This patch expands SPMDization (converting generic execution mode to SPMD for target regions) by guarding code regions that should be executed only by the main thread. Specifically, it generates guarded regions, which only the main thread executes, and the synchronization with worker threads using simple barriers. For correctness, the patch aborts SPMDization for target regions if the same code executes in a parallel region, thus must be not be guarded. This check is implemented using the ParallelLevels AA.
Reviewed By: jhuber6
Differential Revision: https://reviews.llvm.org/D106892
This work provides four flags to disable four different sets of OpenMP optimizations. These flags take effect in llvm/lib/Transforms/IPO/OpenMPOpt.cpp and include the following:
- openmp-opt-disable-deglobalization: Defaults to false, adding this flag sets the variable DisableOpenMPOptDeglobalization to true. This prevents AA registration for HeapToStack and HeapToShared.
- openmp-opt-disable-spmdization: Defaults to false, adding this flag sets the variable DisableOpenMPOptSPMDization to true. This indicates a pessimistic fixpoint in changeToSPMDMode.
- openmp-opt-disable-folding: Defaults to false, adding this flag sets the variable DisableOpenMPOptFolding to true. This indicates a pessimistic fixpoint in the attributor init for AAFoldRuntimeCall.
- openmp-opt-disable-state-machine-rewrite: Defaults to false, adding this flag sets the variable DisableOpenMPOptStateMachineRewrite to true. This first prevents changes to the state machine in rewriteDeviceCodeStateMachine by returning before changes are made, and if a custom state machine is built in buildCustomStateMachine, stops by returning a pessimistic fixpoint.
Reviewed By: jhuber6
Differential Revision: https://reviews.llvm.org/D106802
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
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
In the spirit of TRegions [0], this patch creates a custom state
machine for a generic target region based on the potentially called
parallel regions.
The code analysis is done interprocedurally via an abstract attribute
(AAKernelInfo). All outermost parallel regions are collected and we
check if there might be unknown outermost parallel regions for which
we need an indirect call. Other AAKernelInfo extensions are expected.
[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11
Differential Revision: https://reviews.llvm.org/D101977
In order to simplify future extensions, e.g., the merge of
AAHeapToShared in to AAHeapToStack, we reorganize AAHeapToStack and the
state we keep for each malloc-like call. The result is also less
confusing as we only track malloc-like calls, not all calls. Further, we
only perform the updates necessary for a malloc-like to argue it can go
to the stack, e.g., we won't check all uses if we moved on to the
"must-be-freed" argument.
This patch also uses Attributor helps to simplify the allocated size,
alignment, and the potentially freed objects.
Overall, this is mostly a reorganization and only the use of the
optimistic helpers should change (=improve) the capabilities a bit.
Differential Revision: https://reviews.llvm.org/D104993
Broke check-clang, see https://reviews.llvm.org/D102307#2869065
Ran `git revert -n ebbe149a6f08535ede848a531a601ae6591cfbc5..269416d41908bb670f67af689155d5ab8eea689a`
In the spirit of TRegions [0], this patch creates a custom state
machine for a generic target region based on the potentially called
parallel regions.
The code analysis is done interprocedurally via an abstract attribute
(AAKernelInfo). All outermost parallel regions are collected and we
check if there might be unknown outermost parallel regions for which
we need an indirect call. Other AAKernelInfo extensions are expected.
[0] https://link.springer.com/chapter/10.1007/978-3-030-28596-8_11
Differential Revision: https://reviews.llvm.org/D101977
In order to simplify future extensions, e.g., the merge of
AAHeapToShared in to AAHeapToStack, we reorganize AAHeapToStack and the
state we keep for each malloc-like call. The result is also less
confusing as we only track malloc-like calls, not all calls. Further, we
only perform the updates necessary for a malloc-like to argue it can go
to the stack, e.g., we won't check all uses if we moved on to the
"must-be-freed" argument.
This patch also uses Attributor helps to simplify the allocated size,
alignment, and the potentially freed objects.
Overall, this is mostly a reorganization and only the use of the
optimistic helpers should change (=improve) the capabilities a bit.
Differential Revision: https://reviews.llvm.org/D104993
This patch adds additional remarks, suggesting the use of `noescape` for failed
globalization and indicating when internalization failed.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D105150
Currently OpenMPOpt will only check if a function is a kernel before deciding not to internalize it. Any uncalled function that gets internalized will be trivially dead in the module so this is unnnecessary.
Depends on D102423
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D104890
The metadata added in D102361 introduces a module flag that we can check
to determine if the module was compiled with `-fopenmp` enables. We can
now check for the precense of this instead of scanning the call graph
for OpenMP runtime functions.
Depends on D102361
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D102423
Summary:
This patch adds support for the Attributor to emit remarks on behalf of some
other pass. The attributor can now optionally take a callback function that
returns an OptimizationRemarkEmitter object when given a Function pointer. If
this is availible then a remark will be emitted for the corresponding pass
name.
Depends on D102197
Reviewed By: sstefan1 thegameg
Differential Revision: https://reviews.llvm.org/D102444
Summary:
The changes to globalization introduced in D97680 introduce a large amount of overhead by default. The old globalization method would always ignore globalization code if executing in SPMD mode. This wasn't strictly correct as data sharing is still possible in SPMD mode. The new interface is correct but introduces globalization code even when unnecessary. This optimization will use the existing HeapToStack transformation in the attributor to allow for unneeded globalization to be replaced with thread-private stack memory. This is done using the newly introduced library instances for the RTL functions added in D102087.
Depends on D97818
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D102197
