liuhongt [Wed, 26 Aug 2020 07:24:10 +0000 (15:24 +0800)]
Add expander for movp2hi and movp2qi.
2020-08-30 Uros Bizjak <ubizjak@gmail.com>
gcc/ChangeLog:
PR target/96744
* config/i386/i386-expand.c (split_double_mode): Also handle
E_P2HImode and E_P2QImode.
* config/i386/sse.md (MASK_DWI): New define_mode_iterator.
(mov<mode>): New expander for P2HI,P2QI.
(*mov<mode>_internal): New define_insn_and_split to split
movement of P2QI/P2HI to 2 movqi/movhi patterns after reload.
gotest: use a space rather than a middle dot in target lists
Replace the U+00B7 middle dot character, placed after "mips64p32le"
in the target lists, with a space. The U+00B7 character may not be
considered whitespace by Bourne shell and any non-ASCII character
may render incorrectly in some terminal devices.
Jonathan Wakely [Thu, 27 Aug 2020 21:36:03 +0000 (22:36 +0100)]
libstdc++: Make std::chrono::duration use reduced ratio for period
This implements the changes from P0548 "common_type and duration". That
was a change for C++17, but as it corrects some issues introduced by DRs
I'm also treating it as a DR and changing it for all modes from C++11
up.
The main change is that duration<R,P>::period no longer denotes P, but
rather P::type, the reduced ratio. The unary operator+ and operator-
members of duration should now return a duration using that reduced
ratio.
The requirement that common_type<T>::type is the same type as
common_type<T, T>::type (rather than simply T) was already implemented
for PR 89102.
The standard says that duration::operator+() and duration::operator-()
should return common_type_t<duration>, but that seems unnecessarily
expensive to compute. This change just uses duration<rep, period> which
is the same type, so we don't need to instantiate common_type.
As an optimization, this also adds partial specializations of
common_type for two durations of the same type, a single duration, two
time_points of the same type, and a single time_point. These
specializations avoid instantiating other specializations of common_type
and one or both of __duration_common_type or __timepoint_common_type for
the cases where the answer is trivial to obtain.
libstdc++-v3/ChangeLog:
* include/std/chrono (__duration_common_type): Ensure the
reduced ratio is used. Remove unused partial specialization
using __failure_type.
(common_type): Pass reduced ratios to __duration_common_type.
Add partial specializations for simple cases involving a single
duration or time_point type.
(duration::period): Use reduced ratio.
(duration::operator+(), duration::operator-()): Return duration
type using the reduced ratio.
* testsuite/20_util/duration/requirements/typedefs_neg2.cc:
Adjust expected errors.
* testsuite/20_util/duration/requirements/reduced_period.cc: New test.
Patrick Palka [Thu, 27 Aug 2020 18:11:24 +0000 (14:11 -0400)]
libstdc++: Fix arithmetic bug in chrono::year_month::operator+
This fixes the months-based addition for year_month when the
year_month's month component is 0.
libstdc++-v3/ChangeLog:
* include/std/chrono (year_month::operator+): Properly handle a
month value of 0 by casting the month value to int before
subtracting 1 from it so that the difference is sign-extended in
the subsequent addition.
* testsuite/std/time/year_month/1.cc: Test adding months to a
year_month whose month component is below or above the
normalized range of [1,12].
Patrick Palka [Thu, 27 Aug 2020 18:09:52 +0000 (14:09 -0400)]
libstdc++: Fix operator overload ambiguity with calendar types
We currently don't enforce a constraint on some of the calendar types'
addition/subtraction operator overloads that take a 'months' arguments:
Constraints: If the argument supplied by the caller for the months
parameter is convertible to years, its implicit conversion sequence to
years is worse than its implicit conversion sequence to months.
This constraint is relevant when adding/subtracting a duration to/from,
say, a year_month where the given duration is convertible to both
'months' and to 'years' (as in the new testcases below). The correct
behavior here in light of this constraint is to perform the operation
through the (more efficient) 'years'-based overload, but we currently
emit an ambiguous overload error.
This patch templatizes the 'months'-based addition/subtraction operator
overloads so that in the event of an implicit-conversion tie, we select
the non-template 'years'-based overload. This is the same approach
that the date library takes for enforcing this constraint.
libstdc++-v3/ChangeLog:
* include/std/chrono
(__detail::__months_years_conversion_disambiguator): Define.
(year_month::operator+=): Templatize the 'months'-based overload
so that the 'years'-based overload is selected in case of
equally-ranked implicit conversion sequences to both 'months'
and 'years' from the supplied argument.
(year_month::operator-=): Likewise.
(year_month::operator+): Likewise.
(year_month::operator-): Likewise.
(year_month_day::operator+=): Likewise.
(year_month_day::operator-=): Likewise.
(year_month_day::operator+): Likewise.
(year_month_day::operator-): Likewise.
(year_month_day_last::operator+=): Likewise.
(year_month_day_last::operator-=): Likewise.
(year_month_day_last::operator+): Likewise
(year_month_day_last::operator-): Likewise.
(year_month_day_weekday::operator+=): Likewise
(year_month_day_weekday::operator-=): Likewise.
(year_month_day_weekday::operator+): Likewise.
(year_month_day_weekday::operator-): Likewise.
(year_month_day_weekday_last::operator+=): Likewise
(year_month_day_weekday_last::operator-=): Likewise.
(year_month_day_weekday_last::operator+): Likewise.
(year_month_day_weekday_last::operator-): Likewise.
(testsuite/std/time/year_month/2.cc): New test.
(testsuite/std/time/year_month_day/2.cc): New test.
(testsuite/std/time/year_month_day_last/2.cc): New test.
(testsuite/std/time/year_month_weekday/2.cc): New test.
(testsuite/std/time/year_month_weekday_last/2.cc): New test.
Jakub Jelinek [Thu, 27 Aug 2020 16:44:40 +0000 (18:44 +0200)]
ia32: Fix alignment of _Atomic fields [PR65146]
For _Atomic fields, lowering the alignment of long long or double etc.
fields on ia32 is undesirable, because then one really can't perform atomic
operations on those using cmpxchg8b.
The following patch stops lowering the alignment in fields for _Atomic
types (the x86_field_alignment change) and for -mpreferred-stack-boundary=2
also ensures we don't misalign _Atomic long long etc. automatic variables
(the ix86_{local,minimum}_alignment changes).
Not sure about iamcu_alignment change, I know next to nothing about IA MCU,
but unless it doesn't have cmpxchg8b instruction, it would surprise me if we
don't want to do it as well.
clang apparently doesn't lower the field alignment for _Atomic.
2020-08-27 Jakub Jelinek <jakub@redhat.com>
PR target/65146
* config/i386/i386.c (iamcu_alignment): Don't decrease alignment
for TYPE_ATOMIC types.
(ix86_local_alignment): Likewise.
