llvm-project

28c6ed59 - [mlir][acc] Add ACCImplicitData pass for implicit data attributes (#166472)

[mlir][acc] Add ACCImplicitData pass for implicit data attributes (#166472) This change adds the ACCImplicitData pass which implements the OpenACC specification for "Variables with Implicitly Determined Data Attributes" (OpenACC 3.4 spec, section 2.6.2). The pass automatically generates data clause operations (copyin, copyout, present, firstprivate, etc.) for variables used within OpenACC compute constructs (parallel, kernels, serial) that do not already have explicit data clauses. Key features: - Respects default(none) and default(present) clauses - Handles scalar vs. aggregate variables with different semantics: * Aggregates: present clause (if default(present)) or copy clause * Scalars: copy clause (kernels) or firstprivate (parallel/serial) - Generates privatization recipes when needed for firstprivate clauses - Performs alias analysis to avoid redundant data mappings - Ensures proper data clause ordering for partial entity access - Generates exit operations (copyout, delete) to match entry operations Requirements: - Types must implement acc::MappableType and/or acc::PointerLikeType interfaces to be considered candidates. - Operations accessing partial entities or creating subviews should implement acc::PartialEntityAccess and/or mlir::ViewLikeOpInterface for proper clause ordering. - Optionally pre-register acc::OpenACCSupport and mlir::AliasAnalysis if custom alias analysis, variable name determination, or error reporting is needed.