[OpenMP][AIX] Set worker stack size to 2 x KMP_DEFAULT_STKSIZE if system stack size is too big (#81996)

This patch sets the stack size of worker threads to `2 x
KMP_DEFAULT_STKSIZE` (2 x 4MB) for AIX if the system stack size is too
big. Also defines maximum stack size for 32-bit AIX.

Our usual pattern when issuing an extension warning is to also issue a
default-off diagnostic about the keywords not being compatible with
standards before a certain point. This adds those diagnostics for C11
keywords.

This patch attempts to fix lookup in class template specialization.

The first fixed problem is that during type lookup `DeclContextGetName`
have been dropping template arguments. So when such a name was compared
against a name in `DW_AT_name`, which contains template arguments, false
mismatches have been occurring.

The second fixed problem is that LLDB's printing policy hasn't been
matching Clang's printing policy when it comes to integral non-type
template arguments. This again caused some false mismatches during type
lookup, because Clang puts e.g. `3U` in debug info for class
specializations, but LLDB has been expecting just `3`. This patch brings
printing policy in line with what Clang does.

optnone requires noinline, which is incompatible with alwaysinline.

According to DWARF spec zero entires indicate end of arange. Changed so
that BOLT does not emit zero low_pc arange.

Motivation for this and follow-on patches is to improve codegen for
libc++, where using memcpy limits optimizations, like vectorization for
code iteration over std::vector<std::complex<float>>:
https://godbolt.org/z/f3vqYos3c

Depends on https://github.com/llvm/llvm-project/pull/81289.

PR: https://github.com/llvm/llvm-project/pull/81313

This reverts commit 7b7d411d.

Fix for performance regression introduced by #80061 that slowed
down Fuchsia's MallocFree microbenchmark by 3.5 - 8%

Follow on to #81525 in the series of consolidating bits in TSFlags.

Merge SGPRSpill and VGPRSpill into single Spill bit

Modify isSGPRSpill and isVGPRSpill helper functions to differentiate
VGPR and SGPR spills:

Spill+SALU=SGPR Spill
Spill+VALU=VGPR Spill

The only exception here is SGPR spills to VGPRs which require an
explicit instruction check.

Looks like I lost this last time.

NFCish since previously we'd return false for all presplit coroutines
anyway. This clarifies things a bit.

Enough so we can enable SemaCXX/builtin-overflow.cpp.

to satisfy the __start___llvm_orderfile reference when linking with
-bexpfull and -fprofile-generate on AIX.

This is a fix forward for the Fuchsia build bot
https://lab.llvm.org/buildbot/#/builders/98/builds/33515

I've been diffing the c17 vs c23 latest publicly available drafts and think I
have most of the library related differences. I haven't yet annotated what we
actually support or not.

Link: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2310.pdf (C17)
Link: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf (C23)

This patch Implements AST node creation and appertainment enforcement
for 'parallel', as well as changes the 'not implemented' messages to be
more specific. It does not deal with clauses/clause legality, nor a few
of the other rules from the standard, but this gets us most of the way
for a framework for future construct implementation.

We have a handful of tests that build a driver which links against LLDB.
When running those binaries, we overwrite the dynamic loader library
path to point to the build directory's libs dir, presumably to make sure
we load LLDB from there.

This above becomes an issue when you have libc++ enabled and the driver
is linked against the system's libc++, but the dynamic loader flag
forces it to pick up libc++ from the libs dir.

We could try to make the logic for building the driver smarter and have
it pick up the just-built libc++ like we do for our test binaries, but I
don't think we need to overwrite the library path in the first place.
The build logic to build these drivers already takes care to set the
correct RPATH in the linker.

This patch removes the logic and simplifies the tests.

This patch attempts to fix lookup in class template specialization.

The first fixed problem is that during type lookup `DeclContextGetName`
have been dropping template arguments. So when such a name was compared
against a name in `DW_AT_name`, which contains template arguments, false
mismatches have been occurring.

The second fixed problem is that LLDB's printing policy hasn't been
matching Clang's printing policy when it comes to integral non-type
template arguments. This again caused some false mismatches during type
lookup, because Clang puts e.g. `3U` in debug info for class
specializations, but LLDB has been expecting just `3`. This patch brings
printing policy in line with what Clang does.

