[OpenMP] Added codegen for masked directive

[ABataev]

clang/lib/CodeGen/CGStmtOpenMP.cpp

3853–3855

No need for braces here

clang/test/OpenMP/masked_codegen.cpp

88

Add a test with filter clauses

[cchen]

Update test and fix code format

[ABataev]

LG

[jdoerfert]

Any reason we should not unconditionally use the OMPIRBuilder impl? (btw, many thanks for providing one!)
We have an OMPIRBuilder always around in clang's codegen, so there is little reason not to use it if it is feature complete.

[jdoerfert]

Also, don't forget to mark it as done in https://clang.llvm.org/docs/OpenMPSupport.html :)

[cchen]

In D100514#2693600, @jdoerfert wrote:

Any reason we should not unconditionally use the OMPIRBuilder impl? (btw, many thanks for providing one!)
We have an OMPIRBuilder always around in clang's codegen, so there is little reason not to use it if it is feature complete.

I'm fine using OMPIRBuilder as default. I was not set it as default since most of the clause/directive are still using Clang codegen as default (ex: master, critical, and for are now use Clang codegen as default).

[cchen]

In D100514#2693601, @jdoerfert wrote:

Also, don't forget to mark it as done in https://clang.llvm.org/docs/OpenMPSupport.html :)

I'll mark it as done after combined constructs are also done. Thanks!

[jdoerfert]

In D100514#2695271, @cchen wrote:

In D100514#2693600, @jdoerfert wrote:

Any reason we should not unconditionally use the OMPIRBuilder impl? (btw, many thanks for providing one!)
We have an OMPIRBuilder always around in clang's codegen, so there is little reason not to use it if it is feature complete.

I'm fine using OMPIRBuilder as default. I was not set it as default since most of the clause/directive are still using Clang codegen as default (ex: master, critical, and for are now use Clang codegen as default).

Initially we did not have an OMPIRBuilder object unconditionally, now we have. Let's move over everything that is ready. So master and critical should be good to go as well I suppose.

[cchen]

Initially we did not have an OMPIRBuilder object unconditionally, now we have. Let's move over everything that is ready. So master and critical should be good to go as well I suppose.

While using OMPIRBuilder as default, do we want to just remove codegen in Clang or we have a flag for using Clang codegen?

[jdoerfert]

In D100514#2696106, @cchen wrote:

Initially we did not have an OMPIRBuilder object unconditionally, now we have. Let's move over everything that is ready. So master and critical should be good to go as well I suppose.

While using OMPIRBuilder as default, do we want to just remove codegen in Clang or we have a flag for using Clang codegen?

No duplication where it is not necessary. So if the OMPIRBuilder is fully capable use it remove the clang codegen, please.

[cchen]

Use irbuilder for masked and master construct: https://reviews.llvm.org/D100874.

clang/lib/CodeGen/CGOpenMPRuntime.h

public:
 
   /// Emits a master region.
   /// \param MasterOpGen Generator for the statement associated with the given
   /// master region.
   virtual void emitMasterRegion(CodeGenFunction &CGF,
                                 const RegionCodeGenTy &MasterOpGen,
                                 SourceLocation Loc);
 
+  /// Emits a masked region.
+  /// \param MaskedOpGen Generator for the statement associated with the given
+  /// masked region.
+  virtual void emitMaskedRegion(CodeGenFunction &CGF,
+                                const RegionCodeGenTy &MaskedOpGen,
+                                SourceLocation Loc,
+                                const Expr *Filter = nullptr);
+
   /// Emits code for a taskyield directive.
   virtual void emitTaskyieldCall(CodeGenFunction &CGF, SourceLocation Loc);
 
   /// Emit a taskgroup region.
   /// \param TaskgroupOpGen Generator for the statement associated with the
   /// given taskgroup region.
   virtual void emitTaskgroupRegion(CodeGenFunction &CGF,
                                    const RegionCodeGenTy &TaskgroupOpGen,
public:
 
