Go requires that pointer moves are done 8 bytes at a time,
but gccgo uses libc's memmove and memset which does not require
that, and there are some cases where an 8 byte move might be
done as 4+4.
To enforce 8 byte moves for memmove and memset, this adds a
C implementation in libgo/runtime for memmove and memset to be
used on ppc64le and ppc64. Asm implementations were considered
but discarded to avoid different implementations for different
target ISAs.
Fixesgolang/go#41428
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/294931
In gcc/analyzer/diagnostic-manager.cc the code partitions
saved_diagnostic instances by dedupe_key, and tries to find the "best"
saved_diagnostic for each dedupe_key.
Ideally we would find the shortest feasible path for each
saved_diagnostic and pick the winner in each deduplication set.
Currently we merely approximate that by finding the shortest path for
each saved_diagnostic, and checking to see if it feasible, rejecting
the saved_diagnostic if it is not. The "shortest path, or nothing if
it's infeasible" is not the same as the "shortest feasible path", and
this leads to false negatives, where we reject valid diagnostics,
tracked as PR analyzer/96374.
I have been attempting various fixes for this, but in doing so I
found that the existing structure of the code makes things unnecessarily
awkward: each dedupe_set had a a dedupe_candidate which stored the
best epath for that set, creating it from the shortest path when that
dedupe_candidate was constructed.
This patch eliminates the dedupe_candidate, instead storing the best
epath for each saved_diagnostic within the saved_diagnostic itself,
along with any feasibility_problem, and eliminating a redundant "status"
field. The logic for finding the best epath is moved to a new
epath_finder::get_best_epath subroutine, introducing an epath_finder
class to give a place to cache state.
This patch merely copies over the existing logic to
epath_finder::get_best_epath, so no functional change is intended,
but the patch simplifies the logic and makes it much easier to
experiment with alternate implementations as I try to fix
PR analyzer/96374.
I attempted another version of this patch in which I added a dedupe_set
class and partitioned saved_diagnostics into them as the diagnostics were
added, but in this earlier iteration of the patch there were regressions
e.g. from gcc.dg/analyzer/zlib-4.c where 4 deduplication sets became 3.
The issue was that the deduplication logic needs source locations, which
need gimple statements, and the stmt_finder needs epaths to run. Finding
the epaths needs the full egraph (as opposed to the egraph in its state
at the time when the diagnostic is saved). Hence the partitioning needs to
happen after the egraph is fully explored. I backed up the earlier patch
kit to:
https://dmalcolm.fedorapeople.org/gcc/2021-02-23/feasibility-v0.3-relative-to-72d78655a91bb2f89ac4432cfd6374380d6f9987/
gcc/analyzer/ChangeLog:
PR analyzer/96374
* diagnostic-manager.cc (class epath_finder): New.
(epath_finder::get_best_epath): New.
(saved_diagnostic::saved_diagnostic): Update for replacement of
m_state and m_epath_length with m_best_epath.
(saved_diagnostic::~saved_diagnostic): Delete m_best_epath.
(saved_diagnostic::to_json): Update "path_length" to be optional.
(saved_diagnostic::calc_best_epath): New, based on
dedupe_winners::add and parts of dedupe_key::dedupe_key.
(saved_diagnostic::get_epath_length): New.
(saved_diagnostic::add_duplicate): New.
(dedupe_key::dedupe_key): Drop epath param. Move invocation of
stmt_finder to saved_diagnostic::calc_best_epath.
(class dedupe_candidate): Delete.
(class dedupe_hash_map_traits): Update to use saved_diagnotic *
rather than dedupe_candidate * as the value_type/compare_type.
(dedupe_winners::~dedupe_winners): Don't delete the values.
(dedupe_winners::add): Convert param from shortest_exploded_paths to
epath_finder. Drop "eg" param. Drop dedupe_candidate, moving
path generation and feasiblity checking to
epath_finder::get_best_epath. Update winner-selection for move
of epaths from dedupe_candidate to saved_diagnostic.
(dedupe_winners::emit_best): Update for removal of class
dedupe_candidate.
(dedupe_winners::map_t): Update to use saved_diagnotic * rather
than dedupe_candidate * as the value_type/compare_type.
(diagnostic_manager::emit_saved_diagnostics): Move
shortest_exploded_paths instance into epath_finder and pass that
around instead.
(diagnostic_manager::emit_saved_diagnostic): Drop epath, stmt
and num_dupes params, instead getting these from the
saved_diagnostic. Use correct location in inform_n call.
* diagnostic-manager.h (class epath_finder): New forward decl.
(saved_diagnostic::status): Drop enum.
(saved_diagnostic::set_feasible): Drop.
(saved_diagnostic::set_infeasible): Drop.
(saved_diagnostic::get_status): Drop.
(saved_diagnostic::calc_best_epath): New decl.
(saved_diagnostic::get_best_epath): New decl.
(saved_diagnostic::get_epath_length): New decl.
(saved_diagnostic::set_epath_length): Drop.
(saved_diagnostic::get_epath_length): Drop inline implementation.
(saved_diagnostic::add_duplicate): New.
(saved_diagnostic::get_num_dupes): New.
(saved_diagnostic::m_d): Document ownership.
(saved_diagnostic::m_trailing_eedge): Make const.
(saved_diagnostic::m_status): Drop field.
