Changes

[llvm-exegesis][mips] Add support for memory instructions
Implementing functions used to enable testing of memory instructions.
Differential Revision: https://reviews.llvm.org/D72858

clang-format: fix spacing in `operator const char*()`
Summary: Revision a75f8d98d7ac9e557b238a229a9a2647c71feed1 fixed spacing
for operators, but caused the const and non-const versions to diverge:
```
// With Style.PointerAlignment = FormatStyle::PAS_Left:
struct A {
 operator char*() { return ""; }
 operator const char *() const { return ""; }
};
``` The code was checking if the type specifier was directly preceded by
`operator`. However there could be comments and `const/volatile` in
between.
Reviewers: mprobst
Reviewed By: mprobst
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72911

clang-format: [JS] pragmas for tslint, tsc.
Summary: tslint and tsc (the TypeScript compiler itself) use comment
pragmas of the style:
  // tslint:disable-next-line:foo
 // @ts-ignore
These must not be wrapped and must stay on their own line, in isolation. 
For tslint, this required adding it to the pragma regexp. The comments 
starting with `@` are already left alone, but this change adds test 
coverage for them.
Reviewers: krasimir
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72907

[BasicBlock] fix looping in getPostdominatingDeoptimizeCall
Blindly following unique-successors chain appeared to be a bad idea. In
a degenerate case when block jumps to itself that goes into endless
loop.
Discovered this problem when playing with additional changes, managed to
reproduce it on existing LoopPredication code.
Fix by checking a "visited" set while iterating through unique
successors.
Reviewed By: skatkov
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72908

Revert "[mlir][ods] Support dialect specific content emission via hooks"
This reverts commit 397215cc309df1171a198b11cab3b241db9441db because 
this feature needs more discussion.

[mlir][spirv] Support implied extensions and capabilities
In SPIR-V, when a new version is introduced, it is possible some 
existing extensions will be incorporated into it so that it becomes 
implicitly declared if targeting the new version. This affects 
conversion target specification because we need to take this into 
account when allowing what extensions to use.
For a capability, it may also implies some other capabilities, for
example, the `Shader` capability implies `Matrix` the capability. This
should also be taken into consideration when preparing the conversion
target: when we specify an capability is allowed, all its recursively
implied capabilities are also allowed.
This commit adds utility functions to query implied extensions for a
given version and implied capabilities for a given capability and
updated SPIRVConversionTarget to use them.
This commit also fixes a bug in availability spec. When a symbol
(op or enum case) can be enabled by an extension, we should drop it's
minimal version requirement. Being enabled by an extension naturally
means the symbol can be used by *any* SPIR-V version as long as the
extension is supported. The grammar still encodes the 'version' field
for such cases, but it should be interpreted as a different way: rather
than meaning a minimal version requirement, it says the symbol becomes
core at that specific version.
Differential Revision: https://reviews.llvm.org/D72765

[ARM][MVE] Tail Predicate IsSafeToRemove
Introduce a method to walk through use-def chains to decide whether it's
possible to remove a given instruction and its users. These instructions
are then stored in a set until the end of the transform when they're
erased. This is now used to perform checks on the iteration count
(LoopDec chain), element count (VCTP chain) and the possibly redundant
iteration count.
As well as being able to remove chains of instructions, we know also 
check that the sub feeding the vctp is producing the expected value.
Differential Revision: https://reviews.llvm.org/D71837

[IR] add unit test for Constant::isElementWiseEqual() for undef corner
case; NFC

[IR] fix Constant::isElementWiseEqual() to allow for all undef elements
compare
We could argue that match() should be more flexible here, but I'm not
sure what impact that would have on existing code.

Add `bugprone-reserved-identifier`
This patch adds bugprone-reserved-identifier, which flags uses of
__names _Like
::_this, which are reserved for the implementation. The check can
optionally be inverted, i.e. configured to flag any names that are _not_
reserved, which may be useful for e.g. standard library implementors.

[gn build] Port 42a0355816d

[SelectionDAG] ComputeKnownBits - assert we're computing the 0'th
(difference) result for the SUB/SUBC cases
Matches what we already do for the ADD/ADDC/ADDE case.

[X86] Split X87/SSE compare classes into WriteFCom + WriteFComX
Most X87 compare instructions write to the X87 status word, while the
SSE (U)COMI compares write to rFLAGS. These are often handled very
differently on CPUs (e.g. rFLAGS outputs typically involve a fpu2gpr
transfer), and we shouldn't be grouping all these instructions behind a
single class - so this patch splits off the SSE compares into a new
WriteFComX class (and currently keeps the same behaviours). If there's a
need to distinguish between X87 instructions more closely we can
investigate that in the future, but as we don't handle any of the X87
side effects at the moment its unlikely to have any notable effect.

