In a clean build directory, `check-openmp` or `check-libomptarget` will fail because of missing device RTL .bc files. Ensure that the new targets new custom targets `omptarget.devicertl.nvptx` and `omptarget.devicertl.amdgpu` (corresponding to the plugin rtl targets `omptarget.rtl.cuda`, respectively `omptarget.rlt.amdgpu` ) are dependencies of the regression tests.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D123177

Differential Revision: https://reviews.llvm.org/D122658

If we decided to delete a mapping entry we did not act on it right away
but first issued and waited for memory copies. In the meantime some
other thread might reuse the entry. While there was some logic to avoid
colliding on the actual "deletion" part, there were two races happening:

1) The data transfer back of the thread deleting the entry and
   the data transfer back of the thread taking over the entry raced.
2) The update to the shadow map happened regardless if the entry was
   actually reused by another thread which left the shadow map in a
   inconsistent state.

To fix both issues we will now update the shadow map and delete the
entry only if we are sure the thread is responsible for deletion, hence
no other thread took over the entry and reused it. We also wait for a
potential former data transfer from the device to finish before we issue
another one that would race with it.

Fixes https://github.com/llvm/llvm-project/issues/54216

Differential Revision: https://reviews.llvm.org/D121058

Inline assembly is scary but we need to support it for the OpenMP GPU
device runtime. The new assumption expresses the fact that it may not
have call semantics, that is, it will not call another function but
simply perform an operation or side-effect. This is important for
reachability in the presence of inline assembly.

Differential Revision: https://reviews.llvm.org/D109986

As we mentioned in the code comments for function `ResourcePoolTy::release`,
at some point there could be two identical resources on the two sides of `Next`
mark. It is usually not an issue, unless the following case:
1. Some resources are not returned.
2. We need to iterate the pool and free the element.

That will cause double free, which is the case for event pool. Since we don't release
events hold by the data map, it can happen that the `Next` mark is not reset, and
we have two identical items in the pool. When the pool is destroyed, we will call
`cuEventDestroy` twice on the same event. In the best case, we can only observe
CUDA errors. In the worst case, it can cause internal failures in CUDART and further
crash.

This patch fixes the issue by tracking all resources that have been given using
an `unordered_set`. We don't remove it when a resource is returned. When the pool
is destroyed, we merge the pool (a `vector`) and the set. In this way, we can make
sure that the set contains all resources allocated from the device. We just need
to iterate the set and free the resource accordingly.

For now, only event pool is set to use it. Stream pool is not because we can make
sure all streams are returned when the plugin is destroyed.

Someone might be wondering, why don't we release all events hold in the data map.
That is because, plugins are determined to be destroyed *before* `libomptarget`.
If we can somehow make the plugin outlast `libomptarget`, life will be much
easier.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D122014

This patch adds the necessary AMDGPU calling convention to the ctor /
dtor kernels. These are fundamentally device kenels called by the host
on image load. Without this calling convention information the AMDGPU
plugin is unable to identify them.

Depends on D122504

Fixes #54091

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D122515

This reverts commit b9fd8f34 as it
accidentally contained a unit test change that is not finished (and
unrelated).

This patch solves two problems with the `HostDataToTargetMap` (HDTT
map) which caused races and crashes before:

1) Any access to the HDTT map needs to be exclusive access. This was not
   the case for the "dump table" traversals that could collide with
   updates by other threads. The new `Accessor` and `ProtectedObject`
   wrappers will ensure we have a hard time introducing similar races in
   the future. Note that we could allow multiple concurrent
   read-accesses but that feature can be added to the `Accessor` API
   later.
2) The elements of the HDTT map were `HostDataToTargetTy` objects which
   meant that they could be copied/moved/deleted as the map was changed.
   However, we sometimes kept pointers to these elements around after we
   gave up the map lock which caused potential races again. The new
   indirection through `HostDataToTargetMapKeyTy` will allows us to
   modify the map while keeping the (interesting part of the) entries
   valid. To offset potential cost we duplicate the ordering key of the
   entry which avoids an additional indirect lookup.

We should replace more objects with "protected objects" as we go.

Differential Revision: https://reviews.llvm.org/D121057

The unroll pragma did not properly work as the loop bound was not known
when we optimize the runtime and we then added a "unroll disable"
metadata which prevented unrolling later when the bounds were known.
For now we manually unroll to make sure up to 16 elements are handled
nicely. This helps optimizations to look through the argument passing.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D109164

Differential Revision: https://reviews.llvm.org/D120849

Currently we set ccontext everywhere accordingly, but that causes many
unnecessary function calls. For example, in the resource pool, if we need to
resize the pool, we need to get from allocator. Each call to allocate sets the
current context once, which is unnecessary. In this patch, we set the context
only in the entry interface functions, if needed. Actually in the best way this
should be implemented via RAII, but since `cuCtxSetCurrent` could return error,
and we don't use exception, we can't stop the execution if RAII fails.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D121322

This patch fixes the issue introduced in 14de0820 and D120089, that
if dynamic libraries are used, the `CUmodule` array could be overwritten.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D121308

The modules vector was for some reason special which could lead to it
not being of the same size (=num devices). Easiest solution is to treat
it like we do all the other vectors.

