[Ada] Don't accept illegal (e.g., Integer'(null)) generic actuals

Sem_Util.Wrong_Type usually emits an error message, but in some cases it
does not. The code which prevents emitting an error message was going
too far in some cases, causing illegal constructs to be accepted. For
example, a qualified expression such as Integer'(null) might be passed
in as an actual parameter in an instantiation of a generic and generate
no error message.

Running this command:

  gcc -c inst.ads

On the following sources:

package Inst is
   type Ptr is new Integer;

   generic
      type TElement is private;
      NonDefini : TElement;
   package ArbMgr is
   end ArbMgr;

   package Pack is new ArbMgr (Ptr, Ptr'(null));

   procedure Dummy;
end Inst;

Should produce the following output:

  inst.ads:10:42: expected type "Ptr" defined at line 2
  inst.ads:10:42: found an access type
  compilation abandoned due to previous error

2019-09-17  Steve Baird  <baird@adacore.com>

gcc/ada/

* sem_util.adb (Wrong_Type): In deciding to suppress a message,
it is not enough for In_Instance to be True; in addition,
In_Generic_Actual (Expr) must be False.
* sem_type.adb (In_Generic_Actual): Fix bug where traversal of
parents skips every other node.

From-SVN: r275786

[Ada] Support chained calls to traversal functions in SPARK

This change only affects the SPARK toolset. In the part of semantic
analysis enforcing ownership rules for SPARK, it corrects a crash in
analysis of a declaration of a local borrower whose definition is a
chain of several calls to traversal functions.

2019-09-17  Claire Dross  <dross@adacore.com>

gcc/ada/

* sem_spark.adb (Get_Observed_Or_Borrowed_Expr): If the
definition of a local borrower contains calls to traversal
functions, the borrowed expression is the first parameter of the
first traversal function call in the definition.

From-SVN: r275785

[Ada] Remove section on pragma No_Run_Time

This pragma has been long obsolescent and confuses users.

2019-09-17  Ed Falis  <falis@adacore.com>

gcc/ada/

* doc/gnat_rm/implementation_defined_pragmas.rst: Remove
section.
* gnat_rm.texi, gnat_ugn.texi: Regenerate.

From-SVN: r275784

[Ada] Close file descriptors allocated for tty only once

2019-09-17  Vadim Godunko  <godunko@adacore.com>

gcc/ada/

* libgnat/g-exptty.ads (Close_Input): New subprogram.
* libgnat/g-exptty.adb (Close_Input): New subprogram.
(Close): Move close of TTY to Close_Input.
* terminals.c (__gnat_close_tty): Set file descriptors to
invalid value after close.

From-SVN: r275783

[Ada] GNAT.Expect (Expect_Internal): Try to call 'poll' few times

'poll' returns -1 in case of any error (including interruption by a
signal), so call need to be repeated few times to avoid false failures.

2019-09-17  Vadim Godunko  <godunko@adacore.com>

gcc/ada/

* libgnat/g-expect.adb (Expect_Internal): Try to call 'poll' few
times.

From-SVN: r275782

[Ada] Avoid to close irrelevant file descriptors

'Close' subprogram of GNAT.Expect can close irrelevant file descriptors
when 'Expect' was terminated by Process_Died exception and any file open
operations was done before call to 'Close'.

2019-09-17  Vadim Godunko  <godunko@adacore.com>

gcc/ada/

* libgnat/g-expect.ads, libgnat/g-expect.adb (Close_Input): New
subprogram.
(Get_Command_Output): Call Close_Input to close input stream.
(Expect_Internal): Likewise.
(Close): Likewise.
* libgnat/g-exptty.adb (Close): Likewise.

gcc/testsuite/

* gnat.dg/expect3.adb: New testcase.

From-SVN: r275781

[Ada] A new utility routine for detecting attribute 'Old

Add a utility routine for detecting attribute 'Old. It will be
immediately reused in the GNATprove backend.

2019-09-17  Piotr Trojanek  <trojanek@adacore.com>

gcc/ada/

* sem_util.ads, sem_util.adb (Is_Attribute_Old): New utility
routine.

From-SVN: r275780

[Ada] Do not inline dispatching operations in GNATprove mode

In GNATprove, local subprograms without contracts are candidates for
inlining, so that they are only analyzed in the context of their calls.
This does not apply to dispatching operations, which may be called
through dispatching, in an unknown calling context. Hence such
operations should not be considered as candidates for inlining.

There is no test as this has no effect on compilation.

2019-09-17  Yannick Moy  <moy@adacore.com>

gcc/ada/

* inline.adb (Can_Be_Inlined_In_GNATprove_Mode): Add handling
for dispatching operations.

From-SVN: r275779

[Ada] In a generic use Presanalyze_Spec_Expression on Predicates

When verifying that the meaning of an aspect has not changed between the
freeze point of the entity and the end of the declarations, we analkyze
a copy of the expression to verify its conformance to previous analysis.
If the expression contains overloaded references, these have to be
resolved, which is not done if the expression is only preanalyzed.  This
applies in particular to expressions in predicates.

2019-09-17  Ed Schonberg  <schonberg@adacore.com>

gcc/ada/

* sem_ch13.adb (Check_Aspect_At_End_Of_Declarations): In a
generic context, for a Predicate aspect, use
Preanalyze_Spec_Expression to verify conformance.

gcc/testsuite/

* gnat.dg/predicate13.adb, gnat.dg/predicate13.ads: New
testcase.

From-SVN: r275778

[Ada] Missing tagged type decoration in corresponding record subtypes

The frontend silently skips propagating attribute Is_Tagged_Type to the
constrained corresponding record subtype associated with a protected
type or task type with discriminants. This change does not affect the
functionality of the compiler; it leaves more clean the decoration of
internal entities.

2019-09-17  Javier Miranda  <miranda@adacore.com>

gcc/ada/

* sem_ch3.adb (Constrain_Corresponding_Record): Propagate
attribute Is_Tagged_Type.

From-SVN: r275777

[Ada] Ada 2020: Raise expressions in limited contexts (AI12-0172)

This patch adds support for the use of raise expressions in more
limited contexts (as described in the Ada Isssue AI12-0172).

2019-09-17  Javier Miranda  <miranda@adacore.com>

gcc/ada/

* exp_ch3.adb (Build_Record_Init_Proc): Do not generate code to
adjust the tag component when the record is initialized with a
raise expression.
* sem_aggr.adb (Valid_Limited_Ancestor): Return True for
N_Raise_Expression nodes.
(Valid_Ancestor_Type): Return True for raise expressions.
* sem_ch3.adb (Analyze_Component_Declaration): Do not report an
error when a component is initialized with a raise expression.
* sem_ch4.adb (Analyze_Qualified_Expression): Do not report an
error when the aggregate has a raise expression.

gcc/testsuite/

* gnat.dg/limited4.adb: New testcase.

From-SVN: r275776

[Ada] Ignore missing ALI files in GNATprove mode

This change only affects GNATprove backend, where it avoids spurious
errors on missing ALI files for units indirectly withed from the current
unit and processed as part of a different .gpr project.

No test provided, because only GNATprove is affected.

2019-09-17  Piotr Trojanek  <trojanek@adacore.com>

gcc/ada/

* ali.ads: Fix casing in comment.
* ali-util.ads, ali-util.adb (Read_Withed_ALIs): Remove
Ignore_Errors parameter; it was only set to non-default value of
True when running in GNATprove_Mode and wrongly reset to False
when calling this routine recursively. Now in GNATprove mode we
want it to be always True, so in fact it is equivalent to
GNATProve_Mode flag itself (which was already used in this
routine).

From-SVN: r275775

[Ada] PR ada/91268 Do not redefine macros

This should fix PR ada/91268 by only defining macros if not already
done.

2019-09-17  Arnaud Charlet  <charlet@adacore.com>

gcc/ada/

* adaint.c (_REENTRANT, _THREAD_SAFE): Only define if needed.

From-SVN: r275774

[Ada] Refine change for bit-packed slices

We use Long_Long_Integer'Size / 2 instead of 4 * 8 to support
specifying a target configuration file where the largest integer is
32 bits instead of 64.

2019-09-17  Arnaud Charlet  <charlet@adacore.com>

gcc/ada/

* libgnat/s-bitfie.ads (Val_Bits, Val_Bytes): Define from
Long_Long_Integer'Size.

From-SVN: r275773

[Ada] Adding assertions on extra formals for BIP function calls

This patch adds assertions to ensure that the frontend passes to the
backend the right number of extra parameters required for build in place
function calls. No functional change.

2019-09-17  Javier Miranda  <miranda@adacore.com>

gcc/ada/

* exp_ch6.ads (Needs_BIP_Task_Actuals): New subprogram.
* exp_ch6.adb (Add_Task_Actuals_To_Build_In_Place_Call): Code
cleanup.
(Check_Number_Of_Actuals): New subprogram.
(Make_Build_In_Place_Call_In_Allocator): Adding assertion.
(Make_Build_In_Place_Call_In_Anonymous_Context): Adding
assertion.
(Make_Build_In_Place_Call_In_Assignment): Adding assertion.
(Make_Build_In_Place_Call_In_Object_Declaration): Code cleanup
plus assertion addition.
(Needs_BIP_Task_Actuals): New subprogram.
* sem_ch6.adb (Create_Extra_Formals): Rely on
Needs_BIP_Task_Actuals() to check if the master of the tasks to
be created, and the caller's activation chain formals are
needed.