(ix86_minimum_alignment): Likewise.
(x86_field_alignment): Likewise, and emit a -Wpsabi diagnostic
for it.
Mark Eggleston [Fri, 21 Aug 2020 05:39:30 +0000 (06:39 +0100)]
Fortran : ICE for division by zero in declaration PR95882
A length expression containing a divide by zero in a character
declaration will result in an ICE if the constant is anymore
complicated that a contant divided by a constant.
The cause was that char_len_param_value can return MATCH_YES
even if a divide by zero was seen. Prior to returning check
whether a divide by zero was seen and if so set it to MATCH_ERROR.
2020-08-27 Mark Eggleston <markeggleston@gcc.gnu.org>
gcc/fortran
PR fortran/95882
* decl.c (char_len_param_value): Check gfc_seen_div0 and
if it is set return MATCH_ERROR.
2020-08-27 Mark Eggleston <markeggleston@gcc.gnu.org>
gcc/testsuite/
PR fortran/95882
* gfortran.dg/pr95882_1.f90: New test.
* gfortran.dg/pr95882_2.f90: New test.
* gfortran.dg/pr95882_3.f90: New test.
* gfortran.dg/pr95882_4.f90: New test.
* gfortran.dg/pr95882_5.f90: New test.
Richard Biener [Thu, 27 Aug 2020 09:48:15 +0000 (11:48 +0200)]
tree-optimization/96522 - transfer of flow-sensitive info in copy_ref_info
This removes the bogus tranfer of flow-sensitive info in copy_ref_info
plus fixes one oversight in FRE when flow-sensitive non-NULLness was added to
points-to info.
2020-08-27 Richard Biener <rguenther@suse.de>
PR tree-optimization/96522
* tree-ssa-address.c (copy_ref_info): Reset flow-sensitive
info of the copied points-to. Transfer bigger alignment
via the access type.
* tree-ssa-sccvn.c (eliminate_dom_walker::eliminate_stmt):
Reset all flow-sensitive info.
Richard Biener [Thu, 27 Aug 2020 11:04:19 +0000 (13:04 +0200)]
streamline TARGET_MEM_REF dumping
The following streamlines TARGET_MEM_REF dumping building
on what we do for MEM_REF and thus dumping things like
access type, TBAA type and base/clique. I've changed it
to do semantic dumping aka base + offset + step * index
rather than the odd base: A, step: way.
2020-08-27 Richard Biener <rguenther@suse.de>
* tree-pretty-print.c (dump_mem_ref): Handle TARGET_MEM_REFs.
(dump_generic_node): Use dump_mem_ref also for TARGET_MEM_REF.
Alex Coplan [Thu, 27 Aug 2020 08:49:57 +0000 (09:49 +0100)]
lra: Canonicalize mult to shift in address reloads
Inside a (mem) RTX, it is canonical to write multiplications by powers
of two using a (mult) [0]. Outside of a (mem), the canonical way to
write multiplications by powers of two is using (ashift).
Now I observed that LRA does not quite respect this RTL canonicalization
rule. When compiling gcc/testsuite/gcc.dg/torture/pr34330.c with -Os
-ftree-vectorize, the RTL in the dump "281r.ira" has the insn:
* lra-constraints.c (canonicalize_reload_addr): New.
(curr_insn_transform): Use canonicalize_reload_addr to ensure we
generate canonical RTL for an address reload.
gcc/testsuite/ChangeLog:
* gcc.target/aarch64/mem-shift-canonical.c: New test.
Patrick Palka [Thu, 27 Aug 2020 01:51:48 +0000 (21:51 -0400)]
libstdc++: Implement remaining piece of LWG 3448
Almost all of the proposed resolution for LWG 3448 is already
implemented; the only part left is to adjust the return type of
transform_view::sentinel::operator-.
libstdc++-v3/ChangeLog:
PR libstdc++/95322
* include/std/ranges (transform_view::sentinel::__distance_from):
Give this a deduced return type.
(transform_view::sentinel::operator-): Adjust the return type so
that it's based on the constness of the iterator rather than
that of the sentinel.
* testsuite/std/ranges/adaptors/95322.cc: Refer to LWG 3488.
Patrick Palka [Thu, 27 Aug 2020 01:52:58 +0000 (21:52 -0400)]
libstdc++: elements_view's sentinel and iterator not comparable [LWG 3406]
This implements the proposed resolution for LWG 3406, and adds a
testcase for the example from P1994R1.
libstdc++-v3/ChangeLog:
* include/std/ranges (elements_view::begin): Adjust constraints.
(elements_view::end): Likewise.
(elements_view::_Sentinel::operator==): Templatize to take both
_Iterator<true> and _Iterator<false>.
(elements_view::_Sentinel::operator-): Likewise.
* testsuite/std/ranges/adaptors/elements.cc: Add testcase for
the example from P1994R1.
* testsuite/std/ranges/adaptors/lwg3406.cc: New test.
Patrick Palka [Thu, 27 Aug 2020 01:49:51 +0000 (21:49 -0400)]
libstdc++: Implement P1994R1 changes to ranges::elements_view
The example from the paper doesn't compile without the proposed
resolution for LWG 3406, so we'll add a testcase for this once the
proposed resolution is implemented.
libstdc++-v3/ChangeLog:
* include/std/ranges (elements_view::end): Replace these two
overloads with four new overloads.
(elements_view::_Iterator::operator==): Remove.
(elements_view::_Iterator::operator-): Likewise.
(elements_view::_Sentinel): Define.
Jeff Law [Wed, 26 Aug 2020 23:12:07 +0000 (17:12 -0600)]
Mark various tests that require a c99 libm
A number of i386 math optimisation tests are looking assembly instructions
that are only emitted when the compiler knows the target has a C99 libm
available. Since targets like *-elf may not have such a libm, a C99 runtime
requirement is added to these tests.
Göran Uddeborg [Wed, 26 Aug 2020 23:06:28 +0000 (17:06 -0600)]
Fix documentation of -fprofile-exclude-files
The wording of the description of -fprofile-exclude-files is easy to
misunderstand. One can be led to believe a file is excluded only if
it matches all of the patterns, not just one. This patch tries to
clarify the function. It also adjusts the wording of
-fprofile-filter-files accordingly.
gcc/
PR gcov-profile/96285
* common.opt, doc/invoke.texi: Clarify wording of
-fprofile-exclude-files and adjust -fprofile-filter-files to
match.
MSP430: Simplify and extend shift instruction patterns
The implementation of define_expand and define_insn patterns to handle
shifts in the MSP430 backend is inconsistent, resulting in missed
opportunities to make best use of the architecture's features.
There's now a single define_expand used as the entry point for all valid
shifts, and the decision to either use a helper function to perform the
shift (often required for the 430 ISA), or fall through to the
define_insn patterns can be made from that expander function.