   /// Emits a master region.
   /// \param MasterOpGen Generator for the statement associated with the given
   /// master region.
   void emitMasterRegion(CodeGenFunction &CGF,
                         const RegionCodeGenTy &MasterOpGen,
                         SourceLocation Loc) override;
 
+  /// Emits a masked region.
+  /// \param MaskedOpGen Generator for the statement associated with the given
+  /// masked region.
+  void emitMaskedRegion(CodeGenFunction &CGF,
+                        const RegionCodeGenTy &MaskedOpGen, SourceLocation Loc,
+                        const Expr *Filter = nullptr) override;
+
+  /// Emits a masked region.
+  /// \param MaskedOpGen Generator for the statement associated with the given
+  /// masked region.
+
   /// Emits code for a taskyield directive.
   void emitTaskyieldCall(CodeGenFunction &CGF, SourceLocation Loc) override;
 
   /// Emit a taskgroup region.
   /// \param TaskgroupOpGen Generator for the statement associated with the
   /// given taskgroup region.
   void emitTaskgroupRegion(CodeGenFunction &CGF,
                            const RegionCodeGenTy &TaskgroupOpGen,

clang/lib/CodeGen/CGOpenMPRuntime.cpp

CommonActionTy Action(OMPBuilder.getOrCreateRuntimeFunction(
                             CGM.getModule(), OMPRTL___kmpc_end_master),
                         Args,
                         /*Conditional=*/true);
   MasterOpGen.setAction(Action);
   emitInlinedDirective(CGF, OMPD_master, MasterOpGen);
   Action.Done(CGF);
 }
 
+void CGOpenMPRuntime::emitMaskedRegion(CodeGenFunction &CGF,
+                                       const RegionCodeGenTy &MaskedOpGen,
+                                       SourceLocation Loc, const Expr *Filter) {
+  if (!CGF.HaveInsertPoint())
+    return;
+  // if(__kmpc_masked(ident_t *, gtid, filter)) {
+  //   MaskedOpGen();
+  //   __kmpc_end_masked(iden_t *, gtid);
+  // }
+  // Prepare arguments and build a call to __kmpc_masked
+  llvm::Value *FilterVal = Filter
+                               ? CGF.EmitScalarExpr(Filter, CGF.Int32Ty)
+                               : llvm::ConstantInt::get(CGM.Int32Ty, /*V=*/0);
+  llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc),
+                         FilterVal};
+  llvm::Value *ArgsEnd[] = {emitUpdateLocation(CGF, Loc),
+                            getThreadID(CGF, Loc)};
+  CommonActionTy Action(OMPBuilder.getOrCreateRuntimeFunction(
+                            CGM.getModule(), OMPRTL___kmpc_masked),
+                        Args,
+                        OMPBuilder.getOrCreateRuntimeFunction(
+                            CGM.getModule(), OMPRTL___kmpc_end_masked),
+                        ArgsEnd,
+                        /*Conditional=*/true);
+  MaskedOpGen.setAction(Action);
+  emitInlinedDirective(CGF, OMPD_masked, MaskedOpGen);
+  Action.Done(CGF);
+}
+
 void CGOpenMPRuntime::emitTaskyieldCall(CodeGenFunction &CGF,
                                         SourceLocation Loc) {
   if (!CGF.HaveInsertPoint())
     return;
   if (CGF.CGM.getLangOpts().OpenMPIRBuilder) {
     OMPBuilder.createTaskyield(CGF.Builder);
   } else {
     // Build call __kmpc_omp_taskyield(loc, thread_id, 0);

 void CGOpenMPRuntime::emitInlinedDirective(CodeGenFunction &CGF,
                                            OpenMPDirectiveKind InnerKind,
                                            const RegionCodeGenTy &CodeGen,
                                            bool HasCancel) {
   if (!CGF.HaveInsertPoint())
     return;
   InlinedOpenMPRegionRAII Region(CGF, CodeGen, InnerKind, HasCancel,
                                  InnerKind != OMPD_critical &&
-                                     InnerKind != OMPD_master);
+                                     InnerKind != OMPD_master &&
+                                     InnerKind != OMPD_masked);
   CGF.CapturedStmtInfo->EmitBody(CGF, /*S=*/nullptr);
 }
 
 namespace {
 enum RTCancelKind {
   CancelNoreq = 0,
   CancelParallel = 1,
   CancelLoop = 2,

