Solves #68315

[libomptarget][OpenMP] Initial implementation of omp_target_memset() and omp_target_memset_async() (#68706)

Implement a slow-path version of omp_target_memset*() 

There is a TODO to implement a fast path that uses an on-device
kernel instead of the host-based memory fill operation.  This may
require some additional plumbing to have kernels in libomptarget.so

Summary:
The `libcgpu.a` file provides its own implementation of `__assert_fail`.
This adds a test to make sure it's usable in OpenMP offloading as
expected. Currently this requires linking `libcgpu.a` before the OpenMP
device RTL however. We also disable the test on the CPU as the format of
the string will be different.

For this code:

struct O {
  int &&j;
};

O o1(0);

The generated AST for the initializer of o1 is:

VarDecl 0x62100006ab08 <array.cpp:119:3, col:9> col:5 o1 'O':'O' parenlistinit
`-ExprWithCleanups 0x62100006b250 <col:7, col:9> 'O':'O'
  `-CXXParenListInitExpr 0x62100006b210 <col:7, col:9> 'O':'O'
    `-MaterializeTemporaryExpr 0x62100006b1f0 <col:8> 'int' xvalue
      `-IntegerLiteral 0x62100006abd0 <col:8> 'int' 0

Before this patch, we create a local temporary variable for the
MaterializeTemporaryExpr and destroy it again when destroying the
EvalEmitter we create to interpret the initializer. However, since
O::j is a reference, this reference now points to a local variable
that doesn't exist anymore.

Differential Revision: https://reviews.llvm.org/D156453

[DAG] canCreateUndefOrPoison - remove AssertSext/AssertZext assumption that they never create undef/poison

We need to assume that we generate poison if the assertions failed

Fixes #66603

This reverts revert 19505072.

An issue was fixed in bea36849
and some newly appeared tests updated.

The issue #55208 noticed that std::rint is vectorized by the
SLPVectorizer, but a very similar function, std::lrint, is not.
std::lrint corresponds to ISD::LRINT in the SelectionDAG, and
std::llrint is a familiar cousin corresponding to ISD::LLRINT. Now,
neither ISD::LRINT nor ISD::LLRINT have a corresponding vector variant,
and the LangRef makes this clear in the documentation of llvm.lrint.*
and llvm.llrint.*.

This patch extends the LangRef to include vector variants of
llvm.lrint.* and llvm.llrint.*, and lays the necessary ground-work of
scalarizing it for all targets. However, this patch would be devoid of
motivation unless we show the utility of these new vector variants.
Hence, the RISCV target has been chosen to implement a custom lowering
to the vfcvt.x.f.v instruction. The patch also includes a CostModel for
RISCV, and a trivial follow-up can potentially enable the SLPVectorizer
to vectorize std::lrint and std::llrint, fixing #55208.

The patch includes tests, obviously for the RISCV target, but also for
the X86, AArch64, and PowerPC targets to justify the addition of the
vector variants to the LangRef.

In #69582, I accidentally disabled all tests for the changed introduced
in #69010. This change should use the correct `REQUIRES` syntax to
en-/disable target-specific tests.

This is done by lowering v16i8 loads into LoadV4 operations with i32
results instead of letting ReplaceLoadVector split it into smaller
loads during legalization. This is done at dag-combine1 time, so that
vector operations with i8 elements can be optimised away instead of
being needlessly split during legalization, which involves storing to
the stack and loading it back.

The immediate legality checks are now embedded into the
isOperandLegal(). It is not needed to check it again.

Similar to what we already do for add/sub + saturation variants.

Scalar support will be added in a future patch covering the other variants at the same time.

Alive2: https://alive2.llvm.org/ce/z/rBDrNE

Fixes #69080

As described in: https://github.com/ARM-software/acle/pull/257

Patch by : David Sherwood <david.sherwood@arm.com>

Reviewed By: kmclaughlin

Differential Revision: https://reviews.llvm.org/D151307

We already save the information about signedness ourselves.

When the FPU was selected with "+(no)fp(.dp)" extensions in "-march" or
"-mcpu" options, the FPU used for multilib selection was still the
default one for given architecture or CPU.

Small fix for failing tests after merge of #69010. The tests need
`REQUIRES` to ensure that the correct headers are available. I've also
added a generic x86 build which does not need headers, so there is at
least one run per test.

To fix that ticket we only needed to address the V_LSHLREV_B16 case, but
I did it for all insts just in case.

Fixes #66899

[Flang][OpenMP][Sema] Add directive rewrite pass to support atomic_default_mem_order REQUIRES clause

This patch creates the `OmpRewriteMutator` pass that runs at the end of
`RewriteParseTree()`. This pass is intended to make OpenMP-specific mutations
to the PFT after name resolution.

In the case of the `atomic_default_mem_order` clause of the REQUIRES directive,
name resolution results in populating global symbols with information about the
REQUIRES clauses that apply to that scope. The new rewrite pass is then able to
use this information in order to explicitly set the memory order of ATOMIC
constructs for which that is not already specified.