Shifts by a constant amount have been grouped into one define_insn for
each type of shift, instead of having different define_insn patterns for
shifts by different amounts.
A new target option "-mmax-inline-shift=" has been added to allow tuning
of the number of shift instructions to emit inline, instead of using
a library helper function.
gcc/ChangeLog:
* config/msp430/constraints.md (K): Change unused constraint to
constraint to a const_int between 1 and 19.
(P): New constraint.
* config/msp430/msp430-protos.h (msp430x_logical_shift_right): Remove.
(msp430_expand_shift): New.
(msp430_output_asm_shift_insns): New.
* config/msp430/msp430.c (msp430_rtx_costs): Remove shift costs.
(CSH): Remove.
(msp430_expand_helper): Remove hard-coded generation of some inline
shift insns.
(use_helper_for_const_shift): New.
(msp430_expand_shift): New.
(msp430_output_asm_shift_insns): New.
(msp430_print_operand): Add new 'W' operand selector.
(msp430x_logical_shift_right): Remove.
* config/msp430/msp430.md (HPSI): New define_mode_iterator.
(HDI): Likewise.
(any_shift): New define_code_iterator.
(shift_insn): New define_code_attr.
Adjust unnamed insn patterns searched for by combine.
(ashlhi3): Remove.
(slli_1): Remove.
(430x_shift_left): Remove.
(slll_1): Remove.
(slll_2): Remove.
(ashlsi3): Remove.
(ashldi3): Remove.
(ashrhi3): Remove.
(srai_1): Remove.
(430x_arithmetic_shift_right): Remove.
(srap_1): Remove.
(srap_2): Remove.
(sral_1): Remove.
(sral_2): Remove.
(ashrsi3): Remove.
(ashrdi3): Remove.
(lshrhi3): Remove.
(srli_1): Remove.
(430x_logical_shift_right): Remove.
(srlp_1): Remove.
(srll_1): Remove.
(srll_2x): Remove.
(lshrsi3): Remove.
(lshrdi3): Remove.
(<shift_insn><mode>3): New define_expand.
(<shift_insn>hi3_430): New define_insn.
(<shift_insn>si3_const): Likewise.
(ashl<mode>3_430x): Likewise.
(ashr<mode>3_430x): Likewise.
(lshr<mode>3_430x): Likewise.
(*bitbranch<mode>4_z): Replace renamed predicate msp430_bitpos with
const_0_to_15_operand.
* config/msp430/msp430.opt: New option -mmax-inline-shift=.
* config/msp430/predicates.md (const_1_to_8_operand): New predicate.
(const_0_to_15_operand): Rename msp430_bitpos predicate.
(const_1_to_19_operand): New predicate.
* doc/invoke.texi: Document -mmax-inline-shift=.
Jonathan Wakely [Wed, 26 Aug 2020 18:32:30 +0000 (19:32 +0100)]
libstdc++: Use correct argument type for __use_alloc [PR 96803]
The _Tuple_impl constructor for allocator-extended construction from a
different tuple type uses the _Tuple_impl's own _Head type in the
__use_alloc test. That is incorrect, because the argument tuple could
have a different type. Using the wrong type might select the
leading-allocator convention when it should use the trailing-allocator
convention, or vice versa.
libstdc++-v3/ChangeLog:
PR libstdc++/96803
* include/std/tuple
(_Tuple_impl(allocator_arg_t, Alloc, const _Tuple_impl<U...>&)):
Replace parameter pack with a type parameter and a pack and pass
the first type to __use_alloc.
* testsuite/20_util/tuple/cons/96803.cc: New test.
Jonathan Wakely [Wed, 26 Aug 2020 16:30:31 +0000 (17:30 +0100)]
libstdc++: Fix regression in hash containers
A recent change altered the layout of EBO-helper base classes, resulting
in an ambiguity when the hash function and equality predicate are the
same type.
This modifies the type of one of the base classes, so that we don't get
two base classes of the same type.
libstdc++-v3/ChangeLog:
* include/bits/hashtable_policy.h (_Hash_code_base): Change
index of _Hashtable_ebo_helper base class.
* testsuite/23_containers/unordered_map/dup_types.cc: New test.
Aldy Hernandez [Tue, 4 Aug 2020 04:50:38 +0000 (06:50 +0200)]
Adjust tree-ssa-dom.c for irange API.
This removes all uses of VR_ANTI_RANGE.
gcc/ChangeLog:
* tree-ssa-dom.c (simplify_stmt_for_jump_threading): Abstract code out to...
* tree-vrp.c (find_case_label_range): ...here. Rewrite for to use irange
API.
(simplify_stmt_for_jump_threading): Call find_case_label_range instead of
duplicating the code in simplify_stmt_for_jump_threading.
* tree-vrp.h (find_case_label_range): New prototype.
Richard Biener [Wed, 26 Aug 2020 13:12:17 +0000 (15:12 +0200)]
tree-optimization/96698 - fix ICE when vectorizing nested cycles
This fixes vectorized PHI latch edge updating and delay it until
all of the loop is code generated to deal with the case that the
latch def is a PHI in the same block.
2020-08-26 Richard Biener <rguenther@suse.de>
PR tree-optimization/96698
* tree-vectorizer.h (loop_vec_info::reduc_latch_defs): New.
(loop_vec_info::reduc_latch_slp_defs): Likewise.
* tree-vect-stmts.c (vect_transform_stmt): Only record
stmts to update PHI latches from, perform the update ...
* tree-vect-loop.c (vect_transform_loop): ... here after
vectorizing those PHIs.
(info_for_reduction): Properly handle non-reduction PHIs.
Jonathan Wakely [Wed, 26 Aug 2020 13:47:51 +0000 (14:47 +0100)]
libstdc++: Enable assertions in constexpr string_view members [PR 71960]
Since GCC 6.1 there is no reason we can't just use __glibcxx_assert in
constexpr functions in string_view. As long as the condition is true,
there will be no call to std::__replacement_assert that would make the
function ineligible for constant evaluation.
Patrick Palka [Wed, 26 Aug 2020 13:29:39 +0000 (09:29 -0400)]
libstdc++: Add missing coauthors to ChangeLog entry
The corresponding commit had the Co-authored-by: lines in the middle of
the commit message instead of at the end, so the ChangeLog script didn't
consider them.
Richard Biener [Wed, 26 Aug 2020 12:24:01 +0000 (14:24 +0200)]
tree-optimization/96783 - fix vectorization of negative step SLP
This appropriately uses VMAT_ELEMENTWISE when the vectors cannot be
filled from a single SLP group until we get more explicit support
for negative stride SLP.
2020-08-26 Richard Biener <rguenther@suse.de>
PR tree-optimization/96783
* tree-vect-stmts.c (get_group_load_store_type): Use
VMAT_ELEMENTWISE for negative strides when we cannot
use VMAT_STRIDED_SLP.
* gcc.dg/vect/pr96783-1.c: New testcase.