[clang-tidy] Disable Checks on If constexpr statements in template
Instantiations for BugproneBranchClone and
ReadabilityBracesAroundStatements
Summary: fixes [[ https://bugs.llvm.org/show_bug.cgi?id=32203 |
readability-braces-around-statements broken for if constexpr]] and [[
https://bugs.llvm.org/show_bug.cgi?id=44229 | bugprone-branch-clone
false positive with template functions and constexpr ]] by disabling the
relevant checks on if constexpr statements while inside an instantiated
template. This is due to how the else branch of an if constexpr
statement is folded away to a null statement if the condition evaluates
to false
Reviewers: alexfh, hokein, aaron.ballman, xazax.hun
Reviewed By: aaron.ballman, xazax.hun
Subscribers: rnkovacs, JonasToth, Jim, lebedev.ri, xazax.hun,
cfe-commits
Tags: #clang-tools-extra, #clang
Differential Revision: https://reviews.llvm.org/D71980

Fix a compile error to get bots back to green.
Fixes
http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/13716

Another speculative fix for the Windows bots.
Hopefully fixes: http://45.33.8.238/win/6040/step_4.txt

[Hexagon] Add prev65 subtarget feature
There was a change to trap1 instruction between v62 and v65. This 
feature will allow the assembler/disassembler to handle different 
variants depending on the CPU version.

[Hexagon] Improve HVX version checks

[x86] try harder to form 256-bit unpck*
This is another part of a problem noted in PR42024: 
https://bugs.llvm.org/show_bug.cgi?id=42024
The AVX2 code may use awkward 256-bit shuffles vs. the AVX code that
gets split into the expected 128-bit unpack instructions. We have to be
selective in matching the types where we try to do this though.
Otherwise, we can end up with more instructions (in the case of
v8x32/v4x64).
Differential Revision: https://reviews.llvm.org/D72575

Fix gcc9 "moving a local object in a return statement prevents copy
elision" Wpessimizing-move warnings.

Fix gcc9 "moving a local object in a return statement prevents copy
elision" Wpessimizing-move warning.

Revert rGff3fe145fe48 "Fix gcc9 "moving a local object in a return
statement prevents copy elision" Wpessimizing-move warning."
Fix buildbots

Revert rGb6437b352db9 - "Fix gcc9 "moving a local object in a return
statement prevents copy elision" Wpessimizing-move warnings."
Fix buildbots

AMDGPU: Don't assert on a16 images on targets without FeatureR128A16
Currently the lowering for i16 image coordinates asserts on gfx10. I'm 
somewhat confused by this though. The feature is missing from the gfx10
feature lists, but the a16 bit appears to be present in the manual for
MIMG instructions.

[DataFlow] Factor two worklist implementations out
Right now every dataflow algorithm uses its own worklist implementation. 
This is a first step to reduce this duplication. Some upcoming 
algorithms such as the lifetime analysis is going to use the factored 
out implementations.
Differential Revision: https://reviews.llvm.org/D72380

Renamed traverseDecl to TraverseDecl in a test
RecursiveASTVisitor expects TraverseDecl to be implemented by 
subclasses.

[AArch64] Make AArch64 specific assembly directives case insensitive
Differential Revision: https://reviews.llvm.org/D72923

[lldb] Try to fix writing outside temp dir from
4bafceced6a7641be7b090229c6ccef22cf55bff

[mlir][spirv] Add `const` qualifier for static arrays
This makes the local variable `implies` to have the correct type to
satisfy ArrayRef's constructor:
  /*implicit*/ constexpr ArrayRef(const T (&Arr)[N])
Hopefully this should please GCC 5.
Differential Revision: https://reviews.llvm.org/D72924

[InstCombine] Add test for -expensive-combines option; NFC
This shows that -expensive-combines=0 is ignored.

[InstCombine] Support disabling expensive combines in opt
Currently, there is no way to disable ExpensiveCombines when doing a
standalone opt -instcombine run, as that's the default, and the opt
option can currently only be used to force enable, not to force disable.
The only way to disable expensive combines is via -O1 or -O2, but that
of course also runs the rest of the kitchen sink...
This patch allows using opt -instcombine -expensive-combines=0 to run
InstCombine without ExpensiveCombines.
Differential Revision: https://reviews.llvm.org/D72861

[InstCombine] Split assume test in expensive and not; NFC
The IR difference in @icmp1 serves as a test for D72864.

[InstCombine] Fix worklist management in return combine
There are two related bugs here: First, we don't add the operand we're
replacing to the worklist, which means it may not get DCEd
(see test change). Second, usually this would just get picked up in the
next iteration, but we also do not report the instruction as changed.
This means that we do not get that extra instcombine iteration, and more
importantly, may break the pass pipeline, as the function is not marked
as changed.
Differential Revision: https://reviews.llvm.org/D72864

[mlir] Improve documentation in ModuleTranslation MLIR to LLVM IR
Several functions were missing documentation.

