust gomp_map_vars argument flags to
	'GOMP_MAP_VARS_OPENACC | GOMP_MAP_VARS_ENTER_DATA'.
	(goacc_enter_datum): Likewise for call to gomp_map_vars_async.
	(goacc_enter_data_internal): Likewise.
	* target.c (gomp_map_vars_internal):
	Change checks of GOMP_MAP_VARS_ENTER_DATA to use bit-and (&). Adjust use
	of gomp_attach_pointer for OpenMP cases.
	(gomp_exit_data): Add handling of GOMP_MAP_DETACH.
	(GOMP_target_enter_exit_data): Add handling of GOMP_MAP_ATTACH.
	* testsuite/libgomp.c-c++-common/ptr-attach-1.c: New testcase.

gcc/testsuite/ChangeLog:

2020-11-05  Ilya Leoshkevich  <iii@linux.ibm.com>

	* gcc.target/s390/vector/long-double-callee-abi-scan.c: New test.
	* gcc.target/s390/vector/long-double-caller-abi-run.c: New test.
	* gcc.target/s390/vector/long-double-caller-abi-scan.c: New test.
	* gcc.target/s390/vector/long-double-copysign.c: New test.
	* gcc.target/s390/vector/long-double-fprx2-constant.c: New test.
	* gcc.target/s390/vector/long-double-from-double.c: New test.
	* gcc.target/s390/vector/long-double-from-float.c: New test.
	* gcc.target/s390/vector/long-double-from-i16.c: New test.
	* gcc.target/s390/vector/long-double-from-i32.c: New test.
	* gcc.target/s390/vector/long-double-from-i64.c: New test.
	* gcc.target/s390/vector/long-double-from-i8.c: New test.
	* gcc.target/s390/vector/long-double-from-u16.c: New test.
	* gcc.target/s390/vector/long-double-from-u32.c: New test.
	* gcc.target/s390/vector/long-double-from-u64.c: New test.
	* gcc.target/s390/vector/long-double-from-u8.c: New test.
	* gcc.target/s390/vector/long-double-to-double.c: New test.
	* gcc.target/s390/vector/long-double-to-float.c: New test.
	* gcc.target/s390/vector/long-double-to-i16.c: New test.
	* gcc.target/s390/vector/long-double-to-i32.c: New test.
	* gcc.target/s390/vector/long-double-to-i64.c: New test.
	* gcc.target/s390/vector/long-double-to-i8.c: New test.
	* gcc.target/s390/vector/long-double-to-u16.c: New test.
	* gcc.target/s390/vector/long-double-to-u32.c: New test.
	* gcc.target/s390/vector/long-double-to-u64.c: New test.
	* gcc.target/s390/vector/long-double-to-u8.c: New test.
	* gcc.target/s390/vector/long-double-vec-duplicate.c: New test.
	* gcc.target/s390/vector/long-double-wf.h: New test.
	* gcc.target/s390/vector/long-double-wfaxb.c: New test.
	* gcc.target/s390/vector/long-double-wfcxb-0001.c: New test.
	* gcc.target/s390/vector/long-double-wfcxb-0111.c: New test.
	* gcc.target/s390/vector/long-double-wfcxb-1011.c: New test.
	* gcc.target/s390/vector/long-double-wfcxb-1101.c: New test.
	* gcc.target/s390/vector/long-double-wfdxb.c: New test.
	* gcc.target/s390/vector/long-double-wfixb.c: New test.
	* gcc.target/s390/vector/long-double-wfkxb-0111.c: New test.
	* gcc.target/s390/vector/long-double-wfkxb-1011.c: New test.
	* gcc.target/s390/vector/long-double-wfkxb-1101.c: New test.
	* gcc.target/s390/vector/long-double-wflcxb.c: New test.
	* gcc.target/s390/vector/long-double-wflpxb.c: New test.
	* gcc.target/s390/vector/long-double-wfmaxb-2.c: New test.
	* gcc.target/s390/vector/long-double-wfmaxb-3.c: New test.
	* gcc.target/s390/vector/long-double-wfmaxb-disabled.c: New test.
	* gcc.target/s390/vector/long-double-wfmaxb.c: New test.
	* gcc.target/s390/vector/long-double-wfmsxb-disabled.c: New test.
	* gcc.target/s390/vector/long-double-wfmsxb.c: New test.
	* gcc.target/s390/vector/long-double-wfmxb.c: New test.
	* gcc.target/s390/vector/long-double-wfnmaxb-disabled.c: New test.
	* gcc.target/s390/vector/long-double-wfnmaxb.c: New test.
	* gcc.target/s390/vector/long-double-wfnmsxb-disabled.c: New test.
	* gcc.target/s390/vector/long-double-wfnmsxb.c: New test.
	* gcc.target/s390/vector/long-double-wfsqxb.c: New test.
	* gcc.target/s390/vector/long-double-wfsxb-1.c: New test.
	* gcc.target/s390/vector/long-double-wfsxb.c: New test.
	* gcc.target/s390/vector/long-double-wftcixb-1.c: New test.
	* gcc.target/s390/vector/long-double-wftcixb.c: New test.

