[Clang][OpenMP] Allow num_teams to accept multiple expressions

clang/include/clang/AST/OpenMPClause.h

@@ -6131,60 +6131,77 @@ class OMPMapClause final : public OMPMappableExprListClause<OMPMapClause>,
 /// \endcode
 /// In this example directive '#pragma omp teams' has clause 'num_teams'
 /// with single expression 'n'.
-class OMPNumTeamsClause : public OMPClause, public OMPClauseWithPreInit {
-  friend class OMPClauseReader;
+///
+/// When 'ompx_bare' clause exists on a 'target' directive, 'num_teams' clause
+/// can accept up to three expressions.
+///
+/// \code
+/// #pragma omp target teams ompx_bare num_teams(x, y, z)
+/// \endcode
+class OMPNumTeamsClause final
+    : public OMPVarListClause<OMPNumTeamsClause>,
+      public OMPClauseWithPreInit,
+      private llvm::TrailingObjects<OMPNumTeamsClause, Expr *> {
+  friend OMPVarListClause;
+  friend TrailingObjects;
 
   /// Location of '('.
   SourceLocation LParenLoc;
 
-  /// NumTeams number.
-  Stmt *NumTeams = nullptr;
+  OMPNumTeamsClause(const ASTContext &C, SourceLocation StartLoc,
+                    SourceLocation LParenLoc, SourceLocation EndLoc, unsigned N)
+      : OMPVarListClause(llvm::omp::OMPC_num_teams, StartLoc, LParenLoc, EndLoc,
+                         N),
+        OMPClauseWithPreInit(this) {}
 
-  /// Set the NumTeams number.
-  ///
-  /// \param E NumTeams number.
-  void setNumTeams(Expr *E) { NumTeams = E; }
+  /// Build an empty clause.
+  OMPNumTeamsClause(unsigned N)
+      : OMPVarListClause(llvm::omp::OMPC_num_teams, SourceLocation(),
+                         SourceLocation(), SourceLocation(), N),
+        OMPClauseWithPreInit(this) {}
 
 public:
-  /// Build 'num_teams' clause.
+  /// Creates clause with a list of variables \a VL.
   ///
-  /// \param E Expression associated with this clause.
-  /// \param HelperE Helper Expression associated with this clause.
-  /// \param CaptureRegion Innermost OpenMP region where expressions in this
-  /// clause must be captured.
+  /// \param C AST context.
   /// \param StartLoc Starting location of the clause.
   /// \param LParenLoc Location of '('.
   /// \param EndLoc Ending location of the clause.
-  OMPNumTeamsClause(Expr *E, Stmt *HelperE, OpenMPDirectiveKind CaptureRegion,
-                    SourceLocation StartLoc, SourceLocation LParenLoc,
-                    SourceLocation EndLoc)
-      : OMPClause(llvm::omp::OMPC_num_teams, StartLoc, EndLoc),
-        OMPClauseWithPreInit(this), LParenLoc(LParenLoc), NumTeams(E) {
-    setPreInitStmt(HelperE, CaptureRegion);
-  }
+  /// \param VL List of references to the variables.
+  /// \param PreInit
+  static OMPNumTeamsClause *Create(const ASTContext &C, SourceLocation StartLoc,
+                                   SourceLocation LParenLoc,
+                                   SourceLocation EndLoc, ArrayRef<Expr *> VL,
+                                   Stmt *PreInit);
 
-  /// Build an empty clause.
-  OMPNumTeamsClause()
-      : OMPClause(llvm::omp::OMPC_num_teams, SourceLocation(),
-                  SourceLocation()),
-        OMPClauseWithPreInit(this) {}
+  /// Creates an empty clause with \a N variables.
+  ///
+  /// \param C AST context.
+  /// \param N The number of variables.
+  static OMPNumTeamsClause *CreateEmpty(const ASTContext &C, unsigned N);
 
   /// Sets the location of '('.
   void setLParenLoc(SourceLocation Loc) { LParenLoc = Loc; }
 
   /// Returns the location of '('.
   SourceLocation getLParenLoc() const { return LParenLoc; }
 
-  /// Return NumTeams number.
-  Expr *getNumTeams() { return cast<Expr>(NumTeams); }
+  /// Return NumTeams expressions.
+  ArrayRef<Expr *> getNumTeams() { return getVarRefs(); }
 
