nsw is now added to do-variable increment when -fno-wrapv is enabled as
GFortran seems to do.
That means the option introduced by #91579 isn't necessary any more.
Note that the feature of -flang-experimental-integer-overflow is enabled
by default.
This patch simplifies the representation of OpenMP loop wrapper
operations by introducing the `NoTerminator` trait and updating
accordingly the verifier for the `LoopWrapperInterface`.
Since loop wrappers are already limited to having exactly one region
containing exactly one block, and this block can only hold a single
`omp.loop_nest` or loop wrapper and an `omp.terminator` that does not
return any values, it makes sense to simplify the representation of loop
wrappers by removing the terminator.
There is an extensive list of Lit tests that needed updating to remove
the `omp.terminator`s adding some noise to this patch, but actual
changes are limited to the definition of the `omp.wsloop`, `omp.simd`,
`omp.distribute` and `omp.taskloop` loop wrapper ops, Flang lowering for
those, `LoopWrapperInterface::verifyImpl()`, SCF to OpenMP conversion
and OpenMP dialect documentation.
Code lowering always generates fir.if else blocks for source level if
statements, whether needed or not. Change this to only generate else
blocks that are needed.
This PR contains 2 commits:
1. A commit to reapply changes introduced #91116 (was reverted earlier
due to test suite failures)
2. A commit containing a possible solution for the issue causing the
test suite failures. In particular, it introduces a simple symbol
visitor class to keep track of the current active OMP construct and
marking this active construct as the scope defining the symbol being
visisted.
This patch updates lowering from PFT to MLIR of workshare loops to
follow the loop wrapper approach. Unit tests impacted by this change are
also updated.
As the last patch of the stack, this should compile and pass unit tests.
As part of preparing for the switch to HLFIR lowering, all OpenMP FIR
lowering tests are moved to a subdirectory in the OpenMP directory.
Copies of these tests that work with HLFIR will be created during this
week. After the switch the FIR lowering tests will be removed.
All new tests should be added with the HLFIR flow.
Temporaries created to store worksharing loop index values were
using different types than that of the original index variables.
This caused invalid IR to be produced when an index variable was
used in binary operations which expected its original type.
Fix this by creating temporaries with the types of their original
variables and converting the loop values, that continue to use
the types that OpenMP runtime expects, to them.
Fixes https://github.com/llvm/llvm-project/issues/60870
Reviewed By: kiranchandramohan
Differential Revision: https://reviews.llvm.org/D156803
