AMDGPU plugin equivalent of D95155, build without HSA installed locally

Compiles a new file, plugins/amdgpu/dynamic_hsa/hsa.cpp, to an object file that
exposes the same symbols that the plugin presently uses from hsa. The object
file contains dlopen of hsa and cached dlsym calls. Also provides header files
corresponding to the subset that is used.

This is behind a feature flag, LIBOMPTARGET_FORCE_DLOPEN_LIBHSA, default off.
That allows developers to build against the dlopen/dlsym implementation, e.g.
while testing this mode.

Enabling by default will cause this plugin to build on a wider variety of
machines than it does at present so may break some CI builds. That risk can
be minimised by reviewing the header dependencies of the library and ensuring
it doesn't use any libraries that are not already used by libomptarget.

Separating the implementation from enabling by default in case the latter needs
to be rolled back after wider CI results.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106559

Revision of D102858. Raise dlwrap arity argument to template argument
so the correct value is given in the error message. E.g. '2 == 1' instead of
'2 == trait<>::nargs'.

Arity higher than it should be:
Before diff
```
$/plugins/cuda/dynamic_cuda/cuda.cpp:23:1: error:
      static_assert failed due to requirement '2 == trait<cudaError_enum (*)(unsigned int)>::nargs'
      "Arity Error"
DLWRAP_INTERNAL(cuInit, 2);
^~~~~~~~~~~~~~~~~~~~~~~~~~
...
$/include/dlwrap.h:166:3: note: expanded from macro
      'DLWRAP_COMMON'
  static_assert(ARITY == trait<decltype(&SYMBOL)>::nargs, "Arity Error");      \
```

After diff
In file included from $/plugins/cuda/dynamic_cuda/cuda.cpp:16:
```
$/include/dlwrap.h:131:3: error: static_assert failed due to
      requirement '2UL == 1UL' "Arity Error"
  static_assert(Requested == Required, "Arity Error");
  ^             ~~~~~~~~~~~~~~~~~~~~~
$/plugins/cuda/dynamic_cuda/cuda.cpp:23:1: note: in
      instantiation of function template specialization 'dlwrap::verboseAssert<2UL, 1UL>' requested
      here
DLWRAP_INTERNAL(cuInit, 2);
```

Arity lower than it should be:
Before diff
```
$/plugins/cuda/dynamic_cuda/cuda.cpp:131:10: error: no
      matching function for call to 'dlwrap_cuInit'
  return dlwrap_cuInit(X);
         ^~~~~~~~~~~~~
$/plugins/cuda/dynamic_cuda/cuda.cpp:23:1: note: candidate
      function not viable: requires 0 arguments, but 1 was provided
DLWRAP_INTERNAL(cuInit, 0);
```

After diff
In file included from $/plugins/cuda/dynamic_cuda/cuda.cpp:16:
```
$/include/dlwrap.h:131:3: error: static_assert failed due to
      requirement '0UL == 1UL' "Arity Error"
  static_assert(Requested == Required, "Arity Error");
  ^             ~~~~~~~~~~~~~~~~~~~~~
$/plugins/cuda/dynamic_cuda/cuda.cpp:23:1: note: in
      instantiation of function template specialization 'dlwrap::verboseAssert<0UL, 1UL>' requested
      here
DLWRAP_INTERNAL(cuInit, 0);
```

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106543

Summary:
Fixes some warning given for uninitialized block counts if the exection mode is
not recognized. This shouldn't happen in practice because the execution mode is
checked when it's read from the device.

This class is instantiated once in rtl.cpp before hsa_init is
called. The hsa_signal_create call therefore fails leaving the pool empty.

This signal pool is a legacy from ATMI where it was constructed after hsa_init.
Moving the state into the rtl.cpp global class disabled the initial populating
of the pool without noticeably changing performance. Just rechecked with a fix
that allocates the signals after hsa_init and that also doesn't noticeably
change performance.

