This patch enables tiling in flang. In MLIR tiling is handled by changing the the omp.loop_nest op to be able to represent both collapse and tiling, so the flang front-end will combine the nested constructs into a single MLIR op. The MLIR->LLVM-IR lowering of the LoopNestOp is enhanced to first do the tiling if present, then collapse.
In at least certain cases, notably when equivalence is used (at least for the example this showed up as a problem in) we currently miscategorize symbols as firstprivate when they may not be, as they can throw a false positive when a use symbol from a mod file is picked up. The fix to this is to chase up the appropriate symbol to access the correct details.
The Open ACC spec states that the reduction clause implies the copy clause. Account for this in the check for `default(none)` variables. Add a test that shouldn't error, but did before this PR.
OpenMPBlockConstruct, somewhat confusingly, represents most but not all block-associated constructs. It's derived from OmpBlockConstruct, as are all the remaining block-associated constructs. It does not correspond to any well-defined group of constructs. It's the collection of constructs that don't have their own types (and those that do have their own types do so for their own reasons). Using the broader OmpBlockConstruct in type-based visitors won't cause issues, because the specific overloads (for classes derived from it) will always be preferred.
This fixes two scoping related bugs with OpenACC semantic checking. - Data constructs with open acc now inherit the default Data Sharing Attribute of their parent construct. - Data Sharing Attributes scopes now nest such that if a symbol's DSA wasn't declared by the innermost then lookup looks in the parent construct's data sharing declarations. This fixes the added test cases.
The ASSUME directive is block-associated and whether the end-directive is optional or not depends on the form of the block. This is all taken care of automatically since the AST node for ASSUME inherits from OmpBlockConstruct.
New implementation of `MayNeedCopy()` is used to consolidate copy-in/copy-out checks. `IsAssumedShape()` and `IsAssumedRank()` were simplified and are both now in `Fortran::semantics` workspace. `preparePresentUserCallActualArgument()` in lowering was modified to use `MayNeedCopyInOut()` Fixes https://github.com/llvm/llvm-project/issues/138471
This PR adds workdistribute parser and semantic support in flang. The work in this PR is c-p and updated from @ivanradanov commits from coexecute implementation: flang_workdistribute_iwomp_2024
The current code will crash on the MAP clause with OpenMP version >= 6.0 when the clause does not explicitly list any modifiers. The proper fix is to update the handling of assumed-size arrays for OpenMP 6.0+, but in the short term keep the behavior from 5.2, just avoid the crash.