From-SVN: r275772

[Ada] Avoid touching potentially nonexistent memory

...in cases where the Val_2 might cross a page boundary, and the second
page is now known to exist.

Copy_Bitfield is still disabled in the compiler: no test possible.

2019-09-17  Bob Duff  <duff@adacore.com>

gcc/ada/

* libgnat/s-bituti.adb (Get_Val_2, Set_Val_2): Use new routines
for getting and setting a Val_2, avoiding touching the second
half when that half might not exist.
* exp_ch5.adb (Expand_Assign_Array_Loop_Or_Bitfield): Correct
tests for potential volatile or independent components. In
particular, do not call Prefix unless we know it's a slice.

From-SVN: r275771

[Ada] Support for local unix sockets in GNAT.Sockets API

Sock_Addr_Type has Family_Unix variant now. This variant can be created
with function Unix_Local_Addr call. And this variant is working in
GNAT.Socket routines where it is appropriate.

2019-09-17  Dmitriy Anisimkov  <anisimko@adacore.com>

gcc/ada/

* gsocket.h: Include sys/un.h.
* s-oscons-tmplt.c (AF_UNIX): New constant generation.
(SIZEOF_sockaddr_un): Idem.
* libgnat/g-socket.ads (Family_Type): New value Family_Unix
added.
(Family_Inet_4_6): New subtype only for network families.
(Sock_Addr_Type): Add Unbounded_String field for Family_Unix
variant.
(Unix_Socket_Address): Create Sock_Addr_Type from socket
pathname.
(Network_Socket_Address): Create Sock_Addr_Type from
Inet_Addr_Type and Port_Type parameters.
* libgnat/g-socket.adb: Support local unix address in socket
routines.
(Get_Address_Info): Disable warning about Result may be
referenced before it has a value. Remove duplicated code to exit
from Look_For_Supported.
* libgnat/g-sothco.ads (Unix_Name_Length): New constant defining
maximum number of characters in local socket address path.
(Sockaddr): Add variant for Family_Unix address family. Move
Sin_Port and Sin_Family to Family_Inet section. Add Sin6_Port
and Sin6_Family to Family_Inet6 section.
(Set_Address): Add out parameter Length to return valuable
Sockaddr data length.
(Get_Address): Add input parameter Length to set valuable
Sockaddr data length.
* libgnat/g-sothco.adb: Support local unix address in socket
routines.

From-SVN: r275770

[Ada] Fix wrong value of 'Size for slices of bit-packed arrays

This fixes a long-standing issue in the compiler which would return
a wrong value for the Size attribute applied to slices of bit-packed
arrays whose size is not a multiple of the storage unit.

The problem is that the computation was done in the code generator
after the bit-packed array had been internally rewritten into an
array of bytes, so the Size was always rounded up to the next byte.

The computation is now rewritten into the product of the Length and
Compnent_Size attribute of the slices before being sent to the code
generator.

2019-09-17  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

* exp_attr.adb (Expand_Size_Attribute): Chain the special cases
on the back-end path and rewrite the attribute appled to slices
of bit-packed arrays into the product of the Length and the
Compoent_Size attributes of the slices.
* exp_ch5.adb (Expand_Assign_Array_Bitfield): Use Size attribute
directly to compute the bitfield's size.

gcc/testsuite/

* gnat.dg/pack25.adb: New testcase.

From-SVN: r275769

[Ada] Refine conditions for calling Copy_Bitfield

Avoid calling Copy_Bitfield if there are volatile or independent
components that might be read or written. The test is conservative.

2019-09-17  Bob Duff  <duff@adacore.com>

gcc/ada/

* exp_ch5.adb (Expand_Assign_Array_Loop_Or_Bitfield): Add tests
for potential volatile or independent components.
* libgnat/s-bituti.adb (Copy_Small_Bitfield,
Copy_Large_Bitfield): Move declarations to more appropriate
place.

From-SVN: r275768

Daily bump.

From-SVN: r275763

decl.c (grokdeclarator): Use declspecs->locations and declarator->id_loc in a few error messages.

/cp
2019-09-16  Paolo Carlini  <paolo.carlini@oracle.com>

* decl.c (grokdeclarator): Use declspecs->locations and
declarator->id_loc in a few error messages.
* pt.c (finish_member_template_decl): Use DECL_SOURCE_LOCATION.
(push_template_decl_real): Likewise.

/testsuite
2019-09-16  Paolo Carlini  <paolo.carlini@oracle.com>

* g++.dg/ext/int128-6.C: New.
* c-c++-common/pr68107.c: Test location(s).
* g++.dg/other/large-size-array.C: Likewise.
* g++.dg/template/dtor2.C: Likewise.
* g++.dg/template/error9.C: Likewise.
* g++.dg/tls/diag-2.C: Likewise.
* g++.dg/tls/diag-4.C: Likewise.
* g++.dg/tls/diag-5.C: Likewise.
* g++.old-deja/g++.pt/memtemp71.C: Likewise.

From-SVN: r275759

compiler: fix quoting of //go:linkname in error message

    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/195718

From-SVN: r275758

pr89386.c (foo): Fix return type.

* gcc.target/i386/pr89386.c (foo): Fix return type.
* gcc.target/i386/pr89386-1.c (foo): Ditto.

From-SVN: r275757

* config/i386/sync.md (atomic_store<mode>): Improve comment.

From-SVN: r275755

re PR target/91719 (gcc compiles seq_cst store on x86-64 differently from clang/icc)

PR target/91719
* config/i386/i386.h (TARGET_USE_XCHG_FOR_ATOMIC_STORE): New macro.
* config/i386/x86-tune.def (X86_TUNE_USE_XCHG_FOR_ATOMIC_STORE): New.
* config/i386/sync.md (atomic_store<mode>): emit XCHG for
TARGET_USE_XCHG_FOR_ATOMIC_STORE.

From-SVN: r275754

* Makefile.in (build/genmatch.o): Depend on $(CPPLIB_H).

From-SVN: r275753

Rewrite second part of or_comparisons_1 into match.pd.

2019-09-16  Martin Liska  <mliska@suse.cz>

* gimple-fold.c (or_comparisons_1): Remove rules moved
to ...
* match.pd: ... here.

From-SVN: r275752

Rewrite first part of or_comparisons_1 into match.pd.

2019-09-16  Martin Liska  <mliska@suse.cz>

* gimple-fold.c (or_comparisons_1): Remove rules
moved to ...
* match.pd: ... here.

From-SVN: r275751

Rewrite part of and_comparisons_1 into match.pd.

2019-09-16  Martin Liska  <mliska@suse.cz>

* genmatch.c (dt_node::append_simplify): Do not print
warning when we have duplicate patterns belonging
to a same simplify rule.
* gimple-fold.c (and_comparisons_1): Remove matching moved to match.pd.
(maybe_fold_comparisons_from_match_pd): Handle
tcc_comparison as a results.
* match.pd: Handle (X == CST1) && (X OP2 CST2) conditions.

From-SVN: r275750

Fix PR88784, middle end is missing some optimizations about unsigned

2019-09-16  Li Jia He  <helijia@linux.ibm.com>
    Qi Feng  <ffengqi@linux.ibm.com>

PR middle-end/88784
* match.pd (x >  y  &&  x != XXX_MIN): Optimize into 'x > y'.
(x >  y  &&  x == XXX_MIN): Optimize into 'false'.
(x <= y  &&  x == XXX_MIN): Optimize into 'x == XXX_MIN'.
(x <  y  &&  x != XXX_MAX): Optimize into 'x < y'.
(x <  y  &&  x == XXX_MAX): Optimize into 'false'.
(x >= y  &&  x == XXX_MAX): Optimize into 'x == XXX_MAX'.
(x >  y  ||  x != XXX_MIN): Optimize into 'x != XXX_MIN'.
(x <= y  ||  x != XXX_MIN): Optimize into 'true'.
(x <= y  ||  x == XXX_MIN): Optimize into 'x <= y'.
(x <  y  ||  x != XXX_MAX): Optimize into 'x != XXX_MAX'.
(x >= y  ||  x != XXX_MAX): Optimize into 'true'.
(x >= y  ||  x == XXX_MAX): Optimize into 'x >= y'.
2019-09-16  Li Jia He  <helijia@linux.ibm.com>
    Qi Feng  <ffengqi@linux.ibm.com>

PR middle-end/88784
* gcc.dg/pr88784-1.c: New testcase.
* gcc.dg/pr88784-2.c: New testcase.
* gcc.dg/pr88784-3.c: New testcase.
* gcc.dg/pr88784-4.c: New testcase.
* gcc.dg/pr88784-5.c: New testcase.
* gcc.dg/pr88784-6.c: New testcase.
* gcc.dg/pr88784-7.c: New testcase.
* gcc.dg/pr88784-8.c: New testcase.
* gcc.dg/pr88784-9.c: New testcase.
* gcc.dg/pr88784-10.c: New testcase.
* gcc.dg/pr88784-11.c: New testcase.
* gcc.dg/pr88784-12.c: New testcase.