This patch therefore drops the initialisation. Only change from main is to
drop a DEBUG_PRINT statement that would say the pool initial size is zero.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106515

Function internalization can sometimes occur in situations where we want to
keep the call sites intact. This patch adds an option to disable function
internalization and prevents the device runtime from being internalized while
creating the bitcode library.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106438

This patch introduces `__kmpc_is_generic_main_thread_id` which splits the old
comparison into its own runtime function. The purpose of this is so we can fold
this part independently, so when both this and `is_spmd_mode` are folded the
final function will be folded as well.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106437

Qualified kernels can be transformed from generic-mode to SPMD mode using an
optimization in OpenMPOpt. This patch introduces a new execution mode to
indicate kernels that have been transformed from generic-mode to SPMD-mode.
These kernels have SPMD-mode execution, but need generic-mode semantics for
scheduling the blocks and threads. Without this far too few blocks will be
scheduled for a generic region as SPMD mode expects the trip count to be
divided by the number of threads.

Reviewed By: ggeorgakoudis

Differential Revision: https://reviews.llvm.org/D106460

This patch changes `__kmpc_free_shared` to take an additional argument
corresponding to the associated allocation's size. This makes it easier to
implement the allocator in the runtime.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106496

The patch exposes the libomptarget runtime function that gets the hardware thread id through the kmpc API. This is to be used in SPMDization for checking the thread id to execute regions by a single thread in a block.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106323

Create a hsa_api.h header that includes the ROCr headers in use
Drop some unused headers and _cplusplus macros

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106455

In `deviceRTLs`, the parallel level is stored in a shared variable of type `uint8_t`.
`__kmpc_parallel_level` currently returns a 16-bit interger. This patch first
changes the return type of the function to `uint8_t`, same as the shared variable,
and then corrects function type which was updated in D105955.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106384

This fixes the complaint from FileCheck.

Reviewed By: abhinavgaba, jdoerfert

Differential Revision: https://reviews.llvm.org/D106387

The synchronization of task loop misses hidden helper tasks, causing segmentation
fault reported in https://bugs.llvm.org/show_bug.cgi?id=50002.

Reviewed By: ye-luo

Differential Revision: https://reviews.llvm.org/D106220

Currently the NPVTX work function is marked volatile. This prevents some
optimizations from using this value.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D106310

This reverts commit e9c7291c.

Fix failing tests

D106236 added a new CMake argument for `libomptarget` test, but when user's
input contains white spaces, CMake will add escape char to the final lit command,
which leads to an error. This patch converts the user's input `LIBOMPTARGET_LIT_ARGS`
into a local array, and then passes the array to the function.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D106247

[OpenMP][Offloading] Add a CMake argument LIBOMPTARGET_LIT_ARGS to control behavior of libomptarget lit test

By default, `lit` uses all threads to invoke tests, which  can easily cause out
of memory on GPUs because most of OpenMP offloading test usually take about 1GB
GPU memory, but a typical GPU only has 4-8GB memory. This patch introduce a
CMake argument `LIBOMPTARGET_LIT_ARGS` to allow users to control the behavior of
`libomptarget` tests, similar to `LLVM_LIT_ARGS`.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D106236

Currently when we compile the project in debug mode, `-g` will not be added to
compilation flag. The bc files generated in different mode are of different size.
When using GPU debuggers like `cuda-gdb`, it is expected to provide more info
with a debug version of bc lib.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D106229

Parallel regions are outlined as functions with capture variables explicitly generated as distinct parameters in the function's argument list. That complicates the fork_call interface in the OpenMP runtime: (1) the fork_call is variadic since there is a variable number of arguments to forward to the outlined function, (2) wrapping/unwrapping arguments happens in the OpenMP runtime, which is sub-optimal, has been a source of ABI bugs, and has a hardcoded limit (16) in the number of arguments, (3)  forwarded arguments must cast to pointer types, which complicates debugging. This patch avoids those issues by aggregating captured arguments in a struct to pass to the fork_call.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D102107

[NFC][OpenMP][Offloading] Replaced explicit parallel level computation with function `__kmpc_parallel_level`

There are two places in current deviceRTLs where it computes parallel level explicitly,
which is basically the functionality of `__kmpc_parallel_level`. Starting from
D105787, we plan to introduce a series of function call folding based on information
that can be deducted during compilation time. Computation of parallel level is
the next target. This patch makes steps for the optimization.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D105955

D105812 introduced a regression where if a PTR_AND_OBJ entry was mapped on the device, then the OBJ was deallocated and then reallocated at a different address, the Shadow Pointer Map would still contain an entry for the PTR but pointing to the old address. This caused test `env/base_ptr_ref_count.c` to fail.

