1. [PowerPC] only check the load instruction result number 0. (details)
  2. [GVN] Improve analysis for missed optimization remark (details)
  3. [lld][MachO] Adjust isCodeSection signature (details)
  4. [Statepoint Lowering] Cleanup: remove unused option statepoint-always-spill-base. (details)
  5. [AMDGPU][libomptarget] Remove unused global variables (details)
  6. [Windows SEH]: HARDWARE EXCEPTION HANDLING (MSVC -EHa) - Part 1 (details)
  7. [AMDGPU][Libomptarget] Rename & move g_executables to private (details)
  8. sanitizer_common/symbolizer: fix crashes during exit (details)
  9. [LV] Return both fixed and scalable Max VF from computeMaxVF. (details)
  10. [RDA] Fix printing of regs / reg units. NFC (details)
  11. [NFC][scudo] Reduce test region size on MIPS32 (details)
  12. [lldb][NFC] Remove all uses of StringRef::withNullAsEmpty in LLDB (details)
  13. [ASTimporter] Remove decl from lookup only if it has decl context (details)
  14. [mlir][docs] Fix broken link to Toy example (details)
Commit 15d4ed6d8c6956efcb2d5afb89bea7f0fff6f989 by czhengsz
[PowerPC] only check the load instruction result number 0.

Reviewed By: nemanjai

Differential Revision:
The file was modifiedllvm/lib/Target/PowerPC/PPCISelLowering.cpp
The file was modifiedllvm/test/CodeGen/PowerPC/vsx-shuffle-le-load.ll
Commit ab1f6ffa566ba1f6c7994da130380e6f258f580c by anemet
[GVN] Improve analysis for missed optimization remark

This change tries to handle multiple dominating users of the pointer operand
by choosing the most immediately dominating one, if possible.  While making
this change I also found that the previous implementation had a missing break
statement, making all loads with an odd number of dominating users emit an
OtherAccess value, so that has also been fixed.

Patch by Henrik G Olsson!

Differential Revision:
The file was addedllvm/test/Transforms/GVN/opt-remarks-multiple-users.ll
The file was modifiedllvm/lib/Transforms/Scalar/GVN.cpp
The file was addedllvm/test/Transforms/GVN/opt-remarks-non-dominating.ll
Commit dc2c6cf2749fb1655839704a184067d1c6b48ee5 by alexshap
[lld][MachO] Adjust isCodeSection signature

This diff changes the type of the argument of isCodeSection to const InputSection *.

Test plan: make check-lld-macho

Differential revision:
The file was modifiedlld/MachO/InputSection.h
The file was modifiedlld/MachO/InputSection.cpp
Commit 57c660f3742f2044f0dd555469f87b7b349dba0d by serguei.katkov
[Statepoint Lowering] Cleanup: remove unused option statepoint-always-spill-base.
The file was modifiedllvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp
Commit 3bc2b97b34ff1d5f817793f83961192e62d5fc7b by Pushpinder.Singh
[AMDGPU][libomptarget] Remove unused global variables

This initial patch removes some unused variables from global namespace.
There will more incoming patches for moving global variables to classes
or static members.

Reviewed By: JonChesterfield

Differential Revision:
The file was modifiedopenmp/libomptarget/plugins/amdgpu/impl/internal.h
The file was modifiedopenmp/libomptarget/plugins/amdgpu/impl/system.cpp
The file was modifiedopenmp/libomptarget/plugins/amdgpu/impl/machine.cpp
Commit 797ad701522988e212495285dade8efac41a24d4 by tentzen

This patch is the Part-1 (FE Clang) implementation of HW Exception handling.

This new feature adds the support of Hardware Exception for Microsoft Windows
SEH (Structured Exception Handling).
This is the first step of this project; only X86_64 target is enabled in this patch.

Compiler options:
For clang-cl.exe, the option is -EHa, the same as MSVC.
For clang.exe, the extra option is -fasync-exceptions,
plus -triple x86_64-windows -fexceptions and -fcxx-exceptions as usual.

NOTE:: Without the -EHa or -fasync-exceptions, this patch is a NO-DIFF change.

