Zfh and Zfhmin are extensions for IEEE half precision, both are ratified
in Jan. 2022[1]:

- Zfh has full set of operation like F or D for single or double precision.
- Zfhmin has only provide minimal support for half precision operation,
  like conversion, load, store and move instructions.

[1] https://github.com/riscv/riscv-isa-manual/commit/b35a54079e0da11740ce5b1e6db999d1d5172768

gcc/ChangeLog:

	* common/config/riscv/riscv-common.cc (riscv_implied_info): Add
	zfh and zfhmin.
	(riscv_ext_version_table): Ditto.
	(riscv_ext_flag_table): Ditto.
	* config/riscv/riscv-opts.h (MASK_ZFHMIN): New.
	(MASK_ZFH): Ditto.
	(TARGET_ZFHMIN): Ditto.
	(TARGET_ZFH): Ditto.
	* config/riscv/riscv.cc (riscv_output_move): Handle HFmode move
	for zfh and zfhmin.
	(riscv_emit_float_compare): Handle HFmode.
	* config/riscv/riscv.md (ANYF): Add HF.
	(SOFTF): Add HF.
	(load): Ditto.
	(store): Ditto.
	(truncsfhf2): New.
	(truncdfhf2): Ditto.
	(extendhfsf2): Ditto.
	(extendhfdf2): Ditto.
	(*movhf_hardfloat): Ditto.
	(*movhf_softfloat): Make sure not ZFHMIN.
	* config/riscv/riscv.opt (riscv_zf_subext): New.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/_Float16-zfh-1.c: New.
	* gcc.target/riscv/_Float16-zfh-2.c: Ditto.
	* gcc.target/riscv/_Float16-zfh-3.c: Ditto.
	* gcc.target/riscv/_Float16-zfhmin-1.c: Ditto.
	* gcc.target/riscv/_Float16-zfhmin-2.c: Ditto.
	* gcc.target/riscv/_Float16-zfhmin-3.c: Ditto.
	* gcc.target/riscv/arch-16.c: Ditto.
	* gcc.target/riscv/arch-17.c: Ditto.
	* gcc.target/riscv/predef-21.c: Ditto.
	* gcc.target/riscv/predef-22.c: Ditto.

RISC-V decide use _Float16 as primary IEEE half precision type, and this
already become part of psABI, this patch has added folloing support for
_Float16:

- Soft-float support for _Float16.
- Make sure _Float16 available on C++ mode.
- Name mangling for _Float16 on C++ mode.

gcc/ChangeLog

	* config/riscv/riscv-builtins.cc: include stringpool.h
	(riscv_float16_type_node): New.
	(riscv_init_builtin_types): Ditto.
	(riscv_init_builtins): Call riscv_init_builtin_types.
	* config/riscv/riscv-modes.def (HF): New.
	* gcc/config/riscv/riscv.cc (riscv_output_move): Handle HFmode.
	(riscv_mangle_type): New.
	(riscv_scalar_mode_supported_p): Ditto.
	(riscv_libgcc_floating_mode_supported_p): Ditto.
	(riscv_excess_precision): Ditto.
	(riscv_floatn_mode): Ditto.
	(riscv_init_libfuncs): Ditto.
	(TARGET_MANGLE_TYPE): Ditto.
	(TARGET_SCALAR_MODE_SUPPORTED_P): Ditto.
	(TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P): Ditto.
	(TARGET_INIT_LIBFUNCS): Ditto.
	(TARGET_C_EXCESS_PRECISION): Ditto.
	(TARGET_FLOATN_MODE): Ditto.
	* gcc/config/riscv/riscv.md (mode): Add HF.
	(softload): Add HF.
	(softstore): Ditto.
	(fmt): Ditto.
	(UNITMODE): Ditto.
	(movhf): New.
	(*movhf_softfloat): New.

libgcc/ChangeLog:

	* config/riscv/sfp-machine.h (_FP_NANFRAC_H): New.
	(_FP_NANFRAC_H): Ditto.
	(_FP_NANSIGN_H): Ditto.
	* config/riscv/t-softfp32 (softfp_extensions): Add HF related
	routines.
	(softfp_truncations): Ditto.
	(softfp_extras): Ditto.
	* config/riscv/t-softfp64 (softfp_extras): Add HF related routines.

gcc/testsuite/ChangeLog:

	* gcc/testsuite/g++.target/riscv/_Float16.C: New.
	* gcc/testsuite/gcc.target/riscv/_Float16-soft-1.c: Ditto.
	* gcc/testsuite/gcc.target/riscv/_Float16-soft-2.c: Ditto.
	* gcc/testsuite/gcc.target/riscv/_Float16-soft-3.c: Ditto.
	* gcc/testsuite/gcc.target/riscv/_Float16-soft-4.c: Ditto.
	* gcc/testsuite/gcc.target/riscv/_Float16.c: Ditto.

Add more IEEE half conversion routines:

  - Convert 32-bit/64-bit integer to IEEE half.
  - Convert IEEE half to 32-bit/64-bit integer.

These are needed by RISC-V _Float16 support.

libgcc/ChangeLog:

	* soft-fp/fixhfdi.c: New.
	* soft-fp/fixhfsi.c: Ditto.
	* soft-fp/fixunshfdi.c: Ditto.
	* soft-fp/fixunshfsi.c: Ditto.
	* soft-fp/floatdihf.c: Ditto.
	* soft-fp/floatsihf.c: Ditto.
	* soft-fp/floatundihf.c: Ditto.
	* soft-fp/floatunsihf.c: Ditto.

The following reverts the just added assert that virtual SSA does not
need updating.  It instead goes for a select whitelist of transforms
known to be prone to difficulties with virtual SSA update.

	* tree-vect-loop-manip.cc (vect_do_peeling): Revert assert
	and update virtual SSA form again.  Assert we do so for
	a known set of transforms only.
	* tree-vectorizer.h (vec_info::any_known_not_updated_vssa): New.
	* tree-vect-stmts.cc (vectorizable_load): When vectorizing
	using load-lanes allow virtual SSA update.

Handle reverse_offload, unified_address, and unified_shared_memory
requirements in libgomp by saving them alongside the offload table.
When the device lto1 runs, it extracts the data for mkoffload. The
latter than passes the value on to GOMP_offload_register_ver.

lto1 (either the host one, with -flto [+ ENABLE_OFFLOADING], or in the
offload-device lto1) also does the the consistency check is done,
erroring out when the 'omp requires' clause use is inconsistent.

For all in-principle supported devices, if a requirement cannot be fulfilled,
the device is excluded from the (supported) devices list. Currently, none of
those requirements are marked as supported for any of the non-host devices.

gcc/c/ChangeLog:

	* c-parser.cc (c_parser_omp_target_data, c_parser_omp_target_update,
	c_parser_omp_target_enter_data, c_parser_omp_target_exit_data): Set
	OMP_REQUIRES_TARGET_USED.
	(c_parser_omp_requires): Remove sorry.

gcc/ChangeLog:

	* config/gcn/mkoffload.cc (process_asm): Write '#include <stdint.h>'.
	(process_obj): Pass omp_requires_mask to GOMP_offload_register_ver.
	(main): Ask lto1 to obtain omp_requires_mask and pass it on.
	* config/nvptx/mkoffload.cc (process, main): Likewise.
	* lto-cgraph.cc (omp_requires_to_name): New.
	(input_offload_tables): Save omp_requires_mask.
	(output_offload_tables): Read it, check for consistency,
	save value for mkoffload.
	* omp-low.cc (lower_omp_target): Force output_offloadtables
	call for OMP_REQUIRES_TARGET_USED.

gcc/cp/ChangeLog:

	* parser.cc (cp_parser_omp_target_data,
	cp_parser_omp_target_enter_data, cp_parser_omp_target_exit_data,
	cp_parser_omp_target_update): Set OMP_REQUIRES_TARGET_USED.
	(cp_parser_omp_requires): Remove sorry.

gcc/fortran/ChangeLog:

	* openmp.cc (gfc_match_omp_requires): Remove sorry.
	* parse.cc (decode_omp_directive): Don't regard 'declare target'
	as target usage for 'omp requires'; add more flags to
	omp_requires_mask.

include/ChangeLog:

	* gomp-constants.h (GOMP_VERSION): Bump to 2.
	(GOMP_REQUIRES_UNIFIED_ADDRESS, GOMP_REQUIRES_UNIFIED_SHARED_MEMORY,
	GOMP_REQUIRES_REVERSE_OFFLOAD, GOMP_REQUIRES_TARGET_USED):
	New defines.

libgomp/ChangeLog:

	* libgomp-plugin.h (GOMP_OFFLOAD_get_num_devices): Add
	omp_requires_mask arg.
	* plugin/plugin-gcn.c (GOMP_OFFLOAD_get_num_devices): Likewise;
	return -1 when device available but omp_requires_mask != 0.
	* plugin/plugin-nvptx.c (GOMP_OFFLOAD_get_num_devices): Likewise.
	* oacc-host.c (host_get_num_devices, host_openacc_get_property):
	Update call.
	* oacc-init.c (resolve_device, acc_init_1, acc_shutdown_1,
	goacc_attach_host_thread_to_device, acc_get_num_devices,
	acc_set_device_num, get_property_any): Likewise.
	* target.c (omp_requires_mask): New global var.
	(gomp_requires_to_name): New.
	(GOMP_offload_register_ver): Handle passed omp_requires_mask.
	(gomp_target_init): Handle omp_requires_mask.
	* libgomp.texi (OpenMP 5.0): Update requires impl. status.
	(OpenMP 5.1): Add a missed item.
	(OpenMP 5.2): Mark linear-clause change as supported in C/C++.
	* testsuite/libgomp.c-c++-common/requires-1-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-1.c: New test.
	* testsuite/libgomp.c-c++-common/requires-2-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-2.c: New test.
	* testsuite/libgomp.c-c++-common/requires-3-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-3.c: New test.
	* testsuite/libgomp.c-c++-common/requires-4-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-4.c: New test.
	* testsuite/libgomp.c-c++-common/requires-5-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-5.c: New test.
	* testsuite/libgomp.c-c++-common/requires-6.c: New test.
	* testsuite/libgomp.c-c++-common/requires-7-aux.c: New test.
	* testsuite/libgomp.c-c++-common/requires-7.c: New test.
	* testsuite/libgomp.fortran/requires-1-aux.f90: New test.
	* testsuite/libgomp.fortran/requires-1.f90: New test.

liboffloadmic/ChangeLog:

	* plugin/libgomp-plugin-intelmic.cpp (GOMP_OFFLOAD_get_num_devices):
	Return -1 when device available but omp_requires_mask != 0.

gcc/testsuite/ChangeLog:

	* c-c++-common/gomp/requires-4.c: Update dg-*.
	* c-c++-common/gomp/reverse-offload-1.c: Likewise.
	* c-c++-common/gomp/target-device-ancestor-2.c: Likewise.
	* c-c++-common/gomp/target-device-ancestor-3.c: Likewise.
	* c-c++-common/gomp/target-device-ancestor-4.c: Likewise.
	* c-c++-common/gomp/target-device-ancestor-5.c: Likewise.
	* gfortran.dg/gomp/target-device-ancestor-3.f90: Likewise.
	* gfortran.dg/gomp/target-device-ancestor-4.f90: Likewise.
	* gfortran.dg/gomp/target-device-ancestor-5.f90: Likewise.
	* gfortran.dg/gomp/target-device-ancestor-2.f90: Likewise. Move
	post-FE checks to ...
	* gfortran.dg/gomp/target-device-ancestor-2a.f90: ... this new file.
	* gfortran.dg/gomp/requires-8.f90: Update as we don't regard
	'declare target' for the 'requires' usage requirement.

