3258 Commits

Author SHA1 Message Date
Shilei Tian
e997dca333
[OpenMP] Introduce the initial support for OpenMP kernel language (#66844)
This patch starts the support for OpenMP kernel language, basically to
write
OpenMP target region in SIMT style, similar to kernel languages such as
CUDA.
What included in this first patch is the `ompx_bare` clause for `target
teams`
directive. When `ompx_bare` exists, globalization is disabled such that
local
variables will not be globalized. The runtime init/deinit function calls
will
not be emitted. That being said, almost all OpenMP executable directives
are
not supported in the region, such as parallel, task. This patch doesn't
include
the Sema checks for that, so the use of them is UB. Simple directives,
such as
atomic, can be used. We provide a set of APIs (for C, they are prefix
with
`ompx_`; for C++, they are in `ompx` namespace) to get thread id, block
id, etc.
For more details, you can refer to
https://tianshilei.me/wp-content/uploads/llvm-hpc-2023.pdf.
2023-09-29 13:11:09 -04:00
Jan Svoboda
b0abc9dd44 [clang] NFCI: Use FileEntryRef in ASTReader::GetHeaderFileInfo()
This is the `ASTReader` counterpart to PR #67383.
2023-09-29 09:07:13 -07:00
Chuanqi Xu
7e8a0e4bdc [NFC] [C++20] [Modules] Rename NamedModuleHasInit to NamedModuleHasInit
Address comments in
https://github.com/llvm/llvm-project/pull/67638/files#r1340342453 to
rename the field variable.
2023-09-29 21:49:10 +08:00
Jan Svoboda
de85739ded [clang] NFCI: Use FileEntryRef in additional module maps 2023-09-28 14:49:45 -07:00
Jan Svoboda
6bbccc0bcb
[clang][modules] Adopt FileEntryRef in the HeaderFileInfo block in PCM files (#67383)
This patch adopts `FileEntryRef` in the `HeaderFileInfo`-writing part of
`ASTWriter`.

First, this patch removes the loop over
`FileManager::VirtualFileEntries`. It's redundant, since all virtual
file entries are also present in `SeenFileEntries` and thus already in
`UIDToFiles`.

Second, since we now no longer rely on
`FileEntry::getLastRef()`/`FileEntry::getName()`, this patch takes care
to establish which path gets used for each UID by picking the
`FileEntryRef` with the most "`<`" name (instead of just relying on the
`StringMap` iteration order).

Note that which `FileEntry`/`FileEntryRef` objects we pick for each UID
for serialization into the `llvm::OnDiskChainedHashTable` doesn't really
matter. The hash function only includes the file size and modification
time. The file name only plays role during resolution of hash
collisions, in which case it goes through `FileManager` and resolves to
a `FileEntry` that gets pointer-compared with the queried `FileEntry`.

(Reincarnation of [D143414](https://reviews.llvm.org/D143414) and
[D142780](https://reviews.llvm.org/D142780).)
2023-09-28 09:28:02 -07:00
Chuanqi Xu
989173c09c
[C++20] [Modules] Don't generate call to an imported module that dont init anything (#67638)
Close https://github.com/llvm/llvm-project/issues/56794

And see https://github.com/llvm/llvm-project/issues/67582 for a detailed
backgrond for the issue.

As required by the Itanium ABI, the module units have to generate the
initialization function. However, the importers are allowed to elide the
call to the initialization function if they are sure the initialization
function doesn't do anything.

This patch implemented this semantics.
2023-09-28 23:29:24 +08:00
Sam McCall
0f05096540
[Serialization] Do less redundant work computing affecting module maps (#66933)
We're traversing the same chains of module ancestors and include
locations repeatedly, despite already populating sets that can detect
it!

This is a problem because translateFile() is expensive. I think we can
avoid it entirely, but this seems like an improvement either way.

I removed a callback indirection rather than giving it a more
complicated
signature, and accordingly renamed the lambdas to be more concrete.
2023-09-22 11:23:11 +02:00
Richard Smith
4b163e343c Implement mangling rules for C++20 concepts and requires-expressions.
This implements proposals from:

- https://github.com/itanium-cxx-abi/cxx-abi/issues/24: mangling for
  constraints, requires-clauses, requires-expressions.
- https://github.com/itanium-cxx-abi/cxx-abi/issues/31: requires-clauses and
  template parameters in a lambda expression are mangled into the <lambda-sig>.
- https://github.com/itanium-cxx-abi/cxx-abi/issues/47 (STEP 3): mangling for
  template argument is prefixed by mangling of template parameter declaration
  if it's not "obvious", for example because the template parameter is
  constrained (we already implemented STEP 1 and STEP 2).