The rules for C code:
For C-code, one way (MSVC approach) to achieve SEH -EHa semantic is to follow
three rules:
* First, no exception can move in or out of _try region., i.e., no "potential
  faulty instruction can be moved across _try boundary.
* Second, the order of exceptions for instructions 'directly' under a _try
  must be preserved (not applied to those in callees).
* Finally, global states (local/global/heap variables) that can be read
  outside of _try region must be updated in memory (not just in register)
  before the subsequent exception occurs.

The impact to C++ code:
Although SEH is a feature for C code, -EHa does have a profound effect on C++
side. When a C++ function (in the same compilation unit with option -EHa ) is
called by a SEH C function, a hardware exception occurs in C++ code can also
be handled properly by an upstream SEH _try-handler or a C++ catch(...).
As such, when that happens in the middle of an object's life scope, the dtor
must be invoked the same way as C++ Synchronous Exception during unwinding

A natural way to achieve the rules above in LLVM today is to allow an EH edge
added on memory/computation instruction (previous iload/istore idea) so that
exception path is modeled in Flow graph preciously. However, tracking every
single memory instruction and potential faulty instruction can create many
Invokes, complicate flow graph and possibly result in negative performance
impact for downstream optimization and code generation. Making all
optimizations be aware of the new semantic is also substantial.

This design does not intend to model exception path at instruction level.
Instead, the proposed design tracks and reports EH state at BLOCK-level to
reduce the complexity of flow graph and minimize the performance-impact on CPP
code under -EHa option.

One key element of this design is the ability to compute State number at
block-level. Our algorithm is based on the following rationales:

A _try scope is always a SEME (Single Entry Multiple Exits) region as jumping
into a _try is not allowed. The single entry must start with a seh_try_begin()
invoke with a correct State number that is the initial state of the SEME.
Through control-flow, state number is propagated into all blocks. Side exits
marked by seh_try_end() will unwind to parent state based on existing
Note side exits can ONLY jump into parent scopes (lower state number).
Thus, when a block succeeds various states from its predecessors, the lowest
State triumphs others.  If some exits flow to unreachable, propagation on those
paths terminate, not affecting remaining blocks.
For CPP code, object lifetime region is usually a SEME as SEH _try.
However there is one rare exception: jumping into a lifetime that has Dtor but
has no Ctor is warned, but allowed:

Warning: jump bypasses variable with a non-trivial destructor

In that case, the region is actually a MEME (multiple entry multiple exits).
Our solution is to inject a eha_scope_begin() invoke in the side entry block to
ensure a correct State.

Part-1: Clang implementation described below.

Two intrinsic are created to track CPP object scopes; eha_scope_begin() and eha_scope_end().
_scope_begin() is immediately added after ctor() is called and EHStack is pushed.
So it must be an invoke, not a call. With that it's also guaranteed an
EH-cleanup-pad is created regardless whether there exists a call in this scope.
_scope_end is added before dtor(). These two intrinsics make the computation of
Block-State possible in downstream code gen pass, even in the presence of
ctor/dtor inlining.

Two intrinsic, seh_try_begin() and seh_try_end(), are added for C-code to mark
_try boundary and to prevent from exceptions being moved across _try boundary.
All memory instructions inside a _try are considered as 'volatile' to assure
2nd and 3rd rules for C-code above. This is a little sub-optimized. But it's
acceptable as the amount of code directly under _try is very small.

Part-2 (will be in Part-2 patch): LLVM implementation described below.

For both C++ & C-code, the state of each block is computed at the same place in
BE (WinEHPreparing pass) where all other EH tables/maps are calculated.
In addition to _scope_begin & _scope_end, the computation of block state also
rely on the existing State tracking code (UnwindMap and InvokeStateMap).

For both C++ & C-code, the state of each block with potential trap instruction
is marked and reported in DAG Instruction Selection pass, the same place where
the state for -EHsc (synchronous exceptions) is done.
If the first instruction in a reported block scope can trap, a Nop is injected
before this instruction. This nop is needed to accommodate LLVM Windows EH
implementation, in which the address in IPToState table is offset by +1.
(note the purpose of that is to ensure the return address of a call is in the
same scope as the call address.