Co-authored-by: Chung-Lin Tang <cltang@codesourcery.com>
Co-authored-by: Thomas Schwinge <thomas@codesourcery.com>

The following removes a FIXME where we fail(ed) to keep virtual
SSA up-to-date, patching up the remaining two cases I managed to
trigger.  I've left an assert so that we pick up cases arising
for the cases I wasn't able to trigger.

2022-07-04  Richard Biener  <rguenther@suse.de>

	* tree-vect-loop-manip.cc (vect_do_peeling): Assert that
	no SSA update is needed instead of updating virtual SSA
	form.
	* tree-vect-stmts.cc (vectorizable_load): For hoisted
	invariant load use the loop entry virtual use.
	For emulated gather loads use the virtual use of the
	original stmt like vect_finish_stmt_generation would do.

I've made the mistake multiple times while doing a bisection.
One would expect that gcc-descr w/o an argument would print
revision for the current HEAD and not master.
Thus change it.

contrib/ChangeLog:

	* git-descr.sh: By default print revision for HEAD.

Such questionable arrays types can occur in Ada.

gcc/
	* tree-pretty-print.cc (dump_generic_node) <ARRAY_TYPE>: Add guard
	for direct circularity.

Vector types are represented as array types with DW_AT_GNU_vector attribute
in the debug info and a range [0 .. TYPE_VECTOR_SUBPARTS - 1].  Now that's
obviously skewed toward the C family of languages, therefore the attached
patch changes the lower bound to the default for the language of the CU.

gcc/
	* dwarf2out.cc (gen_array_type_die): Use the default lower bound of
	the language for vector types.

ChangeLog:

	* MAINTAINERS: fix sorting of names

libiberty/
	* rust-demangle.c (demangle_path_maybe_open_generics): Add
	recursion limit.

The nonzero bits and integer ranges compliment each other quite well,
and it only makes sense to make the mask a first class citizen in the
irange.  We do a half assed job of keeping ranges and nonzero bits
somewhat in sync in SSA_NAME_RANGE_INFO, and the goal has always
been to integrate them properly.  This patch does that, in preparation
for streaming out full-resolution iranges between passes (think
SSA_NAME_RANGE_INFO).

Having nonzero bits in the irange allows us to get better results from
things like irange::contains_p() and keeping them in the irange allows
us to propagate the bits throughout with the ranger.  This patch
provides the bare infrastructure, without any optimizations to
range-ops, etc.  Those will come as follow-ups.

A few notes:

Legacy SSA_NAME_RANGE_INFO updates the nonzero bits every time a range
is set.  Here instead, we don't update the nonzero bits on a new
range, but calculate it on the fly when irange::get_nonzero_bits() is
called.  The goal is to only store nonzero bits that provide
meaningful information that can't be gleaned from the range itself.
But you can always call get_nonzero_bits() and get the full
information.

Nonzero bits are not supported in legacy mode.  The mask may be set
as a consequence of propagation or reading global ranges, but no
one from legacy land should be querying irange::get_nonzero_bits.  There
is an assert enforcing this.  However, legacy/global set_nonzero_bits()
continue to work as before.  There is no change to legacy behavior.

There is virtually no performance change with this patch, as there are
no consumers.  The next patch I post will be the SSA_NAME_RANGE_INFO
conversion to the new world, in which I will discuss performance
proper.  Hint: I'll be chewing up the time budget we gained with the
vrange conversion.

Tested and benchmarked on x86-64 Linux.

gcc/ChangeLog:

	* value-range-storage.cc (irange_storage_slot::set_irange): Set
	nonzero bits in irange.
	(irange_storage_slot::get_irange): Get nonzero bits from irange.
	* value-range.cc (irange::operator=): Set nonzero bits.
	(irange::irange_set): Same.
	(irange::irange_set_anti_range): Same.
	(irange::set): Same.
	(irange::verify_range): Same.
	(irange::legacy_equal_p): Check nonzero bits.
	(irange::equal_p): Same.
	(irange::contains_p): Handle nonzero bits.
	(irange::irange_union): Same.
	(irange::irange_intersect): Same.
	(irange::dump): Same.
	(irange::set_nonzero_bits): New.
	(irange::get_nonzero_bits): New.
	(irange::intersect_nonzero_bits): New.
	(irange::union_nonzero_bits): New.
	(irange::dump_bitmasks): New.
	* value-range.h (class irange): Add m_nonzero_mask.
	(gt_ggc_mx): Handle nonzero bits.
	(gt_pch_nx): Same.
	(irange::set_undefined): Set nonzero bits.
	(irange::set_varying): Same.
	(irange::normalize_kind): Call set_undefined.