(saved_diagnostic::m_epath_length): Drop field.
(saved_diagnostic::m_best_epath): New field.
(saved_diagnostic::m_problem): Document ownership.
(saved_diagnostic::m_duplicates): New field.
(diagnostic_manager::emit_saved_diagnostic): Drop params epath,
stmt, and num_dupes.
* engine.cc (exploded_graph_annotator::print_saved_diagnostic):
Update for changes to saved_diagnostic class.
* exploded-graph.h (exploded_path::feasible_p): Drop unused
overloaded decl.
When an abbreviated function template has a complex placeholder return
type such auto& or auto**, the level adjustment performed by
splice_late_return_type directly replaces the 'auto' inside the original
return type with the level-adjusted 'auto', but that breaks
TYPE_CANONICAL caching. Instead, we should rebuild the entire return
type using the adjusted 'auto'.
This patch makes this happen by tsubsting the original return type with
an argument vector that maps the original 'auto' to the adjusted 'auto'.
In passing, this patch also reverts the misguided changes to
find_type_usage in r10-6571 that made find_type_usage return a tree*
instead of a tree so as to discourage this kind of in-place type
modification.
It occurred to me that the constraint also needs to be rebuilt so that
it refers to the adjusted 'auto', but this oversight doesn't seem to
cause any issues at the moment due to how do_auto_deduction "manually"
substitutes the 'auto' inside the constraint before performing
satisfaction. So this'll be fixed later as part of a rework of
placeholder type constraint checking.
gcc/cp/ChangeLog:
PR c++/98990
* pt.c (splice_late_return_type): Rebuild the entire return type
if we have to adjust the level of an auto within.
(type_uses_auto): Adjust call to find_type_usage.
* type-utils.h (find_type_usage): Revert r10-6571 change that
made this function return a pointer to the auto node.
gcc/testsuite/ChangeLog:
PR c++/98990
* g++.dg/concepts/abbrev8.C: New test.
This adds support for the task detach clause to taskwait and taskgroup, and
simplifies the handling of the detach clause by moving most of the extra
handling required for detach tasks to omp_fulfill_event.
2021-02-25 Kwok Cheung Yeung <kcy@codesourcery.com>
Jakub Jelinek <jakub@redhat.com>
libgomp/
PR libgomp/98738
* libgomp.h (enum gomp_task_kind): Add GOMP_TASK_DETACHED.
(struct gomp_task): Replace detach and completion_sem fields with
union containing completion_sem and detach_team. Add deferred_p
field.
(struct gomp_team): Remove task_detach_queue.
* task.c: Include assert.h.
(gomp_init_task): Initialize deferred_p and completion_sem fields.
Rearrange initialization order of fields.
(task_fulfilled_p): Delete.
(GOMP_task): Use address of task as the event handle. Remove
initialization of detach field. Initialize deferred_p field.
Use automatic local for completion_sem. Initialize detach_team field
for deferred tasks.
(gomp_barrier_handle_tasks): Remove handling of task_detach_queue.
Set kind of suspended detach task to GOMP_TASK_DETACHED and
decrement task_running_count. Move finish_cancelled block out of
else branch. Relocate call to gomp_team_barrier_done.
(GOMP_taskwait): Handle tasks with completion events that have not
been fulfilled.
(GOMP_taskgroup_end): Likewise.
(omp_fulfill_event): Use address of task as event handle. Post to
completion_sem for undeferred tasks. Clear detach_team if task
has not finished. For finished tasks, handle post-execution tasks,
call gomp_team_barrier_wake if necessary, and free task.
* team.c (gomp_new_team): Remove initialization of task_detach_queue.
(free_team): Remove free of task_detach_queue.
* testsuite/libgomp.c-c++-common/task-detach-1.c: Fix formatting.
* testsuite/libgomp.c-c++-common/task-detach-2.c: Fix formatting.
* testsuite/libgomp.c-c++-common/task-detach-3.c: Fix formatting.
* testsuite/libgomp.c-c++-common/task-detach-4.c: Fix formatting.
* testsuite/libgomp.c-c++-common/task-detach-5.c: Fix formatting.
Change data-sharing of detach events on enclosing parallel to private.
* testsuite/libgomp.c-c++-common/task-detach-6.c: Likewise. Remove
taskwait directive.
* testsuite/libgomp.c-c++-common/task-detach-7.c: New.
* testsuite/libgomp.c-c++-common/task-detach-8.c: New.
* testsuite/libgomp.c-c++-common/task-detach-9.c: New.
* testsuite/libgomp.c-c++-common/task-detach-10.c: New.
* testsuite/libgomp.c-c++-common/task-detach-11.c: New.
* testsuite/libgomp.fortran/task-detach-1.f90: Fix formatting.
* testsuite/libgomp.fortran/task-detach-2.f90: Fix formatting.
* testsuite/libgomp.fortran/task-detach-3.f90: Fix formatting.
* testsuite/libgomp.fortran/task-detach-4.f90: Fix formatting.
* testsuite/libgomp.fortran/task-detach-5.f90: Fix formatting.
Change data-sharing of detach events on enclosing parallel to private.
* testsuite/libgomp.fortran/task-detach-6.f90: Likewise. Remove
taskwait directive.
* testsuite/libgomp.fortran/task-detach-7.f90: New.