* gcc.dg/vect/pr96783-2.c: Likewise.
Nathan Sidwell [Tue, 25 Aug 2020 19:35:07 +0000 (12:35 -0700)]
c++: template operator lookup caching
Jason's fix to retain operator lookups inside dependent lambda
functions turns out to be needed on the modules branch for all
template functions. Because the context for that lookup no longer
exists in imports. There were also a couple of shortcomings, which
this patch fixes.
(a) we conflate 'we found nothing' and 'we can redo this at
instantiation time'. Fixed by making the former produce
error_mark_node. That needs a fix in name-lookup to know that finding
a binding containing error_mark_node, means 'stop looking' you found
nothing.
(b) we'd continually do lookups for every operator, if nothing needed
to be retained. Fixed by always caching that information, and then
dealing with it when pushing the bindings.
(c) if what we found was that find by a global namespace lookup, we'd
not cache that. But that'd cause us to either find decls declared
after the template, potentially hiding those we expected to find. So
don't do that check.
This still retains only recording on lambdas. As the comment says, we
could enable for all templates.
gcc/cp/
* decl.c (poplevel): A local-binding tree list holds the name in
TREE_PURPOSE.
* name-lookup.c (update_local_overload): Add id to TREE_PURPOSE.
(lookup_name_1): Deal with local-binding error_mark_node marker.
(op_unqualified_lookup): Return error_mark_node for 'nothing
found'. Retain global binding, check class binding here.
(maybe_save_operator_binding): Reimplement to always cache a
result.
(push_operator_bindings): Deal with 'ignore' marker.
gcc/testsuite/
* g++.dg/lookup/operator-1.C: New.
* g++.dg/lookup/operator-2.C: New.
Jakub Jelinek [Wed, 26 Aug 2020 08:30:15 +0000 (10:30 +0200)]
dwarf2out: Fix up dwarf2out_next_real_insn caching [PR96729]
The addition of NOTE_INSN_BEGIN_STMT and NOTE_INSN_INLINE_ENTRY notes
reintroduced quadratic behavior into dwarf2out_var_location.
This function needs to know the next real instruction to which the var
location note applies, but the way final_scan_insn is called outside of
final.c main loop doesn't make it easy to look up the next real insn in
there (and for non-dwarf it is even useless). Usually next real insn is
only a few notes away, but we can have hundreds of thousands of consecutive
notes only followed by a real insn. dwarf2out_var_location to avoid the
quadratic behavior contains a cache, it remembers the next note and when it
is called again on that loc_note, it can use the previously computed
dwarf2out_next_real_insn result, rather than walking the insn chain once
again. But, for NOTE_INSN_{BEGIN_STMT,INLINE_ENTRY} dwarf2out_var_location
is not called while the code puts into the cache those notes, which means if
we have e.g. in the worst case NOTE_INSN_VAR_LOCATION and
NOTE_INSN_BEGIN_STMT notes alternating, the cache is not really used.
The following patch fixes it by looking up the next NOTE_INSN_VAR_LOCATION
if any. While the lookup could be perhaps done together with looking for
the next real insn once (e.g. in dwarf2out_next_real_insn or its copy),
there are other dwarf2out_next_real_insn callers which don't need/want that
behavior and if there are more than two NOTE_INSN_VAR_LOCATION notes
followed by the same real insn, we need to do that "find next
NOTE_INSN_VAR_LOCATION" walk anyway.
On the testcase from the PR this patch speeds it 2.8times, from 0m0.674s
to 0m0.236s (why it takes for the reporter more than 60s is unknown).
2020-08-26 Jakub Jelinek <jakub@redhat.com>
PR debug/96729
* dwarf2out.c (dwarf2out_next_real_insn): Adjust function comment.
(dwarf2out_var_location): Look for next_note only if next_real is
non-NULL, in that case look for the first non-deleted
NOTE_INSN_VAR_LOCATION between loc_note and next_real, if any.
Iain Buclaw [Tue, 4 Aug 2020 16:11:51 +0000 (18:11 +0200)]
libiberty: Add support for `in' and `in ref' storage classes.
The storage class `in' is now a first-class citizen with its own mangle
symbol, of which also permits `in ref'. Previously, `in' was an alias
to `const [scope]', which is a type constructor.
The mangle symbol repurposed for this is `I', which was originally used
by identifier types. However, while TypeIdentifier is part of the
grammar, it must be resolved to some other entity during the semantic
passes, and so shouldn't appear anywhere in the mangled name.
Old tests that are now no longer valid have been removed.
1. Removes prelude assert for constructors and destructors. To trigger
these asserts one needed to construct or destruct an aggregate at the
null memory location. This would crash upon any data member access,
which is required for a constructor or destructor to do anything useful.
2. Disables bounds checking in foreach statements, when the array is
either a static or dynamic array. If we trust the array `.length' to
be correct, then all elements are between `[0 .. length]', and can't
can't be out of bounds.
d: Fix no RVO when returning struct literals initialized with constructor.
Backports a change from upstream dmd that moves front-end NRVO checking
from ReturnStatement semantic to the end of FuncDeclaration semantic.
In the codegen, retStyle has been partially implemented so that only
structs and static arrays return RETstack. This isn't accurate, but
don't need to be for the purposes of semantic analysis.
If a function either has TREE_ADDRESSABLE or must return in memory, then
DECL_RESULT is set as the shidden field for the function. This is used
in the codegen pass for ReturnStatement where it is now detected whether
a function is returning a struct literal or a constructor function, then
the DECL_RESULT is used to directly construct the return value, instead
of doing so via temporaries.
PR d/96156
* d-frontend.cc (retStyle): Only return RETstack for struct and static
array types.
* decl.cc (DeclVisitor::visit (FuncDeclaration *)): Use NRVO return
for all TREE_ADDRESSABLE types. Set shidden to the RESULT_DECL.
* expr.cc (ExprVisitor::visit (CallExp *)): Force TARGET_EXPR if the
'this' pointer reference is a CONSTRUCTOR.
(ExprVisitor::visit (StructLiteralExp *)): Generate assignment to the
symbol to initialize with literal.
* toir.cc (IRVisitor::visit (ReturnStatement *)): Detect returning
struct literals and write directly into the RESULT_DECL.
* dmd/MERGE: Merge upstream dmd fe5f388d8.
Iain Buclaw [Tue, 25 Aug 2020 09:56:18 +0000 (11:56 +0200)]
tilepro: Update generator file to define IN_TARGET_CODE in target file.
The target files tilegx/mul-tables.c and tilepri/mul-tables.c were
updated in SVN r255743, but the generator file that produces them
wasn't, so it was reverting this change during builds.
gcc/ChangeLog:
* config/tilepro/gen-mul-tables.cc (main): Define IN_TARGET_CODE to 1
in the target file.