On z14+, there are instructions for working with 128-bit floats (long
doubles) in vector registers.  It's beneficial to use them instead of
instructions that operate on floating point register pairs, because it
allows to store 4 times more data in registers at a time, relieving
register pressure.  The raw performance of the new instructions is
almost the same as that of the new ones.

Implement by storing TFmode values in vector registers on z14+.  Since
not all operations are available with the new instructions, keep the
old ones available using the new FPRX2 mode, and convert between it and
TFmode when necessary (this is called "forwarder" expanders below).
Change the existing TFmode expanders to call either new- or old-style
ones depending on whether we are on z14+ or older machines
("dispatcher" expanders).

gcc/ChangeLog:

2020-11-03  Ilya Leoshkevich  <iii@linux.ibm.com>

	* config/s390/s390-modes.def (FPRX2): New mode.
	* config/s390/s390-protos.h (s390_fma_allowed_p): New function.
	* config/s390/s390.c (s390_fma_allowed_p): Likewise.
	(s390_build_signbit_mask): Support 128-bit masks.
	(print_operand): Support printing the second word of a TFmode
	operand as vector register.
	(constant_modes): Add FPRX2mode.
	(s390_class_max_nregs): Return 1 for TFmode on z14+.
	(s390_is_fpr128): New function.
	(s390_is_vr128): Likewise.
	(s390_can_change_mode_class): Use s390_is_fpr128 and
	s390_is_vr128 in order to determine whether mode refers to a FPR
	pair or to a VR.
	(s390_emit_compare): Force TFmode operands into registers on
	z14+.
	* config/s390/s390.h (HAVE_TF): New macro.
	(EXPAND_MOVTF): New macro.
	(EXPAND_TF): Likewise.
	* config/s390/s390.md (PFPO_OP_TYPE_FPRX2): PFPO_OP_TYPE_TF
	alias.
	(ALL): Add FPRX2.
	(FP_ALL): Add FPRX2 for z14+, restrict TFmode to z13-.
	(FP): Likewise.
	(FP_ANYTF): New mode iterator.
	(BFP): Add FPRX2 for z14+, restrict TFmode to z13-.
	(TD_TF): Likewise.
	(xde): Add FPRX2.
	(nBFP): Likewise.
	(nDFP): Likewise.
	(DSF): Likewise.
	(DFDI): Likewise.
	(SFSI): Likewise.
	(DF): Likewise.
	(SF): Likewise.
	(fT0): Likewise.
	(bt): Likewise.
	(_d): Likewise.
	(HALF_TMODE): Likewise.
	(tf_fpr): New mode_attr.
	(type): New mode_attr.
	(*cmp<mode>_ccz_0): Use type instead of mode with fsimp.
	(*cmp<mode>_ccs_0_fastmath): Likewise.
	(*cmptf_ccs): New pattern for wfcxb.
	(*cmptf_ccsfps): New pattern for wfkxb.
	(mov<mode>): Rename to mov<mode><tf_fpr>.
	(signbit<mode>2): Rename to signbit<mode>2<tf_fpr>.
	(isinf<mode>2): Renamed to isinf<mode>2<tf_fpr>.
	(*TDC_insn_<mode>): Use type instead of mode with fsimp.