* testsuite/libgomp.fortran/task-detach-8.f90: New.
* testsuite/libgomp.fortran/task-detach-9.f90: New.
* testsuite/libgomp.fortran/task-detach-10.f90: New.
* testsuite/libgomp.fortran/task-detach-11.f90: New.
My r10-7705 patch for PR94521 made us set TFF_NO_FUNCTION_ARGUMENTS when
pretty printing the function scope of a local class type in order to
eliminate infinite recursion with a function signature that contains
decltype([]{}). But due to the way dump_function_decl works, this
change regressed our pretty printing of local class types whose context
contains a class template specialization, as in the testcase below, in
which we wrongly pretty print the two local types as 'A<T>::f<char>::S1'
and 'B<T>::f<int>::S2'.
This patch makes dump_scope pass TFF_NO_TEMPLATE_BINDINGS instead of
TFF_NO_FUNCTION_ARGUMENTS when pretty printing a function scope. It
appears this is the strictly better flag to use: it avoids the infinite
recursion issue, it restores pretty printing of the function parameter
list, and it stops dump_function_decl from trying to print a function
template specialization in its own weird way.
Summary of pretty printing differences for the below testcase:
r10-7704: A<T>::f() [with U = char; T = int]::S1
B<T>::f() [with T = int]::S2
r10-7705: A<T>::f<char>::S1
B<T>::f<int>::S2
this patch: A<int>::f<char>()::S1
B<int>::f()::S2
gcc/cp/ChangeLog:
PR c++/99213
PR c++/94521
* error.c (dump_scope): Pass TFF_NO_TEMPLATE_BINDINGS instead of
TFF_NO_FUNCTION_ARGUMENTS when dumping a function scope.
gcc/testsuite/ChangeLog:
PR c++/99213
PR c++/94521
* g++.dg/diagnostic/local1.C: New test.
When determining whether to rule out initializer-list constructors
during CTAD with a single-element initializer list (as per P0702), the
element type's cv-qualifiers should be irrelevant. This patch fixes
this by making is_spec_or_derived strip cv-qualifiers from the supplied
expression type.
In passing, I noticed in maybe_aggr_guide we were calling
is_spec_or_derived with swapped arguments. This led us to prefer the
aggregate deduction candidate over copying deduction in the second
testcase below with -std=c++20.
gcc/cp/ChangeLog:
PR c++/99103
* pt.c (is_spec_or_derived): Drop cv-qualifiers from 'etype'.
(maybe_aggr_guide): Fix order of arguments to is_spec_or_derived.
gcc/testsuite/ChangeLog:
PR c++/99103
* g++.dg/cpp1z/class-deduction79.C: New test.
* g++.dg/cpp1z/class-deduction80.C: New test.
Here we reject
constexpr const int *p = nullptr;
constexpr int *q = const_cast<int*>(p);
with "conversion of 'const int*' null pointer to 'int*' is not a
constant expression", which seems bogus. This code has been rejected
since r238909 which added the can_convert check when converting a null
pointer. I'm not finding any standard rule that this check was supposed
to enforce. The original discussion was here
<https://gcc.gnu.org/legacy-ml/gcc-patches/2016-06/msg01447.html>
and here
<https://gcc.gnu.org/legacy-ml/gcc-patches/2016-07/msg00280.html>.
Since can_convert never assumes a C-style cast, it rejects casting
away constness as in the test above and in:
constexpr int *q = (int *)(const int *) nullptr;
Removing the check only breaks constexpr-nullptr-2.C by not giving any
diagnostic for line 229:
constexpr B *pb2 = static_cast<B*>(pa0); // { dg-error "not a constant expression" }
but the cast seems to be valid: we do [expr.static.cast]/7, and
[expr.const] only says that a reinterpreter_cast and converting from
void* is invalid in constexpr. The can_convert check rejected convering
from void *, but only when converting from a null pointer, so it's not
good enough. So I've added a check to catch conversions from cv void*.
I realize it's not a great time to be adding additional checking, but
removing the can_convert check would then technically be a regression.
Let's limit the new check to only trigger for integer_zerop and then remove
it in GCC 12.
gcc/cp/ChangeLog:
DR 1312
PR c++/99176
* constexpr.c (is_std_construct_at): New overload.
(is_std_allocator_allocate): New overload.
(cxx_eval_call_expression): Use the new overloads.
(cxx_eval_constant_expression): Reject casting
from void * as per DR 1312. Don't check can_convert.
gcc/testsuite/ChangeLog:
DR 1312
PR c++/99176
* g++.dg/cpp0x/constexpr-nullptr-2.C: Adjust dg-error.
* g++.dg/cpp0x/constexpr-cast2.C: New test.
* g++.dg/cpp0x/constexpr-cast3.C: New test.
As the PR notes, we were calling the promise CTOR with the original
function parameters, not the copy (as pointed, a previous wording of
the section was unambiguous). Fixed thus.
gcc/cp/ChangeLog:
PR c++/97587
* coroutines.cc (struct param_info): Track rvalue refs.
(morph_fn_to_coro): Track rvalue refs, and call the promise
CTOR with the frame copy of passed parms.
gcc/testsuite/ChangeLog:
PR c++/97587
* g++.dg/coroutines/coro1-refs-and-ctors.h: Add a CTOR with two
reference parms, to distinguish the rvalue ref. variant.
