Recommit of

[OpenMP] Initial implementation of code generation for pragma 'distribute parallel for' on host

https://reviews.llvm.org/D29508

This patch makes the following additions:

It abstracts away loop bound generation code from procedures associated with pragma 'for' and loops in general, in such a way that the same procedures can be used for 'distribute parallel for' without the need for a full re-implementation.
It implements code generation for 'distribute parallel for' and adds regression tests. It includes tests for clauses.
It is important to notice that most of the clauses are implemented as part of existing procedures. For instance, firstprivate is already implemented for 'distribute' and 'for' as separate pragmas. As the implementation of 'distribute parallel for' is based on the same procedures, then we automatically obtain implementation for such clauses without the need to add new code. However, this requires regression tests that verify correctness of produced code.

llvm-svn: 301340

1 files changed, 37 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.h b/clang/lib/CodeGen/CGOpenMPRuntime.h
index 7901a6b7a8f..6f460f12179 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.h
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.h
@@ -672,16 +672,50 @@ public:
   ///
   virtual bool isDynamic(OpenMPScheduleClauseKind ScheduleKind) const;
 
+  /// struct with the values to be passed to the dispatch runtime function
+  struct DispatchRTInput {
+    /// Loop lower bound
+    llvm::Value *LB = nullptr;
+    /// Loop upper bound
+    llvm::Value *UB = nullptr;
+    /// Chunk size specified using 'schedule' clause (nullptr if chunk
+    /// was not specified)
+    llvm::Value *Chunk = nullptr;
+    DispatchRTInput() = default;
+    DispatchRTInput(llvm::Value *LB, llvm::Value *UB, llvm::Value *Chunk)
+        : LB(LB), UB(UB), Chunk(Chunk) {}
+  };
+
+  /// Call the appropriate runtime routine to initialize it before start
+  /// of loop.
+
+  /// This is used for non static scheduled types and when the ordered
+  /// clause is present on the loop construct.
+  /// Depending on the loop schedule, it is necessary to call some runtime
+  /// routine before start of the OpenMP loop to get the loop upper / lower
+  /// bounds \a LB and \a UB and stride \a ST.
+  ///
+  /// \param CGF Reference to current CodeGenFunction.
+  /// \param Loc Clang source location.
+  /// \param ScheduleKind Schedule kind, specified by the 'schedule' clause.
+  /// \param IVSize Size of the iteration variable in bits.
+  /// \param IVSigned Sign of the interation variable.
+  /// \param Ordered true if loop is ordered, false otherwise.
+  /// \param DispatchValues struct containing llvm values for lower bound, upper
+  /// bound, and chunk expression.
+  /// For the default (nullptr) value, the chunk 1 will be used.
+  ///
   virtual void emitForDispatchInit(CodeGenFunction &CGF, SourceLocation Loc,
                                    const OpenMPScheduleTy &ScheduleKind,
                                    unsigned IVSize, bool IVSigned, bool Ordered,
-                                   llvm::Value *UB,
-                                   llvm::Value *Chunk = nullptr);
+                                   const DispatchRTInput &DispatchValues);
 
   /// \brief Call the appropriate runtime routine to initialize it before start
   /// of loop.
   ///
-  /// Depending on the loop schedule, it is nesessary to call some runtime
+  /// This is used only in case of static schedule, when the user did not
+  /// specify a ordered clause on the loop construct.
+  /// Depending on the loop schedule, it is necessary to call some runtime
   /// routine before start of the OpenMP loop to get the loop upper / lower
   /// bounds \a LB and \a UB and stride \a ST.
   ///