This only address the tmp name collision.  We still get warnings due to
conflicting ASM.  This is due to the different target attributes on the
function.

On some uArchs, `STP [s|d], [s|d]` first combines the 2 input registers
in a single register using a vector execution unit. IIUC
AArch64StorePairSuppress tries to prevent forming STPs in case the
critical resource are the vector units, in order to prevent adding more
pressure on those units.

The implementation however simply computes the new critical resource
length by adding resource for another STP. If load/store units are the
critical resource, this means we increase that length by one, and
incorrectly prevent forming the STP.

This patch adjusts the resource computation by also removing 2 STRs, as
introducing a STP will remove 2 single stores. This should more
accurately reflect the resource usage after introducing an STP, and does
not prevent forming STPs if load/store units are the critical resources;
in those cases, STP can actually help to reduce resource usage.

PR: https://github.com/llvm/llvm-project/pull/81749

For some reason only IntClamp was added to the Ins64, but not FPClamp.
As is this is NFC, but fails to produce proper dag downstream.

Fix and rename the broken and confusingly named decorator
skipIfHostIncompatibleWithRemote. The decorator is meant to skip test
which uses the inferior test build system (i.e. to build test inferiors)
to build host binaries (e.g. lldb drivers).

The decorator was broken on macOS, where the host and target platform
report macosx, but the decorator overwrote it with Darwin, resulting in
tests incorrectly being skipped.

The decorator was also missing on a handful of tests that use the
buildDriver helper, which this commit fixes as well.

fshl/fshr having first two arguments as same gets lowered to target
specific rotate. But based on the uses, one of the arguments can get
simplified resulting in different arguments performing equivalent
operation.

This patch prevents the simplification of the arguments of lshr/shl if
they are part of fshl pattern.

Closes https://github.com/llvm/llvm-project/pull/73441.

The matchFunnelShift function was doing pattern matching and creating
the fshl/fshr instruction if needed. Moved the pattern matching code to
function convertOrOfShiftsToFunnelShift. It can be reused for other
optimizations.

- #81835
- Fix for platforms where uint64_t is not available

This patch introduces the new MPI dialect into MLIR. The Message Passing
Interface (MPI) is a widely-used standard for distributed programs to
exchange data. This PR goes together with a talk later at today's LLVM
Dev Meeting.

This is just a first, small patch to get going and add the necessary
base files, so that we can add more operations in further patches.

Here's the documentation as generated by `ninja mlir-doc`:
# 'mpi' Dialect

This dialect models the Message Passing Interface (MPI), version 
4.0. It is meant to serve as an interfacing dialect that is targeted
by higher-level dialects. The MPI dialect itself can be lowered to 
multiple MPI implementations and hide differences in ABI. The dialect
models the functions of the MPI specification as close to 1:1 as
possible
while preserving SSA value semantics where it makes sense, and uses 
`memref` types instead of bare pointers.

This dialect is under active development, and while stability is an
eventual goal, it is not guaranteed at this juncture. Given the early 
state, it is recommended to inquire further prior to using this dialect.

For an in-depth documentation of the MPI library interface, please refer
to official documentation such as the 
[OpenMPI online documentation](https://www.open-mpi.org/doc/current/).

[TOC]

## Operation definition

### `mpi.comm_rank` (mpi::CommRankOp)

_Get the current rank, equivalent to `MPI_Comm_rank(MPI_COMM_WORLD,
&rank)`_


Syntax:

```
operation ::= `mpi.comm_rank` attr-dict `:` type(results)
```

Communicators other than `MPI_COMM_WORLD` are not supported for now.

This operation can optionally return an `!mpi.retval` value that can be
used
to check for errors.

#### Results:

| Result | Description |
| :----: | ----------- |
| `retval` | MPI function call return value
| `rank` | 32-bit signless integer


### `mpi.error_class` (mpi::ErrorClassOp)

_Get the error class from an error code, equivalent to the
`MPI_Error_class` function_


Syntax:

```
operation ::= `mpi.error_class` $val attr-dict `:` type($val)
```

`MPI_Error_class` maps return values from MPI calls to a set of
well-known
MPI error classes.