[mlir][spirv] Add lowering from `loop.if` to `spv.selection`
When lowering `loop.if` to `spv.selection` we explicitly create a
selection header block before the control flow diverges and a merge
block where control flow subsequently converges.
Differential Revision: https://reviews.llvm.org/D72836

[VectorOps] Update vector transfer read op comments.
Summary: Update vector transfer read op comments.
Reviewers: nicolasvasilache, aartbik
Reviewed By: nicolasvasilache, aartbik
Subscribers: merge_guards_bot, mehdi_amini, rriddle, jpienaar, burmako,
shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, liufengdb,
llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72731

[InstCombine] Fix worklist management in DSE (PR44552)
Fixes https://bugs.llvm.org/show_bug.cgi?id=44552. We need to make sure
that the store is reprocessed, because performing DSE may expose more
DSE opportunities.
There is a slight caveat here though: We need to make sure that we add
back the store the worklist first, because that means it will be
processed after the operands of the removed store have been processed.
This is a general bug in InstCombine worklist management that I hope to
address at some point, but for now it means we need to do this manually
rather than just returning the instruction as changed.
Differential Revision: https://reviews.llvm.org/D72807

[libTooling] Fix bug in Stencil handling of macro ranges
Summary: Currently, an attempt to rewrite source code inside a macro
expansion succeeds, but results in empty text, rather than failing with
an error.  This patch restructures to the code to explicitly validate
ranges before attempting to edit them.
Reviewers: gribozavr
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72274

[mlir] Generator converting LLVM intrinsics defs to MLIR ODS
Introduce a new generator for MLIR tablegen driver that consumes LLVM IR 
intrinsic definitions and produces MLIR ODS definitions. This is useful
to bulk-generate MLIR operations equivalent to existing LLVM IR
intrinsics, such as additional arithmetic instructions or NVVM.
A test exercising the generation is also added. It reads the main LLVM 
intrinsics file and produces ODS to make sure the TableGen model remains
in sync with what is used in LLVM.
Differential Revision: https://reviews.llvm.org/D72926

[SeparateConstOffsetFromGEP] Fix: sext(a) + sext(b) -> sext(a + b)
matches add and sub instructions with one another
During the SeparateConstOffsetFromGEP pass, signed extensions are
distributed to the values that feed into them and then later recombined.
The recombination stage is somewhat problematic- it doesn't differ add
and sub instructions from another when matching the sext(a) +/- sext(b)
-> sext(a +/- b) pattern in some instances.
An example- the IR contains:
%unextendedA
%unextendedB
%subuAuB = unextendedA - unextendedB
%extA = extend A
%extB = extend B
%addeAeB = extA + extB
The problematic optimization will transform that into:
%unextendedA
%unextendedB
%subuAuB = unextendedA - unextendedB
%extA = extend A
%extB = extend B
%addeAeB = extend subuAuB ; Obviously not semantically equivalent to the
IR input.
This patch fixes that.
Patch by Drew Wock <drew.wock@sas.com> Differential Revision:
https://reviews.llvm.org/D65967

[llvm-nm] Don't report "no symbols" error for files that contain symbols
Previously we were reporting this error if we were list no symbols which
is not the same thing as the file containing no symbols.
Also, always report the filename when printing errors.
This matches the GNU nm behaviour.
This a followup to https://reviews.llvm.org/D52810
Differential Revision: https://reviews.llvm.org/D72658

[mlir][spirv] Explicitly set the size of static arrays

Rename DW_AT_LLVM_isysroot to DW_AT_LLVM_sysroot
This is a purely cosmetic change that is NFC in terms of the binary 
output. I bugs me that I called the attribute DW_AT_LLVM_isysroot since
the "i" is an artifact of GCC command line option syntax
(-isysroot is in the category of -i options) and doesn't carry any 
useful information otherwise.
This attribute only appears in Clang module debug info.
Differential Revision: https://reviews.llvm.org/D71722

[perf-training] Ignore ' (in-process)' prefix from -###
After D69825, the output of clang -### when running in process can be 
prefixed by ' (in-process)'. Skip it.

Revert "[llvm-nm] Don't report "no symbols" error for files that contain
symbols"
This reverts commit ab974161ba699534f3e30b1f4b036eec9c33053c.
This change broke several tests, and the pre-commit bot even warning me
that it would. Doh!

[test] Fix tests after D52810

Reland "[llvm-nm] Don't report "no symbols" error for files that contain
symbols"

[clang] Set function attributes on SEH filter functions correctly.
Summary: When compiling with -munwind-tables, the SEH filter funclet
needs the uwtable function attribute, which gets automatically added if
we use SetInternalFunctionAttributes.  The filter funclet is internal so
this seems appropriate.
Reviewers: rnk
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D72786

[test] Fix test/ELF/lto/thinlto-obj-path.ll after D52810

[mlir] Replace AbstractOperation::classof with a ClassID instance.
Summary: This field is currently not used by anything, and using a
ClassID instance provides better support for more efficient classof.
Reviewers: mehdi_amini, nicolasvasilache
Reviewed By: mehdi_amini
Subscribers: merge_guards_bot, jpienaar, burmako, shauheen, antiagainst,
nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb,
llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72822

[Hexagon] Refactor HexagonShuffle
The check() in HexagonShuffle has been decomposed into smaller steps. No
functionality change is intended with this commit.