 }
 
 void CGOpenMPSIMDRuntime::emitMasterRegion(CodeGenFunction &CGF,
                                            const RegionCodeGenTy &MasterOpGen,
                                            SourceLocation Loc) {
   llvm_unreachable("Not supported in SIMD-only mode");
 }
 
+void CGOpenMPSIMDRuntime::emitMaskedRegion(CodeGenFunction &CGF,
+                                           const RegionCodeGenTy &MasterOpGen,
+                                           SourceLocation Loc,
+                                           const Expr *Filter) {
+  llvm_unreachable("Not supported in SIMD-only mode");
+}
+
 void CGOpenMPSIMDRuntime::emitTaskyieldCall(CodeGenFunction &CGF,
                                             SourceLocation Loc) {
   llvm_unreachable("Not supported in SIMD-only mode");
 }
 
 void CGOpenMPSIMDRuntime::emitTaskgroupRegion(
     CodeGenFunction &CGF, const RegionCodeGenTy &TaskgroupOpGen,
     SourceLocation Loc) {

clang/lib/CodeGen/CGStmt.cpp

case Stmt::OMPTargetTeamsDistributeSimdDirectiveClass:
     break;
   case Stmt::OMPInteropDirectiveClass:
     llvm_unreachable("Interop directive not supported yet.");
     break;
   case Stmt::OMPDispatchDirectiveClass:
     llvm_unreachable("Dispatch directive not supported yet.");
     break;
   case Stmt::OMPMaskedDirectiveClass:
-    llvm_unreachable("Masked directive not supported yet.");
+    EmitOMPMaskedDirective(cast<OMPMaskedDirective>(*S));
     break;
   }
 }
 
 bool CodeGenFunction::EmitSimpleStmt(const Stmt *S,
                                      ArrayRef<const Attr *> Attrs) {
   switch (S->getStmtClass()) {
   default:

clang/lib/CodeGen/CGStmtOpenMP.cpp

if (CGM.getLangOpts().OpenMPIRBuilder) {
 
     return;
   }
   LexicalScope Scope(*this, S.getSourceRange());
   EmitStopPoint(&S);
   emitMaster(*this, S);
 }
 
+static void emitMasked(CodeGenFunction &CGF, const OMPExecutableDirective &S) {
+  auto &&CodeGen = [&S](CodeGenFunction &CGF, PrePostActionTy &Action) {
+    Action.Enter(CGF);
+    CGF.EmitStmt(S.getRawStmt());
+  };
+  Expr *Filter = nullptr;
+  if (const auto *FilterClause = S.getSingleClause<OMPFilterClause>())
+    Filter = FilterClause->getThreadID();
+  CGF.CGM.getOpenMPRuntime().emitMaskedRegion(CGF, CodeGen, S.getBeginLoc(),
+                                              Filter);
+}
+
+void CodeGenFunction::EmitOMPMaskedDirective(const OMPMaskedDirective &S) {
+  if (CGM.getLangOpts().OpenMPIRBuilder) {
+    llvm::OpenMPIRBuilder &OMPBuilder = CGM.getOpenMPRuntime().getOMPBuilder();
+    using InsertPointTy = llvm::OpenMPIRBuilder::InsertPointTy;
+
+    const Stmt *MaskedRegionBodyStmt = S.getAssociatedStmt();
+    const Expr *Filter = nullptr;
+    if (const auto *FilterClause = S.getSingleClause<OMPFilterClause>())
+      Filter = FilterClause->getThreadID();
+    llvm::Value *FilterVal = Filter
+                                 ? EmitScalarExpr(Filter, CGM.Int32Ty)
+                                 : llvm::ConstantInt::get(CGM.Int32Ty, /*V=*/0);
+
+    auto FiniCB = [this](InsertPointTy IP) {
+      OMPBuilderCBHelpers::FinalizeOMPRegion(*this, IP);
+    };
+
+    auto BodyGenCB = [MaskedRegionBodyStmt, this](InsertPointTy AllocaIP,
+                                                  InsertPointTy CodeGenIP,
+                                                  llvm::BasicBlock &FiniBB) {
+      OMPBuilderCBHelpers::InlinedRegionBodyRAII IRB(*this, AllocaIP, FiniBB);
+      OMPBuilderCBHelpers::EmitOMPRegionBody(*this, MaskedRegionBodyStmt,
+                                             CodeGenIP, FiniBB);
+    };
+
+    LexicalScope Scope(*this, S.getSourceRange());
+    EmitStopPoint(&S);
+    Builder.restoreIP(
+        OMPBuilder.createMasked(Builder, BodyGenCB, FiniCB, FilterVal));
+
+    return;
+  }
+  LexicalScope Scope(*this, S.getSourceRange());
+  EmitStopPoint(&S);
+  emitMasked(*this, S);
+}
+
 void CodeGenFunction::EmitOMPCriticalDirective(const OMPCriticalDirective &S) {
   if (CGM.getLangOpts().OpenMPIRBuilder) {
     llvm::OpenMPIRBuilder &OMPBuilder = CGM.getOpenMPRuntime().getOMPBuilder();
     using InsertPointTy = llvm::OpenMPIRBuilder::InsertPointTy;
 
