[Clang][OpenMP] Support for Code Generation of loop bind clause

Support for Code Generation of "#pragma loop bind" clause.
1) bind(parallel)
2) bind(teams)
3) bind(thread)

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D144634

clang/include/clang/AST/StmtOpenMP.h

@@ -281,6 +281,15 @@ class OMPExecutableDirective : public Stmt {
     return Data->getClauses();
   }
 
+  /// Was this directive mapped from an another directive?
+  /// e.g. 1) omp loop bind(parallel) is mapped to OMPD_for
+  ///      2) omp loop bind(teams) is mapped to OMPD_distribute
+  ///      3) omp loop bind(thread) is mapped to OMPD_simd
+  /// It was necessary to note it down in the Directive because of
+  /// clang::TreeTransform::TransformOMPExecutableDirective() pass in
+  /// the frontend.
+  OpenMPDirectiveKind PrevMappedDirective = llvm::omp::OMPD_unknown;
+
 protected:
   /// Data, associated with the directive.
   OMPChildren *Data = nullptr;
@@ -345,6 +354,10 @@ class OMPExecutableDirective : public Stmt {
     return Inst;
   }
 
+  void setMappedDirective(OpenMPDirectiveKind MappedDirective) {
+    PrevMappedDirective = MappedDirective;
+  }
+
 public:
   /// Iterates over expressions/statements used in the construct.
   class used_clauses_child_iterator
@@ -598,6 +611,8 @@ class OMPExecutableDirective : public Stmt {
            "Expected directive with the associated statement.");
     return Data->getRawStmt();
   }
+
+  OpenMPDirectiveKind getMappedDirective() const { return PrevMappedDirective; }
 };
 
 /// This represents '#pragma omp parallel' directive.
@@ -1604,7 +1619,8 @@ class OMPSimdDirective : public OMPLoopDirective {
                                   SourceLocation EndLoc, unsigned CollapsedNum,
                                   ArrayRef<OMPClause *> Clauses,
                                   Stmt *AssociatedStmt,
-                                  const HelperExprs &Exprs);
+                                  const HelperExprs &Exprs,
+                                  OpenMPDirectiveKind ParamPrevMappedDirective);
 
   /// Creates an empty directive with the place
   /// for \a NumClauses clauses.
@@ -1682,7 +1698,8 @@ class OMPForDirective : public OMPLoopDirective {
                                  SourceLocation EndLoc, unsigned CollapsedNum,
                                  ArrayRef<OMPClause *> Clauses,
                                  Stmt *AssociatedStmt, const HelperExprs &Exprs,
-                                 Expr *TaskRedRef, bool HasCancel);
+                                 Expr *TaskRedRef, bool HasCancel,
+                                 OpenMPDirectiveKind ParamPrevMappedDirective);
 
   /// Creates an empty directive with the place
   /// for \a NumClauses clauses.
@@ -4406,7 +4423,8 @@ class OMPDistributeDirective : public OMPLoopDirective {
   static OMPDistributeDirective *
   Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
          unsigned CollapsedNum, ArrayRef<OMPClause *> Clauses,
-         Stmt *AssociatedStmt, const HelperExprs &Exprs);
+         Stmt *AssociatedStmt, const HelperExprs &Exprs,
+         OpenMPDirectiveKind ParamPrevMappedDirective);
 
   /// Creates an empty directive with the place
   /// for \a NumClauses clauses.

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -9886,6 +9886,11 @@ def err_break_not_in_loop_or_switch : Error<
 def warn_loop_ctrl_binds_to_inner : Warning<
   "'%0' is bound to current loop, GCC binds it to the enclosing loop">,
   InGroup<GccCompat>;
+def err_omp_bind_required_on_loop : Error<
+  "expected 'bind' clause for 'loop' construct without an enclosing OpenMP "
+  "construct">;
+def err_omp_loop_reduction_clause : Error<
+  "'reduction' clause not allowed with '#pragma omp loop bind(teams)'">;
 def warn_break_binds_to_switch : Warning<
   "'break' is bound to loop, GCC binds it to switch">,
   InGroup<GccCompat>;

clang/include/clang/Sema/Sema.h

@@ -11194,6 +11194,23 @@ class Sema final {
   /// All `omp assumes` we encountered so far.
   SmallVector<AssumptionAttr *, 4> OMPAssumeGlobal;
 