#### Operands:

| Operand | Description |
| :-----: | ----------- |
| `val` | MPI function call return value

#### Results:

| Result | Description |
| :----: | ----------- |
| `errclass` | MPI function call return value


### `mpi.finalize` (mpi::FinalizeOp)

_Finalize the MPI library, equivalent to `MPI_Finalize()`_


Syntax:

```
operation ::= `mpi.finalize` attr-dict (`:` type($retval)^)?
```

This function cleans up the MPI state. Afterwards, no MPI methods may 
be invoked (excpet for MPI_Get_version, MPI_Initialized, and
MPI_Finalized).
Notably, MPI_Init cannot be called again in the same program.

This operation can optionally return an `!mpi.retval` value that can be
used
to check for errors.

#### Results:

| Result | Description |
| :----: | ----------- |
| `retval` | MPI function call return value


### `mpi.init` (mpi::InitOp)

_Initialize the MPI library, equivalent to `MPI_Init(NULL, NULL)`_


Syntax:

```
operation ::= `mpi.init` attr-dict (`:` type($retval)^)?
```

This operation must preceed most MPI calls (except for very few
exceptions,
please consult with the MPI specification on these).

Passing &argc, &argv is not supported currently.

This operation can optionally return an `!mpi.retval` value that can be
used
to check for errors.

#### Results:

| Result | Description |
| :----: | ----------- |
| `retval` | MPI function call return value


### `mpi.recv` (mpi::RecvOp)

_Equivalent to `MPI_Recv(ptr, size, dtype, dest, tag, MPI_COMM_WORLD,
MPI_STATUS_IGNORE)`_


Syntax:

```
operation ::= `mpi.recv` `(` $ref `,` $tag `,` $rank `)` attr-dict `:` type($ref) `,` type($tag) `,` type($rank)(`->` type($retval)^)?
```

MPI_Recv performs a blocking receive of `size` elements of type `dtype` 
from rank `dest`. The `tag` value and communicator enables the library
to
determine the matching of multiple sends and receives between the same 
ranks.

Communicators other than `MPI_COMM_WORLD` are not supprted for now.
The MPI_Status is set to `MPI_STATUS_IGNORE`, as the status object 
is not yet ported to MLIR.

This operation can optionally return an `!mpi.retval` value that can be
used
to check for errors.

#### Operands:

| Operand | Description |
| :-----: | ----------- |
| `ref` | memref of any type values
| `tag` | 32-bit signless integer
| `rank` | 32-bit signless integer

#### Results:

| Result | Description |
| :----: | ----------- |
| `retval` | MPI function call return value


### `mpi.retval_check` (mpi::RetvalCheckOp)

_Check an MPI return value against an error class_


Syntax:

```
operation ::= `mpi.retval_check` $val `=` $errclass attr-dict `:` type($res)
```

This operation compares MPI status codes to known error class
constants such as `MPI_SUCCESS`, or `MPI_ERR_COMM`.

