Modify ValidateLiveOuts to track 'FalseLaneZeros' more precisely,
including checks on specific operations that can generate non-zeros
from zero values, e.g VMVN. We can then check that any instructions
that retain some information in their output register (all narrowing
instructions) that they only use and def registers that always have
zeros in their falsely predicated bytes, whether or not tail
predication happens.
Most of the logic remains the same, just the names of the data
structures and helpers have been renamed to reflect the change in
logic. The key change, apart from the opcode checkers, is that the
FalseZeros set now strictly contains only instructions which will
always generate zeros, and not instructions that could also have
their false bytes masked away later.
Differential Revision: https://reviews.llvm.org/D76235
Add a flag, 'RetainsPreviousHalfElement', for operations that operate
on top/bottom halves of their input and only write to half of their
destination, leaving the other half to retain its previous value.
Differential Revision: https://reviews.llvm.org/D76608
Normally clang avoids creating expressions when it encounters semantic
errors, even if the parser knows which expression to produce.
This works well for the compiler. However, this is not ideal for
source-level tools that have to deal with broken code, e.g. clangd is
not able to provide navigation features even for names that compiler
knows how to resolve.
The new RecoveryExpr aims to capture the minimal set of information
useful for the tools that need to deal with incorrect code:
source range of the expression being dropped,
subexpressions of the expression.
We aim to make constructing RecoveryExprs as simple as possible to
ensure writing code to avoid dropping expressions is easy.
Producing RecoveryExprs can result in new code paths being taken in the
frontend. In particular, clang can produce some new diagnostics now and
we aim to suppress bogus ones based on Expr::containsErrors.
We deliberately produce RecoveryExprs only in the parser for now to
minimize the code affected by this patch. Producing RecoveryExprs in
Sema potentially allows to preserve more information (e.g. type of an
expression), but also results in more code being affected. E.g.
SFINAE checks will have to take presence of RecoveryExprs into account.
Initial implementation only works in C++ mode, as it relies on compiler
postponing diagnostics on dependent expressions. C and ObjC often do not
do this, so they require more work to make sure we do not produce too
many bogus diagnostics on the new expressions.
See documentation of RecoveryExpr for more details.
original patch from Ilya
This change is based on https://reviews.llvm.org/D61722
Reviewers: sammccall, rsmith
Reviewed By: sammccall, rsmith
Tags: #clang
Differential Revision: https://reviews.llvm.org/D69330
coroutine frame
Currently we move all allocas into the frame when build coroutine frame in
CoroSplit pass. However, this can be relaxed.
Since CoroSplit pass run after Inline pass, we can use lifetime intrinsic to
do such analysis: If the scope of lifetime intrinsic is not across any suspend
point, rather than move the allocas to frame, we can just move them to entry bb
of corresponding function. This reduce the frame size.
More importantly, this also avoid data race in multithread environment.
Consider one inline function by coroutine: it starts a thread which access
local variables, while after inline the movement of allocs to frame also access
them. cause data race.
Differential Revision: https://reviews.llvm.org/D75664
PR35760 shows an example program which, when compiled with `clang -O0`
or gcc at any optimization level, prints '0'. However, llvm transforms
the program in a way that causes it to print '1'.
Fix the issue by having `AllUsesOfValueWillTrapIfNull` return false when
analyzing a load from a global which is used by an `icmp`. This special
case was untested [0] so this is just deleting dead code.
An alternative fix might be to change the GlobalStatus analysis for the
global to report "Stored" instead of "StoredOnce". However, "StoredOnce"
is appropriate when only one value other than the initializer is stored
to the global.
[0]
http://lab.llvm.org:8080/coverage/coverage-reports/coverage/Users/buildslave/jenkins/workspace/coverage/llvm-project/llvm/lib/Transforms/IPO/GlobalOpt.cpp.html#L662
Differential Revision: https://reviews.llvm.org/D76645
Some methods are sometimes declared in the @implementation blocks which
can cause undiagnosed clashes.
Just write a checkObjCDirectMethodClashes() for this purpose.
Also make sure that "unavailable" selectors do not inherit
objc_direct_members.
Differential Revision: https://reviews.llvm.org/D76643
Signed-off-by: Pierre Habouzit <phabouzit@apple.com>
Radar-ID: rdar://problem/59332804, rdar://problem/59782963
The algorithm supports both assigning a fixed offset to a field prior to
layout and allowing fields to have sizes that aren't multiples of their
required alignments. This means that the well-known algorithm of sorting
by decreasing alignment isn't always good enough. Still, we start with
that, and only if that leaves padding around do we fall back on a greedy
padding-minimizing algorithm.
There is no known efficient algorithm for producing a guaranteed-minimal
layout in all cases. In fact, allowing arbitrary fixed-offset fields means
there's a straightforward reduction from bin-packing, making this NP-hard.
But as usual with such problems, we can still efficiently produce adequate
solutions to the cases that matter most to us.