When attempting to manually update SSA form after high-level loop
transforms such as loop versioning it is helpful when the loop-closed
SSA form includes virtual operands.  While we have the special
rewrite_virtuals_into_loop_closed_ssa function that doesn't
presently scale, invoking update_ssa by itself.  So the following
makes the regular loop-closed SSA form also cover virtual operands.
For users of loop_version this allows to use cheaper
TODO_update_ssa_no_phi, skipping dominance frontier compute
(for the whole function) and iterated dominance frontiers for each
copied def.

	* tree-ssa-loop-manip.h
	(rewrite_virtuals_into_loop_closed_ssa): Remove.
	(rewrite_into_loop_closed_ssa_1): Likewise.
	* tree-ssa-loop-manip.cc (rewrite_into_loop_closed_ssa_1):
	Make static.
	(rewrite_into_loop_closed_ssa): Remove loop overload,
	always rewrite virtuals into LC SSA.
	(check_loop_closed_ssa_bb): Also check virtuals.
	* tree-ssa-dce.cc (remove_dead_phis): Preserve virtual
	LC PHIs when in LC SSA.
	* gimple-loop-jam.cc (fuse_loops): Do not rewrite into
	loop-closed SSA here, but ...
	(tree_loop_unroll_and_jam): ... here once.
	* tree-if-conv.cc (version_loop_for_if_conversion): Use
	the cheaper TODO_update_ssa_no_phi.
	* tree-loop-distribution.cc (version_loop_by_alias_check):
	Likewise.
	* tree-ssa-loop-unswitch.cc (tree_unswitch_single_loop):
	Likewise.
	* tree-vect-loop-manip.cc (vect_loop_versioning): Likewise.
	(tree_unswitch_outer_loop): Do not rewrite virtuals into
	LC ssa.
	* tree-parloops.cc (transform_to_exit_first_loop_alt):
	Likewise.
	(pass_parallelize_loops::execute): After finishing rewrite
	into LC SSA again because we do not maintain it properly.

The RM 3.9.2(19) clause says that the controlling tag value is statically
determined to be the tag of the tagged type involved.  As a matter of fact,
the call would be made dispatching only as a by-product of the propagation
of the controlling tag value to the tag-indeternminate actuals, but that's
unnecessary and not done in the equivalent case of a procedure call with
both statically tagged and tag-indeternminate actuals.

gcc/ada/

	* sem_disp.adb (Check_Dispatching_Call): Merge the two special cases
	where there are no controlling actuals but tag-indeternminate ones.

When a dispatching call is made to a primitive function with a controlling
tagged result, the call is dispatching on result and thus must return the
class-wide type of the tagged type to accommodate all possible results.

This was ensured by Expand_Dispatching_Call only in the common case where
the result type is the type of the controlling argument, which does not
cover the case of a primitive function inherited from an ancestor type.

gcc/ada/

	* exp_disp.adb (Expand_Dispatching_Call): Fix detection of calls
	that are dispatching on tagged result.

Target specific runtime files must be added to a the exclude list so the
files don't automatically get copied to other runtimes.

gcc/ada/

	* Makefile.rtl (ADA_EXCLUDE_SRCS): Add s-qnx.ads.

The local function Rewrite_As_Renaming can be called twice in certain
circumstances, which is both not quite safe and unnecessary, so this
replaces it with a local variable whose value is computed only once.

No functional changes.

gcc/ada/

	* exp_ch3.adb (Expand_N_Object_Declaration) <OK_To_Rename_Ref>: New
	local function.
	<Rewrite_As_Renaming>: Change to a local variable whose value is
	computed once and generate a call to Finalize after this is done.
	Simplify the code creating the renaming at the end.

gcc/ada/

	* Makefile.rtl (GCC_SPEC_FILES): Remove vxworks cert files.