#### Attributes:

<table>
<tr><th>Attribute</th><th>MLIR Type</th><th>Description</th></tr>

<tr><td><code>errclass</code></td><td>::mlir::mpi::MPI_ErrorClassEnumAttr</td><td><details><summary>MPI
error class name</summary>{{% markdown %}}Enum cases:
* MPI_SUCCESS (`MPI_SUCCESS`)
* MPI_ERR_ACCESS (`MPI_ERR_ACCESS`)
* MPI_ERR_AMODE (`MPI_ERR_AMODE`)
* MPI_ERR_ARG (`MPI_ERR_ARG`)
* MPI_ERR_ASSERT (`MPI_ERR_ASSERT`)
* MPI_ERR_BAD_FILE (`MPI_ERR_BAD_FILE`)
* MPI_ERR_BASE (`MPI_ERR_BASE`)
* MPI_ERR_BUFFER (`MPI_ERR_BUFFER`)
* MPI_ERR_COMM (`MPI_ERR_COMM`)
* MPI_ERR_CONVERSION (`MPI_ERR_CONVERSION`)
* MPI_ERR_COUNT (`MPI_ERR_COUNT`)
* MPI_ERR_DIMS (`MPI_ERR_DIMS`)
* MPI_ERR_DISP (`MPI_ERR_DISP`)
* MPI_ERR_DUP_DATAREP (`MPI_ERR_DUP_DATAREP`)
* MPI_ERR_ERRHANDLER (`MPI_ERR_ERRHANDLER`)
* MPI_ERR_FILE (`MPI_ERR_FILE`)
* MPI_ERR_FILE_EXISTS (`MPI_ERR_FILE_EXISTS`)
* MPI_ERR_FILE_IN_USE (`MPI_ERR_FILE_IN_USE`)
* MPI_ERR_GROUP (`MPI_ERR_GROUP`)
* MPI_ERR_INFO (`MPI_ERR_INFO`)
* MPI_ERR_INFO_KEY (`MPI_ERR_INFO_KEY`)
* MPI_ERR_INFO_NOKEY (`MPI_ERR_INFO_NOKEY`)
* MPI_ERR_INFO_VALUE (`MPI_ERR_INFO_VALUE`)
* MPI_ERR_IN_STATUS (`MPI_ERR_IN_STATUS`)
* MPI_ERR_INTERN (`MPI_ERR_INTERN`)
* MPI_ERR_IO (`MPI_ERR_IO`)
* MPI_ERR_KEYVAL (`MPI_ERR_KEYVAL`)
* MPI_ERR_LOCKTYPE (`MPI_ERR_LOCKTYPE`)
* MPI_ERR_NAME (`MPI_ERR_NAME`)
* MPI_ERR_NO_MEM (`MPI_ERR_NO_MEM`)
* MPI_ERR_NO_SPACE (`MPI_ERR_NO_SPACE`)
* MPI_ERR_NO_SUCH_FILE (`MPI_ERR_NO_SUCH_FILE`)
* MPI_ERR_NOT_SAME (`MPI_ERR_NOT_SAME`)
* MPI_ERR_OP (`MPI_ERR_OP`)
* MPI_ERR_OTHER (`MPI_ERR_OTHER`)
* MPI_ERR_PENDING (`MPI_ERR_PENDING`)
* MPI_ERR_PORT (`MPI_ERR_PORT`)
* MPI_ERR_PROC_ABORTED (`MPI_ERR_PROC_ABORTED`)
* MPI_ERR_QUOTA (`MPI_ERR_QUOTA`)
* MPI_ERR_RANK (`MPI_ERR_RANK`)
* MPI_ERR_READ_ONLY (`MPI_ERR_READ_ONLY`)
* MPI_ERR_REQUEST (`MPI_ERR_REQUEST`)
* MPI_ERR_RMA_ATTACH (`MPI_ERR_RMA_ATTACH`)
* MPI_ERR_RMA_CONFLICT (`MPI_ERR_RMA_CONFLICT`)
* MPI_ERR_RMA_FLAVOR (`MPI_ERR_RMA_FLAVOR`)
* MPI_ERR_RMA_RANGE (`MPI_ERR_RMA_RANGE`)
* MPI_ERR_RMA_SHARED (`MPI_ERR_RMA_SHARED`)
* MPI_ERR_RMA_SYNC (`MPI_ERR_RMA_SYNC`)
* MPI_ERR_ROOT (`MPI_ERR_ROOT`)
* MPI_ERR_SERVICE (`MPI_ERR_SERVICE`)
* MPI_ERR_SESSION (`MPI_ERR_SESSION`)
* MPI_ERR_SIZE (`MPI_ERR_SIZE`)
* MPI_ERR_SPAWN (`MPI_ERR_SPAWN`)
* MPI_ERR_TAG (`MPI_ERR_TAG`)
* MPI_ERR_TOPOLOGY (`MPI_ERR_TOPOLOGY`)
* MPI_ERR_TRUNCATE (`MPI_ERR_TRUNCATE`)
* MPI_ERR_TYPE (`MPI_ERR_TYPE`)
* MPI_ERR_UNKNOWN (`MPI_ERR_UNKNOWN`)
* MPI_ERR_UNSUPPORTED_DATAREP (`MPI_ERR_UNSUPPORTED_DATAREP`)
* MPI_ERR_UNSUPPORTED_OPERATION (`MPI_ERR_UNSUPPORTED_OPERATION`)
* MPI_ERR_VALUE_TOO_LARGE (`MPI_ERR_VALUE_TOO_LARGE`)
* MPI_ERR_WIN (`MPI_ERR_WIN`)
* MPI_ERR_LASTCODE (`MPI_ERR_LASTCODE`){{% /markdown
%}}</details></td></tr>
</table>

#### Operands:

| Operand | Description |
| :-----: | ----------- |
| `val` | MPI function call return value