     const Stmt *CriticalRegionBodyStmt = S.getAssociatedStmt();
     const Expr *Hint = nullptr;
     if (const auto *HintClause = S.getSingleClause<OMPHintClause>())
if (isOpenMPSimdDirective(D.getDirectiveKind())) {
       }
       (void)GlobalsScope.Privatize();
       CGF.EmitStmt(D.getInnermostCapturedStmt()->getCapturedStmt());
     }
   };
   if (D.getDirectiveKind() == OMPD_atomic ||
       D.getDirectiveKind() == OMPD_critical ||
       D.getDirectiveKind() == OMPD_section ||
-      D.getDirectiveKind() == OMPD_master) {
+      D.getDirectiveKind() == OMPD_master ||
+      D.getDirectiveKind() == OMPD_masked) {
     EmitStmt(D.getAssociatedStmt());
   } else {
     auto LPCRegion =
         CGOpenMPRuntime::LastprivateConditionalRAII::disable(*this, D);
     OMPSimdLexicalScope Scope(*this, D);
     CGM.getOpenMPRuntime().emitInlinedDirective(
         *this,
         isOpenMPSimdDirective(D.getDirectiveKind()) ? OMPD_simd
                                                     : D.getDirectiveKind(),
         CodeGen);
   }
   // Check for outer lastprivate conditional update.
   checkForLastprivateConditionalUpdate(*this, D);
 }

clang/lib/CodeGen/CodeGenFunction.h

   void EmitOMPSimdDirective(const OMPSimdDirective &S);
   void EmitOMPTileDirective(const OMPTileDirective &S);
   void EmitOMPForDirective(const OMPForDirective &S);
   void EmitOMPForSimdDirective(const OMPForSimdDirective &S);
   void EmitOMPSectionsDirective(const OMPSectionsDirective &S);
   void EmitOMPSectionDirective(const OMPSectionDirective &S);
   void EmitOMPSingleDirective(const OMPSingleDirective &S);
   void EmitOMPMasterDirective(const OMPMasterDirective &S);
+  void EmitOMPMaskedDirective(const OMPMaskedDirective &S);
   void EmitOMPCriticalDirective(const OMPCriticalDirective &S);
   void EmitOMPParallelForDirective(const OMPParallelForDirective &S);
   void EmitOMPParallelForSimdDirective(const OMPParallelForSimdDirective &S);
   void EmitOMPParallelSectionsDirective(const OMPParallelSectionsDirective &S);
   void EmitOMPParallelMasterDirective(const OMPParallelMasterDirective &S);
   void EmitOMPTaskDirective(const OMPTaskDirective &S);
   void EmitOMPTaskyieldDirective(const OMPTaskyieldDirective &S);
   void EmitOMPBarrierDirective(const OMPBarrierDirective &S);