Attribute Index, which was added to Ada 2022 by AI12-0143, is resolved
just like attribute Count. However, code duplication rightly triggered a
CodePeer warning.

gcc/ada/

	* sem_attr.adb (Resolve_Attribute): Refactor duplicated code for
	Count and Index attributes.

This changes the expanded code generated for if-expressions of 1-dimensional
arrays to create a static temporary on the stack if a small upper bound can
be computed for the length of a subtype covering the result.  Static stack
allocation is preferred over dynamic allocation for code generation purpose.

This also contains a couple of enhancements to the support code for checks,
so as to avoid generating useless checks during the modified expansion.

gcc/ada/

	* checks.adb (Apply_Length_Check_On_Assignment): Return early if
	the Suppress_Assignment_Checks flag is set.
	(Selected_Range_Checks): Deal with conditional expressions.
	* exp_ch4.adb (Too_Large_Length_For_Array): New constant.
	(Expand_Concatenate): Use it in lieu of Too_Large_Max_Length.
	(Expand_N_If_Expression): If the result has a unidimensional array
	type but the dependent expressions have constrained subtypes with
	known bounds, create a static temporary on the stack with a subtype
	covering the result.
	(Get_First_Index_Bounds): Deal with string literals.
	* uintp.ads (Uint_256): New deferred constant.
	* sinfo.ads (Suppress_Assignment_Checks): Document new usage.

gcc/ada/

	* exp_ch3.adb (Expand_N_Object_Declaration.Rewrite_As_Renaming):
	Do not rewrite if the declaration has got constraints.
	* sinfo.ads (Case Expression Alternative): Fix typo.

This changes the expanded code generated for dynamic concatenations to
use a static array subtype for the temporary created on the stack if a
small upper bound can be computed for the length of the result.  Static
stack allocation is preferred over dynamic allocation for code
generation purposes.

gcc/ada/

	* exp_ch3.adb (Expand_N_Object_Declaration.Rewrite_As_Renaming):
	Be prepared for slices.
	* exp_ch4.adb (Get_First_Index_Bounds): New procedure.
	(Expand_Array_Comparison.Length_Less_Than_4): Call it.
	(Expand_Concatenate): Try to compute a maximum length for
	operands with variable length and a maximum total length at the
	end.  If the concatenation is dynamic, but a sensible maximum
	total length has been computed, use this length to create a
	static array subtype for the temporary and return a slice of it.

If a constrained subtype is given when a deferred constant is declared,
then the subtype given in the completion is required (at compile time)
to be subject to a statically matching constraint. This rule was not
properly enforced in some cases and constructs that should have been
rejected were incorrectly accepted.

gcc/ada/

	* sem_ch3.adb (Check_Possible_Deferred_Completion): Delete
	Prev_Obj_Def formal parameter.  Reorganize code so that
	statically matching check is also performed in the case where
	the subtype given in the initial declaration is constrained and
	the subtype given in the completion is not.

Add predicates on subtypes E and N.

gcc/ada/

	* einfo-utils.ads, einfo-utils.adb: Add predicates on subtypes E
	and N.  Change some parameters to use the unpredicated subtypes,
	because they sometimes return e.g. Empty.  Note that N_Entity_Id
	has a predicate; Entity_Id does not.
	* exp_tss.adb (Base_Init_Proc): Use Entity_Id instead of E,
	because otherwise we fail the predicate. We shouldn't be
	referring to single-letter names from far away anyway.
	* sem_aux.adb (Is_Derived_Type): Likewise.
	* sem_res.adb (Is_Definite_Access_Type): Use N_Entity_Id for
	predicate.
	* types.ads (Entity_Id): Add comment explaining the difference
	between Entity_Id and N_Entity_Id.