Co-Authored-By: Qi Feng <ffengqi@linux.ibm.com>
From-SVN: r275749

Auto-generate maybe_fold_and/or_comparisons from match.pd

2019-09-16  Li Jia He  <helijia@linux.ibm.com>
    Martin Liska  <mliska@suse.cz>

* gimple-fold.c (and_comparisons_1): Add type as first
argument.
(and_var_with_comparison): Likewise.
(and_var_with_comparison_1): Likewise.
(or_comparisons_1): Likewise.
(or_var_with_comparison): Likewise.
(or_var_with_comparison_1): Likewise.
(maybe_fold_and_comparisons): Call maybe_fold_comparisons_from_match_pd.
(maybe_fold_or_comparisons): Likewise.
(maybe_fold_comparisons_from_match_pd): New.
* gimple-fold.h (maybe_fold_and_comparisons): Add type argument.
(maybe_fold_or_comparisons): Likewise.
* gimple.c (gimple_size): Make it public and add num_ops argument.
(gimple_init): New function.
(gimple_alloc): Call gimple_init.
* gimple.h (gimple_size): New.
(gimple_init): Likewise.
* tree-if-conv.c (fold_or_predicates): Pass type.
* tree-ssa-ifcombine.c (ifcombine_ifandif): Likewise.
* tree-ssa-reassoc.c (eliminate_redundant_comparison): Likewise.
(optimize_vec_cond_expr): Likewise.
(ovce_extract_ops): Return type of conditional expression.
* tree-ssanames.c (init_ssa_name_imm_use): New.
(make_ssa_name_fn): Use init_ssa_name_imm_use.
* tree-ssanames.h (init_ssa_name_imm_use): New.

Co-Authored-By: Martin Liska <mliska@suse.cz>
From-SVN: r275748

re PR tree-optimization/91756 (g++.dg/lto/alias-3 FAILs)

2019-09-16  Richard Biener  <rguenther@suse.de>

PR tree-optimization/91756
PR tree-optimization/87132
* tree-ssa-alias.h (enum translate_flags): New.
(get_continuation_for_phi): Use it instead of simple bool flag.
(walk_non_aliased_vuses): Likewise.
* tree-ssa-alias.c (maybe_skip_until): Adjust.
(get_continuation_for_phi): When looking across backedges only
disallow valueization.
(walk_non_aliased_vuses): Adjust.
* tree-ssa-sccvn.c (vn_reference_lookup_3): Avoid valueization
if requested.

* gcc.dg/tree-ssa/ssa-fre-81.c: New testcase.

From-SVN: r275747

PR c++/30277 - int-width bit-field promotion.

Here, if cp_perform_integral_promotions saw that the TREE_TYPE of a
bit-field reference was the same as the type it promotes to, it didn't do
anything.  But then decay_conversion saw that the bit-field reference was
unchanged, and converted it to its declared type.  So I needed to add
something to make it clear that promotion has been done.  But then the 33819
change caused trouble by looking through the NOP_EXPR I just added.  This
was the wrong fix for that bug; I've now fixed that better by recognizing in
cp_perform_integral_promotions that we won't promote a bit-field larger than
32 bits, so we should use the declared type.

PR c++/33819 - long bit-field promotion.
* typeck.c (cp_perform_integral_promotions): Handle large bit-fields
properly.  Handle 32-bit non-int bit-fields properly.
(is_bitfield_expr_with_lowered_type): Don't look through NOP_EXPR.

From-SVN: r275746

PR c++/82165 - enum bitfields and operator overloading.

In this testcase, !f.b0 was failing to call the overloaded operator because
TREE_TYPE is the magic bitfield integer type, and we weren't using
unlowered_expr_type the way we do in other places.  It would be nice if we
could give bit-field COMPONENT_REFs their declared type until genericization
time...

* call.c (build_new_op_1): Use unlowered_expr_type.

From-SVN: r275745

Fix conversions for built-in operator overloading candidates.

While working on C++20 operator<=>, I noticed that build_new_op_1 was doing
too much conversion when a built-in candidate was selected; the standard
says it should only perform user-defined conversions, and then leave the
normal operator semantics to handle any standard conversions.  This is
important for operator<=> because a comparison of two different unscoped
enums is ill-formed; if we promote the enums to int here, cp_build_binary_op
never gets to see the original operand types, so we can't give the error.

* call.c (build_new_op_1): Don't apply any standard conversions to
the operands of a built-in operator.  Don't suppress conversions in
cp_build_unary_op.
* typeck.c (cp_build_unary_op): Do integral promotions for enums.

From-SVN: r275744

Handle location wrappers better in warn_logical_operator.

When we introduced location wrappers, we added fold_for_warn to warnings
that are interested in a constant value, or wrapper-stripping to warnings
that are interested in literal constants.  This particular warning is
looking for a literal constant, but was wrongly changed to use
fold_for_warn; this patch makes it strip instead.

* c-warn.c (warn_logical_operator): Strip location wrappers.  Don't
fold_for_warn in "|| mask" warning.

From-SVN: r275743

Daily bump.

From-SVN: r275741

PR c++/91740 - ICE with constexpr call and ?: in ARRAY_REF.

* pt.c (build_non_dependent_expr): Call build_non_dependent_expr for
the first operand.

* g++.dg/cpp1y/var-templ63.C: New test.

From-SVN: r275736

2019-09-15  Sandra Loosemore  <sandra@codesourcery.com>

gcc/testsuite/
* lib/target-supports.exp
(check_effective_target_arm_neon_fp16_hw)
(check_effective_target_arm_fp16_hw): Use check_runtime
instead of check_runtime_nocache.

From-SVN: r275735

re PR fortran/91727 (ICE in conformable_arrays, at fortran/resolve.c:7490)

2019-09-15  Steven G. Kargl  <kargl@gcc.gnu.org>

PR fortran/91727
* resolve.c (conformable_arrays):  If array-spec is NULL, then
allocate-object is a scalar.  a conformability check only occurs
for an array source-expr.

2019-09-15  Steven G. Kargl  <kargl@gcc.gnu.org>

PR fortran/91727
* gfortran.dg/pr91727.f90: New test.

From-SVN: r275731

Change C++ to C comments.

From-SVN: r275730

re PR fortran/91550 (ICE in do_subscript, at fortran/frontend-passes.c:2652)

2019-09-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

PR fortran/91550
* frontend-passes.c (do_subscript): If step equals
zero, a previuos error has been reported; do nothing
in this case.
* resolve.c (gfc_resolve_iterator): Move error checking
after type conversion.

2019-09-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

PR fortran/91550
* gfortran.dg/do_subscript_6.f90: New test.

From-SVN: r275729

[C++ PATCH] simplify clone predicate

https://gcc.gnu.org/ml/gcc-patches/2019-09/msg00904.html
* cp-tree.h (DECL_CLONED_FUNCTION_P): Reimplement using
IDENTIFIER_CDTOR_P, correct documentation.
(DECL_CLONED_FUNCTION): Directly access field.
(decl_cloned_function_p): Delete.
* class.c (decl_cloned_function_p): Delete.
* pt.c (instantiate_template_1): Check DECL_CHAIN is a decl.

From-SVN: r275727

re PR fortran/91556 (Problems with better interface checking)

2019-09-15  Thomas Koenig  <tkoenig@gcc.gnu.org>

PR fortran/91556
* gfortran.dg/warn_argument_mismatch_1.f90: Remove.

From-SVN: r275726

Daily bump.

From-SVN: r275723

re PR fortran/91557 (Bogus warning about unused dummy argument _formal_*)

2019-09-14  Thomas Koenig  <tkoenig@gcc.gnu.org>

PR fortran/91557
PR fortran/91556
* frontend-passes.c (check_externals_procedure): Reformat argument
list. Use gfc_compare_actual_formal instead of gfc_procedure_use.
* gfortran.h (gfc_symbol): Add flag error.
* interface.c (gfc_compare_interfaces): Reformat.
(argument_rank_mismatch): Add where_formal argument. If it is
present, note that the error is between different calls.
(compare_parameter): Change warnings that previously dependended
on -Wargument-mismatch to unconditional.  Issue an error / warning
on type mismatch only once.  Pass where_formal to
argument_rank_mismatch for artificial variables.
(compare_actual_formal): Change warnings that previously
dependeded on -Wargument-mismatch to unconditional.
(gfc_check_typebound_override): Likewise.
(gfc_get_formal_from_actual_arglist): Set declared_at for
artificial symbol.
* invoke.texi: Extend description of -fallow-argument-mismatch.
Delete -Wargument-mismatch.
* lang.opt: Change -Wargument-mismatch to do-nothing option.
* resolve.c (resolve_structure_cons): Change warnings that
previously depended on -Wargument-mismatch to unconditional.
* trans-decl.c (generate_local_decl): Do not warn if the symbol is
artificial.

2019-09-14  Thomas Koenig  <tkoenig@gcc.gnu.org>

PR fortran/91557
PR fortran/91556
* gfortran.dg/argument_checking_20.f90: New test.
* gfortran.dg/argument_checking_21.f90: New test.
* gfortran.dg/argument_checking_22.f90: New test.
* gfortran.dg/argument_checking_23.f90: New test.
* gfortran.dg/warn_unused_dummy_argument_5.f90: New test.
* gfortran.dg/bessel_3.f90: Add pattern for type mismatch.
* gfortran.dg/g77/20010519-1.f: Adjust dg-warning messages to new
handling.
* gfortran.dg/pr24823.f: Likewise.
* gfortran.dg/pr39937.f: Likewise.