This changes the manglings for a few cases:

- Functions and function templates with constraints.
- Function templates with template parameters with deduced types:
  `typename<auto N> void f();`
- Function templates with template template parameters where the argument has a
  different template-head:
  `template<template<typename...T>> void f(); f<std::vector>();`

In each case where a mangling changed, the change fixes a mangling collision.

Note that only function templates are affected, not class templates or variable
templates, and only new constructs (template parameters with deduced types,
constrained templates) and esoteric constructs (templates with template
template parameters with non-matching template template arguments, most of
which Clang still does not accept by default due to
`-frelaxed-template-template-args` not being enabled by default), so the risk
to ABI stability from this change is relatively low. Nonetheless,
`-fclang-abi-compat=17` can be used to restore the old manglings for cases
which we could successfully but incorrectly mangle before.

Fixes #48216, #49884, #61273

Reviewed By: erichkeane, #libc_abi

Differential Revision: https://reviews.llvm.org/D147655
2023-09-20 12:38:15 -07:00
Chuanqi Xu
45c160510f [C++20] [Modules] [Serialization] Check input file contents with option ForceCheckCXX20ModulesInputFiles enabled
With overriden input files, e,g,. the compiler get the file from an
in-memroy buffer, the compiler can't get correct modified time information
to indicate whehter the input files are changed or not. Then, the
semantics of ForceCheckCXX20ModulesInputFiles are broken.

In this patch, if both ForceCheckCXX20ModulesInputFiles and
ValidateASTInputFilesContent and enabled, the compiler will still check the
hash value of the contents even if their modification time is the same.
2023-09-14 11:27:50 +08:00
Jan Svoboda
f94695b6eb [clang] NFCI: Use FileEntryRef in FileManager::getBufferForFile() 2023-09-13 15:02:20 -07:00
Tianlan Zhou
057564fec5
Fix some typos in comments: evalute -> evaluate (NFC) (#65906) 2023-09-11 04:11:06 +08:00
Jan Svoboda
7ad5b18522 [clang] NFCI: Use FileEntryRef in ASTWriter 2023-09-10 09:36:47 -07:00
Jan Svoboda
45bf8e432b [clang] NFCI: Use FileEntryRef in ASTReader 2023-09-10 09:36:47 -07:00
Jan Svoboda
14498a477e [clang] NFCI: Use FileEntryRef in GlobalModuleIndex 2023-09-09 21:51:03 -07:00
Jan Svoboda
bc933c9047 [clang] NFCI: Use FileEntryRef in ModuleManager 2023-09-09 21:50:38 -07:00
Jan Svoboda
37b08892fc [clang] NFCI: Use FileEntryRef in ModuleMap 2023-09-09 09:12:35 -07:00
Chuanqi Xu
96122b5b71 [C++20] [Modules] Introduce ForceCheckCXX20ModulesInputFiles options for
C++20 modules

Previously, we banned the check for input files from C++20 modules since
we thought the BMI from C++20 modules should be a standalone artifact.

However, during the recent experiment with clangd for modules, I find
it is necessary to tell whether or not a BMI is out-of-date by checking the
input files especially for language servers.

So this patch brings a header search option
ForceCheckCXX20ModulesInputFiles to allow the tools (concretly, clangd)
to check the input files from BMI.
2023-09-08 16:53:12 +08:00
Chuanqi Xu
869111ccf2 [NFC] [C++20] [Modules] Refactor the warning to '-fmodule-file=<BMIPath>' for C++20 modules
Previous implementation of the warning to use `-fmodule-file=<BMIPath>`
for C++20 Modules is not straightforward and it is problematic in case
we read the BMIPath by writing tools based clang components. This patch
refactors it with a simple and direct style.
2023-09-07 17:13:16 +08:00
Chuanqi Xu
f0cd9b2b8a [NFC] [Serialization] Remove unused output parameter 'Imported' in ReadAST 2023-09-07 16:12:53 +08:00
Chris Bieneman
400d3261a0 [HLSL] Cleanup support for this as an l-value
The goal of this change is to clean up some of the code surrounding
HLSL using CXXThisExpr as a non-pointer l-value. This change cleans up
a bunch of assumptions and inconsistencies around how the type of
`this` is handled through the AST and code generation.