clang/test/OpenMP/masked_codegen.cpp

+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -x c++ -emit-llvm %s -fexceptions -fcxx-exceptions -o - | FileCheck %s --check-prefixes=ALL,NORMAL
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -std=c++11 -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -x c++ -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s --check-prefixes=ALL,NORMAL
+// RUN: %clang_cc1 -verify -triple x86_64-apple-darwin10 -fopenmp -fopenmp-version=51 -fexceptions -fcxx-exceptions -debug-info-kind=line-tables-only -x c++ -emit-llvm %s -o - | FileCheck %s --check-prefix=TERM_DEBUG
+// RUN: %clang_cc1 -verify -fopenmp -fopenmp-version=51 -fopenmp-enable-irbuilder -x c++ -emit-llvm %s -fexceptions -fcxx-exceptions -o - | FileCheck %s --check-prefixes=ALL,IRBUILDER
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -fopenmp-enable-irbuilder -x c++ -std=c++11 -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=51 -fopenmp-enable-irbuilder -x c++ -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s --check-prefixes=ALL,IRBUILDER
+
+// RUN: %clang_cc1 -verify -fopenmp-simd -fopenmp-version=51 -x c++ -emit-llvm %s -fexceptions -fcxx-exceptions -o - | FileCheck --check-prefix SIMD-ONLY0 %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -std=c++11 -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=51 -x c++ -triple x86_64-unknown-unknown -fexceptions -fcxx-exceptions -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck --check-prefix SIMD-ONLY0 %s
+// RUN: %clang_cc1 -verify -triple x86_64-apple-darwin10 -fopenmp-simd -fopenmp-version=51 -fexceptions -fcxx-exceptions -debug-info-kind=line-tables-only -x c++ -emit-llvm %s -o - | FileCheck --check-prefix SIMD-ONLY0 %s
+// SIMD-ONLY0-NOT: {{__kmpc|__tgt}}
+// expected-no-diagnostics
+#ifndef HEADER
+#define HEADER
+
+// ALL:       [[IDENT_T_TY:%.+]] = type { i32, i32, i32, i32, i8* }
+
+// ALL:       define {{.*}}void [[FOO:@.+]]()
+
+void foo() { extern void mayThrow(); mayThrow(); }
+
+// ALL-LABEL: @main
+// TERM_DEBUG-LABEL: @main
+int main() {
+  // ALL:           [[A_ADDR:%.+]] = alloca i8
+  char a;
+
+// ALL:             [[GTID:%.+]] = call {{.*}}i32 @__kmpc_global_thread_num([[IDENT_T_TY]]* [[DEFAULT_LOC:@.+]])
+// ALL:             [[RES:%.+]] = call {{.*}}i32 @__kmpc_masked([[IDENT_T_TY]]* [[DEFAULT_LOC]], i32 [[GTID]], i32 0)
+// ALL-NEXT:        [[IS_MASKED:%.+]] = icmp ne i32 [[RES]], 0
+// ALL-NEXT:        br i1 [[IS_MASKED]], label {{%?}}[[THEN:.+]], label {{%?}}[[EXIT:.+]]
+// ALL:             [[THEN]]
+// ALL-NEXT:        store i8 2, i8* [[A_ADDR]]
+// ALL-NEXT:        call {{.*}}void @__kmpc_end_masked([[IDENT_T_TY]]* [[DEFAULT_LOC]], i32 [[GTID]])
+// ALL-NEXT:        br label {{%?}}[[EXIT]]
+// ALL:             [[EXIT]]
+#pragma omp masked
+  a = 2;