From-SVN: r275719

re PR middle-end/83889 (new failures on some arm targets after r256644)

2019-09-14  Sandra Loosemore  <sandra@codesourcery.com>

PR testsuite/83889

gcc/testsuite/
* g++.dg/vect/pr87914.cc: Remove explicit dg-do run.

From-SVN: r275718

Formatting and comment syntax adjustments.

From-SVN: r275717

Consider doloop IV in IVOPTs

   For the targets supporting low-overhead loops, IVOPTs has to take care of
   the loops which will probably be transformed in RTL doloop optimization,
   to try to make selected IV candidate set optimal.  The process of doloop
   support includes:

   1) Analyze the current loop will be transformed to doloop or not, find and
      mark its compare type IV use as doloop use (iv_group field doloop_p), and
      set flag doloop_use_p of ivopts_data to notify subsequent processings on
      doloop.  See analyze_and_mark_doloop_use and its callees for the details.
      The target hook predict_doloop_p can be used for target specific checks.

   2) Add one doloop dedicated IV cand {(may_be_zero ? 1 : (niter + 1)), +, -1},
      set flag doloop_p of iv_cand, step cost is set as zero and no extra cost
      like biv.  For cost determination between doloop IV cand and IV use, the
      target hooks doloop_cost_for_generic and doloop_cost_for_address are
      provided to add on extra costs for generic type and address type IV use.
      Zero cost is assigned to the pair between doloop IV cand and doloop IV
      use, and bound zero is set for IV elimination.

   3) With the cost setting in step 2), the current cost model based IV
      selection algorithm will process as usual, pick up doloop dedicated IV if
      profitable.

gcc/ChangeLog

2019-09-14  Kewen Lin  <linkw@gcc.gnu.org>

    PR middle-end/80791
    * config/rs6000/rs6000.c (TARGET_HAVE_COUNT_REG_DECR_P): New macro.
    (TARGET_DOLOOP_COST_FOR_GENERIC): Likewise.
    (TARGET_DOLOOP_COST_FOR_ADDRESS): Likewise.
    * target.def (have_count_reg_decr_p): New hook.
    (doloop_cost_for_generic): Likewise.
    (doloop_cost_for_address): Likewise.
    * doc/tm.texi.in (TARGET_HAVE_COUNT_REG_DECR_P): Likewise.
    (TARGET_DOLOOP_COST_FOR_GENERIC): Likewise.
    (TARGET_DOLOOP_COST_FOR_ADDRESS): Likewise.
    * doc/tm.texi: Regenerate.
    * tree-ssa-loop-ivopts.c (comp_cost::operator+=): Consider infinite cost
    addend.
    (record_group): Init doloop_p.
    (add_candidate_1): Add optional argument doloop, change the handlings
    accordingly.
    (add_candidate): Likewise.
    (generic_predict_doloop_p): Update attribute.
    (force_expr_to_var_cost): Add costing for expressions COND_EXPR/LT_EXPR/
    LE_EXPR/GT_EXPR/GE_EXPR/EQ_EXPR/NE_EXPR/UNORDERED_EXPR/ORDERED_EXPR/
    UNLT_EXPR/UNLE_EXPR/UNGT_EXPR/UNGE_EXPR/UNEQ_EXPR/LTGT_EXPR/MAX_EXPR/
    MIN_EXPR.
    (get_computation_cost): Update for doloop IV cand extra cost.
    (determine_group_iv_cost_cond): Update for doloop IV cand.
    (determine_iv_cost): Likewise.
    (ivopts_estimate_reg_pressure): Likewise.
    (may_eliminate_iv): Update handlings for doloop IV cand.
    (add_iv_candidate_for_doloop): New function.
    (find_iv_candidates): Call function add_iv_candidate_for_doloop.
    (iv_ca_set_no_cp): Update for doloop IV cand.
    (iv_ca_set_cp): Likewise.
    (iv_ca_dump): Dump register cost.
    (find_doloop_use): New function.
    (analyze_and_mark_doloop_use): Likewise.
    (tree_ssa_iv_optimize_loop): Call function analyze_and_mark_doloop_use.

gcc/testsuite/ChangeLog

2019-09-14  Kewen Lin  <linkw@gcc.gnu.org>

    PR middle-end/80791
    * gcc.dg/tree-ssa/ivopts-3.c: Adjust for doloop change.
    * gcc.dg/tree-ssa/ivopts-lt.c: Likewise.
    * gcc.dg/tree-ssa/pr32044.c: Likewise.

From-SVN: r275713

Daily bump.

From-SVN: r275709

re PR fortran/91566 (ICE in gfc_constructor_copy, at fortran/constructor.c:103)

2019-09-13  Steven G. Kargl  <kargl@gcc.gnu.org>

PR fortran/91566
* simplify.c (gfc_simplify_merge): Need to simplify expression
after insertation of parenthesis.

2019-09-13  Steven G. Kargl  <kargl@gcc.gnu.org>

PR fortran/91566
* gfortran.dg/pr91566.f90:

From-SVN: r275704

libgomp plugin - init string

libgomp/
2019-09-13  Tobias Burnus  <tobias@codesourcery.com>

        * plugin/plugin-hsa.c (hsa_warn, hsa_fatal, hsa_error): Ensure
        string is initialized.

From-SVN: r275703

gnatmake: Accept the `--sysroot=' GCC driver option

According to `gnatmake' documentation:

"Any uppercase or multi-character switch that is not a 'gnatmake' switch
is passed to 'gcc' (e.g., '-O', '-gnato,' etc.)"

however the `--sysroot=' switch is actually rejected:

gnatmake: invalid switch: --sysroot=...

likely because it is one of the very few GCC driver options that have a
leading double dash and therefore we don't have a blanket fall-through
for such switches that would satisfy what our documentation claims.

The option is actually shared between the compiler and the linker, so
pass the switch to both build stages if requested, removing GNAT
testsuite issues like:

gnatmake: invalid switch: --sysroot=.../sysroot
compiler exited with status 1
Executing on host: .../gcc/gnatclean -c -q -n ./abstract_with_anonymous_result   (timeout = 300)
spawn -ignore SIGHUP .../gcc/gnatclean -c -q -n ./abstract_with_anonymous_result
PASS: gnat.dg/abstract_with_anonymous_result.adb (test for excess errors)
UNRESOLVED: gnat.dg/abstract_with_anonymous_result.adb compilation failed to produce executable

in a test environment where `--with-build-sysroot=.../sysroot' has been
used to build a cross-compiler.  Passing to the compilation stage only
would lead to errors like:

.../bin/riscv64-linux-gnu-ld: cannot find crt1.o: No such file or directory
.../bin/riscv64-linux-gnu-ld: cannot find -lc
collect2: error: ld returned 1 exit status
gnatlink: error when calling .../gcc/xgcc
gnatmake: *** link failed.
compiler exited with status 1
Executing on host: .../gcc/gnatclean -c -q -n ./abstract_with_anonymous_result   (timeout = 300)
spawn -ignore SIGHUP .../gcc/gnatclean -c -q -n ./abstract_with_anonymous_result
./abstract_with_anonymous_result.ali
./abstract_with_anonymous_result.o
FAIL: gnat.dg/abstract_with_anonymous_result.adb (test for excess errors)
Excess errors:
.../bin/riscv64-linux-gnu-ld: cannot find crt1.o: No such file or directory
.../bin/riscv64-linux-gnu-ld: cannot find -lc
gnatlink: error when calling .../gcc/xgcc

UNRESOLVED: gnat.dg/abstract_with_anonymous_result.adb compilation failed to produce executable

instead.

gcc/ada/
* make.adb (Scan_Make_Arg): Also accept `--sysroot=' for the
compiler and the linker.

From-SVN: r275702

re PR middle-end/91708 ([ARM] Bootstrap fails in gen_movsi, at config/arm/arm.md:5258)

2019-09-13  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        PR middle-end/91708
        * cse.c (cse_insn): Do not replace anything with a
        MEM.

From-SVN: r275701

libgo: don't use \? in grep pattern

    It's not supported by Solaris grep.  Just use * instead; it matches
    more but it shouldn't matter.

    Fixes https://gcc.gnu.org/PR91764

    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/195238

From-SVN: r275700

* doc/invoke.texi (Optimize Options): Fix typo.

From-SVN: r275699

re PR fortran/91716 (ICE in output_constant, at varasm.c:5026)

2019-09-13  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        PR fortran/91716
        * trans-array.c (gfc_conv_array_initializer): Always assign the
        array type of the field to the string constant.

testsuite:
2019-09-13  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        PR fortran/91716
        * gfortran.dg/pr91716.f90: New test.

From-SVN: r275698

[PATCH][GCC] Update my email address

gcc/ChangeLog
2019-09-13  Sam Tebbs  <sam.tebbs@arm.com>

* MAINTAINERS (Sam Tebbs): Update email address.

From-SVN: r275697

re PR fortran/91717 (ICE on concatenating deferred-length character and character literal)

2019-09-13  Paul Thomas  <pault@gcc.gnu.org>

PR fortran/91717
* dependency.c (gfc_dep_resolver): Flag identical components
and exit with return value 1 if set and no array refs.

2019-09-13  Paul Thomas  <pault@gcc.gnu.org>

PR fortran/91717
* gfortran.dg/dependency_55.f90 : New test.