The handler for catch(...) for -EHa must handle HW exception. So it is
'adjective' flag is reset (it cannot be IsStdDotDot (0x40) that only catches
C++ exceptions).
Suppress push/popTerminate() scope (from noexcept/noTHrow) so that HW
exceptions can be passed through.

Original llvm-dev [RFC] discussions can be found in these two threads below:

Differential Revision:
The file was modifiedclang/lib/AST/JSONNodeDumper.cpp
The file was addedclang/test/CodeGen/windows-seh-EHa-TryInFinally.cpp
The file was modifiedclang/lib/CodeGen/MicrosoftCXXABI.cpp
The file was modifiedclang/lib/Sema/JumpDiagnostics.cpp
The file was modifiedllvm/lib/IR/Verifier.cpp
The file was modifiedclang/include/clang/Basic/LangOptions.def
The file was modifiedclang/lib/CodeGen/CGStmt.cpp
The file was modifiedllvm/docs/LangRef.rst
The file was modifiedclang/lib/CodeGen/CodeGenFunction.h
The file was modifiedllvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
The file was modifiedclang/lib/Serialization/ASTWriterStmt.cpp
The file was modifiedclang/lib/CodeGen/CGCleanup.cpp
The file was modifiedclang/lib/CodeGen/CodeGenModule.cpp
The file was addedclang/test/CodeGen/windows-seh-EHa-CppCondiTemps.cpp
The file was modifiedclang/lib/AST/TextNodeDumper.cpp
The file was modifiedclang/lib/CodeGen/CGException.cpp
The file was addedclang/test/CodeGen/windows-seh-EHa-CppDtors01.cpp
The file was modifiedclang/include/clang/Driver/
The file was modifiedclang/lib/CodeGen/EHScopeStack.h
The file was modifiedclang/lib/Driver/ToolChains/Clang.cpp
The file was modifiedllvm/include/llvm/IR/
The file was modifiedclang/include/clang/AST/Stmt.h
The file was modifiedclang/lib/CodeGen/CodeGenFunction.cpp
The file was modifiedclang/lib/Serialization/ASTReaderStmt.cpp
The file was addedclang/test/CodeGen/windows-seh-EHa-CppCatchDotDotDot.cpp
Commit d7503c3bce491e2672386906ec879c7df5ede7a5 by Pushpinder.Singh
[AMDGPU][Libomptarget] Rename & move g_executables to private

This patch moves g_executables to private member of Runtime class
and is renamed to HSAExecutables following LLVM naming convention.

This movement required making Runtime::Initialize and Runtime::Finalize
non-static. Verified the correctness of this change by running
libomptarget tests on gfx906.

Reviewed By: JonChesterfield

Differential Revision:
The file was modifiedopenmp/libomptarget/plugins/amdgpu/impl/atmi.cpp
The file was modifiedopenmp/libomptarget/plugins/amdgpu/impl/rt.h
The file was modifiedopenmp/libomptarget/plugins/amdgpu/impl/system.cpp
The file was modifiedopenmp/libomptarget/plugins/amdgpu/src/rtl.cpp
Commit 00a1007545ba8ad2105876a41364b35235749e2a by dvyukov
sanitizer_common/symbolizer: fix crashes during exit

Override __cxa_atexit and ignore callbacks.
This prevents crashes in a configuration when the symbolizer
is built into sanitizer runtime and consequently into the test process.
LLVM libraries have some global objects destroyed during exit,
so if the test process triggers any bugs after that, the symbolizer crashes.
An example stack trace of such crash:

For the standalone llvm-symbolizer this does not hurt,
we just don't destroy few global objects on exit.

Reviewed By: kda

Differential Revision:
The file was modifiedcompiler-rt/lib/sanitizer_common/symbolizer/sanitizer_symbolize.cpp
The file was addedcompiler-rt/test/tsan/atexit4.cpp
Commit 81fdc73e5dc74bfe7cda1e16f01f23836406d709 by sander.desmalen
[LV] Return both fixed and scalable Max VF from computeMaxVF.

This patch introduces a new class, MaxVFCandidates, that holds the
maximum vectorization factors that have been computed for both scalable
and fixed-width vectors.