Differential Revision: https://reviews.llvm.org/D105947

Currently, libomptarget will always perform a host-to-device memory transfer in
order to update the device pointer of a PTR_AND_OBJ entry. This is not always
necessary because the device pointer may have been set to the correct pointee
address already, so we can eliminate the redundant memory transfer.

Simplifies control flow to allow store/load forwarding

This change folds two basic blocks into one, leaving a single store to parallelLevel.
This is a step towards spmd kernels with sufficiently aggressive inlining folding
the loads from parallelLevel and thus discarding the nested parallel handling
when it is unused.

Transform:
```
int threadId = GetThreadIdInBlock();
if (threadId == 0) {
  parallelLevel[0] = expr;
} else if (GetLaneId() == 0) {
  parallelLevel[GetWarpId()] = expr;
}
// =>
if (GetLaneId() == 0) {
  parallelLevel[GetWarpId()] = expr;
}
// because
unsigned GetLaneId() { return GetThreadIdInBlock() & (WARPSIZE - 1);}
// so whenever threadId == 0, GetLaneId() is also 0.
```

That replaces a store in two distinct basic blocks with as single store.

A more aggressive follow up is possible if the threads in the warp/wave
race to write the same value to the same address. This is not done as
part of this change.

```
if (GetLaneId() == 0) {
  parallelLevel[GetWarpId()] = expr;
}
// =>
parallelLevel[GetWarpId()] = expr;
// because
unsigned GetWarpId() { return GetThreadIdInBlock() / WARPSIZE; }
// so GetWarpId will index the same element for every thread in the warp
// and, because expr is lane-invariant in this case, every lane stores the
// same value to this unique address
```

Reviewed By: tianshilei1992

Differential Revision: https://reviews.llvm.org/D105699

In order to fold calls based on high-level knowledge and control flow
tracking it helps to expose the information as a runtime call. The
logic: `!SPMD && getTID() == getMasterTID()` was used in various places
and is now encapsulated in `__kmpc_is_generic_main_thread`. As part of
this rewrite we replaced eager computation of arguments with on-demand
computation, especially helpful if the calls can be folded and arguments
don't need to be computed consequently.

Differential Revision: https://reviews.llvm.org/D105768

In order to avoid malloc/free, up to NUM_SHARED_VARIABLES_IN_SHARED_MEM
(=64) variables are communicated in dedicated shared memory instead. The
simplification does avoid the need for an "init" and requires "deinit"
only if we ever communicate more than NUM_SHARED_VARIABLES_IN_SHARED_MEM
variables.

Differential Revision: https://reviews.llvm.org/D105767

We had multiple functions to determine the execution mode (SPMD/Generic)
and runtime status (initialized/uninitialized) but that just increased
complexity without a real benefit. Especially with D102307 in mind it
is helpful to reduce the dependence on the `ident_t` flags.

Differential Revision: https://reviews.llvm.org/D105586

In the spirit of TRegions [0], this patch provides a simpler and uniform
interface for a kernel to set up the device runtime. The OMPIRBuilder is
used for reuse in Flang. A custom state machine will be generated in the
follow up patch.

The "surplus" threads of the "master warp" will not exit early anymore
so we need to use non-aligned barriers. The new runtime will not have an
extra warp but also require these non-aligned barriers.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

This was in parts extracted from D59319.

Reviewed By: ABataev, JonChesterfield

Differential Revision: https://reviews.llvm.org/D101976

Broke check-clang, see https://reviews.llvm.org/D102307#2869065
Ran `git revert -n ebbe149a..269416d4`

We had multiple functions to determine the execution mode (SPMD/Generic)
and runtime status (initialized/uninitialized) but that just increased
complexity without a real benefit. Especially with D102307 in mind it
is helpful to reduce the dependence on the `ident_t` flags.

Differential Revision: https://reviews.llvm.org/D105586

In the spirit of TRegions [0], this patch provides a simpler and uniform
interface for a kernel to set up the device runtime. The OMPIRBuilder is
used for reuse in Flang. A custom state machine will be generated in the
follow up patch.