	(fixuns_trunc<FP:mode><GPR:mode>2): Rename to
	fixuns_trunc<FP:mode><GPR:mode>2<FP:tf_fpr>.
	(fix_trunctf<mode>2): Rename to fix_trunctf<mode>2_fpr.
	(floatdi<mode>2): Rename to floatdi<mode>2<tf_fpr>, use type
	instead of mode with itof.
	(floatsi<mode>2): Rename to floatsi<mode>2<tf_fpr>, use type
	instead of mode with itof.
	(*floatuns<GPR:mode><FP:mode>2): Use type instead of mode for
	itof.
	(floatuns<GPR:mode><FP:mode>2): Rename to
	floatuns<GPR:mode><FP:mode>2<tf_fpr>.
	(trunctf<mode>2): Rename to trunctf<mode>2_fpr, use type instead
	of mode with fsimp.
	(extend<DSF:mode><BFP:mode>2): Rename to
	extend<DSF:mode><BFP:mode>2<BFP:tf_fpr>.
	(<FPINT:fpint_name><BFP:mode>2): Rename to
	<FPINT:fpint_name><BFP:mode>2<BFP:tf_fpr>, use type instead of
	mode with fsimp.
	(rint<BFP:mode>2): Rename to rint<BFP:mode>2<BFP:tf_fpr>, use
	type instead of mode with fsimp.
	(<FPINT:fpint_name><DFP:mode>2): Use type instead of mode for
	fsimp.
	(rint<DFP:mode>2): Likewise.
	(trunc<BFP:mode><DFP_ALL:mode>2): Rename to
	trunc<BFP:mode><DFP_ALL:mode>2<BFP:tf_fpr>.
	(trunc<DFP_ALL:mode><BFP:mode>2): Rename to
	trunc<DFP_ALL:mode><BFP:mode>2<BFP:tf_fpr>.
	(extend<BFP:mode><DFP_ALL:mode>2): Rename to
	extend<BFP:mode><DFP_ALL:mode>2<BFP:tf_fpr>.
	(extend<DFP_ALL:mode><BFP:mode>2): Rename to
	extend<DFP_ALL:mode><BFP:mode>2<BFP:tf_fpr>.
	(add<mode>3): Rename to add<mode>3<tf_fpr>, use type instead of
	mode with fsimp.
	(*add<mode>3_cc): Use type instead of mode with fsimp.
	(*add<mode>3_cconly): Likewise.
	(sub<mode>3): Rename to sub<mode>3<tf_fpr>, use type instead of
	mode with fsimp.
	(*sub<mode>3_cc): Use type instead of mode with fsimp.
	(*sub<mode>3_cconly): Likewise.
	(mul<mode>3): Rename to mul<mode>3<tf_fpr>, use type instead of
	mode with fsimp.
	(fma<mode>4): Restrict using s390_fma_allowed_p.
	(fms<mode>4): Restrict using s390_fma_allowed_p.
	(div<mode>3): Rename to div<mode>3<tf_fpr>, use type instead of
	mode with fdiv.
	(neg<mode>2): Rename to neg<mode>2<tf_fpr>.
	(*neg<mode>2_cc): Use type instead of mode with fsimp.
	(*neg<mode>2_cconly): Likewise.
	(*neg<mode>2_nocc): Likewise.
	(*neg<mode>2): Likeiwse.
	(abs<mode>2): Rename to abs<mode>2<tf_fpr>, use type instead of
	mode with fdiv.
	(*abs<mode>2_cc): Use type instead of mode with fsimp.
	(*abs<mode>2_cconly): Likewise.
	(*abs<mode>2_nocc): Likewise.
	(*abs<mode>2): Likewise.
	(*negabs<mode>2_cc): Likewise.
	(*negabs<mode>2_cconly): Likewise.
	(*negabs<mode>2_nocc): Likewise.
	(*negabs<mode>2): Likewise.
	(sqrt<mode>2): Rename to sqrt<mode>2<tf_fpr>, use type instead