-  /// Return NumTeams number.
-  Expr *getNumTeams() const { return cast<Expr>(NumTeams); }
+  /// Return NumTeams expressions.
+  ArrayRef<Expr *> getNumTeams() const {
+    return const_cast<OMPNumTeamsClause *>(this)->getNumTeams();
+  }
 
-  child_range children() { return child_range(&NumTeams, &NumTeams + 1); }
+  child_range children() {
+    return child_range(reinterpret_cast<Stmt **>(varlist_begin()),
+                       reinterpret_cast<Stmt **>(varlist_end()));
+  }
 
   const_child_range children() const {
-    return const_child_range(&NumTeams, &NumTeams + 1);
+    auto Children = const_cast<OMPNumTeamsClause *>(this)->children();
+    return const_child_range(Children.begin(), Children.end());
   }
 
   child_range used_children() {

clang/include/clang/AST/RecursiveASTVisitor.h

@@ -3793,8 +3793,8 @@ bool RecursiveASTVisitor<Derived>::VisitOMPMapClause(OMPMapClause *C) {
 template <typename Derived>
 bool RecursiveASTVisitor<Derived>::VisitOMPNumTeamsClause(
     OMPNumTeamsClause *C) {
+  TRY_TO(VisitOMPClauseList(C));
   TRY_TO(VisitOMPClauseWithPreInit(C));
-  TRY_TO(TraverseStmt(C->getNumTeams()));
   return true;
 }
 

clang/include/clang/Sema/SemaOpenMP.h

@@ -1226,7 +1226,8 @@ class SemaOpenMP : public SemaBase {
       const OMPVarListLocTy &Locs, bool NoDiagnose = false,
       ArrayRef<Expr *> UnresolvedMappers = std::nullopt);
   /// Called on well-formed 'num_teams' clause.
-  OMPClause *ActOnOpenMPNumTeamsClause(Expr *NumTeams, SourceLocation StartLoc,
+  OMPClause *ActOnOpenMPNumTeamsClause(ArrayRef<Expr *> VarList,
+                                       SourceLocation StartLoc,
                                        SourceLocation LParenLoc,
                                        SourceLocation EndLoc);
   /// Called on well-formed 'thread_limit' clause.

clang/lib/AST/OpenMPClause.cpp

@@ -1720,6 +1720,24 @@ const Expr *OMPDoacrossClause::getLoopData(unsigned NumLoop) const {
   return *It;
 }
 
+OMPNumTeamsClause *
+OMPNumTeamsClause::Create(const ASTContext &C, SourceLocation StartLoc,
+                          SourceLocation LParenLoc, SourceLocation EndLoc,
+                          ArrayRef<Expr *> VL, Stmt *PreInit) {
+  void *Mem = C.Allocate(totalSizeToAlloc<Expr *>(VL.size()));
+  OMPNumTeamsClause *Clause =
+      new (Mem) OMPNumTeamsClause(C, StartLoc, LParenLoc, EndLoc, VL.size());
+  Clause->setVarRefs(VL);
+  Clause->setPreInitStmt(PreInit);
+  return Clause;
+}
+
+OMPNumTeamsClause *OMPNumTeamsClause::CreateEmpty(const ASTContext &C,
+                                                  unsigned N) {
+  void *Mem = C.Allocate(totalSizeToAlloc<Expr *>(N));
+  return new (Mem) OMPNumTeamsClause(N);
+}
+
 //===----------------------------------------------------------------------===//
 //  OpenMP clauses printing methods
 //===----------------------------------------------------------------------===//
@@ -1977,9 +1995,11 @@ void OMPClausePrinter::VisitOMPDeviceClause(OMPDeviceClause *Node) {
 }
 
 void OMPClausePrinter::VisitOMPNumTeamsClause(OMPNumTeamsClause *Node) {
-  OS << "num_teams(";
-  Node->getNumTeams()->printPretty(OS, nullptr, Policy, 0);
-  OS << ")";
+  if (!Node->varlist_empty()) {
+    OS << "num_teams";
+    VisitOMPClauseList(Node, '(');
+    OS << ")";
+  }
 }
 