* g++.dg/coroutines/pr97587.C: New test.
The FE contains a mechanism for cleaning up return expressions if a
function throws during the execution of cleanups prior to the return.
If the original function has a return value with a non-trivial DTOR
and the body contains a var with a DTOR that might throw, the function
decl is marked "throwing_cleanup".
However, we do not [in the coroutine ramp function, which is
synthesised], use any body var types with DTORs that might throw.
The original body [which will then contain the type with the throwing
DTOR] is transformed into the actor function which only contains void
returns, and is also wrapped in a try-catch block.
So (a) the 'throwing_cleanup' is no longer correct for the ramp and
(b) we do not need to transfer it to the actor which only contains
void returns.
gcc/cp/ChangeLog:
PR c++/95822
* coroutines.cc (morph_fn_to_coro): Unconditionally remove any
set throwing_cleanup marker.
gcc/testsuite/ChangeLog:
PR c++/95822
* g++.dg/coroutines/pr95822.C: New test.
The armv8_arm manual [C6.2.226, ROR (immediate)] uses a # in front
of the immediate rotation quantity.
Although, it seems, GAS is able to infer the # (or is leninent about
its absence) assemblers based on the LLVM back end expect it.
gcc/ChangeLog:
* config/aarch64/aarch64.md (<optab>_rol<mode>3): Add a '#'
mark in front of the immediate quantity.
(<optab>_rolsi3_uxtw): Likewise.
Commit r10-6017 relaxed the constraint on thumb2 calls to
__gnu_cmse_nonsecure_call to allow any register for the call address.
Although the initial code expansion continues to use r4 with the FPCXT
extension is not enabled, the change was unsafe because subsequent
optimizations could use the additional freedom to change which
register was being used.
To fix this we need to split the output patterns in the machine
description to use distinct recognizers: one with the additional
freedom when FPCXT is enabled an another that retains the original
restrictions when the extension is not available.
gcc:
PR target/99271
* config/arm/thumb2.md (nonsecure_call_reg_thumb2_fpcxt): New pattern.
(nonsecure_call_value_reg_thumb2_fpcxt): Likewise.
(nonsecure_call_reg_thumb2): Restrict to using r4 for the callee
address and disable when the FPCXT is not available.
(nonsecure_call_value_reg_thumb2): Likewise.
gcc/testsuite:
* gcc.target/arm/cmse/cmse-18.c: New test.
I realized that the just-added flang-note-module-read option should
also cover module writes, and was therefore misnamed. This addresses
that, replacing it with a -flang-note-module-cmi pair of options. As
this was such a recent addition, I didn't leave the old option
available.
PR c++/99166
gcc/c-family/
* c.opt (-flang-info-module-cmi): Renamed option.
gcc/
* doc/invoke.texi (flang-info-module-cmi): Renamed option.
gcc/cp/
* module.cc (module_state::inform_cmi_p): Renamed field.
(module_state::do_import): Adjust.
(init_modules, finish_module_processing): Likewise.
(handle_module_option): Likewise.
gcc/testsuite/
* g++.dg/modules/pr99166_a.X: Adjust.
* g++.dg/modules/pr99166_b.C: Adjust.
* g++.dg/modules/pr99166_c.C: Adjust.
* g++.dg/modules/pr99166_d.C: Adjust.
PR98318 also pointed out that the NETWORKING #define was being checked
with both #if and #ifdef. Let's consistently use one form.
c++tools/
* server.cc: Use #if NETWORKING not #ifdef, to be consistent
with elsewhere.
I don't know what it is that ix86, x86_64, Solaris and
apparently CRIS has in common here.
According to
https://gcc.gnu.org/pipermail/gcc-testresults/2021-February/652763.html
m68k-unknown-linux-gnu is also in that bunch, but since
there's a *-*-solaris* in the target specifier and also m68k
vs. m68k*, I'm leaving the adjustment to a maintainer.
gcc/testsuite:
* gfortran.dg/pr95690.f90: CRIS error appears on line 5.
The given testcase shows that one of the children of the complex MUL contains a
PHI node. This results in the vectorizer having a child that's (nil).
The pattern matcher handles this correctly, but optimize_load_redistribution_1
needs to not traverse/inspect the NULL nodes.
This however does high-light a missed opportunity. This testcase seems to
result in a different canonicalization than normally.
Normally the expressions are right leaning. But sometimes, especially when type
casts are introduced the trees suddenly become left leaning. For instance this
testcase (even without type casts) won't detect the FMA form because the addition
gets the MUL node in the left and not right node as it expects.
Checking all forms would be quite expensive so for GCC 12 it probably makes sense to make
forms with type casts in them have the same form as those without?
gcc/ChangeLog:
* tree-vect-slp.c (optimize_load_redistribution_1): Abort on NULL nodes.
gcc/testsuite/ChangeLog:
* g++.dg/vect/simd-complex-num-null-node.cc: New test.
The test in question is assumed to work only for little endian target.
gcc/testsuite/ChangeLog:
PR testsuite/99233
* gcc.target/powerpc/pr96264.c: Run it only for powerpc64le.
Skip test when -shared is not supported.