Given that this rewrite happens before semantics checks, the check of the order
in which ATOMIC constructs without explicit memory order and REQUIRES
directives with `atomic_default_mem_order` appear is moved earlier into the
rewrite pass. Otherwise, these problems would not be caught by semantics
checks, since the PFT would be modified by that stage.

This is patch 4/5 of a series splitting D149337 to simplify review.

Depends on D157983.

Differential Revision: https://reviews.llvm.org/D158096

This reverts commit 3353f7dd.

Fixed test bug (unspecified order of arg evaluation)

Building helloworld.c currently errors with "undefined symbol:
__llvm_libc_syscall"

See: https://github.com/llvm/llvm-project/pull/67032

This reverts commit c122b972 but fixes
tests that were added between submitting #69329 for review and landing
it for the first time.

As described in: https://github.com/ARM-software/acle/pull/257

Patch by : Sander de Smalen<sander.desmalen@arm.com>

Reviewed By: dtemirbulatov

Differential Revision: https://reviews.llvm.org/D151199

This reverts commit f6812257. That
commit changed the organization of the tests of the transform dialect
interpreter but did not take into account some tests that were added in
the meantime.

The _mm_cmpistri instruction can be used to quickly parse identifiers.

With this patch activated, clang pre-processes <iostream> 1.8% faster,
and sqlite3.c amalgametion 1.5% faster, based on time measurements and
number of executed instructions as measured by valgrind.

The introduction of an extra helper function in the regular case has no
impact on performance, see


https://llvm-compile-time-tracker.com/compare.php?from=30240e428f0ec7d4a6d1b84f9f807ce12b46cfd1&to=12bcb016cde4579ca7b75397762098c03eb4f264&stat=instructions:u



---------

Co-authored-by: serge-sans-paille <sguelton@mozilla.com>

A recent commit (#69190) broke the bazel builds. Turns out that Bazel
uses symlinks for providing the test files, which the path expansion of
the module loading mechanism did not handle correctly. This PR fixes
that.

It also reorganizes the tests better: It puts all `.mlir` files that are
included by some other test into a common `include` folder. This greatly
simplifies the definition of the dependencies between the different
`.mlir` files in Bazel's `BUILD` file. The commit also adds a comment to
all included files why these aren't tested themselves direclty and uses
the `%{fs-sep}` expansion for paths more consistently. Finally, it
uncomments all but one of the tests excluded in Bazel because they seem
to run now. (The remaining one includes a file that it itself a test, so
it would have to live *in* and *outside* of the `include` folder.)

Adds a new `__builtin_vectorelements()` function which returns the
number of elements for a given vector either at compile-time for
fixed-sized vectors, e.g., created via `__attribute__((vector_size(N)))`
or at runtime via a call to `@llvm.vscale.i32()` for scalable vectors,
e.g., SVE or RISCV V.

The new builtin follows a similar path as `sizeof()`, as it essentially
does the same thing but for the number of elements in vector instead of
the number of bytes. This allows us to re-use a lot of the existing
logic to handle types etc.

A small side addition is `Type::isSizelessVectorType()`, which we need
to distinguish between sizeless vectors (SVE, RISCV V) and sizeless
types (WASM).

This is the [corresponding
discussion](https://discourse.llvm.org/t/new-builtin-function-to-get-number-of-lanes-in-simd-vectors/73911).

Add tests with argmem variations.

This PR adds `nvvm.stmatrix` Op to NVVM dialect. The Op collectively
store one or more matrices across all threads in a warp to the given
address location in shared memory.

It's only beneficial when cond is setcc with integer equality condition
code. For other case, it has same instruction count as the original.

* `dump`, added in https://github.com/llvm/llvm-project/pull/68793
* `!repr`, added in https://github.com/llvm/llvm-project/pull/68716

The keyword `assert` was missing, so I have added that too.

* `dump`, added in https://github.com/llvm/llvm-project/pull/68793
* `!repr`, added in https://github.com/llvm/llvm-project/pull/68716

This patch fixes:

  compiler-rt/lib/builtins/cpu_model.c:590:5: error: unannotated
  fall-through between switch labels [-Werror,-Wimplicit-fallthrough]

by adding a missing "break;".

The keyword is intended for debugging purpose. It prints a message to
stderr.

This patch is based on code originally written by Adam Nemet, and on the
feedback received by the reviewers in
https://reviews.llvm.org/D157492.

Fixes https://github.com/llvm/llvm-project/issues/69369.
Fixes https://github.com/clangd/clangd/issues/1700.

replaceValuesPerBlockEntry() only handled simple and coerced load
values, however the load may also be referenced by a select value.

Additionally, I suspect that the previous code might have been incorrect
if a load had an offset, as it always constructed the AvailableValue
from scratch.

Fixes https://github.com/llvm/llvm-project/issues/69301.