buildbots, NFC.

Most of LLVM and almost all of lld/MachO uses `/*foo=*/bar` style.
No behavior change.

1. No need to call `areAllUsersVectorized` as later the cost is
   calculated only if the instruction has one use and gets vectorized.
2. Need to calculate the cost of the dead extractelement more precisely,
   taking the vector type of the vector operand, not the resulting
   vector type.

Part of D57059.

Differential Revision: https://reviews.llvm.org/D99980

Add restrictions on type layout (PR48099):
- Types passed by pointer or reference must be standard layout types.
- Types passed by value must be POD types.

Patch by olestrohm (Ole Strohm)!

Differential Revision: https://reviews.llvm.org/D100471

This allows out-of-tree users to derive PyConcreteAttribute to bind custom
attributes.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D101063

https://reviews.llvm.org/D62335 added some C++ for OpenCL specific
builtins to opencl-c.h, but these were not mirrored to the TableGen
builtin functions yet.

The TableGen builtins machinery does not have dedicated version
handling for C++ for OpenCL at the moment: all builtin versioning is
tied to `LangOpts.OpenCLVersion` (i.e., the OpenCL C version).  As a
workaround, to add builtins that are only available in C++ for OpenCL,
we define a function extension guarded by the __cplusplus macro.

Differential Revision: https://reviews.llvm.org/D100935

Fixes PR50041.

This reverts commit 96dc8d7e.

It breaks a few builds.

We don't have a specific instruction for these, so they should be expanded to
whatever separate division & multiplication is needed.

This reverts commit 04733181 which was
failing for multiple people.

Different distributions have different strategies migrating the `python` symlink. Debian and its derivatives provide `python-is-python2` and `python-is-python3`. If neither is installed, the user gets no `/usr/bin/python`. The clang-format-diff script and consequently `arc diff` can thus fail with a python not found error.  Since we require python greater than 3.6 as part of llvm prerequisites (https://llvm.org/docs/GettingStarted.html#software), let's go ahead and update this shebang.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D100968

This patch adds strings content checking to printf-2.ll via --check-globals flag.

Split off from D100724.

Reviewed By: xbolva00

Differential Revision: https://reviews.llvm.org/D101034

Split off from D100724.

Reviewed By: xbolva00

Differential Revision: https://reviews.llvm.org/D101032

It is proper to relax non-negative limitation of step_vector.
Also this patch adds more combines for step_vector:
(sub X, step_vector(C)) -> (add X,  step_vector(-C))

Differential Revision: https://reviews.llvm.org/D100812

This operation a counterpart of `memref.reshape`.

RFC [Reshape Ops Restructuring](https://llvm.discourse.group/t/rfc-reshape-ops-restructuring/3310)

Differential Revision: https://reviews.llvm.org/D100971

SmallSet may use operator `<` when we insert MIRef elements, so we
cannot limit the comparison between different BBs.

We allow MIRef() to be less that any initialized MIRef object, otherwise,
we always reture false when compare between different BBs.

Differential Revision: https://reviews.llvm.org/D101039

"EmptyNodeIntrospection.inc.in" needs to be a source of the action,
so that ninja knows to rerun this action if that input changes.

This addresses post-commit feedback to cd64273f.

Document oldest libstdc++ as 4.8.3, remove a hack for a 4.6 issue.

Differential Revision: https://reviews.llvm.org/D100465

We found issues with a number of intrinsics when building them with
C++, so it makes sense to guard these tests with some extra RUN lines
to build the tests in C++ mode.

Objective-C++ is not yet suppoerted.

rdar://76729552

Differential Revision: https://reviews.llvm.org/D100955

Eliminate empty shapes from the operands, partially fold all constant shape
operands, and fix normal folding.

Differential Revision: https://reviews.llvm.org/D100634

`InsertSequence` doesn't take ownership of the pointer so releasing this pointer
is just leaking memory.

Follow up to D100806 that was fixing other leak sanitizer test failures

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D100846

These flags are being generated by `clang-scan-deps` and it makes sense to ensure it keeps doing so.

It seems we can't find the symbols of static members on Windows? The bug is not
 relevant to what this test is actually testing so let's just XFAIL it.

This way we can add support for other nodes without duplication.

Differential Revision: https://reviews.llvm.org/D98774

Some linters get rather upset upon seeing
`std::unordered_map<const char*`, because it looks like a map of
strings but isn't. lldb uses interned strings so this is not a problem.
DenseMap is a better data structure for this anyways, so use that
instead.

This patch fixes an issue in which ConstantAsMetadata arguments to a
DIArglist, as well as the Constant values referenced by that metadata,
would not be always be emitted correctly into bitcode. This patch fixes
this issue firstly by searching for ConstantAsMetadata in DIArgLists
(previously we would only search for them when directly wrapped in
MetadataAsValue), and secondly by enumerating all of a DIArgList's
arguments directly prior to enumerating the DIArgList itself.

This patch also adds a number of asserts, and no longer treats the
arguments to a DIArgList as optional fields when reading/writing to
bitcode.

Differential Revision: https://reviews.llvm.org/D100572

From https://bugs.llvm.org/show_bug.cgi?id=49739:

Currently, `#pragma clang fp` are ignored for matrix types.

For the code below, the `contract` fast-math flag should be added to the generated call to `llvm.matrix.multiply` and `fadd`

```
typedef float fx2x2_t __attribute__((matrix_type(2, 2)));

void foo(fx2x2_t &A, fx2x2_t &C, fx2x2_t &B) {
  #pragma clang fp contract(fast)
  C = A*B + C;
}
```

Reviewed By: fhahn, mibintc

Differential Revision: https://reviews.llvm.org/D100834

This is a llvm12 only bug, and is already avoided in trunk, but we should keep track of it.