2021-02-25 Christophe Lyon <christophe.lyon@linaro.org>
gcc/testsuite/
PR middle-end/97172
* gcc.dg/pr97172-2.c: Add dg-require-effective-target shared.
User reported this typo: '0' and '-' are right next to each other, and
as it happened I always had networking, so it went unnoticed.
PR c++/98318
gcc/cp/
* mapper-client.cc (module_client::open_module_client): Fix typo
of fd init.
Implement P1682R2 as just approved for C++23.
libstdc++-v3/ChangeLog:
* include/std/utility (to_underlying): Define.
* include/std/version (__cpp_lib_to_underlying): Define.
* testsuite/20_util/to_underlying/1.cc: New test.
* testsuite/20_util/to_underlying/version.cc: New test.
This fixes an ordering problem with verifying that no intermediate
computations in a reduction path are used outside of the chain. The
check was disabled for value-preserving conversions at the tail
but whether a stmt was a conversion or not was only computed after
the first use. The following fixes this by re-ordering things
accordingly.
2021-02-25 Richard Biener <rguenther@suse.de>
PR tree-optimization/99253
* tree-vect-loop.c (check_reduction_path): First compute
code, then verify out-of-loop uses.
* gcc.dg/vect/pr99253.c: New testcase.
> So I wonder what other optimizations are prevented here?
> Why does uninit warn with VCE but not with NOP_EXPR? Or does the
> warning disappear because of those other optimizations you mention?
The optimization that it prevents is in this particular case in tree-vrp.c
(vrp_simplify_cond_using_ranges):
if (!is_gimple_assign (def_stmt)
|| !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
return;
so it punts on VIEW_CONVERT_EXPR, with NOP_EXPR it optimizes that:
_9 = (bool) maybe_a$4_7;
if (_9 != 0)
into:
_9 = (bool) maybe_a$4_7;
if (maybe_a$4_7 != 0)
Now, if I apply my patch but manually disable this
vrp_simplify_cond_using_ranges optimization, then the uninit warning is
back, so on the uninit side it is not about VIEW_CONVERT_EXPR vs. NOP_EXPR,
both are bad there, uninit wants the guarding condition to be
that SSA_NAME and not some demotion cast thereof.
We have:
# maybe_a$m_6 = PHI <_5(4), maybe_a$m_4(D)(6)>
# maybe_a$4_7 = PHI <1(4), 0(6)>
...
One of:
_9 = VIEW_CONVERT_EXPR<bool>(maybe_a$4_7);
if (_9 != 0)
or:
_9 = (bool) maybe_a$4_7;
if (_9 != 0)
or:
if (maybe_a$4_7 != 0)
followed by:
goto <bb 11>; [0.00%]
else
goto <bb 14>; [0.00%]
...
<bb 11> [count: 0]:
set (maybe_a$m_6);
and uninit wants to see that maybe_a$m_4(D) is not used if
bb 11 is encountered.
This patch fixes it by teaching vrp_simplify_cond_using_ranges
to handle VCE (when from an integral type) in addition to
NOP_EXPR/CONVERT_EXPR, of course as long as the VCE or demotion
doesn't change any values, i.e. when the range of the VCE or
conversion operand fits into the target type.
2021-02-25 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/80635
* tree-vrp.c (vrp_simplify_cond_using_ranges): Also handle
VIEW_CONVERT_EXPR if modes are the same, innerop is integral and
has mode precision.
* g++.dg/warn/pr80635-1.C: New test.
* g++.dg/warn/pr80635-2.C: New test.
This avoids interleaving pattern recognition and load redistribution
optimization since the load_map used in the latter is fragile with
respect to release and reuse of SLP nodes, something which can also
occur within the pattern recognition machinery.
2021-02-25 Richard Biener <rguenther@suse.de>
* tree-vect-slp.c (optimize_load_redistribution_1): Delay
load_map population.
(vect_match_slp_patterns_2): Revert part of last change.
(vect_analyze_slp): Do not interleave optimize_load_redistribution
with pattern detection but do it afterwards. Dump the
whole SLP graph after pattern recognition and load
redistribution optimization finished.
PR analyzer/99193 describes various false positives from
-Wanalyzer-mismatching-deallocation on realloc(3) calls
of the form:
| 31 | void *p = malloc (1024);
| | ^~~~~~~~~~~~~
| | |
| | (1) allocated here (expects deallocation with ‘free’)
| 32 | void *q = realloc (p, 4096);
| | ~~~~~~~~~~~~~~~~~
| | |
| | (2) deallocated with ‘realloc’ here; allocation at (1) expects deallocation with ‘free’
|
The underlying issue is that the analyzer has no knowledge of
realloc(3), and realloc has awkward semantics.
Unfortunately, the analyzer is currently structured so that each call
statement can only have at most one successor state; there is no
way to "bifurcate" the state, or have N-way splits into multiple
outcomes. The existing "on_stmt" code works on a copy of the next
state, updating it in place, rather than copying it and making any
necessary changes. I did this as an optimization to avoid unnecessary
copying of state objects, but it makes it hard to support multiple
outcomes. (ideally our state objects would be immutable and thus
support trivial copying, alternatively, C++11 move semantics may
help here)
I attempted a few approaches to implementing bifurcation within the
existing state-update framework, but they were messy and thus likely
buggy; a proper implementation would rework state-updating to
generate copies, but this would be a major change, and seems too
late for GCC 11.