This patch corrects removes some code duplication within the GNAT
compiler.

gcc/ada/

	* exp_util.adb (Remove_Side_Effects): Combine identical
	branches.
	* sem_attr.adb (Analyze_Attribute): Combine identical cases
	Attribute_Has_Same_Storage and Attribute_Overlaps_Storage.
	* sem_prag.adb (Check_Role): Combine E_Out_Parameter case with
	general case for parameters.
	* sem_util.adb (Accessibility_Level): Combine identical
	branches.
	* sprint.adb (Sprint_Node_Actual): Combine cases for
	N_Real_Range_Specification and N_Signed_Integer_Type_Definition.

This patch corrects an issue in the compiler whereby calling
Quote_Argument with an argument that is of size 1 may lead to a
CONSTRAINT_ERROR raised at runtime due to an undersized buffer.

gcc/ada/

	* libgnat/s-os_lib.adb (Quote_Argument): Modify the result
	buffer size calculation to handle the case where Arg'Length is
	1.

For X'Access, the designated subtype of the access type must statically
match the nominal subtype of X.  This patch fixes a bug where the error
was not detected when there is an unrelated declaration of the form "Y :
T := X;", where T is an unconstrained array subtype.

gcc/ada/

	* exp_util.adb (Expand_Subtype_From_Expr): Generate a new
	subtype when Is_Constr_Subt_For_UN_Aliased is True, so the
	Is_Constr_Subt_For_U_Nominal flag will not be set on the
	preexisting subtype.
	* sem_attr.adb, sem_ch3.adb: Minor.

It was only used in specific cases for controlled types but no longer
provides any significant benefit in practice.

gcc/ada/

	* debug.adb (d.9): Remove usage.
	* exp_ch6.adb (Expand_Simple_Function_Return): Remove redundant
	test on Debug_Flag_Dot_L.
	(Is_Build_In_Place_Result_Type): Return false for nonlimited types.
	(Is_Build_In_Place_Function): Tidy up and remove redundant test on
	Debug_Flag_Dot_L.

This changes the compiler to build in place almost all objects that need
finalization and are initialized with the result of a function call, thus
saving a pair of Adjust/Finalize calls for the anonymous return object.

gcc/ada/

	* exp_ch3.adb (Expand_N_Object_Declaration): Don't adjust the object
	if the expression is a function call.
	<Rewrite_As_Renaming>: Return true if the object needs finalization
	and is initialized  with the result of a function call returned on
	the secondary stack.
	* exp_ch6.adb (Expand_Ctrl_Function_Call): Add Use_Sec_Stack boolean
	parameter.  Early return if the parent is an object declaration and
	Use_Sec_Stack is false.
	(Expand_Call_Helper): Adjust call to Expand_Ctrl_Function_Call.
	* exp_ch7.adb (Find_Last_Init): Be prepared for initialization still
	present in the object declaration.
	* sem_ch3.adb (Analyze_Object_Declaration): Call the predicates
	Needs_Secondary_Stack and Needs_Finalization to guard the renaming
	optimization.

This patch adds the new Generic_Keys.Key function to the set children
of Ada.Containers.

gcc/ada/

	* libgnat/a-cbhase.ads, libgnat/a-cborse.ads,
	libgnat/a-cihase.ads, libgnat/a-ciorse.ads,
	libgnat/a-cohase.ads, libgnat/a-coorse.ads (Key): New function
	that takes a Container parameter, implemented as an expression
	function, so it is self explanatory (doesn't need a comment).

gcc/ada/

	* doc/gnat_rm/the_gnat_library.rst: Fix length of title
	underlines.

In some cases when a legal allocator which defines a new subtype for the
allocated object occurs as part of a record component constraint
expression, the compiler would incorrectly reject the allocator.

gcc/ada/

	* sem_ch4.adb (Analyze_Allocator): After calling Insert_Action
	to insert a subtype declaration associated with an allocator,
	the subtype declaration will usually be analyzed. But not
	always. Add an explicit call to Preanalyze to cope with the
	unusual case. The subtype declaration must be at least
	preanalyzed before the call to Sem_Ch3.Process_Subtype a little
	while later, during which we analyze an identifier that refers
	to the subtype.

