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
This patch introduces a new abstract attributor instance that propagates
assumption information from functions. Conceptually, if a function is
only called by functions that have certain assumptions, then we can
apply the same assumptions to that function. This problem is similar to
calculating the dominator set, but the assumptions are merged instead of
nodes.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D111054
This patch adds functionality to check assumption attributes on call
sites as well.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D109376
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
Broke check-clang, see https://reviews.llvm.org/D102307#2869065
Ran `git revert -n ebbe149a6f08535ede848a531a601ae6591cfbc5..269416d41908bb670f67af689155d5ab8eea689a`
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
The `assume` attribute is a way to provide additional, arbitrary
information to the optimizer. For now, assumptions are restricted to
strings which will be accumulated for a function and emitted as comma
separated string function attribute. The key of the LLVM-IR function
attribute is `llvm.assume`. Similar to `llvm.assume` and
`__builtin_assume`, the `assume` attribute provides a user defined
assumption to the compiler.
A follow up patch will introduce an LLVM-core API to query the
assumptions attached to a function. We also expect to add more options,
e.g., expression arguments, to the `assume` attribute later on.
The `omp [begin] asssumes` pragma will leverage this attribute and
expose the functionality in the absence of OpenMP.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D91979
Johannes Doerfert