As a workaround, this patch implements enough of realloc(3) to
suppress the false positives.
This fixes the false positives in PR analyzer/99193.
I've filed PR analyzer/99260 to track "properly" implementing realloc(3).
gcc/analyzer/ChangeLog:
PR analyzer/99193
* region-model-impl-calls.cc (region_model::impl_call_realloc): New.
* region-model.cc (region_model::on_call_pre): Call it.
* region-model.h (region_model::impl_call_realloc): New decl.
* sm-malloc.cc (enum wording): Add WORDING_REALLOCATED.
(malloc_state_machine::m_realloc): New field.
(use_after_free::describe_state_change): Add case for
WORDING_REALLOCATED.
(use_after_free::describe_final_event): Likewise.
(malloc_state_machine::malloc_state_machine): Initialize
m_realloc.
(malloc_state_machine::on_stmt): Handle realloc by calling...
(malloc_state_machine::on_realloc_call): New.
gcc/testsuite/ChangeLog:
PR analyzer/99193
* gcc.dg/analyzer/pr99193-1.c: New test.
* gcc.dg/analyzer/pr99193-2.c: New test.
* gcc.dg/analyzer/pr99193-3.c: New test.
* gcc.dg/analyzer/realloc-1.c: New test.
The code path in __floating_to_chars_precision for handling long double
by going through printf now also handles __float128, so the condition
that guards this code path needs to get updated accordingly.
libstdc++-v3/ChangeLog:
* src/c++17/floating_to_chars.cc (__floating_to_chars_precision):
Relax the condition that guards the printf code path to accept
F128_type as well as long double.
This fixes some issues with macro maps. We were incorrectly
calculating the number of macro expansions in a location span, and I
had a workaround that partially covered that up. Further, while macro
location spans are monotonic, that is not true of ordinary location
spans. Thus we need to insert an indirection array when binary
searching the latter. (We load ordinary locations before loading
imports, but macro locations afterwards. We make sure an import
location is de-macrofied, if needed.)
PR c++/98718
gcc/cp/
* module.cc (ool): New indirection vector.
(loc_spans::maybe_propagate): Location is not optional.
(loc_spans::open): Likewise. Assert monotonically advancing.
(module_for_ordinary_loc): Use ool indirection vector.
(module_state::write_prepare_maps): Do not count empty macro
expansions. Elide empty spans.
(module_state::write_macro_maps): Skip empty expansions.
(ool_cmp): New qsort comparator.
(module_state::write): Create and destroy ool vector.
(name_pending_imports): Fix dump push/pop.
(preprocess_module): Likewise. Add more dumping.
(preprocessed_module): Likewise.
libcpp/
* include/line-map.h
* line-map.c
gcc/testsuite/
* g++.dg/modules/pr98718_a.C: New.
* g++.dg/modules/pr98718_b.C: New.
The OpenMP standard says:
"A teams region can only be strictly nested within the implicit parallel region
or a target region. If a teams construct is nested within a target construct,
that target construct must contain no statements, declarations or directives
outside of the teams construct."
We weren't diagnosing that restriction, because we need to allow e.g.
#pragma omp target
{{{{{{
#pragma omp teams
;
}}}}}}
and as target doesn't need to have teams nested in it, using some special
parser of the target body didn't feel right. And after the parsing,
the question is if e.g. already parsing of the clauses doesn't add some
statements before the teams statement (gimplification certainly will).
As we now have a bugreport where we ICE on the invalid code, this just
diagnoses a subset of the invalid programs, in particular those where
nest to the teams strictly nested in targets the target region contains
some other OpenMP construct.
2021-02-24 Jakub Jelinek <jakub@redhat.com>
PR fortran/99226
* omp-low.c (struct omp_context): Add teams_nested_p and
nonteams_nested_p members.
(scan_omp_target): Diagnose teams nested inside of target with other
directives strictly nested inside of the same target.
(check_omp_nesting_restrictions): Set ctx->teams_nested_p or
ctx->nonteams_nested_p as needed.
* c-c++-common/gomp/pr99226.c: New test.
* gfortran.dg/gomp/pr99226.f90: New test.
When these functions are called with integer minimum, there is UB on the libgcc
side. Fixed in the obvious way, the code in the end wants ABSU_EXPR behavior.
2021-02-24 Jakub Jelinek <jakub@redhat.com>
PR libgcc/99236
* libgcc2.c (__powisf2, __powidf2, __powitf2, __powixf2): Perform
negation of m in unsigned type.
Inline asm in question has empty constraint which means anything
including memory with invalid address. To check used hard regs we
used decompose_mem_address which assumes memory with valid address.
The patch implements the same semantics without assuming valid
addresses.
gcc/ChangeLog:
PR inline-asm/99123
* lra-constraints.c (uses_hard_regs_p): Don't use decompose_mem_address.
gcc/testsuite/ChangeLog:
PR inline-asm/99123
* gcc.target/i386/pr99123.c: New.
This patch reimplements std::chrono::year_month_day_last:day() which yields the
last day of a particular month. The current implementation uses a look-up table
implemented as an unsigned[12] array. The new implementation instead
is based on
the fact that a month m in [1, 12], except for m == 2 (February), is
either 31 or
30 days long and m's length depends on two things: m's parity and whether m >= 8
or not. These two conditions are determined by the 0th and 3th bit of m and,
therefore, cheap and straightforward bit-twiddling can provide the right result.