 void OMPClausePrinter::VisitOMPThreadLimitClause(OMPThreadLimitClause *Node) {

clang/lib/AST/StmtProfile.cpp

@@ -843,9 +843,8 @@ void OMPClauseProfiler::VisitOMPAllocateClause(const OMPAllocateClause *C) {
   VisitOMPClauseList(C);
 }
 void OMPClauseProfiler::VisitOMPNumTeamsClause(const OMPNumTeamsClause *C) {
+  VisitOMPClauseList(C);
   VistOMPClauseWithPreInit(C);
-  if (C->getNumTeams())
-    Profiler->VisitStmt(C->getNumTeams());
 }
 void OMPClauseProfiler::VisitOMPThreadLimitClause(
     const OMPThreadLimitClause *C) {

clang/lib/CodeGen/CGOpenMPRuntime.cpp

@@ -6036,8 +6036,9 @@ const Expr *CGOpenMPRuntime::getNumTeamsExprForTargetDirective(
             dyn_cast_or_null<OMPExecutableDirective>(ChildStmt)) {
       if (isOpenMPTeamsDirective(NestedDir->getDirectiveKind())) {
         if (NestedDir->hasClausesOfKind<OMPNumTeamsClause>()) {
-          const Expr *NumTeams =
-              NestedDir->getSingleClause<OMPNumTeamsClause>()->getNumTeams();
+          const Expr *NumTeams = NestedDir->getSingleClause<OMPNumTeamsClause>()
+                                     ->getNumTeams()
+                                     .front();
           if (NumTeams->isIntegerConstantExpr(CGF.getContext()))
             if (auto Constant =
                     NumTeams->getIntegerConstantExpr(CGF.getContext()))
@@ -6062,7 +6063,7 @@ const Expr *CGOpenMPRuntime::getNumTeamsExprForTargetDirective(
   case OMPD_target_teams_distribute_parallel_for_simd: {
     if (D.hasClausesOfKind<OMPNumTeamsClause>()) {
       const Expr *NumTeams =
-          D.getSingleClause<OMPNumTeamsClause>()->getNumTeams();
+          D.getSingleClause<OMPNumTeamsClause>()->getNumTeams().front();
       if (NumTeams->isIntegerConstantExpr(CGF.getContext()))
         if (auto Constant = NumTeams->getIntegerConstantExpr(CGF.getContext()))
           MinTeamsVal = MaxTeamsVal = Constant->getExtValue();

clang/lib/CodeGen/CGStmtOpenMP.cpp

@@ -6859,7 +6859,7 @@ static void emitCommonOMPTeamsDirective(CodeGenFunction &CGF,
   const auto *NT = S.getSingleClause<OMPNumTeamsClause>();
   const auto *TL = S.getSingleClause<OMPThreadLimitClause>();
   if (NT || TL) {
-    const Expr *NumTeams = NT ? NT->getNumTeams() : nullptr;
+    const Expr *NumTeams = NT ? NT->getNumTeams().front() : nullptr;
     const Expr *ThreadLimit = TL ? TL->getThreadLimit() : nullptr;
 
     CGF.CGM.getOpenMPRuntime().emitNumTeamsClause(CGF, NumTeams, ThreadLimit,

clang/lib/Parse/ParseOpenMP.cpp

@@ -3098,7 +3098,6 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
   case OMPC_simdlen:
   case OMPC_collapse:
   case OMPC_ordered:
-  case OMPC_num_teams:
   case OMPC_thread_limit:
   case OMPC_priority:
   case OMPC_grainsize:
@@ -3252,6 +3251,13 @@ OMPClause *Parser::ParseOpenMPClause(OpenMPDirectiveKind DKind,
                  ? ParseOpenMPSimpleClause(CKind, WrongDirective)
                  : ParseOpenMPClause(CKind, WrongDirective);
     break;
+  case OMPC_num_teams:
+    if (!FirstClause) {
+      Diag(Tok, diag::err_omp_more_one_clause)
+          << getOpenMPDirectiveName(DKind) << getOpenMPClauseName(CKind) << 0;
+      ErrorFound = true;
+    }
+    [[clang::fallthrough]];
   case OMPC_private:
   case OMPC_firstprivate:
   case OMPC_lastprivate:

clang/lib/Sema/SemaOpenMP.cpp

@@ -13785,6 +13785,16 @@ StmtResult SemaOpenMP::ActOnOpenMPTargetTeamsDirective(
     return StmtError();
   }
 