	of mode with fsqrt.
	(cbranch<mode>4): Use FP_ANYTF instead of FP.
	(copysign<mode>3): Rename to copysign<mode>3<tf_fpr>, use type
	instead of mode with fsimp.
	* config/s390/s390.opt (flag_vx_long_double_fma): New
	undocumented option.
	* config/s390/vector.md (V_HW): Add TF for z14+.
	(V_HW2): Likewise.
	(VFT): Likewise.
	(VF_HW): Likewise.
	(V_128): Likewise.
	(tf_vr): New mode_attr.
	(tointvec): Add TF.
	(mov<mode>): Rename to mov<mode><tf_vr>.
	(movetf): New dispatcher.
	(*vec_tf_to_v1tf): Rename to *vec_tf_to_v1tf_fpr, restrict to
	z13-.
	(*vec_tf_to_v1tf_vr): New pattern for z14+.
	(*fprx2_to_tf): Likewise.
	(*mov_tf_to_fprx2_0): Likewise.
	(*mov_tf_to_fprx2_1): Likewise.
	(add<mode>3): Rename to add<mode>3<tf_vr>.
	(addtf3): New dispatcher.
	(sub<mode>3): Rename to sub<mode>3<tf_vr>.
	(subtf3): New dispatcher.
	(mul<mode>3): Rename to mul<mode>3<tf_vr>.
	(multf3): New dispatcher.
	(div<mode>3): Rename to div<mode>3<tf_vr>.
	(divtf3): New dispatcher.
	(sqrt<mode>2): Rename to sqrt<mode>2<tf_vr>.
	(sqrttf2): New dispatcher.
	(fma<mode>4): Restrict using s390_fma_allowed_p.
	(fms<mode>4): Likewise.
	(neg_fma<mode>4): Likewise.
	(neg_fms<mode>4): Likewise.
	(neg<mode>2): Rename to neg<mode>2<tf_vr>.
	(negtf2): New dispatcher.
	(abs<mode>2): Rename to abs<mode>2<tf_vr>.
	(abstf2): New dispatcher.
	(float<mode>tf2_vr): New forwarder.
	(float<mode>tf2): New dispatcher.
	(floatuns<mode>tf2_vr): New forwarder.
	(floatuns<mode>tf2): New dispatcher.
	(fix_trunctf<mode>2_vr): New forwarder.
	(fix_trunctf<mode>2): New dispatcher.
	(fixuns_trunctf<mode>2_vr): New forwarder.
	(fixuns_trunctf<mode>2): New dispatcher.
	(<FPINT:fpint_name><VF_HW:mode>2<VF_HW:tf_vr>): New pattern.
	(<FPINT:fpint_name>tf2): New forwarder.
	(rint<mode>2<tf_vr>): New pattern.
	(rinttf2): New forwarder.
	(*trunctfdf2_vr): New pattern.
	(trunctfdf2_vr): New forwarder.
	(trunctfdf2): New dispatcher.
	(trunctfsf2_vr): New forwarder.
	(trunctfsf2): New dispatcher.
	(extenddftf2_vr): New pattern.
	(extenddftf2): New dispatcher.
	(extendsftf2_vr): New forwarder.
	(extendsftf2): New dispatcher.
	(signbittf2_vr): New forwarder.
	(signbittf2): New dispatchers.
	(isinftf2_vr): New forwarder.
	(isinftf2): New dispatcher.
	* config/s390/vx-builtins.md (*vftci<mode>_cconly): Use VF_HW
	instead of VECF_HW, add missing constraint, add vw support.
	(vftci<mode>_intcconly): Use VF_HW instead of VECF_HW.
	(*vftci<mode>): Rename to vftci<mode>, use VF_HW instead of
	VECF_HW, and vw support.
	(vftci<mode>_intcc): Use VF_HW instead of VECF_HW.