Measurements in x86_64 [1] suggest a 10% performance boost. Although this does
not seem to be huge, notice that measurements are done in hot L1 cache
conditions which might not be very representative of production runs. Also
freeing L1 cache from holding the look-up table might allow performance
improvements elsewhere.
References:
[1] https://github.com/cassioneri/calendar
libstdc++-v3/ChangeLog:
* include/std/chrono (year_month_day_last:day): New
implementation.
This patch reimplements std::chrono::year::is_leap(). Leap year check is
ubiquitously implemented (including here) as:
y % 4 == 0 && (y % 100 != 0 || y % 400 == 0).
The rationale being that testing divisibility by 4 first implies an earlier
return for 75% of the cases, therefore, avoiding the needless calculations of
y % 100 and y % 400. Although this fact is true, it does not take into account
the cost of branching. This patch, instead, tests divisibility by 100 first:
(y % 100 != 0 || y % 400 == 0) && y % 4 == 0.
It is certainly counterintuitive that this could be more efficient since among
the three divisibility tests (4, 100 and 400) the one by 100 is the only one
that can never provide a definitive answer and a second divisibility test (by 4
or 400) is always required. However, measurements [1] in x86_64 suggest this is
3x more efficient! A possible explanation is that checking divisibility by 100
first implies a split in the execution path with probabilities of (1%, 99%)
rather than (25%, 75%) when divisibility by 4 is checked first. This decreases
the entropy of the branching distribution which seems to help prediction.
Given that y belongs to [-32767, 32767] [time.cal.year.members], a more
efficient algorithm [2] to check divisibility by 100 is used (instead of
y % 100 != 0). Measurements suggest that this optimization improves performance
by 20%.
The patch adds a test that exhaustively compares the result of this
implementation with the ubiquitous one for all y in [-32767, 32767]. Although
its completeness, the test completes in a matter of seconds.
References:
[1] https://stackoverflow.com/a/60646967/1137388
[2] https://accu.org/journals/overload/28/155/overload155.pdf#page=16
libstdc++-v3/ChangeLog:
* include/std/chrono (year::is_leap): New implementation.
* testsuite/std/time/year/2.cc: New test.
This patch reimplements std::chrono::year_month_day::_M_days_since_epoch()
which calculates the number of elapsed days since 1970/01/01. The new
implementation is based on Proposition 6.2 of Neri and Schneider, "Euclidean
Affine Functions and Applications to Calendar Algorithms" available at
https://arxiv.org/abs/2102.06959.
The aforementioned paper benchmarks the implementation against several
counterparts, including libc++'s (which is identical to the current
implementation). The results, shown in Figure 3, indicate the new algorithm is
1.7 times faster than the current one.
The patch adds a test which loops through all dates in [-32767/01/01,
32767/12/31], and for each of them, gets the number of days and compares the
result against its expected value. The latter is calculated using a much
simpler and easy to understand algorithm but which is also much slower.
The dates used in the test covers the full range of possible values
[time.cal.year.members]. Despite its completeness the test runs in matter of
seconds.
libstdc++-v3/ChangeLog:
* include/std/chrono (year_month_day::_M_days_since_epoch):
New implementation.
* testsuite/std/time/year_month_day/4.cc: New test.
This patch reimplements std::chrono::year_month_day::_S_from_days() which
retrieves a date from the number of elapsed days since 1970/01/01. The new
implementation is based on Proposition 6.3 of Neri and Schneider, "Euclidean
Affine Functions and Applications to Calendar Algorithms" available at
https://arxiv.org/abs/2102.06959.
The aforementioned paper benchmarks the implementation against several
counterparts, including libc++'s (which is identical to the current
implementation). The results, shown in Figure 4, indicate the new algorithm is
2.2 times faster than the current one.
The patch adds a test which loops through all integers in [-12687428, 11248737],
and for each of them, gets the corresponding date and compares the result
against its expected value. The latter is calculated using a much simpler and
easy to understand algorithm but which is also much slower.
The interval used in the test covers the full range of values for which a
roundtrip must work [time.cal.ymd.members]. Despite its completeness the test
runs in a matter of seconds.
libstdc++-v3/ChangeLog:
* include/std/chrono (year_month_day::_S_from_days): New
implementation.
* testsuite/std/time/year_month_day/3.cc: New test.
All the bits were there, used with a pre-existing
-mmax-stackframe=SIZE which unfortunately seems to lack
test-cases.
Note that the early-return for -mno-prologue-epilogue (what
some targets call -mnaked) is deliberately not clearing
current_function_static_stack_size, as I consider that
erroneous usage but don't really care to emit a better error
message.
For stack-usage-1.c, like most ILP32 targets, CRIS (at -O0)
needs 4 bytes for the return-address. The default size of
256 seems ill chosen but not worth fixing.
gcc:
* config/cris/cris.c (cris_expand_prologue): Set
current_function_static_stack_size, if flag_stack_usage_info.
gcc/testsuite:
* gcc.dg/stack-usage-1.c: Adjust for CRIS.