From-SVN: r275696

Daily bump.

From-SVN: r275695

libgo: update to Go1.13

    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194698

From-SVN: r275691

re PR tree-optimization/89386 (Generation of vectorized MULHRS (Multiply High with Round and Scale) instruction)

PR tree-optimization/89386
* config/i386/sse.md (smulhrs<mode>3): New expander.
(smulhrsv4hi3): Ditto.

testsuite/ChangeLog:

PR tree-optimization/89386
* gcc.target/i386/pr89386.c: New test.
* gcc.target/i386/pr89386-1.c: Ditto.

From-SVN: r275689

re PR tree-optimization/91750 (Induction vectorization introduces signed overflows)

2019-09-12  Richard Biener  <rguenther@suse.de>

PR tree-optimization/91750
* tree-vect-loop.c (vectorizable_induction): Compute IV increments
in the type of the evolution.

* gcc.dg/vect/pr91750.c: New testcase.

From-SVN: r275685

PR libstdc++/91748 fix std::for_each_n for random access iterators

PR libstdc++/91748
* include/bits/stl_algo.h (for_each_n): Fix random access iterator
case.
* testsuite/25_algorithms/for_each/for_each_n.cc: Test with random
access iterators.

From-SVN: r275683

Vectorise multiply high with scaling operations (PR 89386)

2019-09-12  Yuliang Wang  <yuliang.wang@arm.com>

gcc/
PR tree-optimization/89386
* config/aarch64/aarch64-sve2.md (<su>mull<bt><Vwide>)
(<r>shrnb<mode>, <r>shrnt<mode>): New SVE2 patterns.
(<su>mulh<r>s<mode>3): New pattern for MULHRS.
* config/aarch64/iterators.md (UNSPEC_SMULLB, UNSPEC_SMULLT)
(UNSPEC_UMULLB, UNSPEC_UMULLT, UNSPEC_SHRNB, UNSPEC_SHRNT)
(UNSPEC_RSHRNB, UNSPEC_RSHRNT, UNSPEC_SMULHS, UNSPEC_SMULHRS)
UNSPEC_UMULHS, UNSPEC_UMULHRS): New unspecs.
(MULLBT, SHRNB, SHRNT, MULHRS): New int iterators.
(su, r): Handle the unspecs above.
(bt): New int attribute.
* internal-fn.def (IFN_MULHS, IFN_MULHRS): New internal functions.
* internal-fn.c (first_commutative_argument): Commutativity info for
above.
* optabs.def (smulhs_optab, smulhrs_optab, umulhs_optab)
(umulhrs_optab): New optabs.
* doc/md.texi (smulhs$var{m3}, umulhs$var{m3})
(smulhrs$var{m3}, umulhrs$var{m3}): Documentation for the above.
* tree-vect-patterns.c (vect_recog_mulhs_pattern): New pattern
function.
(vect_vect_recog_func_ptrs): Add it.
* testsuite/gcc.target/aarch64/sve2/mulhrs_1.c: New test.
* testsuite/gcc.dg/vect/vect-mulhrs-1.c: As above.
* testsuite/gcc.dg/vect/vect-mulhrs-2.c: As above.
* testsuite/gcc.dg/vect/vect-mulhrs-3.c: As above.
* testsuite/gcc.dg/vect/vect-mulhrs-4.c: As above.
* doc/sourcebuild.texi (vect_mulhrs_hi): Document new target selector.
* testsuite/lib/target-supports.exp
(check_effective_target_vect_mulhrs_hi): Return true for AArch64
with SVE2.

From-SVN: r275682

Daily bump.

From-SVN: r275680

re PR middle-end/83889 (new failures on some arm targets after r256644)

2019-09-11  Sandra Loosemore  <sandra@codesourcery.com>

PR testsuite/83889

gcc/testsuite/
* gcc.dg/vect/pr81740-2.c: Remove explicit dg-do run.
* gcc.dg/vect/pr88598-1.c: Likewise.
* gcc.dg/vect/pr88598-2.c: Likewise.
* gcc.dg/vect/pr88598-3.c: Likewise.
* gcc.dg/vect/pr88598-4.c: Likewise.
* gcc.dg/vect/pr88598-5.c: Likewise.
* gcc.dg/vect/pr88598-6.c: Likewise.
* gcc.dg/vect/pr89440.c: Likewise.
* gcc.dg/vect/pr90018.c: Likewise.
* gcc.dg/vect/pr91293-1.c: Likewise.
* gcc.dg/vect/pr91293-2.c: Likewise.
* gcc.dg/vect/pr91293-3.c: Likewise.

From-SVN: r275667

re PR fortran/91553 (ICE in gfc_real2complex, at fortran/arith.c:2208)

2019-09-11  Steven G. Kargl  <kargl@gcc.gnu.org>

PR fortran/91553
* simplify.c (gfc_convert_constant):  During conversion check if the
constant is enclosed in parenthesis, and simplify expression.

2019-09-11  Steven G. Kargl  <kargl@gcc.gnu.org>

PR fortran/91553
* gfortran.dg/pr91553.f90: New test.

From-SVN: r275657

re PR fortran/91642 (ICE: Bad IO basetype (transfer_expr, at fortran/trans-io.c:2507))

2019-09-11  Steven G. Kargl  <kargl@gcc.gnu.org>

PR fortran/91642
* io.c (gfc_match_inquire): null() cannot be in an iolength inquire
list.

2019-09-11  Steven G. Kargl  <kargl@gcc.gnu.org>

PR fortran/91642
* gfortran.dg/pr91642.f90: New test.

From-SVN: r275655

Simplify the code.

2019-09-11  Michael Meissner  <meissner@linux.ibm.com>

* config/rs6000/predicates.md (non_add_cint_operand): Simplify the
code.

From-SVN: r275652

compiler: suppress type descriptor generation for aliases

    Change Named_object::get_backend to ignore aliases when creating type
    descriptors for types, to be consistent with
    Type::needs_specific_type_functions and the Specific_type_functions
    traversal class. For example, when compiling a package that creates an
    alias to an an externally defined type, e.g.

       import "foo"
       type MyFoo = foo.Foo

    it makes sense to skip the alias (not try to generate type specific
    functions for it) and let the normal mechanisms take care of the alias
    target, depending on whether the target is defined locally or defined
    elsewhere.

    Testcase for this problen can be found in CL 193261.

    Fixes golang/go#33866.

    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/191961

From-SVN: r275651

golang.org/x/sys/cpu: define doinit when needed

    Should fix the build on riscv64 and other systems.

    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194641

From-SVN: r275650

gotest: force test package to be imported first

    When compiling the x_test package, force the test package to be
    imported first.  That ensures that we will see the types defined in
    the test package before the types defined in the non-test version of
    the package.  This matters if the types differ in some way, such as by
    adding a new method.

    This avoids a failure in internal/poll on Solaris, in which the test
    package adds a method to a type (FD.EOFError).  I think it was Solaris-
    specific because files are sorted in a different order by default.

    The go tool handles this kind of thing correctly, by rebuilding
    dependent packages.  This is just a hack sufficient to run the libgo
    testsuite without using the go tool.

    Fixes https://gcc.gnu.org/PR91712

    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194637

From-SVN: r275648

Fix Xmethod for shared_ptr::use_count()

This was reported in https://bugzilla.redhat.com/show_bug.cgi?id=1749578

* python/libstdcxx/v6/xmethods.py (SharedPtrUseCountWorker.__call__):
Fix syntax error.

From-SVN: r275644

Fix libstdc++ tests for -Wvolatile warnings in C++2a mode

* testsuite/20_util/result_of/sfinae_friendly_1.cc: Add -Wno-volatile
for C++2a and up. Define HAS_52748_FIXED and fix incorrect tests.
* testsuite/tr1/3_function_objects/result_of.cc: Add -Wno-volatile
for C++2a and up.

From-SVN: r275643

re PR rtl-optimization/89435 (wrong code with -O1 -march=armv4 -fno-forward-propagate with __builtin_sub_overflow())

PR rtl-optimization/89435
PR rtl-optimization/89795
PR rtl-optimization/91720
* gcc.dg/pr89435.c: New test.
* gcc.dg/pr89795.c: New test.
* gcc.dg/pr91720.c: New test.

From-SVN: r275642

[PATCH] some tree struct marking

https://gcc.gnu.org/ml/gcc-patches/2019-09/msg00697.html
gcc/
* tree.h (MARK_TS_TYPE_NON_COMMON): New.
* tree.c (tree_node_structure_for_code): Reformat and alphabetize.

gcc/cp/
* c-objcp-common.c (cp-objcp-common.c): Alphababetize and
correctly mark all C++ nodes.

From-SVN: r275641

lto-opts.c (lto_write_options): Stream -g when debug is enabled.

2019-09-11  Richard Biener  <rguenther@suse.de>

* lto-opts.c (lto_write_options): Stream -g when debug is enabled.
* lto-wrapper.c (merge_and_complain): Pick up -g.
(append_compiler_options): Likewise.
(run_gcc): Re-instantiate handling -g0 at link-time.
* doc/invoke.texi (flto): Document debug info generation.

From-SVN: r275640

re PR tree-optimization/90387 (__builtin_constant_p and -Warray-bounds warnings)

2019-09-11  Richard Biener  <rguenther@suse.de>

PR tree-optimization/90387
* vr-values.c (vr_values::extract_range_basic): After inlining
simplify non-constant __builtin_constant_p to false.