+  auto NumTeamsClauseItr =
+      llvm::find_if(Clauses, llvm::IsaPred<OMPNumTeamsClause>);
+  if (NumTeamsClauseItr != Clauses.end()) {
+    ArrayRef<const Expr *> NumTeams =
+        cast<OMPNumTeamsClause>(*NumTeamsClauseItr)->getNumTeams();
+    if (!HasBareClause && NumTeams.size() > 1) {
+      return StmtError();
+    }
+  }
+
   return OMPTargetTeamsDirective::Create(getASTContext(), StartLoc, EndLoc,
                                          Clauses, AStmt);
 }
@@ -14925,9 +14935,6 @@ OMPClause *SemaOpenMP::ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind,
   case OMPC_ordered:
     Res = ActOnOpenMPOrderedClause(StartLoc, EndLoc, LParenLoc, Expr);
     break;
-  case OMPC_num_teams:
-    Res = ActOnOpenMPNumTeamsClause(Expr, StartLoc, LParenLoc, EndLoc);
-    break;
   case OMPC_thread_limit:
     Res = ActOnOpenMPThreadLimitClause(Expr, StartLoc, LParenLoc, EndLoc);
     break;
@@ -15031,6 +15038,7 @@ OMPClause *SemaOpenMP::ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind,
   case OMPC_affinity:
   case OMPC_when:
   case OMPC_bind:
+  case OMPC_num_teams:
   default:
     llvm_unreachable("Clause is not allowed.");
   }
@@ -16894,6 +16902,9 @@ OMPClause *SemaOpenMP::ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
         static_cast<OpenMPDoacrossClauseModifier>(ExtraModifier),
         ExtraModifierLoc, ColonLoc, VarList, StartLoc, LParenLoc, EndLoc);
     break;
+  case OMPC_num_teams:
+    Res = ActOnOpenMPNumTeamsClause(VarList, StartLoc, LParenLoc, EndLoc);
+    break;
   case OMPC_if:
   case OMPC_depobj:
   case OMPC_final:
@@ -16924,7 +16935,6 @@ OMPClause *SemaOpenMP::ActOnOpenMPVarListClause(OpenMPClauseKind Kind,
   case OMPC_device:
   case OMPC_threads:
   case OMPC_simd:
-  case OMPC_num_teams:
   case OMPC_thread_limit:
   case OMPC_priority:
   case OMPC_grainsize:
@@ -21587,32 +21597,39 @@ const ValueDecl *SemaOpenMP::getOpenMPDeclareMapperVarName() const {
   return cast<DeclRefExpr>(DSAStack->getDeclareMapperVarRef())->getDecl();
 }
 
-OMPClause *SemaOpenMP::ActOnOpenMPNumTeamsClause(Expr *NumTeams,
+OMPClause *SemaOpenMP::ActOnOpenMPNumTeamsClause(ArrayRef<Expr *> VarList,
                                                  SourceLocation StartLoc,
                                                  SourceLocation LParenLoc,
                                                  SourceLocation EndLoc) {
-  Expr *ValExpr = NumTeams;
-  Stmt *HelperValStmt = nullptr;
-
-  // OpenMP [teams Constrcut, Restrictions]
-  // The num_teams expression must evaluate to a positive integer value.
-  if (!isNonNegativeIntegerValue(ValExpr, SemaRef, OMPC_num_teams,
-                                 /*StrictlyPositive=*/true))
+  if (VarList.empty())
     return nullptr;
 