#### Results:

| Result | Description |
| :----: | ----------- |
| `res` | 1-bit signless integer


### `mpi.send` (mpi::SendOp)

_Equivalent to `MPI_Send(ptr, size, dtype, dest, tag, MPI_COMM_WORLD)`_


Syntax:

```
operation ::= `mpi.send` `(` $ref `,` $tag `,` $rank `)` attr-dict `:` type($ref) `,` type($tag) `,` type($rank)(`->` type($retval)^)?
```

MPI_Send performs a blocking send of `size` elements of type `dtype` to
rank
`dest`. The `tag` value and communicator enables the library to
determine
the matching of multiple sends and receives between the same ranks.

Communicators other than `MPI_COMM_WORLD` are not supprted for now.

This operation can optionally return an `!mpi.retval` value that can be
used
to check for errors.

#### Operands:

| Operand | Description |
| :-----: | ----------- |
| `ref` | memref of any type values
| `tag` | 32-bit signless integer
| `rank` | 32-bit signless integer

#### Results:

| Result | Description |
| :----: | ----------- |
| `retval` | MPI function call return value


## Attribute definition

### MPI_ErrorClassEnumAttr

MPI error class name

Syntax:

```
#mpi.errclass<
  ::mlir::mpi::MPI_ErrorClassEnum   # value
>
```

Enum cases:
* MPI_SUCCESS (`MPI_SUCCESS`)
* MPI_ERR_ACCESS (`MPI_ERR_ACCESS`)
* MPI_ERR_AMODE (`MPI_ERR_AMODE`)
* ... *all other MPI error codes*

#### Parameters:

| Parameter | C++ type | Description |
| :-------: | :-------: | ----------- |
| value | `::mlir::mpi::MPI_ErrorClassEnum` | an enum of type
MPI_ErrorClassEnum |

## Type definition

### RetvalType

MPI function call return value

Syntax: `!mpi.retval`

This type represents a return value from an MPI function vall.
This value can be MPI_SUCCESS, MPI_ERR_IN_STATUS, or any error code.

This return value can be compared agains the known MPI error classes
represented by `#mpi.errclass` using the `mpi.retval_check` operation.

#80757 has been merged.

The two types duplicated mostly the same values.
Here they are decomposed to carry orthogonal and complimentary
information.

Use `utils::IteratorType` instead of `mesh::IteratorType`. It now has
only parallel and reduction values.

Rename `Partial` to `ReductionKind`.

Add `getReductionLoopIteratorKinds` method to `ShardingInterface`.

Add test case for store suppression that still trigger after
https://github.com/llvm/llvm-project/pull/81749

- Add a single `cmp` function to derive all comparison operators
 - Use the `friend` version of the member functions for symmetry
 - Add a `is_neg` function to factor sign extraction
 - Implement binary op through macro expansion

This caused links to fail with:

  lld/MachO/Symbols.cpp:97:
  virtual uint64_t lld::macho::Defined::getVA() const:
  Assertion `target->usesThunks()' failed.

or crash when asserts are disabled. See comment on
https://github.com/llvm/llvm-project/pull/79894

> Enable chained fixups in lld when all platform and version criteria are
> met. This is an attempt at simplifying the logic used in ld 907:
>
> https://github.com/apple-oss-distributions/ld64/blob/93d74eafc37c0558b4ffb88a8bc15c17bed44a20/src/ld/Options.cpp#L5458-L5549
>
> Some changes were made to simplify the logic:
> - only enable chained fixups for macOS from 13.0 to avoid the arch check
> - only enable chained fixups for iphonesimulator from 16.0 to avoid the
> arch check
> - don't enable chained fixups for not specifically listed platforms
> - don't enable chained fixups for arm64_32

This reverts commit 775c2856.

If a split memory access introduced by SROA accesses precisely a single
field of the original operation's !tbaa.struct, use the !tbaa tag for
the accessed field directly instead of the full !tbaa.struct.

InstCombine already had a similar logic.

Motivation for this and follow-on patches is to improve codegen for
libc++, where using memcpy limits optimizations, like vectorization for
code iteration over std::vector<std::complex<float>>:
https://godbolt.org/z/f3vqYos3c

Depends on https://github.com/llvm/llvm-project/pull/81285.