The problem is the bitwise/logical dichotomy for operators and the
transition from the former to the latter for boolean types: if they
are 1-bit, that's straightforward but, if they are larger, then you
need to be careful because you cannot, on the one hand, turn a bitwise
AND into a logical AND and, on the other hand, *not* turn e.g. a
bitwise NOT into a logical NOT if they occur in the same computation,
as the first change will drop the masking that may need to be applied
after the bitwise NOT if it is not also changed.

Given that the ranger turns bitwise AND/OR into logical AND/OR for
booleans,  the patch does the same for bitwise NOT.

gcc/ChangeLog:
	* range-op.cc (operator_logical_not::fold_range): Tidy up.
	(operator_logical_not::op1_range): Call above method.
	(operator_bitwise_not::fold_range): If the type is compatible
	with boolean, call op_logical_not.fold_range.
	(operator_bitwise_not::op1_range): If the type is compatible
	with boolean, call op_logical_not.op1_range.

gcc/testsuite/ChangeLog:
	* gnat.dg/opt88.adb: New test.

This makes get_expr_value_id cheap and completes the
constant value-id simplification by turning the constant_value_expressions
into a direct map instead of a set of pre_exprs for the value.

2020-11-10  Richard Biener  <rguenther@suse.de>

	* tree-ssa-pre.c (pre_expr_d::value_id): Add.
	(constant_value_expressions): Turn into an array of pre_expr.
	(get_or_alloc_expr_for_nary): New function.
	(get_or_alloc_expr_for_reference): Likewise.
	(add_to_value): For constant values only ever add a single
	CONSTANT.
	(get_expr_value_id): Return the new value_id member.
	(vn_valnum_from_value_id): Split out and simplify constant
	value id handling.
	(get_or_alloc_expr_for_constant): Set the value_id member.
	(phi_translate_1): Use get_or_alloc_expr_for_*.
	(compute_avail): Likewise.
	(bitmap_find_leader): Simplify constant value id handling.

These tests should be skipped for arm targets as the instrinsics
are only supported on aarch64.

gcc/testsuite/ChangeLog

2020-11-10  David Candler  <david.candler@arm.com>

	* gcc.target/aarch64/advsimd-intrinsics/vqrshrn_high_n.c: Added skip
	directive.
	* gcc.target/aarch64/advsimd-intrinsics/vqrshrun_high_n.c: Likewise.
	* gcc.target/aarch64/advsimd-intrinsics/vqshrn_high_n.c: Likewise.
	* gcc.target/aarch64/advsimd-intrinsics/vqshrun_high_n.c: Likewise.

gcc/ChangeLog:

	* doc/md.texi (Modifiers): Fix grammar in description of
	earlyclobber constraint modifier.

This patch fixes a thinko in the left-endian push_partial_def path.
As the testcase shows, we have 3 bitfields in the struct,
bitoff  bitsize
0       3
3       28
31      1
the corresponding read is the byte at offset 3 (i.e. 24 bits)
and push_partial_def first handles the full store ({}) to all bits
and then is processing the store to the middle bitfield with value of -1.
Here are the interesting spots:
  pd.offset -= offseti;
this adjusts the pd to { -21, 28 }, the (for little-endian lowest) 21
bits aren't interesting to us, we only care about the upper 7.
          len = native_encode_expr (pd.rhs, this_buffer, bufsize,
                                    MAX (0, -pd.offset) / BITS_PER_UNIT);
native_encode_expr has the offset parameter in bytes and we tell it
that we aren't interested in the first (lowest) two bytes of the number.
It encodes 0xff, 0xff with len == 2 then.
      HOST_WIDE_INT size = pd.size;
      if (pd.offset < 0)
        size -= ROUND_DOWN (-pd.offset, BITS_PER_UNIT);
we get 28 - 16, i.e. 12 - the 16 is subtracting those 2 bytes that we
omitted in native_encode_expr.
          size = MIN (size, (HOST_WIDE_INT) needed_len * BITS_PER_UNIT);
needed_len is how many bytes the read at most needs, and that is 1,
so we get size 8 and copy all 8 bits (i.e. a single byte plus nothing)
from the native_encode_expr filled this_buffer; this incorrectly sets
the byte to 0xff when we want 0x7f.  The above line is correct for the
pd.offset >= 0 case when we don't skip anything, but for the pd.offset < 0
case we need to subtract also the remainder of the bits we aren't interested
in (the code shifts the bytes by that number of bits).
If it weren't for the big-endian path, we could as well do
      if (pd.offset < 0)
        size += pd.offset;
but the big-endian path needs it differently.
With the following patch, amnt is 3 and we subtract from 12 the (8 - 3)
bits and thus get the 7 which is the value we want.