I intend to use this in coroutine frame layout, where the retcon lowerings
very badly want to minimize total space usage, and where the switch lowering
can indeed produce a header with interior padding if the promise field is
highly-aligned. But it may be useful in a much wider variety of situations.
The declarations for these were already part of transforms utils, but
the definitions were left in affine transforms. Move definitions to loop
transforms utils.
Signed-off-by: Uday Bondhugula <uday@polymagelabs.com>
Differential Revision: https://reviews.llvm.org/D76633
Add a unit test for vfs::YAMLVFSWriter.
This patch exposes an issue in the writer: when we call addFileMapping
with a directory, the VFS writer will emit it as a regular file, causing
any of the nested files or directories to not be found.
For MTE error reporting we will need to expose interfaces for crash handlers
to use to interpret scudo headers and metadata. The intent is that these
interfaces will live in scudo/interface.h.
Move the existing interface.h into an include/scudo directory and make it
independent of the internal headers, so that we will be able to add the
interfaces there.
Differential Revision: https://reviews.llvm.org/D76648
Summary:
While here, simplify the lexer a bit by eliminating the unneeded 'operator'
classification of certain sigils, they can just be treated as 'punctuation'.
Reviewers: rriddle!
Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76647
When we find something like this:
```
%a:_(s32) = G_SOMETHING ...
...
%select:_(s32) = G_SELECT %cond(s1), %a, %a
```
We can remove the select and just replace it entirely with `%a` because it's
always going to result in `%a`.
Same if we have
```
%select:_(s32) = G_SELECT %cond(s1), %a, %b
```
where we can deduce that `%a == %b`.
This implements the following cases:
- `%select:_(s32) = G_SELECT %cond(s1), %a, %a` -> `%a`
- `%select:_(s32) = G_SELECT %cond(s1), %a, %some_copy_from_a` -> `%a`
- `%select:_(s32) = G_SELECT %cond(s1), %a, %b` -> `%a` when `%a` and `%b`
are defined by identical instructions
This gives a few minor code size improvements on CTMark at -O3 for AArch64.
Differential Revision: https://reviews.llvm.org/D76523
struct stack_t on Linux x86_64 has internal padding which may be left
uninitialized. The check should be replaced with multiple checks for
individual fields of the struct. For now, remove the check altogether.
An analysis of real world code turned up a number of patterns with BUILD_VECTOR
of nodes resulting from operations on extracted vector elements for which we
produce poor code. This addresses those cases. No attempt is made for
completeness as that would entail a large amount of work for something that
there is no evidence of in real code.
Differential revision: https://reviews.llvm.org/D72660
The e500 core has a silicon bug that triggers an illegal instruction
program trap on any sync other than msync. Other cores will typically
ignore illegal sync types, and the documentation even implies that the
'illegal' bits are ignored.
Address this hardware deficiency by only using msync, like the PPC440.
Differential Revision: https://reviews.llvm.org/D76614
Summary:
When building a large Xcode project with multiple module dependencies, and mixed Objective-C & Swift, I observed a large number of clang processes stalling at zero CPU for 30+ seconds throughout the build. This was especially prevalent on my 18-core iMac Pro.
After some sampling, the major cause appears to be the lock file implementation for precompiled modules in the module cache. When the lock is heavily contended by multiple clang processes, the exponential backoff runs in lockstep, with some of the processes sleeping for 30+ seconds in order to acquire the file lock.
In the attached patch, I implemented a more aggressive polling mechanism that limits the sleep interval to a max of 500ms, and randomizes the wait time. I preserved a limited form of exponential backoff. I also updated the code to use cross-platform timing, thread sleep, and random number capabilities available in C++11.
On iMac Pro (2.3 GHz Intel Xeon W, 18 core):
Xcode 11.1 bundled clang:
502.2 seconds (average of 5 runs)
Custom clang build with LockFileManager patch applied:
276.6 seconds (average of 5 runs)
This is a 1.82x speedup for this use case.
On MacBook Pro (4 core 3.1GHz Intel i7):
Xcode 11.1 bundled clang:
539.4 seconds (average of 2 runs)
Custom clang build with LockFileManager patch applied:
509.5 seconds (average of 2 runs)
As expected, machines with fewer cores benefit less from this change.