* gcc.dg/Warray-bounds-44.c: New testcase.

From-SVN: r275639

re PR rtl-optimization/89795 (wrong code with -O2 -fno-dce -fno-forward-propagate -fno-sched-pressure)

PR rtl-optimization/89795
* rtlanal.c (nonzero_bits1) <SUBREG>: Do not propagate results from
inner REGs to paradoxical SUBREGs if WORD_REGISTER_OPERATIONS is set.

From-SVN: r275635

re PR tree-optimization/91723 (builtin fma is not optimized or vectorized as *+)

PR tree-optimization/91723
* tree-vect-stmts.c (vectorizable_call): Use types_compatible_p check
instead of pointer equality when checking if argument vectypes are
the same.

* gcc.dg/vect/vect-fma-3.c: New test.

From-SVN: r275634

re PR middle-end/91725 (ICE in get_nonzero_bits starting with r275587)

PR middle-end/91725
* match.pd ((A / (1 << B)) -> (A >> B)): Call tree_nonzero_bits instead
of get_nonzero_bits, only call it for integral types.

* gcc.c-torture/compile/pr91725.c: New test.

From-SVN: r275633

revert: match.pd: Add flag_unsafe_math_optimizations check before deciding on the widest type in...

2019-09-11  Richard Biener  <rguenther@suse.de>

Revert
2019-09-09  Barnaby Wilks  <barnaby.wilks@arm.com>

* match.pd: Add flag_unsafe_math_optimizations check
before deciding on the widest type in a binary math operation.

* gcc.dg/fold-binary-math-casts.c: New test.

From-SVN: r275632

Update my email address

2019-09-10  Tobias Burnus  <tobias@codesourcery.com>

        * MAINTAINERS: Update my email address.

From-SVN: r275631

Daily bump.

From-SVN: r275622

PR c++/91673 - ICE with noexcept in alias-declaration.

* parser.c (CP_PARSER_FLAGS_DELAY_NOEXCEPT): New parser flag.
(cp_parser_lambda_declarator_opt): Pass CP_PARSER_FLAGS_NONE to
cp_parser_exception_specification_opt.
(cp_parser_direct_declarator): Adjust a call to
cp_parser_exception_specification_opt.
(cp_parser_member_declaration): Pass CP_PARSER_FLAGS_DELAY_NOEXCEPT
to cp_parser_declarator if not processing a friend or typedef
declaration.
(cp_parser_late_noexcept_specifier): Adjust a call to
cp_parser_noexcept_specification_opt.
(cp_parser_noexcept_specification_opt): New parameter for parser flags,
drop the FRIEND_P parameter.  Use the new parameter.
(cp_parser_exception_specification_opt): Likewise.
(cp_parser_transaction): Adjust a call to
cp_parser_noexcept_specification_opt.
(cp_parser_transaction_expression): Likewise.

* g++.dg/cpp1z/using7.C: New test.
* g++.dg/cpp1z/using8.C: New test.

From-SVN: r275617

PR c++/91705 - constexpr evaluation rejects ++/-- on floats.

* constexpr.c (cxx_eval_increment_expression): Call fold_simple on
the offset.

* g++.dg/cpp1y/constexpr-incr2.C: New test.

From-SVN: r275613

libgo: Solaris and x/sys/cpu compatibility fixes

    Restore Solaris compatibility fixes lost when internal/x/net/lif moved
    to golang.org/x/net/lif.  Also fix the Makefile for x/net/lif and
    x/net/route.

    Change x/sys/cpu to get the cache line size from goarch.sh as the
    gofrontend version of internal/cpu does.

    Partially based on work by Rainer Orth.

    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194438

From-SVN: r275611

re PR go/91621 (libgo/mksysinfo.sh: please avoid test ==)

PR go/91621
    mksysinfo: change test == to test =

    Fixes https://gcc.gnu.org/PR91621

    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194569

From-SVN: r275608

go/internal/gccgoimporter: support embedded field in pointer loop

    Backport of https://golang.org/cl/194440.  Original description:

        If an embedded field refers to a type via a pointer, the parser needs
        to know the name of the embedded field. It is possible that the
        pointer type is not yet resolved. This CL fixes the parser to handle
        that case by setting the pointer element type to the unresolved named
        type while the pointer is being resolved.

    Updates golang/go#34182

    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/194562

From-SVN: r275606

Remove call_really_used_regs

After previous patches, it's now possible for call_used_regs to be
the "real" set of call-clobbered registers, without any special
handling for fixed registers.  This patch therefore removes the
separate call_really_used_regs and updates the targets that define
CALL_REALLY_USED_REGISTERS so that they handle call_used_regs in
the same way that they used to handle call_really_used_regs.

With this change, it's no longer necessary for targets that define
CALL_REALLY_USED_REGISTERS to define CALL_USED_REGISTER as well.

2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
* doc/tm.texi.in: Document that exactly one of CALL_USED_REGISTERS
and CALL_REALLY_USED_REGISTERS must be defined, and that
CALL_REALLY_USED_REGISTERS is preferred.
* doc/tm.texi: Regenerate.
* hard-reg-set.h (target_hard_regs::x_call_really_used_regs): Delete.
(call_really_used_regs): Likewise.
* reginfo.c: Raise an #error if both CALL_USED_REGISTERS and
CALL_REALLY_USED_REGISTERS are defined.
(initial_call_used_regs): Use CALL_REALLY_USED_REGISTERS as the
initial value if defined.
(initial_call_really_used_regs): Delete.
(saved_call_really_used_regs): Likewise.
(CALL_REALLY_USED_REGNO_P): Likewise.
(init_reg_sets): Remove handling of call_really_used_regs.
(save_register_info, restore_register_info, globalize_reg): Likewise.
(init_reg_sets_1): Likewise.  Use call_used_regs instead of
CALL_REALLY_USED_REGNO_P.  Don't set call_used_regs for registers
outside operand_reg_set.
(fix_register): Don't change call_used_regs if
CALL_REALLY_USED_REGISTERS is defined.
* config/csky/csky.h (CALL_USED_REGISTERS): Delete.
* config/csky/csky.c (get_csky_live_regs): Use call_used_regs
instead of call_really_used_regs.
(csky_conditional_register_usage): Remove the old handling of
call_used_regs and change the handling of call_really_used_regs
to use call_used_regs instead.
* config/ia64/ia64.h (CALL_USED_REGISTERS): Delete.
* config/ia64/ia64.c (fix_range): Don't set call_used_regs when
making a register fixed.
* config/m32r/m32r.h (CALL_USED_REGISTERS): Delete.
* config/m32r/m32r.c (MUST_SAVE_REGISTER): Use call_used_regs
instead of call_really_used_regs.
(m32r_conditional_register_usage): Don't set call_used_regs when
making a register fixed.
* config/mips/mips.h (CALL_USED_REGISTERS): Delete.
* config/mips/mips.c (mips_global_pointer): Use call_used_regs
instead of call_really_used_regs.
(mips_interrupt_extra_call_saved_reg_p): Likewise.
(mips_cfun_call_saved_reg_p): Likewise.
(mips_swap_registers): Remove the old handling of call_used_regs
and change the handling of call_really_used_regs to use call_used_regs
instead.
(mips_conditional_register_usage): Likewise.
* config/mn10300/mn10300.h (CALL_USED_REGISTERS): Delete.
* config/mn10300/mn10300.c (fp_regs_to_save): Use call_used_regs
instead of call_really_used_regs.
(mn10300_get_live_callee_saved_regs): Likewise.
(mn10300_expand_prologue, mn10300_expand_epilogue): Likewise.
(mn10300_conditional_register_usage): Don't set call_used_regs when
making a register fixed.
* config/rs6000/rs6000.h (CALL_USED_REGISTERS): Delete.
* config/rs6000/rs6000.c (rs6000_conditional_register_usage):
Remove the old handling of call_used_regs and change the handling
of call_really_used_regs to use call_used_regs instead.
* config/s390/s390.h (CALL_USED_REGISTERS): Delete.
* config/s390/s390.c (s390_regs_ever_clobbered): Use call_used_regs
instead of call_really_used_regs.
(s390_register_info_gprtofpr, s390_register_info): Likewise.
(s390_hard_regno_rename_ok, s390_hard_regno_scratch_ok): Likewise.
(s390_emit_prologue, s300_set_up_by_prologue): Likewise.
(s390_can_use_return_insn, s390_optimize_prologue): Likewise.
(s390_conditional_register_usage): Remove the old handling of
call_used_regs and change the handling of call_really_used_regs
to use call_used_regs instead.
* config/sh/sh.h (CALL_USED_REGISTERS): Delete.
* config/sh/sh.c (output_stack_adjust, calc_live_regs): Likewise.
(sh_fix_range, reg_unused_after): Likewise.
(sh_conditional_register_usage): Remove the old handling of
call_used_regs and change the handling of call_really_used_regs
to use call_used_regs instead.
* config/sparc/sparc.h (CALL_USED_REGISTERS): Delete.
* config/sparc/sparc.c (sparc_conditional_register_usage): Don't set
call_used_regs when making a register fixed.
* config/tilegx/tilegx.h (CALL_USED_REGISTERS): Delete.
* config/tilegx/tilegx.c (tilegx_conditional_register_usage): Don't set
call_used_regs when making a register fixed.
* config/tilepro/tilepro.h (CALL_USED_REGISTERS): Delete.
* config/tilepro/tilepro.c (tilepro_conditional_register_usage): Don't
set call_used_regs when making a register fixed.
* config/visium/visium.h (CALL_USED_REGISTERS): Delete.
* config/visium/visium.c (visium_conditional_register_usage): Remove
the old handling of call_used_regs and change the handling of
call_really_used_regs to use call_used_regs instead.