* d-lang.cc (d_parse_file): Use read() to load contents from stdin,
allow the front-end to free the memory after parsing.
* dmd/MERGE: Merge upstream dmd 2cc25c219.
Iain Buclaw [Tue, 25 Aug 2020 09:05:57 +0000 (11:05 +0200)]
d: Fix small struct literals that have non-deterministic hash values
Same issue as the initial commit that addressed PR96153, only this time to fix
it also for structs that are not returned in memory. Tests have been added
that triggered an assertion on x86_64, however the original test was failing
on SPARC 64-bit targets.
gcc/d/ChangeLog:
PR d/96153
* d-codegen.cc (build_address): Create a temporary for CALL_EXPRs
returning trivial aggregates, pre-filling it with zeroes.
(build_memset_call): Use build_zero_cst if setting the entire object.
Iain Buclaw [Mon, 24 Aug 2020 22:39:17 +0000 (00:39 +0200)]
d: Fix no NRVO when returning an array of a non-POD struct
TREE_ADDRESSABLE was not propagated from the RECORD_TYPE to the ARRAY_TYPE, so
NRVO code generation was not being triggered.
gcc/d/ChangeLog:
PR d/96157
* d-codegen.cc (d_build_call): Handle TREE_ADDRESSABLE static arrays.
* types.cc (make_array_type): Propagate TREE_ADDRESSABLE from base
type to static array.
gcc/testsuite/ChangeLog:
PR d/96157
* gdc.dg/pr96157a.d: New test.
* gdc.dg/pr96157b.d: New test.
Iain Buclaw [Fri, 21 Aug 2020 10:24:20 +0000 (12:24 +0200)]
d: Move lowering of each tree node to separate functions
gcc/d/ChangeLog:
* d-gimplify.cc (d_gimplify_expr): Move lowering of each tree node to
separate functions.
(d_gimplify_modify_expr): New function.
(d_gimplify_addr_expr): New function.
(d_gimplify_call_expr): New function.
(d_gimplify_unsigned_rshift_expr): New function.
François Dumont [Mon, 20 Jan 2020 07:21:10 +0000 (08:21 +0100)]
libstdc++: Rename _Hashtable _H1, _H2 and _Hash template parameters
Limit our _Hashtable implementation to ranged hash. _H1 is now rename
to _Hash matching the _Hash functor used for unordered containers. _H2
is now renamed to _RangeHash. Former _Hash simply becomes _Unused. Remove
_ExtractKey storage.
David Malcolm [Fri, 21 Aug 2020 22:34:16 +0000 (18:34 -0400)]
analyzer: fix leak false positive/widening on pointer iteration [PR94858]
PR analyzer/94858 reports a false diagnostic from
-Wanalyzer-malloc-leak, where the allocated pointer is pointed to by a
field of a struct, and a loop writes to a buffer, writing through an
iterating pointer value.
There were several underlying problems, relating to clobbering of the
struct holding the malloc-ed pointer; in each case the analyzer was
conservatively assuming that a write could affect this region,
clobbering it to "unknown", and this was detected as a leak.
The initial write within the loop dereferences the initial value of
a field, and the analyzer was assuming that that pointer could
point to the result of the malloc call. The patch extends
store::eval_alias_1 so that it "knows" that the initial value of a
pointer at the beginning of a path can't point to a region that was
allocated on the heap after the beginning of the path.
On fixing that, the next issue is that within the loop the iterated
pointer value becomes "unknown", and hence *ptr becomes a write to a
symbolic region, and thus might clobber the struct (which it can't).
This patch adds enough logic to svalue::can_merge_p to merge the
iterating pointer value so that at the 2nd iteration analyzing
the loop it becomes a widening_svalue from the initial svalue, so
that this becomes a fixed point of the analysis, and is not an
unknown_svalue. The patch further extends store::eval_alias_1 so that
it "knows" that this widening_svalue can only point to the same base
region as the initial value did; in particular, symbolic writes through
this pointer can only clobber that base region, not the struct holding
the malloc-ed pointer.
gcc/analyzer/ChangeLog:
PR analyzer/94858
* region-model-manager.cc
(region_model_manager::get_or_create_widening_svalue): Assert that
neither of the inputs are themselves widenings.
* store.cc (store::eval_alias_1): The initial value of a pointer
can't point to a region that was allocated on the heap after the
beginning of the path. A widened pointer value can't alias anything
that the initial pointer value can't alias.
* svalue.cc (svalue::can_merge_p): Merge BINOP (X, OP, CST) with X
to a widening svalue. Merge
BINOP(WIDENING(BASE, BINOP(BASE, X)), X) and BINOP(BASE, X) to
to the LHS of the first BINOP.
gcc/testsuite/ChangeLog:
PR analyzer/94858
* gcc.dg/analyzer/loop-start-up-to-end-by-1.c: Remove xfail.
* gcc.dg/analyzer/pr94858-1.c: New test.
* gcc.dg/analyzer/pr94858-2.c: New test.
* gcc.dg/analyzer/torture/loop-inc-ptr-2.c: Update expected number
of enodes.
* gcc.dg/analyzer/torture/loop-inc-ptr-3.c: Likewise.
David Malcolm [Tue, 25 Aug 2020 13:26:05 +0000 (09:26 -0400)]
analyzer: fix ICE on initializers for unsized array fields [PR96777]
gcc/analyzer/ChangeLog:
PR analyzer/96777
* region-model.h (class compound_svalue): Document that all keys
must be concrete.
(compound_svalue::compound_svalue): Move definition to svalue.cc.
* store.cc (binding_map::apply_ctor_to_region): Handle
initializers for trailing arrays with incomplete size.
* svalue.cc (compound_svalue::compound_svalue): Move definition
here from region-model.h. Add assertion that all keys are
concrete.
gcc/testsuite/ChangeLog:
PR analyzer/96777
* gcc.dg/analyzer/pr96777.c: New test.
H.J. Lu [Fri, 26 Jun 2020 21:56:40 +0000 (14:56 -0700)]
x86: Change CTZ_DEFINED_VALUE_AT_ZERO to return 0/2
Change CTZ_DEFINED_VALUE_AT_ZERO/CTZ_DEFINED_VALUE_AT_ZERO to return 0/2
to enable table-based clz/ctz optimization:
-- Macro: CLZ_DEFINED_VALUE_AT_ZERO (MODE, VALUE)
-- Macro: CTZ_DEFINED_VALUE_AT_ZERO (MODE, VALUE)
A C expression that indicates whether the architecture defines a
value for 'clz' or 'ctz' with a zero operand. A result of '0'
indicates the value is undefined. If the value is defined for only
the RTL expression, the macro should evaluate to '1'; if the value
applies also to the corresponding optab entry (which is normally
the case if it expands directly into the corresponding RTL), then
the macro should evaluate to '2'. In the cases where the value is
defined, VALUE should be set to this value.