```
Call graph:
2992 Thread_393602 DispatchQueue_1: com.apple.main-thread (serial)
2992 start (in libdyld.dylib) + 1 [0x7fff6a1683d5]
2992 main (in clang) + 297 [0x1097a1059]
2992 driver_main(int, char const**) (in clang) + 2803 [0x1097a5513]
2992 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (in clang) + 1608 [0x1097a7cc8]
2992 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (in clang) + 3299 [0x1097dace3]
2992 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (in clang) + 509 [0x1097dcc1d]
2992 clang::FrontendAction::Execute() (in clang) + 42 [0x109818b3a]
2992 clang::ParseAST(clang::Sema&, bool, bool) (in clang) + 185 [0x10981b369]
2992 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&) (in clang) + 37 [0x10983e9b5]
2992 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&) (in clang) + 141 [0x10983ecfd]
2992 clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*) (in clang) + 695 [0x10983f3b7]
2992 clang::Parser::ParseObjCAtDirectives(clang::Parser::ParsedAttributesWithRange&) (in clang) + 637 [0x10a9be9bd]
2992 clang::Parser::ParseModuleImport(clang::SourceLocation) (in clang) + 170 [0x10c4841ba]
2992 clang::Parser::ParseModuleName(clang::SourceLocation, llvm::SmallVectorImpl<std::__1::pair<clang::IdentifierInfo*, clang::SourceLocation> >&, bool) (in clang) + 503 [0x10c485267]
2992 clang::Preprocessor::Lex(clang::Token&) (in clang) + 316 [0x1098285cc]
2992 clang::Preprocessor::LexAfterModuleImport(clang::Token&) (in clang) + 690 [0x10cc7af62]
2992 clang::CompilerInstance::loadModule(clang::SourceLocation, llvm::ArrayRef<std::__1::pair<clang::IdentifierInfo*, clang::SourceLocation> >, clang::Module::NameVisibilityKind, bool) (in clang) + 7989 [0x10bba6535]
2992 compileAndLoadModule(clang::CompilerInstance&, clang::SourceLocation, clang::SourceLocation, clang::Module*, llvm::StringRef) (in clang) + 296 [0x10bba8318]
2992 llvm::LockFileManager::waitForUnlock() (in clang) + 91 [0x10b6953ab]
2992 nanosleep (in libsystem_c.dylib) + 199 [0x7fff6a22c914]
2992 __semwait_signal (in libsystem_kernel.dylib) + 10 [0x7fff6a2a0f32]
```
Differential Revision: https://reviews.llvm.org/D69575
Summary:
The default behavior of Platform::PutFile is to open the file and
truncate it if it already exists. This works fine and is a sensible
default, but it interacts badly with code-signing on iOS, as doing so
invalidates the signature of the file (even if the new content has a
valid code signature).
We have a couple tests which on purpose reload a different binary with
the same name. Those tests are currently broken because of the above
interaction.
This patch simply makes the Darwin platform unconditionally delete the
destination file before sending the new one to work around this issue.
Reviewers: jasonmolenda
Subscribers: lldb-commits
Tags: #lldb
Differential Revision: https://reviews.llvm.org/D76450
Add the relevant magic bits to allow "-mllvm=-load=plugin.so" etc.
This is now using export_executable_symbols_for_plugins, so symbols are
only exported if plugins are enabled.
Differential Revision: https://reviews.llvm.org/D75879
There seems to be a small benefit to the legalized sequence for v2f16
round with packed instructions, so allow vectorizing it by reducing
the cost.
An unintended side effect is vectorization of f32 round also
happens. The current FMA logic seems off to me, and isn't checking for
packed instructions.
On Windows, when the LLVM toolchain is in the current path (%PATH%), fusing the linker yields c:\{path}\lld.exe whereas the hip tests did not expect the .exe part.
This only happens if LLD is not present in the build folder, which consequently makes the code in Driver::GetProgramPath() to fall back to %PATH% and platform-specific search, which includes the .exe part (see https://github.com/llvm/llvm-project/blob/master/clang/lib/Driver/Driver.cpp#L4733).
Differential Revision: https://reviews.llvm.org/D76631
TableGen and .def files (which are meant to be used with the preprocessor) come
with obvious downsides. One of those issues is that generated switch-case
branches have to be identical. This pushes corner cases either to an outer code
block, or into the generated code.
Inspect the removed code in AnalysisConsumer::DigestAnalyzerOptions. You can see
how corner cases like a not existing output file, the analysis output type being
set to PD_NONE, or whether to complement the output with additional diagnostics
on stderr lay around the preprocessor generated code. This is a bit problematic,
as to how to deal with such errors is not in the hands of the users of this
interface (those implementing output types, like PlistDiagnostics etc).
This patch changes this by moving these corner cases into the generated code,
more specifically, into the called functions. In addition, I introduced a new
output type for convenience purposes, PD_TEXT_MINIMAL, which always existed
conceptually, but never in the actual Analyses.def file. This refactoring
allowed me to move TextDiagnostics (renamed from ClangDiagPathDiagConsumer) to
its own file, which it really deserved.
Also, those that had the misfortune to gaze upon Analyses.def will probably
enjoy the sight that a clang-format did on it.
Differential Revision: https://reviews.llvm.org/D76509
Debian and some other distributions install llvm-strip as llvm-strip-$major (e.g. `/usr/bin/llvm-strip-9`)
D54193 made it work with llvm-strip-$major but did not add a test.
The behavior was regressed by D69146.
Fixes https://github.com/ClangBuiltLinux/linux/issues/940
Reviewed By: alexshap
Differential Revision: https://reviews.llvm.org/D76562
Sam Parker