+  for (Expr *ValExpr : VarList) {
+    // OpenMP [teams Constrcut, Restrictions]
+    // The num_teams expression must evaluate to a positive integer value.
+    if (!isNonNegativeIntegerValue(ValExpr, SemaRef, OMPC_num_teams,
+                                   /*StrictlyPositive=*/true))
+      return nullptr;
+  }
+
   OpenMPDirectiveKind DKind = DSAStack->getCurrentDirective();
   OpenMPDirectiveKind CaptureRegion = getOpenMPCaptureRegionForClause(
       DKind, OMPC_num_teams, getLangOpts().OpenMP);
-  if (CaptureRegion != OMPD_unknown &&
-      !SemaRef.CurContext->isDependentContext()) {
+  if (CaptureRegion == OMPD_unknown || SemaRef.CurContext->isDependentContext())
+    return OMPNumTeamsClause::Create(getASTContext(), StartLoc, LParenLoc,
+                                     EndLoc, VarList, /*PreInit=*/nullptr);
+
+  llvm::MapVector<const Expr *, DeclRefExpr *> Captures;
+  SmallVector<Expr *, 3> Vars;
+  for (Expr *ValExpr : VarList) {
     ValExpr = SemaRef.MakeFullExpr(ValExpr).get();
-    llvm::MapVector<const Expr *, DeclRefExpr *> Captures;
     ValExpr = tryBuildCapture(SemaRef, ValExpr, Captures).get();
-    HelperValStmt = buildPreInits(getASTContext(), Captures);
+    Vars.push_back(ValExpr);
   }
 
-  return new (getASTContext()) OMPNumTeamsClause(
-      ValExpr, HelperValStmt, CaptureRegion, StartLoc, LParenLoc, EndLoc);
+  Stmt *PreInit = buildPreInits(getASTContext(), Captures);
+  return OMPNumTeamsClause::Create(getASTContext(), StartLoc, LParenLoc, EndLoc,
+                                   Vars, PreInit);
 }
 
 OMPClause *SemaOpenMP::ActOnOpenMPThreadLimitClause(Expr *ThreadLimit,

clang/lib/Sema/TreeTransform.h

@@ -2065,10 +2065,11 @@ class TreeTransform {
   ///
   /// By default, performs semantic analysis to build the new statement.
   /// Subclasses may override this routine to provide different behavior.
-  OMPClause *RebuildOMPNumTeamsClause(Expr *NumTeams, SourceLocation StartLoc,
+  OMPClause *RebuildOMPNumTeamsClause(ArrayRef<Expr *> VarList,
+                                      SourceLocation StartLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation EndLoc) {
-    return getSema().OpenMP().ActOnOpenMPNumTeamsClause(NumTeams, StartLoc,
+    return getSema().OpenMP().ActOnOpenMPNumTeamsClause(VarList, StartLoc,
                                                         LParenLoc, EndLoc);
   }
 
@@ -10872,7 +10873,7 @@ TreeTransform<Derived>::TransformOMPAllocateClause(OMPAllocateClause *C) {
 template <typename Derived>
 OMPClause *
 TreeTransform<Derived>::TransformOMPNumTeamsClause(OMPNumTeamsClause *C) {
-  ExprResult E = getDerived().TransformExpr(C->getNumTeams());
+  ExprResult E = getDerived().TransformExpr(C->getNumTeams().front());
   if (E.isInvalid())
     return nullptr;
   return getDerived().RebuildOMPNumTeamsClause(

clang/lib/Serialization/ASTReader.cpp

@@ -104,6 +104,7 @@
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/ScopeExit.h"
+#include "llvm/ADT/Sequence.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
@@ -10562,7 +10563,7 @@ OMPClause *OMPClauseReader::readClause() {
     break;
   }
   case llvm::omp::OMPC_num_teams:
-    C = new (Context) OMPNumTeamsClause();
+    C = OMPNumTeamsClause::CreateEmpty(Context, Record.readInt());
     break;
   case llvm::omp::OMPC_thread_limit:
     C = new (Context) OMPThreadLimitClause();
@@ -11350,8 +11351,13 @@ void OMPClauseReader::VisitOMPAllocateClause(OMPAllocateClause *C) {
 
 void OMPClauseReader::VisitOMPNumTeamsClause(OMPNumTeamsClause *C) {
   VisitOMPClauseWithPreInit(C);
-  C->setNumTeams(Record.readSubExpr());
   C->setLParenLoc(Record.readSourceLocation());
+  unsigned NumVars = C->varlist_size();
+  SmallVector<Expr *, 16> Vars;
+  Vars.reserve(NumVars);
+  for ([[maybe_unused]] unsigned I : llvm::seq<unsigned>(NumVars))
+    Vars.push_back(Record.readSubExpr());
+  C->setVarRefs(Vars);
 }
 
 void OMPClauseReader::VisitOMPThreadLimitClause(OMPThreadLimitClause *C) {