This is my proposed fix to PR middle-end/87256 where synth_mult takes an
unreasonable amount of CPU time determining an optimal sequence of
instructions to perform multiplication by (large) integer constants on hppa.
One workaround proposed in bugzilla, is to increase the hash table used
to cache/reuse intermediate results. This helps but is a workaround for
the (hidden) underlying problem.
The real issue is that the hppa_rtx_costs function is providing wildly
inaccurate values (estimates) to the middle-end. For example, (p*q)+(r*s)
would appear to be cheaper than a single multiplication. Another
example is that "(ashiftrt:di regA regB)" is claimed to be only be
COST_N_INSNS(1) when in fact the hppa backend actually generates
slightly more than a single instruction.
It turns out that simply tightening up the logic in hppa_rtx_costs to
return more reasonable values, dramatically reduces the number of recursive
invocations in synth_mult for the test case in PR87256, and presumably
also produces faster code (that should be observable in benchmarks).
2020-08-25 Roger Sayle <roger@nextmovesoftware.com>
gcc/ChangeLog
PR middle-end/87256
* config/pa/pa.c (hppa_rtx_costs_shadd_p): New helper function
to check for coefficients supported by shNadd and shladd,l.
(hppa_rtx_costs): Rewrite to avoid using estimates based upon
FACTOR and enable recursing deeper into RTL expressions.
Roger Sayle [Tue, 25 Aug 2020 17:57:55 +0000 (18:57 +0100)]
hppa: Improve expansion of ashldi3 when !TARGET_64BIT
This patch improves the code generated on PA-RISC for DImode
(double word) left shifts by small constants (1-31). This target
has a very cool shd instruction that can be recognized by combine
for simple shifts, but relying on combine is fragile for more
complicated functions. This patch tweaks pa.md's ashldi3 expander,
to form the optimal two instruction shd/zdep sequence at RTL
expansion time.
As an example of the benefits of this approach, the simple function
unsigned long long u9(unsigned long long x) { return x*9; }
currently generates 9 instructions and with this patch now requires
only 7.
2020-08-25 Roger Sayle <roger@nextmovesoftware.com>
* config/pa/pa.md (ashldi3): Additionally, on !TARGET_64BIT
generate a two instruction shd/zdep sequence when shifting
registers by suitable constants.
(shd_internal): New define_expand to provide gen_shd_internal.
Jonathan Wakely [Tue, 25 Aug 2020 15:30:45 +0000 (16:30 +0100)]
libstdc++: Remove tests for self-move debug assertions
I recently removed the debug mode checks for self-move assignment, which
means these tests now fail when _GLIBCXX_DEBUG is added to the options
or when the check-debug target is used. Remove all the tests.
Patrick Palka [Tue, 25 Aug 2020 14:23:59 +0000 (10:23 -0400)]
libstdc++: Add more C++20 additions to <chrono>
This patch adds the C++20 calendar types and their methods as defined in
[time.cal] (modulo the parsing/printing support). This patch also
implements [time.hms] and [time.12], and a few more bits of
[time.clock]. The remaining C++20 additions to <chrono> from P0355 and
P1466 depend on [time.zone] and <format>, so they will come later, as
will more optimized versions of some of the algorithms added here.
The non-member operator overloads for the calendar types are defined as
namespace-scope functions in the standard, but here we instead define
these operator overloads as hidden friends. This simplifies the
implementation somewhat and lets us reap the benefits of hidden friends
for these overloads.
The bulk of this work is based on a patch from Ed Smith-Rowland, which can
be found at the Git branch users/redi/heads/calendar.
Co-authored-by: Ed Smith-Rowland <3dw4rd@verizon.net> Co-authored-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/std/chrono (time_point::operator++)
(time_point::operator--): Define.
(utc_clock, tai_clock, gps_clock): Forward declare.
(utc_time, utc_seconds, tai_time, tai_seconds, gps_time)
(gps_seconds): Define.
(is_clock<utc_clock>, is_clock<tai_clock>, is_clock<gps_clock>)
(is_clock_v<utc_clock>, is_clock_v<tai_clock>)
(is_clock_v<gps_clock>): Define these specializations.
(leap_second_info): Define.
(day, month, year, weekday, weekday_indexed)
(weekday_last, month_day, month_day_last, month_weekday)
(month_weekday_last, year_month, year_month_day)
(year_month_day_last, year_month_weekday, year_month_weekday_last):
Declare and later define.
(last_spec, last, __detail::__days_per_month)
(__detail::__days_per_month, __detail::__last_day): Define.
(January, February, March, April, May, June, July, August)
(September, October, November, December, Sunday, Monday, Tuesday)
(Wednesday, Thursday, Friday, Saturday): Define.
(weekday::operator[]): Define out-of-line.
(year_month_day::_S_from_days, year_month_day::M_days_since_epoch):
Likewise.
(year_month_day::year_month_day, year_month_day::ok): Likewise.
(__detail::__pow10, hh_mm_ss): Define.
(literals::chrono_literals::operator""d)
(literals::chrono_literals::operator""y): Define.
(is_am, is_pm, make12, make24): Define.
* testsuite/20_util/time_point/4.cc: New test.
* testsuite/std/time/day/1.cc: New test.
* testsuite/std/time/hh_mm_ss/1.cc: New test.
* testsuite/std/time/is_am/1.cc: New test.
* testsuite/std/time/is_pm/1.cc: New test.
* testsuite/std/time/make12/1.cc: New test.
* testsuite/std/time/make24/1.cc: New test.
* testsuite/std/time/month/1.cc: New test.
* testsuite/std/time/month_day/1.cc: New test.
* testsuite/std/time/month_day_last/1.cc: New test.
* testsuite/std/time/month_weekday/1.cc: New test.
* testsuite/std/time/month_weekday_last/1.cc: New test.
* testsuite/std/time/weekday/1.cc: New test.
* testsuite/std/time/weekday_indexed/1.cc: New test.
* testsuite/std/time/weekday_last/1.cc: New test.
* testsuite/std/time/year/1.cc: New test.
* testsuite/std/time/year_month/1.cc: New test.
* testsuite/std/time/year_month_day/1.cc: New test.
* testsuite/std/time/year_month_day_last/1.cc: New test.
* testsuite/std/time/year_month_weekday/1.cc: New test.
* testsuite/std/time/year_month_weekday_last/1.cc: New test.
aarch64: Tweaks to the handling of fixed-length SVE types
This patch is really four things rolled into one, since separating
them seemed artificial:
- Update the mangling of the fixed-length SVE ACLE types to match
the upcoming spec. The idea is to mangle:
VLAT __attribute__((arm_sve_vector_bits(N)))
as an instance __SVE_VLS<VLAT, N> of the template:
__SVE_VLS<typename, unsigned>
- Give the fixed-length types their own TYPE_DECL. This is needed
to make the above mangling fix work, but should also be a minor
QoI improvement for error reporting. Unfortunately, the names are
quite verbose, e.g.:
Previously we would complain that the type isn't an SVE type;
now we complain that it isn't a vector type.