This change is be mostly NFC for HLSL, and completely NFC for other
language modes.

This change introduces a new member to query for the this object's type
and seeks to clarify the normal usages of the this type.

With the introudction of HLSL to clang, CXXThisExpr may now be an
l-value and behave like a reference type rather than C++'s normal
method of it being an r-value of pointer type.

With this change there are now three ways in which a caller might need
to query the type of `this`:

* The type of the `CXXThisExpr`
* The type of the object `this` referrs to
* The type of the implicit (or explicit) `this` argument

This change codifies those three ways you may need to query
respectively as:

* CXXMethodDecl::getThisType()
* CXXMethodDecl::getThisObjectType()
* CXXMethodDecl::getThisArgType()

This change then revisits all uses of `getThisType()`, and in cases
where the only use was to resolve the pointee type, it replaces the
call with `getThisObjectType()`. In other cases it evaluates whether
the desired returned type is the type of the `this` expr, or the type
of the `this` function argument. The `this` expr type is used for
creating additional expr AST nodes and for member lookup, while the
argument type is used mostly for code generation.

Additionally some cases that used `getThisType` in simple queries could
be substituted for `getThisObjectType`. Since `getThisType` is
implemented in terms of `getThisObjectType` calling the later should be
more efficient if the former isn't needed.

Reviewed By: aaron.ballman, bogner

Differential Revision: https://reviews.llvm.org/D159247
2023-09-05 19:38:50 -05:00
Jens Massberg
c2bf9baf59 Add a concept AST node.
This patch adds a concept AST node (`ConceptLoc`) and uses it at the corresponding places.

There are three objects that might have constraints via concepts:
`TypeConstraint`,  `ConceptSpecializationExpr` and `AutoTypeLoc`.
The first two inherit from `ConceptReference` while the latter has
the information about a possible constraint directly stored in `AutoTypeLocInfo`. It would be nice if the concept information would be stored the same way in all three cases.

Moreover the current structure makes it difficult to deal with these concepts. For example in Clangd accessing the locations of constraints of a `AutoTypeLoc` can only be done with quite ugly hacks.

So we think that it makes sense to create a new AST node for such concepts.

In details we propose the following:
- Rename `ConceptReference` to `ConceptLoc` (or something else what is approriate)
and make it the new AST node.
- `TypeConstraint` and `ConceptSpecializationExpr` do not longer inherit from `ConceptReference` but store a pointer to a `ConceptLoc`.
- `AutoTypeLoc` stores a pointer to `ConceptLoc` instead of storing the concept info in `AutoTypeLocInfo`.

This patch implements a first version of this idea which compiles and where the existing tests pass.
To make this patch as small as possible we keep the existing member functions to access concept data. Later these can be replaced by directly calling the corresponding functions of the `ConceptLoc`s.

Differential Revision: https://reviews.llvm.org/D155858
2023-08-31 10:22:21 +02:00
Jan Svoboda
dd850f0bae [llvm][clang][modules] Fix test failure on big-endian bots
After 6fb08d8f558a6f28db7835acdb88cab83aea2eb4,`clang/test/Modules/ModuleDebugInfoDwoId.cpp` started failing on a number of big-endian build bots (clang-ppc64be-linux-multistage, clang-ppc64be-linux-test-suite). This patch attempts to fix that by creating an API on `llvm::BitstreamWriter` that allows backpatching individual bytes. This API is then used from `clang::ASTWriter` to avoid endianness mismatch.
2023-08-28 13:18:40 -07:00
Jan Svoboda
b9b81e37fe [clang][modules] NFC: Use local instead of ModuleFile member 2023-08-28 09:54:39 -07:00
Jan Svoboda
6fb08d8f55 Reland "[clang][modules] Move UNHASHED_CONTROL_BLOCK up in the AST file"
This reverts commit b6ba804f7775f89f230ee1e62526a2f8225c7966, effectively relanding commit 7d1565727dad3acb54fe76a908630843835d7bc8.