2020-11-10  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/97764
	* tree-ssa-sccvn.c (vn_walk_cb_data::push_partial_def): For
	little-endian stores with negative pd.offset, subtract
	BITS_PER_UNIT - amnt from size if amnt is non-zero.

	* gcc.c-torture/execute/pr97764.c: New test.

gcc/fortran/ChangeLog:

	PR fortran/95847
	* trans-decl.c (gfc_get_symbol_decl): Do not (re)set the location
	of an external procedure.
	(build_entry_thunks, generate_coarray_init, create_main_function,
	gfc_generate_function_code): Use fndecl's location in BIND_EXPR.

gcc/testsuite/ChangeLog:

	PR fortran/95847
	* gfortran.dg/coverage.f90: New test.

This makes sure we reject reduction paths with a live stmt that
is not the last one altering the value.  This is because we do not
handle this in the epilogue unless there's a scalar epilogue loop.

2020-11-09  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/97760
	* tree-vect-loop.c (check_reduction_path): Reject
	reduction paths we do not handle in epilogue generation.

	* gcc.dg/vect/pr97760.c: New testcase.

The problem here is that the representation for VARYING in
-fstrict-enums is different between value_range and irange.

The helper function irange::normalize_min_max() will normalize to
VARYING only if setting the range to the entire domain of the
underlying type.  That is, [0, 0xff..ff], not the domain as defined by
-fstrict-enums.  This causes problems because the multi-range version
of varying_p() will return true if the range is the domain as defined
by -fstrict-enums.  Thus, normalize_min_max and varying_p have
different concepts of varying for multi-ranges.

(BTW, legacy ranges are different because they never look at the
extremes of a range to determine varying-ness.  They only look at the
kind field.)

One approach is to change all the code to limit ranges to the domain
in the -fstrict-enums world, but this won't work because there are
various instances of gimple where the values assigned or compared are
beyond the limits of TYPE_{MIN,MAX}_VALUE.  One example is the
addition of 0xffffffff to represent subtraction.

This patch fixes multi-range varying_p() and set_varying() to agree
with the normalization code, using the extremes of the underlying type,
to represent varying.

gcc/ChangeLog:

	PR tree-optimization/97767
	* value-range.cc (dump_bound_with_infinite_markers): Use
	wi::min_value and wi::max_value.
	(range_tests_strict_enum): New.
	(range_tests): Call range_tests_strict_enum.
	* value-range.h (irange::varying_p): Use wi::min_value
	and wi::max_value.
	(irange::set_varying): Same.
	(irange::normalize_min_max): Remove comment.

gcc/testsuite/ChangeLog:

	* g++.dg/opt/pr97767.C: New test.

gcc/testsuite/ChangeLog

	* gcc.target/i386/keylocker-aesdec128kl.c: Adjust regex patterns.
	* gcc.target/i386/keylocker-aesdec256kl.c: Likewise.
	* gcc.target/i386/keylocker-aesdecwide128kl.c: Likewise.
	* gcc.target/i386/keylocker-aesdecwide256kl.c: Likewise.
	* gcc.target/i386/keylocker-aesenc128kl.c: Likewise.
	* gcc.target/i386/keylocker-aesencwide128kl.c: Likewise.
	* gcc.target/i386/keylocker-aesencwide256kl.c: Likewise.
	* gcc.target/i386/keylocker-encodekey128.c: Likewise.
	* gcc.target/i386/keylocker-encodekey256.c: Likewise.
	* gcc.target/i386/keylocker-aesenc256kl.c: New test.