- Don't allow arm_sve_vector_bits(N) to be applied to existing
fixed-length SVE types.
gcc/
* config/aarch64/aarch64-sve-builtins.cc (add_sve_type_attribute):
Take the ACLE name of the type as a parameter and add it as fourth
argument to the "SVE type" attribute.
(register_builtin_types): Update call accordingly.
(register_tuple_type): Likewise. Construct the name of the type
earlier in order to do this.
(get_arm_sve_vector_bits_attributes): New function.
(handle_arm_sve_vector_bits_attribute): Report a more sensible
error message if the attribute is applied to an SVE tuple type.
Don't allow the attribute to be applied to an existing fixed-length
SVE type. Mangle the new type as __SVE_VLS<type, vector-bits>.
Add a dummy TYPE_DECL to the new type.
gcc/testsuite/
* g++.target/aarch64/sve/acle/general-c++/attributes_2.C: New test.
* g++.target/aarch64/sve/acle/general-c++/mangle_6.C: Likewise.
* g++.target/aarch64/sve/acle/general-c++/mangle_7.C: Likewise.
* g++.target/aarch64/sve/acle/general-c++/mangle_8.C: Likewise.
* g++.target/aarch64/sve/acle/general-c++/mangle_9.C: Likewise.
* g++.target/aarch64/sve/acle/general-c++/mangle_10.C: Likewise.
* gcc.target/aarch64/sve/acle/general/attributes_7.c: Check the
error messages reported when arm_sve_vector_bits is applied to
SVE tuple types or to existing fixed-length SVE types.
aarch64: Update the mangling of single SVE vectors and predicates
GCC was implementing an old mangling scheme for single SVE
vectors and predicates (based on the Advanced SIMD one).
The final definition instead put them in the vendor built-in
namespace via the "u" prefix.
gcc/
* config/aarch64/aarch64-sve-builtins.cc (DEF_SVE_TYPE): Add a
leading "u" to each mangled name.
gcc/testsuite/
* g++.target/aarch64/sve/acle/general-c++/mangle_1.C: Add a leading
"u" to the mangling of each SVE vector and predicate type.
* g++.target/aarch64/sve/acle/general-c++/mangle_2.C: Likewise.
* g++.target/aarch64/sve/acle/general-c++/mangle_3.C: Likewise.
* g++.target/aarch64/sve/acle/general-c++/mangle_5.C: Likewise.
Jakub Jelinek [Tue, 25 Aug 2020 11:49:40 +0000 (13:49 +0200)]
gimple: Ignore *0 = {CLOBBER} in path isolation [PR96722]
Clobbers of MEM_REF with NULL address are just fancy nops, something we just
ignore and don't emit any code for it (ditto for other clobbers), they just
mark end of life on something, so we shouldn't infer from those that there
is some UB.
Jakub Jelinek [Tue, 25 Aug 2020 11:47:10 +0000 (13:47 +0200)]
strlen: Fix handle_builtin_string_cmp [PR96758]
The following testcase is miscompiled, because handle_builtin_string_cmp
sees a strncmp call with constant last argument 4, where one of the strings
has an upper bound of 5 bytes (due to it being an array of that size) and
the other has a known string length of 1 and the result is used only in
equality comparison.
It is folded into __builtin_strncmp_eq (str1, str2, 4), which is
incorrect, because that means reading 4 bytes from both strings and
comparing that. When one of the strings has known strlen of 1, we want to
compare just 2 bytes, not 4, as strncmp shouldn't compare any bytes beyond
the null.
So, the last argument to __builtin_strncmp_eq should be the minimum of the
provided strncmp last argument and the known string length + 1 (assuming
the other string has only a known upper bound due to array size).
Besides that, I've noticed the code has been written with the intent to also
support the case where we know exact string length of both strings (but not
the string content, so we can't compute it at compile time). In that case,
both cstlen1 and cstlen2 are non-negative and both arysiz1 and arysiz2 are
negative. We wouldn't optimize that, cmpsiz would be either the strncmp
last argument, or for strcmp the first string length, but varsiz would be
-1 and thus cmpsiz would be never < varsiz. The patch fixes it by using the
correct length, in that case using the minimum of the two and for strncmp
also the last argument.
2020-08-25 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/96758
* tree-ssa-strlen.c (handle_builtin_string_cmp): If both cstlen1
and cstlen2 are set, set cmpsiz to their minimum, otherwise use the
one that is set. If bound is used and smaller than cmpsiz, set cmpsiz
to bound. If both cstlen1 and cstlen2 are set, perform the optimization.
Martin Jambor [Tue, 25 Aug 2020 11:33:44 +0000 (13:33 +0200)]
sra: Bail out when encountering accesses with negative offsets (PR 96730)
I must admit I was quite surprised to see that SRA does not disqualify
an aggregate from any transformations when it encounters an offset for
which get_ref_base_and_extent returns a negative offset. It may not
matter too much because I sure hope such programs always have
undefined behavior (SRA candidates are local variables on stack) but
it is probably better not to perform weird transformations on them as
build ref model with the new build_reconstructed_reference function
currently happily do for negative offsets (they just copy the existing
expression which is then used as the expression of a "propagated"
access) and of course the compiler must not ICE (as it currently does
because the SRA forest verifier does not like the expression).
gcc/ChangeLog:
2020-08-24 Martin Jambor <mjambor@suse.cz>
PR tree-optimization/96730
* tree-sra.c (create_access): Disqualify any aggregate with negative
offset access.
(build_ref_for_model): Add assert that offset is non-negative.
gcc/testsuite/ChangeLog:
2020-08-24 Martin Jambor <mjambor@suse.cz>
PR tree-optimization/96730
* gcc.dg/tree-ssa/pr96730.c: New test.
PR tree-optimization/21137 is now an old enhancement request pointing out
that an optimization I added back in 2006, to optimize "((x>>31)&64) != 0"
as "x < 0", doesn't fire in the presence of unanticipated type conversions.
The fix is to call STRIP_NOPS at the appropriate point.
2020-08-25 Roger Sayle <roger@nextmovesoftware.com>
gcc/ChangeLog
PR tree-optimization/21137
* fold-const.c (fold_binary_loc) [NE_EXPR/EQ_EXPR]: Call
STRIP_NOPS when checking whether to simplify ((x>>C1)&C2) != 0.
gcc/testsuite/ChangeLog
PR tree-optimization/21137
* gcc.dg/pr21137.c: New test.
Andrew Pinski [Tue, 25 Aug 2020 06:17:52 +0000 (14:17 +0800)]
MIPS: Fix __builtin_longjmp (PR 64242)
The problem here is mips has its own builtin_longjmp
pattern and it was not fixed when expand_builtin_longjmp
was fixed. We need to read the new fp and gp before
restoring the stack as the buffer might be a local
variable.