The original commit incorrectly called `ASTWriter::writeUnhashedControlBlock()` before `ASTWriter::collectNonAffectingInputFiles()`, causing SourceLocations/FileIDs in the pragma diagnostic mappings block to be invalid. This is now tested by `clang/test/Modules/diag-mappings-affecting.c`.
2023-08-28 09:54:39 -07:00
Jan Svoboda
d4a9121534 Reland "[clang][modules] Use relative offsets for input files"
This reverts commit 870f1583eed0f22ddfb1a1979a90198c3dc09927, effectively relanding commit b9d78bdc730b2fcfe029a7579c24020536c3fa25.
2023-08-28 09:54:39 -07:00
Fazlay Rabbi
e4c7298bea [OpenMP 5.1] Parsing and Sema support for scope directive
structured-block

where clause is one of the following:

private(list)
reduction([reduction-modifier ,] reduction-identifier : list)
nowait

Differential Revision: https://reviews.llvm.org/D157933
2023-08-24 18:13:52 -07:00
Jan Svoboda
870f1583ee Revert "[clang][modules] Use relative offsets for input files"
This reverts commit b9d78bdc730b2fcfe029a7579c24020536c3fa25. After this change, all libc++ `clang_modules_include.gen.py` tests started failing on Linux builders: https://luci-milo.appspot.com/ui/p/fuchsia/builders/toolchain.ci/clang-linux-arm64/b8771862804321535569/test-results
2023-08-24 14:43:23 -07:00
Jan Svoboda
b6ba804f77 Revert "[clang][modules] Move UNHASHED_CONTROL_BLOCK up in the AST file"
This reverts commit 7d1565727dad3acb54fe76a908630843835d7bc8.
2023-08-24 14:43:23 -07:00
Jan Svoboda
7d1565727d [clang][modules] Move UNHASHED_CONTROL_BLOCK up in the AST file
When loading (transitively) imported AST file, `ModuleManager::addModule()` first checks it has the expected signature via `readASTFileSignature()`. The signature is part of `UNHASHED_CONTROL_BLOCK`, which is placed at the end of the AST file. This means that just to verify signature of an AST file, we need to skip over all top-level blocks, paging in the whole AST file from disk. This is pretty slow.

This patch moves `UNHASHED_CONTROL_BLOCK` to the start of the AST file, so that it can be read more efficiently. To achieve this, we use dummy signature when first emitting the unhashed control block, and then backpatch the real signature at the end of the serialization process.

This speeds up dependency scanning by over 9% and significantly reduces run-to-run variability of my benchmarks.

Depends on D158572.

Reviewed By: benlangmuir

Differential Revision: https://reviews.llvm.org/D158573
2023-08-24 09:16:04 -07:00
Jan Svoboda
b9d78bdc73 [clang][modules] Use relative offsets for input files
This patch replaces absolute offsets into the input files block with offsets relative to the block start. This makes the whole section "relocatable". I confirmed all other uses of `GetCurrentBitNo()` are turned into relative offsets before being serialized into the AST file.

Reviewed By: benlangmuir

Differential Revision: https://reviews.llvm.org/D158572
2023-08-24 09:16:04 -07:00
Jan Svoboda
6a11557832 [clang][modules] Avoid storing command-line macro definitions into implicitly built PCM files
With implicit modules, it's impossible to load a PCM file that was built using different command-line macro definitions. This is guaranteed by the fact that they contribute to the context hash. This means that we don't need to store those macros into PCM files for validation purposes. This patch avoids serializing them in those circumstances, since there's no other use for command-line macro definitions (besides "-module-file-info").

For a typical Apple project, this speeds up the dependency scan by 5.6% and shrinks the cache with scanning PCMs by 26%.

Reviewed By: benlangmuir

Differential Revision: https://reviews.llvm.org/D158136
2023-08-17 11:11:29 -07:00
dingfei
91c4b5550e [clang] Update NumFunctionDeclBits for FunctionDeclBitfields
NumFunctionDeclBits is not updated when DeductionCandidateKind is
incremented.

Fixes https://github.com/llvm/llvm-project/issues/64171

Reviewed By: cor3ntin, balazske, aaron.ballman

Differential Revision: https://reviews.llvm.org/D158145
2023-08-17 20:28:41 +08:00
Volodymyr Sapsai
52c62d46a0
Reland "[modules] Fix error about the same module being defined in different .pcm files when using VFS overlays."
Fixing Windows buildbot by not using "BuildTemporaries/module.modulemap"
because it is interpreted as defining a module in "BuildTemporaries" directory.