An event pool, similar to the stream pool, needs to be kept per device.
For one, events are associated with cuda contexts which means we cannot
destroy the former after the latter. Also, CUDA documentation states
streams and events need to be associated with the same context, which
we did not ensure at all.

Differential Revision: https://reviews.llvm.org/D120142

There are two problems this patch tries to address:
1) We currently free resources in a random order wrt. plugin and
   libomptarget destruction. This patch should ensure the CUDA plugin
   is less fragile if something during the deinitialization goes wrong.
2) We need to support (hard) pause runtime calls eventually. This patch
   allows us to free all associated resources, though we cannot
   reinitialize the device yet.

Follow up patch will associate one event pool per device/context.

Differential Revision: https://reviews.llvm.org/D120089

Differential Revision: https://reviews.llvm.org/D121060

This reverts commit ff50e81b as it broke
the buildbots, see https://reviews.llvm.org/D121060#3362737.

Differential Revision: https://reviews.llvm.org/D121060

`LIBOMPTARGET_LLVM_INCLUDE_DIRS` is currently checked and included for
multiple times redundantly. This patch is simply a clean up.

Reviewed By: jhuber6

Differential Revision: https://reviews.llvm.org/D121055

Libomptarget uses some shared variables to track certain internal stated
in the runtime. This causes problems when we have code that contains no
OpenMP kernels. These variables are normally initialized upon kernel
entry, but if there are no kernels we will see no initialization.
Currently we load the runtime into each source file when not running in
LTO mode, so these variables will be erroneously considered undefined or
dead and removed, causing miscompiles. This patch temporarily works
around the most obvious case, but others still exhibit this problem. We
will need to fix this more soundly later.

Fixes #54208.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D121007

Differential Revision: https://reviews.llvm.org/D120846

This is target definition only.

Differential Revision: https://reviews.llvm.org/D120688

[OpenMP][libomptarget] Delay restore of shadow pointers in structs to after H2D memory copies are completed

When using asynchronous plugin calls, shadow pointer restore could happen before the D2H copy for the entire struct has completed, effectively leaving a device pointer in a host struct.
This patch fixes the problem by delaying restore's to after a synchronization happens (target regions) and by calling early synchronization (target update).

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D119968

The runtime uses thread state values to indicate when we use an ICV or
are in nested parallelism. This is done for OpenMP correctness, but it
not needed in the majority of cases. The new flag added is
`-fopenmp-assume-no-thread-state`.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D120106

`bug49334.cpp` has one issue that causes flaky result reported in #53730.
The root cause is `BlockedC` is never initialized but in `BlockMatMul_TargetNowait`
it is directly read and written (via `+=`). Fixes #53730.

Reviewed By: jhuber6

Differential Revision: https://reviews.llvm.org/D119988

The `IsSPMD` global can only be read by threads other than the main
thread *after* initialization is complete. To allow usage of
`mapping::getBlockSize` before initialization is done, we can pass the
`IsSPMD` state explicitly. This is similar to other APIs that take
`IsSPMD` explicitly to avoid such a race, e.g.,
`mapping::isInitialThreadInLevel0(IsSPMD)`

Fixes https://github.com/llvm/llvm-project/issues/53857

This patch adds a new target to the OpenMP CPU offloading tests. This
tests the usage of the new driver for CPU offloading. If this all works
then we can move to transition to the new driver as the default.

Depends on D119613

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D119736

Currently whenever we compile the device runtime we get the following
'Mapping.cpp:32:32: warning: inline function '_OMP::impl::getGridValue'
is not defined [-Wundefined-inline]' warning. This can be silenced by
removing the constexpr attribute for this function. Doing this doesn't
change the generated bitcode at all but prevents the screen from getting
filled with warnings whenver we build the runtime.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D119747

This patch fixes the issue that the for loop in `applyToShadowMapEntries`
is infinite because `Itr` is not incremented in `CB`. Fixes #53727.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D119471

`bug49334.cpp` directly uses `!=` to compare two floating point values,
which is almost wrong.

Reviewed By: jhuber6

Differential Revision: https://reviews.llvm.org/D119485

Currently we have a hard team limit, which is set to 65536. It says no matter whether the device can support more teams, or users set more teams, as long as it is larger than that hard limit, the final number to launch the kernel will always be that hard limit. It is way less than the actual hardware limit. For example, my workstation has GTX2080, and the hardware limit of grid size is 2147483647, which is exactly the largest number a `int32_t` can represent. There is no limitation mentioned in the spec. This patch simply removes it.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D119313