2020-08-25 Andrew Pinski <apinski@marvell.com>
gcc/ChangeLog:
PR middle-end/64242
* config/mips/mips.md (builtin_longjmp): Restore the frame
pointer and stack pointer and gp.
Richard Biener [Mon, 24 Aug 2020 12:12:01 +0000 (14:12 +0200)]
debug/96690 - mangle symbols eventually used by late dwarf output
The following makes sure to, at early debug generation time, mangle
symbols we eventually end up outputting during late finish.
2020-08-24 Richard Biener <rguenther@suse.de>
PR debug/96690
* dwarf2out.c (reference_to_unused): Make FUNCTION_DECL
processing more consistent with respect to
symtab->global_info_ready.
(tree_add_const_value_attribute): Unconditionally call
rtl_for_decl_init to do all mangling early but throw
away the result if early_dwarf.
Jakub Jelinek [Tue, 25 Aug 2020 05:21:26 +0000 (07:21 +0200)]
match.pd: Simplify copysign (x, -x) to -x [PR96715]
The following patch implements an optimization suggested in the PR,
copysign(x,-x) can be optimized into -x (even without -ffast-math,
should work fine even for signed zeros and infinities or nans).
2020-08-25 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/96715
* match.pd (copysign(x,-x) -> -x): New simplification.
Jakub Jelinek [Tue, 25 Aug 2020 05:19:41 +0000 (07:19 +0200)]
c++: Fix up ptr.~PTR () handling [PR96721]
The following testcase is miscompiled, because build_trivial_dtor_call
handles the case when instance is a pointer by adding a clobber to what
the pointer points to (which is desirable e.g. for delete) rather than the
pointer itself. That is I think always desirable behavior for references,
but for pointers for the pseudo dtor case it is not.
2020-08-25 Jakub Jelinek <jakub@redhat.com>
PR c++/96721
* cp-tree.h (build_trivial_dtor_call): Add bool argument defaulted
to false.
* call.c (build_trivial_dtor_call): Add NO_PTR_DEREF argument. If
instance is a pointer and NO_PTR_DEREF is true, clobber the pointer
rather than what it points to.
* semantics.c (finish_call_expr): Call build_trivial_dtor_call with
true as NO_PTR_DEREF.
Jakub Jelinek [Tue, 25 Aug 2020 05:17:10 +0000 (07:17 +0200)]
gimple-fold: Don't optimize wierdo floating point value reads [PR95450]
My patch to introduce native_encode_initializer to fold_ctor_reference
apparently broke gnulib/m4 on powerpc64.
There it uses a const union with two doubles and corresponding IBM double
double long double which actually is the largest normalizable long double
value (1 ulp higher than __LDBL_MAX__). The reason our __LDBL_MAX__ is
smaller is that we internally treat the double double type as one having
106-bit precision, but it actually has a variable 53-bit to 2000-ish bit precision
and for the
0x1.fffffffffffff7ffffffffffffc000p+1023L
value gnulib uses we need 107-bit precision, therefore for GCC __LDBL_MAX__
is
0x1.fffffffffffff7ffffffffffff8000p+1023L
Before my changes, we wouldn't be able to fold_ctor_reference it and it
worked fine at runtime, but with the change we are able to do that, but
because it is larger than anything we can handle internally, we treat it
weirdly. Similar problem would be if somebody creates this way valid,
but much more than 106 bit precision e.g. 1.0 + 1.0e-768.
Now, I think similar problem could happen e.g. on i?86/x86_64 with long
double there, it also has some weird values in the format, e.g. the
unnormals, pseudo infinities and various other magic values.
This patch for floating point types (including vector and complex types
with such elements) will try to encode the returned value again and punt
if it has different memory representation from the original. Note, this
is only done in the path where native_encode_initializer was used, in order
not to affect e.g. just reading an unpunned long double value; the value
should be compiler generated in that case and thus should be properly
representable. It will punt also if e.g. the padding bits are initialized
to non-zero values.
I think the verification that what we encode can be interpreted back
woiuld be only an internal consistency check (so perhaps for ENABLE_CHECKING
if flag_checking only, but if both directions perform it, then we need
to avoid mutual recursion).
While for the other direction (interpretation), at least for the broken by
design long doubles we just know we can't represent in GCC all valid values.
The other floating point formats are just theoretical case, perhaps we would
canonicalize something to a value that wouldn't trigger invalid exception
when without canonicalization it would trigger it at runtime, so let's just
ignore those.
Adjusted (so far untested) patch to do it in native_interpret_real instead
and limit it to the MODE_COMPOSITE_P cases, for which e.g.
fold-const.c/simplify-rtx.c punts in several other places too because we just
know we can't represent everything.
E.g.
/* Don't constant fold this floating point operation if the
result may dependent upon the run-time rounding mode and
flag_rounding_math is set, or if GCC's software emulation
is unable to accurately represent the result. */
if ((flag_rounding_math
|| (MODE_COMPOSITE_P (mode) && !flag_unsafe_math_optimizations))
&& (inexact || !real_identical (&result, &value)))
return NULL_TREE;
Or perhaps guard it with MODE_COMPOSITE_P (mode) && !flag_unsafe_math_optimizations
too, thus break what gnulib / m4 does with -ffast-math, but not normally?
2020-08-25 Jakub Jelinek <jakub@redhat.com>
PR target/95450
* fold-const.c (native_interpret_real): For MODE_COMPOSITE_P modes
punt if the to be returned REAL_CST does not encode to the bitwise
same representation.
Jason Merrill [Fri, 21 Aug 2020 20:23:03 +0000 (16:23 -0400)]
c++: Emit as-base 'tor symbols for final class. [PR95428]
For PR70462 I stopped emitting the as-base constructor and destructor
variants for final classes, because they can never be called. Except that
it turns out that clang calls base variants from complete variants, even for
classes with virtual bases, and in some cases inlines them such that the
calls to the base variant are exposed. So we need to continue to emit the
as-base symbols, even though they're unreachable by G++-compiled code.
This implements the proposed resolution of LWG 3446. I'm also adding
another new constrained specialization which isn't proposed by 3446, to
resolve the ambiguity when a type has both value_type and element_type
but denoting different types.
libstdc++-v3/ChangeLog:
* include/bits/iterator_concepts.h (indirectly_readable): Add
partial specializations to resolve ambiguities (LWG 3446).
* testsuite/24_iterators/associated_types/readable.traits.cc:
Check types with both value_type and element_type.
Nathan Sidwell [Mon, 24 Aug 2020 13:28:37 +0000 (06:28 -0700)]
c++: overload dumper
I frequently need to look at overload sets, and debug_node spews more
information than is useful, most of the time. Here's a dumper for
overloads, that just tells you their full name and where they came from.