Fix errors like
> module 'MultiPath' is defined in both 'path/to/modules.cache/3JR48BPRU7BCG/MultiPath-1352QHUF8RNMU.pcm' and 'path/to/modules.cache/3JR48BPRU7BCG/MultiPath-20HNSLLIUDDV1.pcm'

To avoid building extra identical modules `-ivfsoverlay` option is not a
part of the hash like "/3JR48BPRU7BCG/". And it is build system's
responsibility to provide `-ivfsoverlay` options that don't cause
observable differences.  We also need to make sure the hash like
"-1352QHUF8RNMU" is not affected by `-ivfsoverlay`. As this hash is
defined by the module map path, use the path prior to any VFS
remappings.

rdar://111921464

Differential Revision: https://reviews.llvm.org/D156749
2023-08-16 18:27:17 -07:00
Elizabeth Andrews
c70dab026d [NFC][Clang] Fix static analyzer concern about null value dereference
Differential Revision: https://reviews.llvm.org/D157885
2023-08-14 13:07:24 -07:00
Volodymyr Sapsai
fe9c332408
Revert "Reland "[modules] Fix error about the same module being defined in different .pcm files when using VFS overlays.""
This reverts commit b070be82bb8fb4414a8a6eb4fbfc77921d89fa4b.
2023-08-10 15:14:26 -07:00
Volodymyr Sapsai
b070be82bb
Reland "[modules] Fix error about the same module being defined in different .pcm files when using VFS overlays."
Fixing Windows buildbot by using the same separators for `-F` and `-I`
paths both in VFS overlay and on command line.

Fix errors like
> module 'MultiPath' is defined in both 'path/to/modules.cache/3JR48BPRU7BCG/MultiPath-1352QHUF8RNMU.pcm' and 'path/to/modules.cache/3JR48BPRU7BCG/MultiPath-20HNSLLIUDDV1.pcm'

To avoid building extra identical modules `-ivfsoverlay` option is not a
part of the hash like "/3JR48BPRU7BCG/". And it is build system's
responsibility to provide `-ivfsoverlay` options that don't cause
observable differences.  We also need to make sure the hash like
"-1352QHUF8RNMU" is not affected by `-ivfsoverlay`. As this hash is
defined by the module map path, use the path prior to any VFS
remappings.

rdar://111921464

Differential Revision: https://reviews.llvm.org/D156749
2023-08-10 14:52:49 -07:00
Volodymyr Sapsai
91b10f6974
Revert "[modules] Fix error about the same module being defined in different .pcm files when using VFS overlays."
This reverts commit 97dfaf4cd27814bdf9aa9d2eafc21fdb4f76c56d.

llvm-clang-x86_64-sie-win buildbot is failing with the added test.
2023-08-10 11:27:08 -07:00
Volodymyr Sapsai
97dfaf4cd2
[modules] Fix error about the same module being defined in different .pcm files when using VFS overlays.
Fix errors like
> module 'MultiPath' is defined in both 'path/to/modules.cache/3JR48BPRU7BCG/MultiPath-1352QHUF8RNMU.pcm' and 'path/to/modules.cache/3JR48BPRU7BCG/MultiPath-20HNSLLIUDDV1.pcm'

To avoid building extra identical modules `-ivfsoverlay` option is not a
part of the hash like "/3JR48BPRU7BCG/". And it is build system's
responsibility to provide `-ivfsoverlay` options that don't cause
observable differences.  We also need to make sure the hash like
"-1352QHUF8RNMU" is not affected by `-ivfsoverlay`. As this hash is
defined by the module map path, use the path prior to any VFS
remappings.

rdar://111921464

Differential Revision: https://reviews.llvm.org/D156749
2023-08-10 10:47:51 -07:00
Chi Chun Chen
8ab62da18d [Clang][OpenMP] Support for Code Generation of loop bind clause
Support for Code Generation of "#pragma loop bind" clause.
1) bind(parallel)
2) bind(teams)
3) bind(thread)

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D144634
2023-08-09 14:26:38 -05:00
Ben Langmuir
dc5cbba319 [clang][modules] Add -Wsystem-headers-in-module=
Add a way to enable -Wsystem-headers only for a specific module. This is
useful for validating a module that would otherwise not see system
header diagnostics without being flooded by diagnostics for unrelated
headers/modules. It's relatively common for a module to be marked
[system] but still wish to validate itself explicitly.

rdar://113401565

Differential Revision: https://reviews.llvm.org/D156948
2023-08-09 10:40:53 -07:00
Jan Svoboda
dcd3a0c9f1 [clang][modules][deps] Create more efficient API for visitation of ModuleFile inputs
The current `ASTReader::visitInputFiles()` function calls into `FileManager` to create `FileEntryRef` objects. This ends up being fairly costly in `clang-scan-deps`, where we mostly only care about file paths.