The long double std::to_chars testcase currently verifies the
correctness of its output by comparing it to that of printf, so if
there's a mismatch between to_chars and printf, the test FAILs. This
works well for the scientific, fixed and general formatting modes,
because the corresponding printf conversion specifiers (%e, %f and %g)
are rigidly specified.
But this doesn't work well for the hex formatting mode because the
corresponding printf conversion specifier %a is more flexibly specified.
For instance, the hexadecimal forms 0x1p+0, 0x2p-1, 0x4p-2 and 0x8p-3
are all equivalent and valid outputs of the %a specifier for the number 1.
The apparent freedom here is the choice of leading hex digit -- the
standard just requires that the leading hex digit is nonzero for
normalized numbers.
Currently, our hexadecimal formatting implementation uses 0/1/2 as the
leading hex digit for floating point types that have an implicit leading
mantissa bit which in practice means all supported floating point types
except x86 long double. The latter type has a 64 bit mantissa with an
explicit leading mantissa bit, and for this type our implementation uses
the most significant four bits of the mantissa as leading hex digit.
This seems to be consistent with most printf implementations, but not
all, as PR98384 illustrates.
In order to avoid false-positive FAILs due to arbitrary disagreement
between to_chars and printf about the choice of leading hex digit, this
patch makes the testcase's verification via printf conditional on the
leading hex digits first agreeing. An additional verification step is
also added: round-tripping the output of to_chars through from_chars
should recover the value exactly.
libstdc++-v3/ChangeLog:
PR libstdc++/98384
* testsuite/20_util/to_chars/long_double.cc: Include <optional>.
(test01): Simplify verifying the nearby values by using a
2-iteration loop and a dedicated output buffer to check that the
nearby values are different. Factor out the printf-based
verification into a local function, and check that the leading
hex digits agree before comparing to the output of printf. Also
verify the output by round-tripping it through from_chars.
When we read preprocessed source, we deal with a couple of special
location lines at the start of the file. These provide information
about the original filename of the source and the current directory,
so we can process the source in the same manner. When updating that
code, I had a somewhat philosophical question: Should the line table
contain evidence of the filename the user provided to the compiler? I
figured to leave it there, as it did no harm. But this defect shows
an issue. It's in the line table and our (non optimizing) line table
serializer emits that filename. Which means if one re-preprocesses
the original source to a differently-named intermediate file, the
resultant CMI is different. Boo. That's a difference that doesn't
matter, except the CRC matching then fails. We should elide the
filename, so that one can preprocess to mktemp intermediate filenames
for whatever reason.
This patch takes the approach of expunging it from the line table --
so the line table will end up with exactly the same form. That seems
a better bet than trying to fix up mismatching line tables in CMI
emission.
PR c++/99072
libcpp/
* init.c (read_original_filename): Expunge all evidence of the
original filename.
gcc/testsuite/
* g++.dg/modules/pr99072.H: New.
This adds overloads of std::to_chars for powerpc64's __ieee128, so that
std::to_chars can be used for long double when -mabi=ieeelongdouble is
in used.
Eventually we'll want to extend these new overloads to work for
__float128 on all targets that support that type. For now, we're only
doing it for powerpc64 when the new long double type is supported in
parallel to the old long double type.
Additionally the existing std::to_chars overloads for long double
are given the right symbol version, resolving PR libstdc++/98389.
libstdc++-v3/ChangeLog:
PR libstdc++/98389
* config/abi/pre/gnu.ver (GLIBCXX_3.4.29): Do not match to_chars
symbols for long double arguments mangled as 'g'.
* config/os/gnu-linux/ldbl-extra.ver: Likewise.
* config/os/gnu-linux/ldbl-ieee128-extra.ver: Likewise.
* src/c++17/Makefile.am [GLIBCXX_LDBL_ALT128_COMPAT_TRUE]:
Use -mabi=ibmlongdouble for floating_to_chars.cc.
* src/c++17/Makefile.in: Regenerate.
* src/c++17/floating_to_chars.cc (floating_type_traits_binary128):
New type defining type traits of IEEE binary128 format.
(floating_type_traits<__float128>): Define specialization.
(floating_type_traits<long double>): Define in terms of
floating_type_traits_binary128 when appropriate.
(floating_to_shortest_scientific): Handle __float128.
(sprintf_ld): New function template for printing a long double
or __ieee128 value using sprintf.
(__floating_to_chars_shortest, __floating_to_chars_precision):
Use sprintf_ld.
(to_chars): Define overloads for __float128.
2021-02-24 Paul Thomas <pault@gcc.gnu.org>
gcc/fortran
PR fortran/98342
* trans-expr.c (gfc_conv_derived_to_class): Add optional arg.
'derived_array' to hold the fixed, parmse expr in the case of
assumed rank formal arguments. Deal with optional arguments.
(gfc_conv_procedure_call): Null 'derived' array for each actual
argument. Add its address to the call to gfc_conv_derived_to_
class. Access the 'data' field of scalar descriptors before
deallocating allocatable components. Also strip NOPs before the
calls to gfc_deallocate_alloc_comp. Use 'derived' array as the
input to gfc_deallocate_alloc_comp if it is available.
* trans.h : Include the optional argument 'derived_array' to
the prototype of gfc_conv_derived_to_class. The default value
is NULL_TREE.
gcc/testsuite/
PR fortran/98342
* gfortran.dg/assumed_rank_21.f90 : New test.
