Some changes introduced in https://reviews.llvm.org/D88655 cause compiler
warnings. Since in Flang warnings are treated as errors (`-Werror` is on by
default), these are in practice compiler errors (verified with clang-10 and
clang-11, gcc-10). This patches fixes these warning/failures.

Warning/error 1:
```
llvm-project/flang/lib/Semantics/check-omp-structure.cpp:107:3: error:
unannotated fall-through between switch labels [-Werror,-Wimplicit-fallthrough]
```

Warning/error 2:
```
llvm-project/flang/lib/Semantics/check-directive-structure.h:39:9: error: field
'currentDirective_' will be initialized after field 'upperCaseDirName_'
[-Werror,-Wreorder-ctor]
```

Failing buildbot:
* http://lab.llvm.org:8011/#/builders/33/builds/386

[AMDGPU] SILowerControlFlow::removeMBBifRedundant. Refactoring plus fix for the null MBB pointer in MF->splice

Detailed description: This change addresses the refactoring adviced by foad. It also contain the fix for the case when getNextNode is null if the successor block is the last in MachineFunction.

Reviewed By: foad

Differential Revision: https://reviews.llvm.org/D90314

MSVC builds were failing because the constexpr wasn't couldn't be captured by the lamdba.

Fix an implicit double to float truncation warning as well.

Fixes clang-tidy warnings.

A common pattern when using SmallString is to repeatedly call append to build a larger string.
The issue here is the optimizer can't see through this and often has to check there is enough space in the storage for each string you try to append.
This results in lots of conditional branches and potentially multiple calls to grow needing to be emitted if the buffer wasn't large enough.
By taking an initializer_list of StringRefs, SmallString can preallocate the storage it needs for all of the StringRefs which only need to grow one time at most, then use a fast path of copying all the strings into its storage knowing there is guaranteed to be enough capacity.
By using StringRefs, this also means you can append different string like types in one go as they will all be implicitly converted to a StringRef.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D90386

Differential Revision: https://reviews.llvm.org/D90407

Currently we fail to eliminate some noop stores if there is a kill-able
store between the starting def and the load. This is because we
eliminate noop stores first.

In practice it seems like eliminating noop stores after the main
elimination for a def covers slightly more cases.

This patch improves the number of stores slightly in 2 cases for X86 -O3
-flto

Same hash: 235 (filtered out)
Remaining: 2
Metric: dse.NumRedundantStores

Program                                          base      patch diff
 test-suite...ce/Benchmarks/PAQ8p/paq8p.test     2.00   3.00 50.0%
 test-suite...006/453.povray/453.povray.test    18.00  21.00 16.7%

There might be other phase ordering issues, but it appears that they do
not show up in the test-suite/SPEC2000/SPEC2006. We can always tune the
ordering later.

Partly fixes PR47887.

Reviewed By: asbirlea, zoecarver

Differential Revision: https://reviews.llvm.org/D89650

We shouldn't be including the libc++ headers from the source tree directly, since those headers are not configured (i.e. they don't use the __config_site) header like they should, which could mean up to ABI differences

Reviewed By: vitalybuka, phosek, ldionne

Differential Revision: https://reviews.llvm.org/D89915

This op returns a boolean value indicating whether 2 ops are
broadcastable or not. This follows the same logic as the other ops with
broadcast in their names in the shape dialect.

Concretely, shape.is_broadcastable returning true implies that
shape.broadcast will not give an error, and shape.cstr_broadcastable
will not result in an assertion failure. Similarly, false implies an
error or assertion failure.

Simplifies the code and fixes the build on SPARC.
See discussion in: http://lists.llvm.org/pipermail/llvm-dev/2020-October/145937.html

Author: glaubitz (John Paul Adrian Glaubitz)
Reviewed-in: https://reviews.llvm.org/D89940

If we've got an SCEVPtrToIntExpr(op), where op is not an SCEVUnknown,
we want to sink the SCEVPtrToIntExpr into an operand,
so that the operation is performed on integers,
and eventually we end up with just an `SCEVPtrToIntExpr(SCEVUnknown)`.

Reviewed By: mkazantsev

Differential Revision: https://reviews.llvm.org/D89692

And use it to model LLVM IR's `ptrtoint` cast.

This is essentially an alternative to D88806, but with no chance for
all the problems it caused due to having the cast as implicit there.
(see rG7ee6c402)

As we've established by now, there are at least two reasons why we want this:
* It will allow SCEV to actually model the `ptrtoint` casts
  and their operands, instead of treating them as `SCEVUnknown`
* It should help with initial problem of PR46786 - this should eventually allow us
  to not loose pointer-ness of an expression in more cases

As discussed in [[ https://bugs.llvm.org/show_bug.cgi?id=46786 | PR46786 ]], in principle,
we could just extend `SCEVUnknown` with a `is ptrtoint` cast, because `ScalarEvolution::getPtrToIntExpr()`
should sink the cast as far down into the expression as possible,
so in the end we should always end up with `SCEVPtrToIntExpr` of `SCEVUnknown`.

