[OPENMP] Improved codegen for implicit/explicit 'barrier' constructs.

Replace boolean IsExplicit parameter of OpenMPRuntime::emitBarrierCall() method by OpenMPDirectiveKind Kind for better compatibility with the runtime library. Also add processing of 'nowait' clause on worksharing directives.
Differential Revision: http://reviews.llvm.org/D8659

llvm-svn: 233511

3 files changed, 33 insertions, 17 deletions

diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index ef2d2147aca..2dbaae5624c 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -179,7 +179,7 @@ void CGOpenMPRegionInfo::EmitBody(CodeGenFunction &CGF, const Stmt *S) {
   if (PrivateScope.Privatize())
     // Emit implicit barrier to synchronize threads and avoid data races.
     CGF.CGM.getOpenMPRuntime().emitBarrierCall(CGF, Directive.getLocStart(),
-                                               /*IsExplicit=*/false);
+                                               OMPD_unknown);
   CGCapturedStmtInfo::EmitBody(CGF, S);
 }
 
@@ -1138,11 +1138,23 @@ void CGOpenMPRuntime::emitSingleRegion(CodeGenFunction &CGF,
 }
 
 void CGOpenMPRuntime::emitBarrierCall(CodeGenFunction &CGF, SourceLocation Loc,
-                                      bool IsExplicit) {
+                                      OpenMPDirectiveKind Kind) {
   // Build call __kmpc_cancel_barrier(loc, thread_id);
-  auto Flags = static_cast<OpenMPLocationFlags>(
-      OMP_IDENT_KMPC |
-      (IsExplicit ? OMP_IDENT_BARRIER_EXPL : OMP_IDENT_BARRIER_IMPL));
+  OpenMPLocationFlags Flags = OMP_IDENT_KMPC;
+  if (Kind == OMPD_for) {
+    Flags =
+        static_cast<OpenMPLocationFlags>(Flags | OMP_IDENT_BARRIER_IMPL_FOR);
+  } else if (Kind == OMPD_sections) {
+    Flags = static_cast<OpenMPLocationFlags>(Flags |
+                                             OMP_IDENT_BARRIER_IMPL_SECTIONS);
+  } else if (Kind == OMPD_single) {
+    Flags =
+        static_cast<OpenMPLocationFlags>(Flags | OMP_IDENT_BARRIER_IMPL_SINGLE);
+  } else if (Kind == OMPD_barrier) {
+    Flags = static_cast<OpenMPLocationFlags>(Flags | OMP_IDENT_BARRIER_EXPL);
+  } else {
+    Flags = static_cast<OpenMPLocationFlags>(Flags | OMP_IDENT_BARRIER_IMPL);
+  }
   // Build call __kmpc_cancel_barrier(loc, thread_id);
   // Replace __kmpc_barrier() function by __kmpc_cancel_barrier() because this
   // one provides the same functionality and adds initial support for
diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.h b/clang/lib/CodeGen/CGOpenMPRuntime.h
index f8849e627c8..d32e2ab1732 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.h
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.h
@@ -358,11 +358,12 @@ public:
                                 ArrayRef<const Expr *> DstExprs,
                                 ArrayRef<const Expr *> AssignmentOps);
 
-  /// \brief Emits explicit barrier for OpenMP threads.
-  /// \param IsExplicit true, if it is explicitly specified barrier.
+  /// \brief Emit an implicit/explicit barrier for OpenMP threads.
+  /// \param Kind Directive for which this implicit barrier call must be
+  /// generated. Must be OMPD_barrier for explicit barrier generation.
   ///
   virtual void emitBarrierCall(CodeGenFunction &CGF, SourceLocation Loc,
-                               bool IsExplicit = true);
+                               OpenMPDirectiveKind Kind);
 
   /// \brief Check if the specified \a ScheduleKind is static non-chunked.
   /// This kind of worksharing directive is emitted without outer loop.
diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 9af74749f17..f74e47a4ca5 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -785,8 +785,9 @@ void CodeGenFunction::EmitOMPForDirective(const OMPForDirective &S) {
   EmitOMPWorksharingLoop(S);
 
   // Emit an implicit barrier at the end.
-  CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(),
-                                         /*IsExplicit*/ false);
+  if (!S.getSingleClause(OMPC_nowait)) {
+    CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(), OMPD_for);
+  }
 }
 
 void CodeGenFunction::EmitOMPForSimdDirective(const OMPForSimdDirective &) {
@@ -886,9 +887,11 @@ void CodeGenFunction::EmitOMPSectionsDirective(const OMPSectionsDirective &S) {
   }
 
   // Emit an implicit barrier at the end.
-  if (!S.getSingleClause(OMPC_nowait))
-    CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(),
-                                           /*IsExplicit=*/false);
+  if (!S.getSingleClause(OMPC_nowait)) {
+    CGM.getOpenMPRuntime().emitBarrierCall(
+        *this, S.getLocStart(),
+        (CS && CS->size() > 1) ? OMPD_sections : OMPD_single);
+  }
 }
 
 void CodeGenFunction::EmitOMPSectionDirective(const OMPSectionDirective &S) {
@@ -927,9 +930,9 @@ void CodeGenFunction::EmitOMPSingleDirective(const OMPSingleDirective &S) {
     EnsureInsertPoint();
   }, S.getLocStart(), CopyprivateVars, SrcExprs, DstExprs, AssignmentOps);
   // Emit an implicit barrier at the end.
-  if (!S.getSingleClause(OMPC_nowait))
-    CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(),
-                                           /*IsExplicit=*/false);
+  if (!S.getSingleClause(OMPC_nowait)) {
+    CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(), OMPD_single);
+  }
 }
 
 void CodeGenFunction::EmitOMPMasterDirective(const OMPMasterDirective &S) {
@@ -1001,7 +1004,7 @@ void CodeGenFunction::EmitOMPTaskyieldDirective(
 }
 
 void CodeGenFunction::EmitOMPBarrierDirective(const OMPBarrierDirective &S) {
-  CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart());
+  CGM.getOpenMPRuntime().emitBarrierCall(*this, S.getLocStart(), OMPD_barrier);
 }
 
 void CodeGenFunction::EmitOMPTaskwaitDirective(const OMPTaskwaitDirective &) {