This patch is intended to be NFC for fixed-width vectors, although
considering a scalable max VF (which is disabled by default) pessimises
tail-loop elimination, since it can no longer determine if any chosen VF
(less than fixed/scalable MaxVFs) is guaranteed to handle all vector
iterations if the trip-count is known. This issue will be addressed in
a future patch.

Reviewed By: fhahn, david-arm

Differential Revision:
The file was modifiedllvm/lib/Transforms/Vectorize/LoopVectorize.cpp
The file was modifiedllvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h
The file was addedllvm/test/Transforms/LoopVectorize/AArch64/eliminate-tail-predication.ll
Commit b3d38327b2bfcc92b5e34d0d2f2fa52a1ba063a0 by
[RDA] Fix printing of regs / reg units. NFC

It was printing RegUnits as Regs, leading to much confusion in the debug
The file was modifiedllvm/lib/CodeGen/ReachingDefAnalysis.cpp
Commit 2e92f1a9bcd5550761be936ac9c0848e6d9fcb40 by Vitaly Buka
[NFC][scudo] Reduce test region size on MIPS32
The file was modifiedcompiler-rt/lib/scudo/standalone/tests/primary_test.cpp
Commit bbea361039c11dc2e6e281c80fa8aa569f1c7c2d by Raphael Isemann
[lldb][NFC] Remove all uses of StringRef::withNullAsEmpty in LLDB

A long time ago LLDB wanted to start using StringRef instead of
C-Strings/ConstString but was blocked by the fact that the StringRef constructor
that takes a C-string was asserting that the C-string isn't a nullptr. To
workaround this, D24697 introduced a special function called `withNullAsEmpty`
and that's what LLDB (and only LLDB) started to use to build StringRefs from

A bit later it seems that `withNullAsEmpty` was declared too awkward to use and
instead the assert in the StringRef constructor got removed (see D24904). The
rest of LLDB was then converted to StringRef by just calling the now perfectly
usable implicit constructor.

However, all the calls to `withNullAsEmpty` just remained and are now just
strange artefacts in the code base that just look out of place. It's also
curiously a LLDB-exclusive function and no other project ever called it since
it's introduction half a decade ago.

This patch removes all uses of `withNullAsEmpty`. The follow up will be to
remove the function from StringRef.

Reviewed By: JDevlieghere

Differential Revision:
The file was modifiedlldb/source/Commands/CommandObjectType.cpp
The file was modifiedlldb/source/API/SBLanguageRuntime.cpp
The file was modifiedlldb/include/lldb/Interpreter/OptionValueString.h
The file was modifiedlldb/source/API/SBPlatform.cpp
The file was modifiedlldb/source/API/SBDebugger.cpp
The file was modifiedlldb/source/API/SBTypeCategory.cpp
The file was modifiedlldb/source/Commands/CommandObjectTarget.cpp
The file was modifiedlldb/source/Breakpoint/BreakpointResolverName.cpp
The file was modifiedlldb/source/Interpreter/CommandInterpreter.cpp
The file was modifiedlldb/source/Interpreter/OptionValue.cpp
The file was modifiedlldb/source/Commands/CommandObjectFrame.cpp
The file was modifiedlldb/include/lldb/Interpreter/OptionValueRegex.h
The file was modifiedlldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntimeV2.cpp
The file was modifiedlldb/source/Target/ThreadPlanStepInRange.cpp
Commit 88ee91cd87794813f4394f82d2c693c8d766e1d2 by balazs.benics
[ASTimporter] Remove decl from lookup only if it has decl context

In the case of TypedefDecls we set the DeclContext after we imported it.
It turns out, it could lead to null pointer dereferences during the
cleanup part of a failed import.

This patch demonstrates this issue and fixes it by checking if the
DeclContext is available or not.

Reviewed By: shafik

Differential Revision:
The file was modifiedclang/unittests/AST/ASTImporterTest.cpp
The file was modifiedclang/lib/AST/ASTImporter.cpp
Commit dfd929d26174108ccfe84de33abf23d660e1373d by marius.brehler
[mlir][docs] Fix broken link to Toy example
The file was modifiedmlir/docs/