From-SVN: r275605

Hide call_used_regs in target-independent code

Now that tests of call_used_regs go through call_used_or_fixed_reg_p,
we can hide call_used_regs from target-independent code.  (It still
needs to be available to targets for the conditional register usage
hooks.)

2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
* hard-reg-set.h (call_used_regs): Only define if IN_TARGET_CODE.
(call_used_or_fixed_reg_p): Expand definition of call_used_regs.
* reginfo.c (call_used_regs): New macro.

From-SVN: r275604

Remove redundant fixed_regs tests

This patch removes redundant fixed_regs tests in things like:

  !fixed_regs[i] && !call_used_or_fixed_reg_p (i)

2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
* config/alpha/alpha.c (alpha_compute_frame_layout): Remove redundant
fixed_regs test.
* config/bpf/bpf.c (bpf_compute_frame_layout, bpf_expand_prologue)
(bpf_expand_epilogue): Likewise.
* config/c6x/c6x.c (c6x_save_reg): Likewise.
* config/ft32/ft32.c (ft32_expand_prologue): Likewise.
(ft32_expand_epilogue): Likewise.
* config/i386/i386.c (ix86_save_reg): Likewise.
* config/moxie/moxie.c (moxie_expand_prologue): Likewise.
(moxie_expand_epilogue): Likewise.
* config/tilegx/tilegx.c (need_to_save_reg): Likewise.
* config/tilepro/tilepro.c (need_to_save_reg): Likewise.
* config/xtensa/xtensa.c (xtensa_call_save_reg): Likewise.

From-SVN: r275603

Add call_used_or_fixed_reg_p

Similarly to the call_used_or_fixed_regs patch, this one replaces
tests of call_used_regs[i] with call_used_or_fixed_reg_p (i).
The only remaining direct uses of call_used_regs are in reginfo.c
and in the conditional register usage hooks.

Again, this is purely mechanical.  A later patch will clear up the
oddities in config/ code.

2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
* hard-reg-set.h (call_used_or_fixed_reg_p): New macro.
* cfgloopanal.c (init_set_costs): Use call_used_or_fixed_reg_p
instead of testing call_used_regs directly.
* config/aarch64/aarch64.c (aarch64_layout_frame): Likewise.
(aarch64_components_for_bb): Likewise.
* config/alpha/alpha.c (alpha_compute_frame_layout): Likewise.
* config/arc/arc.c (arc_must_save_register): Likewise.
(arc_epilogue_uses): Likewise.
* config/arm/arm.c (arm_option_override, use_return_insn): Likewise.
(legitimize_pic_address, callee_saved_reg_p): Likewise.
(arm_compute_save_reg0_reg12_mask): Likewise.
(arm_compute_save_core_reg_mask): Likewise.
(arm_get_vfp_saved_size, arm_compute_frame_layout): Likewise.
(arm_save_coproc_regs, thumb1_extra_regs_pushed): Likewise.
(cmse_nonsecure_entry_clear_before_return): Likewise.
(thumb1_expand_epilogue, arm_expand_epilogue_apcs_frame): Likewise.
(arm_expand_epilogue): Likewise.
* config/avr/avr.c (avr_regs_to_save, sequent_regs_live): Likewise.
(avr_function_arg_advance, avr_find_unused_d_reg): Likewise.
(_reg_unused_after): Likewise.
* config/bfin/bfin.c (must_save_p, expand_prologue_reg_save): Likewise.
(expand_epilogue_reg_restore, n_regs_saved_by_prologue): Likewise.
(add_to_reg, hwloop_optimize): Likewise.
* config/bpf/bpf.c (bpf_compute_frame_layout, bpf_expand_prologue)
(bpf_expand_epilogue): Likewise.
* config/c6x/c6x.c (c6x_save_reg, c6x_regno_reg_class): Likewise.
* config/cr16/cr16.c (cr16_compute_save_regs): Likewise.
* config/cris/cris.c (cris_reg_saved_in_regsave_area): Likewise.
* config/epiphany/epiphany.c (epiphany_init_reg_tables): Likewise.
(epiphany_compute_function_type, MUST_SAVE_REGISTER): Likewise.
(epiphany_output_mi_thunk, epiphany_start_function): Likewise.
* config/fr30/fr30.c (fr30_num_arg_regs): Likewise.
* config/frv/frv.c (frv_stack_info): Likewise.
* config/ft32/ft32.c (ft32_compute_frame): Likewise.
(ft32_expand_prologue, ft32_expand_epilogue): Likewise.
* config/gcn/gcn.c (gcn_compute_frame_offsets): Likewise.
(move_callee_saved_registers): Likewise.
* config/h8300/h8300.c (byte_reg): Likewise.
* config/i386/i386-options.c (ix86_set_current_function): Likewise.
* config/i386/i386.c (ix86_save_reg, ix86_expand_prologue): Likewise.
(ix86_expand_epilogue, x86_order_regs_for_local_alloc): Likewise.
* config/i386/predicates.md (sibcall_memory_operand): Likewise.
* config/ia64/ia64.c (emit_safe_across_calls, find_gr_spill): Likewise.
(next_scratch_gr_reg, ia64_compute_frame_size): Likewise.
* config/iq2000/iq2000.h (MUST_SAVE_REGISTER): Likewise.
* config/lm32/lm32.c (lm32_compute_frame_size): Likewise.
* config/m32c/m32c.c (need_to_save): Likewise.
* config/m68k/m68k.c (m68k_save_reg): Likewise.
* config/mcore/mcore.c (calc_live_regs): Likewise.
* config/microblaze/microblaze.c (microblaze_must_save_register):
Likewise.
* config/mmix/mmix.c (mmix_local_regno): Likewise.
(mmix_initial_elimination_offset, mmix_reorg): Likewise.
(mmix_use_simple_return, mmix_expand_prologue): Likewise.
(mmix_expand_epilogue): Likewise.
* config/moxie/moxie.c (moxie_compute_frame): Likewise.
(moxie_expand_prologue, moxie_expand_epilogue): Likewise.
* config/msp430/msp430.c (msp430_preserve_reg_p): Likewise.
* config/nds32/nds32.h (nds32_16bit_address_type): Likewise.
(NDS32_REQUIRED_CALLEE_SAVED_P): Likewise.
* config/nios2/nios2.c (prologue_saved_reg_p): Likewise.
* config/or1k/or1k.c (callee_saved_regno_p): Likewise.
* config/pa/pa.c (pa_expand_prologue, pa_expand_epilogue): Likewise.
* config/pdp11/pdp11.c (pdp11_saved_regno): Likewise.
* config/pru/pru.c (prologue_saved_reg_p): Likewise.
* config/riscv/riscv.c (riscv_save_reg_p): Likewise.
(riscv_epilogue_uses, riscv_hard_regno_mode_ok): Likewise.
* config/rl78/rl78.c (need_to_save): Likewise.
* config/rs6000/rs6000-logue.c (save_reg_p): Likewise.
(rs6000_stack_info, generate_set_vrsave): Likewise.
(rs6000_emit_prologue, rs6000_emit_epilogue): Likewise.
* config/rs6000/rs6000.c (rs6000_debug_reg_print): Likewise.
* config/rx/rx.c (rx_get_stack_layout): Likewise.
* config/s390/s390.c (s390_call_saved_register_used): Likewise.
* config/sh/sh.c (calc_live_regs, sh_output_mi_thunk): Likewise.
* config/sparc/sparc.c (save_global_or_fp_reg_p): Likewise.
(save_local_or_in_reg_p): Likewise.
* config/stormy16/stormy16.c (REG_NEEDS_SAVE): Likewise.
(xstormy16_epilogue_uses): Likewise.
* config/tilegx/tilegx.c (need_to_save_reg): Likewise.
* config/tilepro/tilepro.c (need_to_save_reg): Likewise.
* config/v850/v850.c (compute_register_save_size): Likewise.
* config/vax/vax.c (vax_expand_prologue): Likewise.
* config/visium/visium.c (visium_save_reg_p): Likewise.
* config/xtensa/xtensa.c (xtensa_call_save_reg): Likewise.
* cselib.c (cselib_process_insn): Likewise.
* df-scan.c (df_get_entry_block_def_set): Likewise.
* function.c (aggregate_value_p): Likewise.
* haifa-sched.c (alloc_global_sched_pressure_data): Likewise.
* ira-lives.c (process_bb_node_lives): Likewise.
* ira.c (do_reload): Likewise.
* lra-lives.c (process_bb_lives): Likewise.
* lra-remat.c (lra_remat): Likewise.
* lra.c (lra): Likewise.
* postreload.c (reload_combine_recognize_pattern): Likewise.
(reload_cse_move2add): Likewise.
* recog.c (peep2_find_free_register): Likewise.
* regrename.c (check_new_reg_p): Likewise.
* reload.c (find_equiv_reg): Likewise.
* reload1.c (reload, find_reg): Likewise.
* sel-sched.c (init_hard_regs_data): Likewise.

