[Clang] Refactor `__attribute__((assume))` (#84934)

This is a followup to #81014 and #84582: Before this patch, Clang
would accept `__attribute__((assume))` and `[[clang::assume]]` as
nonstandar

[Clang] Refactor `__attribute__((assume))` (#84934)

This is a followup to #81014 and #84582: Before this patch, Clang
would accept `__attribute__((assume))` and `[[clang::assume]]` as
nonstandard spellings for the `[[omp::assume]]` attribute; this
resulted in a potentially very confusing name clash with C++23’s
`[[assume]]` attribute (and GCC’s `assume` attribute with the same
semantics).

This pr replaces every usage of `__attribute__((assume))` with
`[[omp::assume]]` and makes `__attribute__((assume))` and
`[[clang::assume]]` alternative spellings for C++23’s `[[assume]]`;
this shouldn’t cause any problems due to differences in appertainment
and because almost no-one was using this variant spelling to begin
with (a use in libclc has already been changed to use a different
attribute).

show more ...

[OpenMP] Introduce the KernelLaunchEnvironment as implicit argument (#70401)

The KernelEnvironment is for compile time information about a kernel. It
allows the compiler to feed information to the

[OpenMP] Introduce the KernelLaunchEnvironment as implicit argument (#70401)

The KernelEnvironment is for compile time information about a kernel. It
allows the compiler to feed information to the runtime. The
KernelLaunchEnvironment is for dynamic information *per* kernel launch.
It allows the rutime to feed information to the kernel that is not
shared with other invocations of the kernel. The first use case is to
replace the globals that synchronize teams reductions with per-launch
versions. This allows concurrent teams reductions. More uses cases will
follow, e.g., per launch memory pools.

Fixes: https://github.com/llvm/llvm-project/issues/70249

show more ...

[OpenMP] Introduce kernel environment

This patch introduces per kernel environment. Previously, flags such as execution mode are set through global variables with name like `__kernel_name_exec_mode`

[OpenMP] Introduce kernel environment

This patch introduces per kernel environment. Previously, flags such as execution mode are set through global variables with name like `__kernel_name_exec_mode`. They are accessible on the host by reading the corresponding global variable, but not from the device. Besides, some assumptions, such as no nested parallelism, are not per kernel basis, preventing us applying per kernel optimization in the device runtime.

This is a combination and refinement of patch series D116908, D116909, and D116910.

Depend on D155886.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D142569

show more ...

Revert commits for kernel environment

This reverts commits for kernel environments as they causes issues in AMD BB.

[OpenMP] Introduce kernel environment

This patch introduces per kernel environment. Previously, flags such as execution mode are set through global variables with name like `__kernel_name_exec_mode`

[OpenMP] Introduce kernel environment

This patch introduces per kernel environment. Previously, flags such as execution mode are set through global variables with name like `__kernel_name_exec_mode`. They are accessible on the host by reading the corresponding global variable, but not from the device. Besides, some assumptions, such as no nested parallelism, are not per kernel basis, preventing us applying per kernel optimization in the device runtime.

This is a combination and refinement of patch series D116908, D116909, and D116910.

Depend on D155886.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D142569

show more ...

[OpenMP][OMPIRBuilder] Rename IsEmbedded and IsTargetCodegen flags

This patch renames the `OpenMPIRBuilderConfig` flags to reduce confusion over
their meaning. `IsTargetCodegen` becomes `IsGPU`, whe

[OpenMP][OMPIRBuilder] Rename IsEmbedded and IsTargetCodegen flags

This patch renames the `OpenMPIRBuilderConfig` flags to reduce confusion over
their meaning. `IsTargetCodegen` becomes `IsGPU`, whereas `IsEmbedded` becomes
`IsTargetDevice`. The `-fopenmp-is-device` compiler option is also renamed to
`-fopenmp-is-target-device` and the `omp.is_device` MLIR attribute is renamed
to `omp.is_target_device`. Getters and setters of all these renamed properties
are also updated accordingly. Many unit tests have been updated to use the new
names, but an alias for the `-fopenmp-is-device` option is created so that
external programs do not stop working after the name change.

`IsGPU` is set when the target triple is AMDGCN or NVIDIA PTX, and it is only
valid if `IsTargetDevice` is specified as well. `IsTargetDevice` is set by the
`-fopenmp-is-target-device` compiler frontend option, which is only added to
the OpenMP device invocation for offloading-enabled programs.

Differential Revision: https://reviews.llvm.org/D154591

show more ...

Revert "[OpenMP] Introduce kernel environment"

This reverts commit 35cfadfbe2decd9633560b3046fa6c17523b2fa9.

It makes a couple of buildbots unhappy because of the following test failures:
- `Transf

Revert "[OpenMP] Introduce kernel environment"

This reverts commit 35cfadfbe2decd9633560b3046fa6c17523b2fa9.

It makes a couple of buildbots unhappy because of the following test failures:
- `Transforms/OpenMP/add_attributes.ll'`
- `mapping/declare_mapper_target_data.cpp` on AMDGPU

show more ...