But i think that it isn't the best solution, because it doesn't really matter
from memory consumption side - there probably won't be *that* many `SCEVPtrToIntExpr`s
for it to matter, and it allows for much better discoverability.

Reviewed By: mkazantsev

Differential Revision: https://reviews.llvm.org/D89456

Differential revision: https://reviews.llvm.org/D90321

From D89768

Previously they were separated into "instance" and "kind" aliases, and also required that the dialect know ahead of time all of the instances that would have a corresponding alias. This approach was very clunky and not ergonomic to interact with. The new approach is to provide the dialect with an instance  of an attribute/type to provide an alias for, fully replacing the original split approach.

Differential Revision: https://reviews.llvm.org/D89354

The existing logic in determining whether an alloca should live on the frame only looks explicit def-use relationships. However a value defined by an alloca may be implicitly needed across suspension points, either because an alias has across-suspension-point def-use relationship, or escaped by store/call/memory intrinsics. To properly handle all these cases, we have to properly visit the alloca pointer up-front. Thie patch extends the exisiting alloca use visitor to determine whether an alloca should live on the frame.

Differential Revision: https://reviews.llvm.org/D89768

We have the `--check-prefixes` invocation for a single suffix.
It is cleaner to use `--check-prefix` in this case.

Almost any sanitizer can try to install interceptors.

This adds some initial content as well as structure to the new OpenMP
Sphinx documentation hosted at http://openmp.llvm.org/docs/ .

The content contains some useful links but most pages are still empty.

This uses a "custom" theme which is a copy of the default "agogo" one
with minor modifications to get a nicer table of content in the sidebar.
This way we can also adjust the theme as we go.

Reviewed By: jhuber6, JonChesterfield

Differential Revision: https://reviews.llvm.org/D90256

ParseOpenMP.cpp was pretty much clang-formatted except a few minor
locations. Let's make it a clang formatted file.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D90440

If MCContext has an error, MCAssembler::layout may stop early
and some MCFragment's may not finalize.

In the Linux kernel, arch/x86/lib/memcpy_64.S could trigger the assert before
"x86_64: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S"

From below mentioned standard references
OpenACC 3.0 Standards document
840 • A program may not branch into or out of an OpenACC parallel construct

OpenMP 5.0 Standards document
A program that branches into or out of a parallel region is non-conforming.

This patch
Resolves the issue of exit out of a parallel region, other branching out issues like goto statements are not handled with this patch.
Moves code from D87906 to be reused by other OpenMP/OpenACC to check-directive-structure.h.
Adds support in OpenMP parallel construct and a test case to verify.

Reviewed By: clementval

Differential Revision: https://reviews.llvm.org/D88655

Fixes check-all with LLVM_USE_SANITIZER=Memory

It is semantically equivalent, but the intent was really lost there.
This fixes a warning/error from MSVC as well, see PR48013

Allow standalone builds to inherit the LLVM_LIT_ARGS.

[MC] Add SMLoc to MCStreamer::emitSymbolAttribute and report changed binding warnings/errors for ELF

This patch is mainly doing two things:

1. Adding support for parentheses, making the combination of target features
   more diverse;
2. Making the priority of ’,‘ is higher than that of '|' by default. So I need
   to make some change with PTX Builtin function.

Differential Revision: https://reviews.llvm.org/D89184

Temporarily XFAIL'ing TestTypeGetModule.py while the DWO failure is
being investigated.

Differential revision: https://reviews.llvm.org/D88483

prune-eh will not be ported to the NPM. Instead, a combination of
function-attrs and simplifycfg should be used (as described in
https://reviews.llvm.org/D44415).

This pins most tests using -prune-eh to the legacy PM. Some of these
were testing legacy PM infra (mostly the CGPassManager). Some of these
can be tested in the NPM using function-attrs and simplifycfg.

One interesting case is simplenoreturntest.ll. function-attrs +
simplifycfg does not yet make a caller of a caller of a noreturn
function end with unreachable like prune-eh does. That can be added in
the future.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D90012

Pass AAQI in places where it was missed.

Part of D89991.
Author: haoranxu510 (Haoran Xu)

Recognize the __apple_ sections as debug info sections and make sure
they're included in the --show-sections-sizes output.

Differential revision: https://reviews.llvm.org/D90433