+  /// OMPD_loop is mapped to OMPD_for, OMPD_distribute or OMPD_simd depending
+  /// on the parameter of the bind clause. In the methods for the
+  /// mapped directives, check the parameters of the lastprivate clause.
+  bool checkLastPrivateForMappedDirectives(ArrayRef<OMPClause *> Clauses);
+  /// Depending on the bind clause of OMPD_loop map the directive to new
+  /// directives.
+  ///    1) loop bind(parallel) --> OMPD_for
+  ///    2) loop bind(teams) --> OMPD_distribute
+  ///    3) loop bind(thread) --> OMPD_simd
+  /// This is being handled in Sema instead of Codegen because of the need for
+  /// rigorous semantic checking in the new mapped directives.
+  bool mapLoopConstruct(llvm::SmallVector<OMPClause *> &ClausesWithoutBind,
+                        ArrayRef<OMPClause *> Clauses,
+                        OpenMPBindClauseKind BindKind,
+                        OpenMPDirectiveKind &Kind,
+                        OpenMPDirectiveKind &PrevMappedDirective);
+
 public:
   /// The declarator \p D defines a function in the scope \p S which is nested
   /// in an `omp begin/end declare variant` scope. In this method we create a
@@ -11489,7 +11506,8 @@ class Sema final {
   StmtResult ActOnOpenMPExecutableDirective(
       OpenMPDirectiveKind Kind, const DeclarationNameInfo &DirName,
       OpenMPDirectiveKind CancelRegion, ArrayRef<OMPClause *> Clauses,
-      Stmt *AStmt, SourceLocation StartLoc, SourceLocation EndLoc);
+      Stmt *AStmt, SourceLocation StartLoc, SourceLocation EndLoc,
+      OpenMPDirectiveKind PrevMappedDirective = llvm::omp::OMPD_unknown);
   /// Called on well-formed '\#pragma omp parallel' after parsing
   /// of the  associated statement.
   StmtResult ActOnOpenMPParallelDirective(ArrayRef<OMPClause *> Clauses,

clang/lib/AST/StmtOpenMP.cpp

@@ -297,11 +297,10 @@ OMPParallelDirective *OMPParallelDirective::CreateEmpty(const ASTContext &C,
                                                     /*NumChildren=*/1);
 }
 
-OMPSimdDirective *
-OMPSimdDirective::Create(const ASTContext &C, SourceLocation StartLoc,
-                         SourceLocation EndLoc, unsigned CollapsedNum,
-                         ArrayRef<OMPClause *> Clauses, Stmt *AssociatedStmt,
-                         const HelperExprs &Exprs) {
+OMPSimdDirective *OMPSimdDirective::Create(
+    const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
+    unsigned CollapsedNum, ArrayRef<OMPClause *> Clauses, Stmt *AssociatedStmt,
+    const HelperExprs &Exprs, OpenMPDirectiveKind ParamPrevMappedDirective) {
   auto *Dir = createDirective<OMPSimdDirective>(
       C, Clauses, AssociatedStmt, numLoopChildren(CollapsedNum, OMPD_simd),
       StartLoc, EndLoc, CollapsedNum);
@@ -321,6 +320,7 @@ OMPSimdDirective::Create(const ASTContext &C, SourceLocation StartLoc,
   Dir->setDependentInits(Exprs.DependentInits);
   Dir->setFinalsConditions(Exprs.FinalsConditions);
   Dir->setPreInits(Exprs.PreInits);
+  Dir->setMappedDirective(ParamPrevMappedDirective);
   return Dir;
 }
 
@@ -336,7 +336,8 @@ OMPSimdDirective *OMPSimdDirective::CreateEmpty(const ASTContext &C,
 OMPForDirective *OMPForDirective::Create(
     const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
     unsigned CollapsedNum, ArrayRef<OMPClause *> Clauses, Stmt *AssociatedStmt,
-    const HelperExprs &Exprs, Expr *TaskRedRef, bool HasCancel) {
+    const HelperExprs &Exprs, Expr *TaskRedRef, bool HasCancel,
+    OpenMPDirectiveKind ParamPrevMappedDirective) {
   auto *Dir = createDirective<OMPForDirective>(
       C, Clauses, AssociatedStmt, numLoopChildren(CollapsedNum, OMPD_for) + 1,
       StartLoc, EndLoc, CollapsedNum);
@@ -366,6 +367,7 @@ OMPForDirective *OMPForDirective::Create(
   Dir->setPreInits(Exprs.PreInits);
   Dir->setTaskReductionRefExpr(TaskRedRef);
   Dir->setHasCancel(HasCancel);
+  Dir->setMappedDirective(ParamPrevMappedDirective);
   return Dir;
 }
 
@@ -1515,7 +1517,7 @@ OMPParallelMaskedTaskLoopSimdDirective::CreateEmpty(const ASTContext &C,
 OMPDistributeDirective *OMPDistributeDirective::Create(
     const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
     unsigned CollapsedNum, ArrayRef<OMPClause *> Clauses, Stmt *AssociatedStmt,
-    const HelperExprs &Exprs) {
+    const HelperExprs &Exprs, OpenMPDirectiveKind ParamPrevMappedDirective) {
   auto *Dir = createDirective<OMPDistributeDirective>(
       C, Clauses, AssociatedStmt,
       numLoopChildren(CollapsedNum, OMPD_distribute), StartLoc, EndLoc,
@@ -1544,6 +1546,7 @@ OMPDistributeDirective *OMPDistributeDirective::Create(
   Dir->setDependentInits(Exprs.DependentInits);
   Dir->setFinalsConditions(Exprs.FinalsConditions);
   Dir->setPreInits(Exprs.PreInits);
+  Dir->setMappedDirective(ParamPrevMappedDirective);
   return Dir;
 }