The -gnatwc switch enables warnings for test condition outcomes that are
known at compile time. Such warnings are unlikely to be useful in the
case of an assertion expression (or a subexpression thereof), so do not
generate them in that case.

gcc/ada/

	* sem_warn.adb (Warn_On_Constant_Valid_Condition): Do not
	generate a warning if the expression in question is an assertion
	expression, or a subexpression thereof. But do call
	Test_Comparison so that it can generate warnings for the cases
	that it generates warnings for.
	* sem_prag.ads: Modify Assertion_Expression_Pragma constant so
	that the predicate Sem_Util.In_Assertion_Expression_Pragma
	returns True for the expression of a Compile_Time_Error pragma.

Modify the RM to take into account the new functional container.

gcc/ada/

	* doc/gnat_rm/the_gnat_library.rst: Add the new entry.
	* gnat_rm.texi: Regenerate.

When the code responsible for giving errors on ambiguous operands of
comparison and equality operators was moved from the 1st phase (analysis)
to the 2nd phase (resolution) of semantic processing, it was incorrectly
restricted to the operator case, which was valid during the 1st phase but
is not during the 2nd phase.

gcc/ada/

	* sem_res.adb (Resolve_Comparison_Op): Deal with ambiguous operands
	in all cases.
	(Resolve_Equality_Op): Likewise, except for the case of the implicit
	inequality operator created for a user-defined operator that is not
	an intrinsic subprogram.

This patch adds some Ada 2022 features to the set children of
Ada.Containers.

gcc/ada/

	* libgnat/a-cbhase.adb, libgnat/a-cbhase.ads,
	libgnat/a-cborse.adb, libgnat/a-cborse.ads,
	libgnat/a-cihase.adb, libgnat/a-cihase.ads,
	libgnat/a-ciorse.adb, libgnat/a-ciorse.ads,
	libgnat/a-cohase.adb, libgnat/a-cohase.ads,
	libgnat/a-conhel.adb, libgnat/a-conhel.ads,
	libgnat/a-coorse.adb, libgnat/a-coorse.ads: Add Has_Element,
	Element, Query_Element, and Next subprograms that take a Set
	parameter. Add Tampering_With_Cursors_Prohibited function. These
	are all new in Ada 2022.

Functional containers are now controlled. Update the documentation
accordingly.

gcc/ada/

	* doc/gnat_rm/the_gnat_library.rst: Functional vectors, sets,
	and maps are now controlled.
	* gnat_rm.texi: Regenerate.

All assertion pragmas are enabled by default when using -gnata. We need
to add the GNAT specific ones to the list.

gcc/ada/

	* doc/gnat_ugn/building_executable_programs_with_gnat.rst
	(Debugging and Assertion Control): Add GNAT specific assertion
	pragmas to the equivalent Assertion_Policy for the -gnata
	option.
	* gnat_ugn.texi: Regenerate.

This patch corrects an error in the compiler whereby the presence of a
call to a function returning a type with an access discriminant within
an expanded loop condition caused the wrong value to be supplied for the
extra- accessibility-of-result actual, thus causing incorrect checks
within the callee at the point of return.

This change also corrects a problem where spurious "null value not
allowed" warnings were generated for tagged type declarations with an
access discriminant specified as "null."

gcc/ada/

	* sem_disp.adb (Most_Descendant_Use_Clause): Remove call to
	deprecated Is_Internal.
	* sem_util.adb (Innermost_Master_Scope_Depth): Use
	Find_Enclosing_Scope instead of Nearest_Dynamic_Scope to avoid
	cases where relevant scopes get skipped leading to an incorrect
	scope depth calculation.

When the result type of a function requiring built-in-place return is
only visible through a limited_with clause, the compiled needs to wait
for the nonlimited view to be available in order to compute whether
the built-in-place return is needed, and this comprises tagging the
function with the Returns_By_Ref flag.

gcc/ada/

	* exp_ch6.adb (Build_In_Place_Formal): Also compute Returns_By_Ref
	for the function if the extra formals were not built initially.