The original fix was incorrect and results in loss of opportunities.
Revert the original fix. When processing logical chains, do not
follow chains outside of the current basic block.  Use the import
value instead.

	gcc/
	PR tree-optimization/97567
	* gimple-range-gori.cc: (gori_compute::logical_combine): False
	OR operations should intersect the 2 results.
	(gori_compute::compute_logical_operands_in_chain): If def chains
	are outside the current basic block, don't follow them.
	gcc/testsuite/
	* gcc.dg/pr97567-2.c: New.

Following Joseph's change for C to allow duplicate C2x standard attributes
<https://gcc.gnu.org/pipermail/gcc-patches/2020-October/557272.html>,
this patch does a similar thing for C++.  This is DR 1914, to be resolved by
<wg21.link/p2156>, which is not part of the standard yet, but has wide
support so looks like a shoo-in.  The duplications now produce warnings
instead, but only if the attribute wasn't specified via a macro.

gcc/c-family/ChangeLog:

	DR 1914
	* c-common.c (attribute_fallthrough_p): Tweak the warning
	message.

gcc/cp/ChangeLog:

	DR 1914
	* parser.c (cp_parser_check_std_attribute): Return bool.  Add a
	location_t parameter.  Return true if the attribute wasn't duplicated.
	Give a warning instead of an error.  Check more attributes.
	(cp_parser_std_attribute_list): Don't add duplicated attributes to
	the list.  Pass location to cp_parser_check_std_attribute.

gcc/testsuite/ChangeLog:

	DR 1914
	* c-c++-common/attr-fallthrough-2.c: Adjust dg-warning.
	* g++.dg/cpp0x/fallthrough2.C: Likewise.
	* g++.dg/cpp0x/gen-attrs-60.C: Turn dg-error into dg-warning.
	* g++.dg/cpp1y/attr-deprecated-2.C: Likewise.
	* g++.dg/cpp2a/attr-likely2.C: Adjust dg-warning.
	* g++.dg/cpp2a/nodiscard-once.C: Turn dg-error into dg-warning.
	* g++.dg/cpp0x/gen-attrs-72.C: New test.

A large source of cache misses in satisfy_atom is caused by the identity
of an (atom,args) pair within the satisfaction cache being determined by
the entire set of supplied template arguments rather than by the subset
of template arguments that the atom actually depends on.  For instance,
consider

  template <class T> concept range = range_v<T>;
  template <class U> void foo () requires range<U>;
  template <class U, class V> void bar () requires range<U>;

The associated constraints of foo and bar are equivalent: they both
consist of the atom range_v<T> (with mapping T -> U).  But the sat_cache
currently will never reuse a satisfaction value between the two atoms
because foo has one template parameter and bar has two, and the
satisfaction cache conservatively assumes that all template parameters
of the constrained decl are relevant to a satisfaction value of one of
its atoms.

This patch eliminates this assumption and makes the sat_cache instead
care about just the subset of args of an (atom,args) pair that is
relevant to satisfaction.

This patch additionally fixes a seemingly latent bug that was found when
testing against range-v3.  In the testcase concepts-decltype2.C below,
during normalization of f's constraints we end up forming a TARGET_EXPR
whose _SLOT has a DECL_CONTEXT that points to g instead of f because
current_function_decl is not updated before we start normalizing.
This patch fixes this accordingly, and also adds a sanity check to
keep_template_parm to verify each found parameter has a valid index.

With this patch, compile time and memory usage for the cmcstl2 test
test/algorithm/set_symmetric_difference4.cpp drops from 8.5s/1.2GB to
3.5s/0.4GB.

gcc/cp/ChangeLog:

	* constraint.cc (norm_info::norm_info): Initialize orig_decl.
	(norm_info::orig_decl): New data member.
	(normalize_atom): When caching an atom for the first time,
	compute a list of template parameters used in the targets of the
	parameter mapping and store it in the TREE_TYPE of the mapping.
	(get_normalized_constraints_from_decl): Set current_function_decl
	appropriately when normalizing.  As an optimization, don't
	set up a push_nested_class_guard when decl has no constraints.
	(sat_hasher::hash): Use this list to hash only the template
	arguments that are relevant to the atom.
	(satisfy_atom): Use this list to compare only the template
	arguments that are relevant to the atom.
	* pt.c (keep_template_parm): Do a sanity check on the parameter's
	index when flag_checking.