This patch introduces new `ASTReader` API that gives clients access to just the serialized paths. Since the scanner needs both the as-requested path and the on-disk one (and doesn't want to transform the former into the latter via `FileManager`), this patch starts serializing both of them into the PCM file if they differ.

This increases the size of scanning PCMs by 0.1% and speeds up scanning by 5%.

Reviewed By: benlangmuir, vsapsai

Differential Revision: https://reviews.llvm.org/D157066
2023-08-09 10:19:36 -07:00
Nico Weber
5f8d332027 Revert "[Clang][OpenMP] Support for Code Generation of loop bind clause."
This reverts commit 8e7f0320ad7fb760fff598aba4b2c86528c58c2d.
As requested on https://reviews.llvm.org/rG8e7f0320ad7fb760f#1236457
2023-08-08 13:12:25 -04:00
Sunil Kuravinakop
8e7f0320ad [Clang][OpenMP] Support for Code Generation of loop bind clause. 2023-08-08 09:23:00 -05:00
Nico Weber
fab49721b4 Revert "[Clang][OpenMP] Support for Code Generation of loop bind clause"
This reverts commit 4097a24584121dba562d471fab97d3dfec1b5bff.
Breaks tests on macOS, see https://reviews.llvm.org/rG4097a2458412#1235854
2023-08-07 12:01:54 -04:00
Sunil Kuravinakop
4097a24584 [Clang][OpenMP] Support for Code Generation of loop bind clause 2023-08-07 07:58:59 -05:00
Jon Roelofs
2fb1c1082c
cmake: add missing dependencies on ClangDriverOptions tablegen
The modules build trips over this frequently because there is no textual
include of the tablegen output, but the module includes it.

Differential revision: https://reviews.llvm.org/D157119
2023-08-04 10:27:19 -07:00
Richard Smith
61c7a9140b Commit to a primary definition for a class when we load its first
member.

Previously, we wouldn't do this if the first member loaded is within a
definition that's added to a class via an update record, which happens
when template instantiation adds a class definition to a declaration
that was imported from an AST file.

This would lead to classes having member functions whose getParent
returned a class declaration that wasn't the primary definition, which
in turn caused the vtable builder to build broken vtables.

I don't yet have a reduced testcase for the wrong-code bug here, because
the setup required to get us into the broken state is very subtle, but
have confirmed that this fixes it.
2023-07-25 15:59:21 -07:00
Johannes Doerfert
08a220764b Reapply "[OpenMP] Add the ompx_attribute clause for target directives"
This reverts commit 0d12683046ca75fb08e285f4622f2af5c82609dc and
reapplies ef9ec4bbcca2fa4f64df47bc426f1d1c59ea47e2 with an extension to
fix the Flang build.

Differential Revision: https://reviews.llvm.org/D156184
2023-07-25 10:40:35 -07:00
Aaron Ballman
0d12683046 Revert "[OpenMP] Add the ompx_attribute clause for target directives"
This reverts commit ef9ec4bbcca2fa4f64df47bc426f1d1c59ea47e2.

The changes broke several bots:
https://lab.llvm.org/buildbot/#/builders/176/builds/3408
https://lab.llvm.org/buildbot/#/builders/198/builds/4028
https://lab.llvm.org/buildbot/#/builders/197/builds/8491
https://lab.llvm.org/buildbot/#/builders/197/builds/8491
2023-07-25 07:57:36 -04:00
Johannes Doerfert
ef9ec4bbcc [OpenMP] Add the ompx_attribute clause for target directives
CUDA and HIP have kernel attributes to tune the code generation (in the
backend). To reuse this functionality for OpenMP target regions we
introduce the `ompx_attribute` clause that takes these kernel
attributes and emits code as if they had been attached to the kernel
fuction (which is implicitly generated).

To limit the impact, we only support three kernel attributes:
`amdgpu_waves_per_eu`, for AMDGPU
`amdgpu_flat_work_group_size`, for AMDGPU
`launch_bounds`, for NVPTX

The existing implementations of those attributes are used for error
checking and code generation. `ompx_attribute` can be attached to any
executable target region and it can hold more than one kernel attribute.

Differential Revision: https://reviews.llvm.org/D156184
2023-07-24 22:04:45 -07:00