The "surplus" threads of the "master warp" will not exit early anymore
so we need to use non-aligned barriers. The new runtime will not have an
extra warp but also require these non-aligned barriers.

[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11

This was in parts extracted from D59319.

Reviewed By: ABataev, JonChesterfield

Differential Revision: https://reviews.llvm.org/D101976

This patch is an attempt to do for `targetDataBegin` what D104924 does
for `targetDataEnd`:

* Eliminates a lock/unlock of the data mapping table.
* Clarifies the logic that determines whether a struct member's
  host-to-device transfer occurs.  The old logic, which checks the
  parent struct's reference count, is a leftover from back when we had
  a different map interface (as pointed out at
  <https://reviews.llvm.org/D104924#2846972>).

Additionally, it eliminates the `DeviceTy::getMapEntryRefCnt`, which
is no longer used after this patch.

While D104924 does not change the computation of `IsLast`, I found I
needed to change the computation of `IsNew` for this patch.  As far as
I can tell, the change is correct, and this patch does not cause any
additional `openmp` tests to fail.  However, I'm not sure I've thought
of all use cases.  Please advise.

Reviewed By: jdoerfert, jhuber6, protze.joachim, tianshilei1992, grokos, RaviNarayanaswamy

Differential Revision: https://reviews.llvm.org/D105121

The patch has the following benefits:

* Eliminates a lock/unlock of the data mapping table.
* Clarifies the logic that determines whether a struct member's
  device-to-host transfer occurs.  The old logic, which checks the
  parent struct's reference count, is a leftover from back when we had
  a different map interface (as pointed out at
  <https://reviews.llvm.org/D104924#2846972>).

Reviewed By: grokos

Differential Revision: https://reviews.llvm.org/D104924

If the base is used in a map clause and later we have a memberexpr with
this base, and the member is a pointer, and this pointer is dereferenced
anyhow (subscript, array section, dereference, etc.), such components
should be considered as overlapped, otherwise it may lead to incorrect
size computations, since we try to map a pointee as a part of the whole
struct, which is not true for the pointer members.

Differential Revision: https://reviews.llvm.org/D105562

[libomptarget][nfc] Group environment variables, drop accesses to DeviceInfo global

Folds some duplicates logic into a helper function, passes the new environment
struct into getLaunchVals which no longer reads the DeviceInfo global.

Implemented on top of D105237

Reviewed By: dhruvachak

Differential Revision: https://reviews.llvm.org/D105239

D97883 introduced a compile-time error in the experimental remote offloading
libomptarget plugin, this patch fixes it and resolves a number of
inconsistencies in the plugin as well:

1. Non-functional Asynchronous API
2. Unnecessarily verbose debug printing
3. Misc. code clean ups

This is not intended to make any functional changes to the plugin.

Differential Revision: https://reviews.llvm.org/D105325

`DeviceTy::getOrAllocTgtPtr` just returns a target pointer. In addition,
two bool values (`IsNew` and `IsHostPtr`) are passed by reference to make the
change in the function available in callee.

In this patch, a struct, which contains the target pointer, two flags, and an
iterator to the map table entry corresponding to the queried host pointer, will
be returned. In addition to make the logic clearer regarding the two bool values,
this paves the way for the next patch to fix the data race in `bug49334.cpp` by
attaching an event to the map table entry (and that's why we need the iterator).

Reviewed By: grokos

Differential Revision: https://reviews.llvm.org/D104382

Change getLaunchVals to return the integers used for launch

Reviewed By: pdhaliwal

Differential Revision: https://reviews.llvm.org/D105237

This reverts commit 2240b41e.
A value of 0 for KernDescVal WG_Size implies it is unknown, so it should be
set to the default. The above change was made without this assumption.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D105250

A step towards making this function adequately self contained that it
can be tested easily. No functional change intended here, left variable
names unchanged.

Reviewed By: ronlieb

Differential Revision: https://reviews.llvm.org/D105229

Removes stdarg header, drops uses of iostream, fix some format string errors.
Also changes a C style struct to C++ style to avoid a warning from clang/

Reviewed By: pdhaliwal

Differential Revision: https://reviews.llvm.org/D104923