This improves the effectiveness of caching in satisfy_atom by querying
the cache again after we've instantiated the atom's parameter mapping.

Before instantiating its mapping, the identity of an (atom,args) pair
within the satisfaction cache is determined by idiosyncratic things like
the level and index of each template parameter used in targets of the
parameter mapping.  For example, the associated constraints of foo in

  template <class T> concept range = range_v<T>;
  template <class U, class V> void foo () requires range<U> && range<V>;

are range_v<T> (with mapping T -> U) /\ range_v<T> (with mapping T -> V).
If during satisfaction the template arguments supplied for U and V are
the same, then the satisfaction value of these two atoms will be the
same (despite their uninstantiated parameter mappings being different).

But sat_cache doesn't see this because it compares the uninstantiated
parameter mapping and the supplied template arguments of sat_entry's
independently.  So satisy_atom on this latter atom will end up fully
evaluating it instead of reusing the satisfaction value of the former.

But there is a point when the two atoms do look the same to sat_cache,
and that's after instantiating their parameter mappings.  By querying
the cache again at this point, we can avoid substituting the same
instantiated parameter mapping into the same expression a second time
around.

With this patch, compile time and memory usage for the cmcstl2 test
test/algorithm/set_symmetric_diference4.cpp drops from 11s/1.4GB to
8.5s/1.2GB with an --enable-checking=release compiler.

gcc/cp/ChangeLog:

	* cp-tree.h (ATOMIC_CONSTR_MAP_INSTANTIATED_P): Define this flag
	for ATOMIC_CONSTRs.
	* constraint.cc (sat_hasher::hash): Use hash_atomic_constraint
	if the flag is set, otherwise keep using a pointer hash.
	(sat_hasher::equal): Return false if the flag's setting differs
	on two atoms.  Call atomic_constraints_identical_p if the flag
	is set, otherwise keep using a pointer equality test.
	(satisfy_atom): After instantiating the parameter mapping, form
	another ATOMIC_CONSTR using the instantiated mapping and query
	the cache again.  Cache the satisfaction value of both atoms.
	(diagnose_atomic_constraint): Simplify now that the supplied
	atom has an instantiated mapping.

Profiling revealed that sat_hasher::equal accounts for nearly 40% of
compile time in some cmcstl2 tests.

This patch eliminates this bottleneck by caching the ATOMIC_CONSTRs
returned by normalize_atom.  This in turn allows us to replace the
expensive atomic_constraints_identical_p check in sat_hasher::equal
with cheap pointer equality, with no loss in cache hit rate.

With this patch, compile time for the cmcstl2 test
test/algorithm/set_symmetric_difference4.cpp drops from 19s to 11s with
an --enable-checking=release compiler.

gcc/cp/ChangeLog:

	* constraint.cc (atom_cache): Define this deletable hash_table.
	(normalize_atom): Use it to cache ATOMIC_CONSTRs when not
	generating diagnostics.
	(sat_hasher::hash): Use htab_hash_pointer instead of
	hash_atomic_constraint.
	(sat_hasher::equal): Test for pointer equality instead of
	atomic_constraints_identical_p.
	* cp-tree.h (struct atom_hasher): Moved and renamed from ...
	* logic.cc (struct constraint_hash): ... here.
	(clause::m_set): Adjust accordingly.

This patch (naively) extends the PR93907 fix to also apply to variadic
concepts invoked with a type argument pack.  Without this, we ICE on
the below testcase (a variadic version of concepts-using2.C) in the same
manner as we used to on concepts-using2.C before r10-7133.

gcc/cp/ChangeLog:

	PR c++/93907
	* constraint.cc (tsubst_parameter_mapping): Also canonicalize
	the type arguments of a TYPE_ARGUMENT_PACk.

gcc/testsuite/ChangeLog:

	PR c++/93907
	* g++.dg/cpp2a/concepts-using3.C: New test, based off of
	concepts-using2.C.

2020-11-09  Pat Bernardi  <bernardi@adacore.com>

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