Changes

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.