[OpenMP50] Add parallel master construct

Reviewers: ABataev, jdoerfert

Reviewed By: ABataev

Subscribers: rnk, jholewinski, guansong, arphaman, jfb, cfe-commits, sandoval, dreachem

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70726

1 files changed, 35 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 1e6933df708..a5190007406 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -2897,13 +2897,17 @@ void CodeGenFunction::EmitOMPSingleDirective(const OMPSingleDirective &S) {
   }
 }
 
-void CodeGenFunction::EmitOMPMasterDirective(const OMPMasterDirective &S) {
+static void emitMaster(CodeGenFunction &CGF, const OMPExecutableDirective &S) {
   auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
     Action.Enter(CGF);
     CGF.EmitStmt(S.getInnermostCapturedStmt()->getCapturedStmt());
   };
+  CGF.CGM.getOpenMPRuntime().emitMasterRegion(CGF, CodeGen, S.getBeginLoc());
+}
+
+void CodeGenFunction::EmitOMPMasterDirective(const OMPMasterDirective &S) {
   OMPLexicalScope Scope(*this, S, OMPD_unknown);
-  CGM.getOpenMPRuntime().emitMasterRegion(*this, CodeGen, S.getBeginLoc());
+  emitMaster(*this, S);
 }
 
 void CodeGenFunction::EmitOMPCriticalDirective(const OMPCriticalDirective &S) {
@@ -2947,6 +2951,35 @@ void CodeGenFunction::EmitOMPParallelForSimdDirective(
                                  emitEmptyBoundParameters);
 }
 
+void CodeGenFunction::EmitOMPParallelMasterDirective(
+    const OMPParallelMasterDirective &S) {
+  // Emit directive as a combined directive that consists of two implicit
+  // directives: 'parallel' with 'master' directive.
+  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
+    Action.Enter(CGF);
+    OMPPrivateScope PrivateScope(CGF);
+    bool Copyins = CGF.EmitOMPCopyinClause(S);
+    (void)CGF.EmitOMPFirstprivateClause(S, PrivateScope);
+    if (Copyins) {
+      // Emit implicit barrier to synchronize threads and avoid data races on
+      // propagation master's thread values of threadprivate variables to local
+      // instances of that variables of all other implicit threads.
+      CGF.CGM.getOpenMPRuntime().emitBarrierCall(
+          CGF, S.getBeginLoc(), OMPD_unknown, /*EmitChecks=*/false,
+          /*ForceSimpleCall=*/true);
+    }
+    CGF.EmitOMPPrivateClause(S, PrivateScope);
+    CGF.EmitOMPReductionClauseInit(S, PrivateScope);
+    (void)PrivateScope.Privatize();
+    emitMaster(CGF, S);
+    CGF.EmitOMPReductionClauseFinal(S, /*ReductionKind=*/OMPD_parallel);
+  };
+  emitCommonOMPParallelDirective(*this, S, OMPD_master, CodeGen,
+                                 emitEmptyBoundParameters);
+  emitPostUpdateForReductionClause(*this, S,
+                                   [](CodeGenFunction &) { return nullptr; });
+}
+
 void CodeGenFunction::EmitOMPParallelSectionsDirective(
     const OMPParallelSectionsDirective &S) {
   // Emit directive as a combined directive that consists of two implicit