[OpenMP] Introduce kernel environment

This patch introduces per kernel environment. Previously, flags such as execution mode are set through global variables with name like `__kernel_name_exec_mode`

[OpenMP] Introduce kernel environment

This patch introduces per kernel environment. Previously, flags such as execution mode are set through global variables with name like `__kernel_name_exec_mode`. They are accessible on the host by reading the corresponding global variable, but not from the device. Besides, some assumptions, such as no nested parallelism, are not per kernel basis, preventing us applying per kernel optimization in the device runtime.

This is a combination and refinement of patch series D116908, D116909, and D116910.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D142569

show more ...

[OpenMP][NFCI] Remove effectively dead code in clang and the runtime

Differential Revision: https://reviews.llvm.org/D136903

Revert "[OpenMP][NFCI] Remove effectively dead code in clang and the runtime"

This reverts commit c1c8cbbf5f29257d084a23a2f6c4236c40b7afb9. One of the
tests seems to be flaky/non-deterministic.

[OpenMP][NFCI] Remove effectively dead code in clang and the runtime

[OpenMP][FIX] Adjust to clang tests after D136740

Revert "[OpenMP] Codegen aggregate for outlined function captures"

This reverts commit 7539e9cf811e590d9f12ae39673ca789e26386b4.

[OpenMP] Codegen aggregate for outlined function captures

Parallel regions are outlined as functions with capture variables explicitly generated as distinct parameters in the function's argument lis

[OpenMP] Codegen aggregate for outlined function captures

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, jhuber6, ABataev

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

show more ...

[test] Remove references to -fexperimental-new-pass-manager in tests

This has been the default for a while and we're in the process of removing the legacy PM optimization pipeline.

Revert "[OpenMP] Codegen aggregate for outlined function captures"

This reverts commit 1d66649adf28d48ae1731516d87fb899426e3349.

Revert to fix AMG GPU issue.

[OpenMP] Codegen aggregate for outlined function captures

Parallel regions are outlined as functions with capture variables explicitly generated as distinct parameters in the function's argument lis

[OpenMP] Codegen aggregate for outlined function captures

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, jhuber6

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

show more ...

Revert "[OpenMP] Codegen aggregate for outlined function captures"

This reverts commit e9c7291cb25f071f1a1dfa4049ed9f5a8a217b3e.

Fix failing tests

[OpenMP] Codegen aggregate for outlined function captures

Parallel regions are outlined as functions with capture variables explicitly generated as distinct parameters in the function's argument lis

[OpenMP] Codegen aggregate for outlined function captures

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

show more ...

[OpenMP] Add IDs to OpenMP remarks

This patch adds unique idenfitiers to the existing OpenMP remarks. This makes
it easier to identify the corresponding documentation for each remark that will
be ho

[OpenMP] Add IDs to OpenMP remarks

This patch adds unique idenfitiers to the existing OpenMP remarks. This makes
it easier to identify the corresponding documentation for each remark that will
be hosted in the OpenMP webpage.

Depends on D105898

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D105939

show more ...

[OpenMP] Rework OpenMP remarks

This patch rewrites and reworks a few of the existing remarks to make the mmore
concise and consistent prior to writing the documentation for them.

Reviewed By: jdoer

[OpenMP] Rework OpenMP remarks

This patch rewrites and reworks a few of the existing remarks to make the mmore
concise and consistent prior to writing the documentation for them.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D105898

show more ...

[OpenMP] Detect SPMD compatible kernels and execute them as such

In the spirit of TRegions [0], this patch analyzes a kernel and tracks
if it can be executed in SPMD-mode. If so, we flip the argumen

[OpenMP] Detect SPMD compatible kernels and execute them as such

In the spirit of TRegions [0], this patch analyzes a kernel and tracks
if it can be executed in SPMD-mode. If so, we flip the arguments of
the __kmpc_target_init and deinit call to enable the mode. We also
update the `<kernel>_exec_mode` flag to indicate to the runtime we
changed the mode to SPMD.

The code analysis is done interprocedurally by extending the
AAKernelInfo abstract attribute to track SPMD compatibility as well.

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

Differential Revision: https://reviews.llvm.org/D102307

show more ...

[OpenMP][NFCI] Re-enable two remarks tests after D101977 landed

[OpenMP] Unified entry point for SPMD & generic kernels in the device RTL

In the spirit of TRegions [0], this patch provides a simpler and uniform
interface for a kernel to set up the device runtime

[OpenMP] Unified entry point for SPMD & generic kernels in the device RTL

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

show more ...

[OpenMP] Internalize functions in OpenMPOpt to improve IPO passes

Summary:
Currently the attributor needs to give up if a function has external linkage.
This means that the optimization introduced i

[OpenMP] Internalize functions in OpenMPOpt to improve IPO passes

Summary:
Currently the attributor needs to give up if a function has external linkage.
This means that the optimization introduced in D97818 will only apply to static
functions. This change uses the Attributor to internalize OpenMP device
routines by making a copy of each function with private linkage and replacing
the uses in the module with it. This allows for the optimization to be applied
to any regular function.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D102824

show more ...