From-SVN: r275602

Make more use of regs_invalidated_by_call

This cleans up a couple of places in which the previous patch had:

  call_used_or_fixed_regs & ~fixed_reg_set

In that context, regs_invalidated_by_call is IMO more obvious.

2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
* config/frv/frv.c (frv_ifcvt_modify_tests): Use
regs_invalidated_by_call & ~fixed_reg_set instead of
call_used_or_fixed_regs & ~fixed_reg_set.
* config/sh/sh.c (output_stack_adjust): Likewise.

From-SVN: r275601

Replace call_used_reg_set with call_used_or_fixed_regs

CALL_USED_REGISTERS and call_used_regs infamously contain all fixed
registers (hence the need for CALL_REALLY_USED_REGISTERS etc.).
We try to recover from this to some extent with:

  /* Contains 1 for registers that are set or clobbered by calls.  */
  /* ??? Ideally, this would be just call_used_regs plus global_regs, but
     for someone's bright idea to have call_used_regs strictly include
     fixed_regs.  Which leaves us guessing as to the set of fixed_regs
     that are actually preserved.  We know for sure that those associated
     with the local stack frame are safe, but scant others.  */
  HARD_REG_SET x_regs_invalidated_by_call;

Since global registers are added to fixed_reg_set and call_used_reg_set
too, it's always the case that:

  call_used_reg_set == regs_invalidated_by_call | fixed_reg_set

This patch replaces all uses of call_used_reg_set with a new macro
call_used_or_fixed_regs to make this clearer.

This is part of a series that allows call_used_regs to be what is
now call_really_used_regs.  It's a purely mechanical replacement;
later patches clean up obvious oddities like
"call_used_or_fixed_regs & ~fixed_regs".

2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
* hard-reg-set.h (target_hard_regs::x_call_used_reg_set): Delete.
(call_used_reg_set): Delete.
(call_used_or_fixed_regs): New macro.
* reginfo.c (init_reg_sets_1, globalize_reg): Remove initialization
of call_used_reg_set.
* caller-save.c (setup_save_areas): Use call_used_or_fixed_regs
instead of call_used_regs.
(save_call_clobbered_regs): Likewise.
* cfgcleanup.c (old_insns_match_p): Likewise.
* config/c6x/c6x.c (c6x_call_saved_register_used): Likewise.
* config/epiphany/epiphany.c (epiphany_conditional_register_usage):
Likewise.
* config/frv/frv.c (frv_ifcvt_modify_tests): Likewise.
* config/sh/sh.c (output_stack_adjust): Likewise.
* final.c (collect_fn_hard_reg_usage): Likewise.
* ira-build.c (ira_build): Likewise.
* ira-color.c (calculate_saved_nregs): Likewise.
(allocno_reload_assign, calculate_spill_cost): Likewise.
* ira-conflicts.c (ira_build_conflicts): Likewise.
* ira-costs.c (ira_tune_allocno_costs): Likewise.
* ira-lives.c (process_bb_node_lives): Likewise.
* ira.c (setup_reg_renumber): Likewise.
* lra-assigns.c (find_hard_regno_for_1, lra_assign): Likewise.
* lra-constraints.c (need_for_call_save_p): Likewise.
(need_for_split_p, inherit_in_ebb): Likewise.
* lra-lives.c (process_bb_lives): Likewise.
* lra-remat.c (call_used_input_regno_present_p): Likewise.
* postreload.c (reload_combine): Likewise.
* regrename.c (find_rename_reg): Likewise.
* reload1.c (reload_as_needed): Likewise.
* rtlanal.c (find_all_hard_reg_sets): Likewise.
* sel-sched.c (mark_unavailable_hard_regs): Likewise.
* shrink-wrap.c (requires_stack_frame_p): Likewise.

From-SVN: r275600

Remove no_caller_save_reg_set

Reusing the reasoning from the call_fixed_reg_set patch:

  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
    for (j = 1; j <= MOVE_MAX_WORDS; j++)
      if (reg_save_code (i,regno_save_mode[i][j]) == -1)

should be true whenever regno_save_mode[i][j] == VOIDmode,
which it is for:

  ~call_used_reg_set | ~have_save_mode

So this condition amounts to:

  ~call_used_reg_set | ~have_save_mode | ~have_save_insn
  == ~call_used_reg_set | ~savable_regs

no_caller_save_reg_set is then set if call_used_regs[i], so
no_caller_save_reg_set is:

  call_used_reg_set & (~call_used_reg_set | ~savable_regs)
  == call_used_reg_set & ~savable_regs

This patch expands its single user accordingly.

Note that ~savable_regs is always empty on LRA targets.

2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
* hard-reg-set.h (target_hard_regs::x_no_caller_save_reg_set): Delete.
(no_caller_save_reg_set): Delete.
* caller-save.c (init_caller_save): Don't initialize it.
* ira-conflicts.c (ira_build_conflicts): Calculate
no_caller_save_reg_set locally from call_used_reg_set and savable_regs.

From-SVN: r275599

Remove call_fixed_reg_set

On targets that use reload, call_fixed_reg_set is structurally:

  fixed_reg_set                           -- reginfo.c
  | (call_used_reg_set & ~have_save_mode) -- first loop in init_caller_save
  | ~have_save_insn                       -- final loop in init_caller_save

(where "have_save_mode" and "have_save_insn" are just my names).
But the final loop in init_caller_save does:

  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
    for (j = 1; j <= MOVE_MAX_WORDS; j++)
      if (reg_save_code (i,regno_save_mode[i][j]) == -1)

This last condition ought to be true whenever:

  regno_save_mode[i][j] == VOIDmode

since either targetm.hard_regno_mode_ok (i, VOIDmode) should be
false or the VOIDmode save & restore shouldn't match any move insn.
And after the first loop, regno_save_mode[i][j] == VOIDmode whenever
!call_used_regs[i].  So the above is actually:

  fixed_reg_set
  | (call_used_reg_set & ~have_save_mode)
  | (~call_used_reg_set | ~have_save_insn)

which simplifies to:

  fixed_reg_set                        -- reginfo.c
  | ~have_save_mode                    -- first loop in init_caller_save
  | ~have_save_insn                    -- final loop in init_caller_save
  | ~call_used_reg_set                 -- final loop in init_caller_save

So:

  ~call_fixed_reg_set == (~fixed_reg_set
          & have_save_mode
  & have_save_insn
  & call_used_reg_set)  [A]

All users have the form:

  (call_used_reg_set or some subset) & ~(call_fixed_reg_set | ...)

i.e.:

  (call_used_reg_set or some subset) & ~call_fixed_reg_set & ~(...)

We can therefore drop the "& call_used_reg_set" from [A], leaving:

  ~fixed_reg_set & have_save_mode & have_save_insn

This patch combines have_save_mode & have_save_insn into a single
condition "a save is possible", represented as savable_regs.
We can then substitute:

  ~call_fixed_reg_set --> ~fixed_reg_set & savable_regs
                          (registers we can actually save around calls)

The patch also sets regno_save_mode[i][j] for all registers,
in case non-default ABIs require a save when the default ABI
doesn't.  This ensures that savable_regs (like fixed_reg_set but
unlike call_fixed_reg_set) isn't affected by the ABI.  This only
becomes significant with later patches and at this point is just
a simplification.

Since init_caller_save is only called for reload targets,
the default assumption for LRA is that all registers are savable,
just like the default assumption before the patch was that
(~)call_fixed_reg_set == (~)fixed_reg_set.

2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
* hard-reg-set.h (target_hard_regs::x_call_fixed_reg_set): Delete.
(target_hard_regs::x_savable_regs): New field.
(call_fixed_reg_set): Delete.
(savable_regs): New macro,
* reginfo.c (globalize_reg): Don't set call_fixed_reg_set.
(init_reg_sets_1): Likewise.  Initialize savable_regs.
* caller-save.c (init_caller_save): Invoke HARD_REGNO_CALLER_SAVE_MODE
for all registers.  Set savable_regs instead of call_fixed_reg_set.
(setup_save_areas, save_call_clobbered_regs): Replace uses of
~call_fixed_reg_set with ~fixed_reg_set & savable_regs.
* config/sh/sh.c (output_stack_adjust): Likewise.

From-SVN: r275598

Move c6x REGNO_REG_CLASS out of line

I have a series of patches that hides call_used_regs from target-
independent code, a knock-on effect of which is that (public) target
macros can't use call_used_regs either.  This patch fixes the only
case in which that was a problem.

2019-09-10  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
* config/c6x/c6x-protos.h (c6x_set_return_address): Declare.
* config/c6x/c6x.h (REGNO_REG_CLASS): Move implementation to
* config/c6x/c6x.c (c6x_regno_reg_class): ...this new function.

From-SVN: r275597

Implement std::common_reference for C++20

* include/std/type_traits (__do_common_type_impl): Implement
additional COND-RES(CREF(D1), CRED(D2)) condition for C++20.
(basic_common_reference, common_reference, common_reference_t): Define
for C++20.
* testsuite/20_util/common_reference/requirements/alias_decl.cc: New
test.
* testsuite/20_util/common_reference/requirements/
explicit_instantiation.cc: New test.
* testsuite/20_util/common_reference/requirements/typedefs.cc: New
test.

From-SVN: r275594