+// IRBUILDER:       [[GTID:%.+]] = call {{.*}}i32 @__kmpc_global_thread_num([[IDENT_T_TY]]* [[DEFAULT_LOC:@.+]])
+// ALL:             [[RES:%.+]] = call {{.*}}i32 @__kmpc_masked([[IDENT_T_TY]]* [[DEFAULT_LOC]], i32 [[GTID]], i32 2)
+// ALL-NEXT:        [[IS_MASKED:%.+]] = icmp ne i32 [[RES]], 0
+// ALL-NEXT:        br i1 [[IS_MASKED]], label {{%?}}[[THEN:.+]], label {{%?}}[[EXIT:.+]]
+// ALL:             [[THEN]]
+// IRBUILDER-NEXT:  call {{.*}}void [[FOO]]()
+// NORMAL-NEXT:     invoke {{.*}}void [[FOO]]()
+// ALL:             call {{.*}}void @__kmpc_end_masked([[IDENT_T_TY]]* [[DEFAULT_LOC]], i32 [[GTID]])
+// ALL-NEXT:        br label {{%?}}[[EXIT]]
+// ALL:             [[EXIT]]
+#pragma omp masked filter(2)
+  foo();
+// ALL:                         store i32 9, i32* [[X:.+]],
+// ALL:                         [[X_VAL:%.+]] = load i32, i32* [[X]]
+// IRBUILDER:       [[GTID:%.+]] = call {{.*}}i32 @__kmpc_global_thread_num([[IDENT_T_TY]]* [[DEFAULT_LOC:@.+]])
+// ALL:             [[RES:%.+]] = call {{.*}}i32 @__kmpc_masked([[IDENT_T_TY]]* [[DEFAULT_LOC]], i32 [[GTID]], i32 [[X_VAL]])
+// ALL-NEXT:        [[IS_MASKED:%.+]] = icmp ne i32 [[RES]], 0
+// ALL-NEXT:        br i1 [[IS_MASKED]], label {{%?}}[[THEN:.+]], label {{%?}}[[EXIT:.+]]
+// ALL:             [[THEN]]
+// IRBUILDER-NEXT:  call {{.*}}void [[FOO]]()
+// NORMAL-NEXT:     invoke {{.*}}void [[FOO]]()
+// ALL:             call {{.*}}void @__kmpc_end_masked([[IDENT_T_TY]]* [[DEFAULT_LOC]], i32 [[GTID]])
+// ALL-NEXT:        br label {{%?}}[[EXIT]]
+// ALL:             [[EXIT]]
+  int x = 9;
+#pragma omp masked filter(x)
+  foo();
+  // ALL-NOT:   call i32 @__kmpc_masked
+  // ALL-NOT:   call void @__kmpc_end_masked
+  return a;
+}
+
+// ALL-LABEL:        lambda_masked
+// TERM_DEBUG-LABEL: lambda_masked
+void lambda_masked(int a, int b) {
+  auto l = [=]() {
+#pragma omp masked
+    {
+      // ALL: call i32 @__kmpc_masked(
+      int c = a + b;
+    }
+  };
+
+  l();
+
+  auto l1 = [=]() {
+#pragma omp parallel
+#pragma omp masked filter(1)
+    {
+      // ALL: call i32 @__kmpc_masked(
+      int c = a + b;
+    }
+  };
+
+  l1();
+
+  int y = 1;
+  auto l2 = [=](int yy) {
+#pragma omp parallel
+#pragma omp masked filter(yy)
+    {
+      // ALL: call i32 @__kmpc_masked(
+      int c = a + b;
+    }
+  };
+
+  l2(y);
+}
+
+// ALL-LABEL:      parallel_masked
+// TERM_DEBUG-LABEL: parallel_masked
+void parallel_masked() {
+#pragma omp parallel
+#pragma omp masked filter(1)
+  // TERM_DEBUG-NOT: __kmpc_global_thread_num
+  // TERM_DEBUG:     call i32 @__kmpc_masked({{.+}}), !dbg [[DBG_LOC_START:![0-9]+]]
+  // TERM_DEBUG:     invoke void {{.*}}foo{{.*}}()
+  // TERM_DEBUG:     unwind label %[[TERM_LPAD:.+]],
+  // TERM_DEBUG-NOT: __kmpc_global_thread_num
+  // TERM_DEBUG:     call void @__kmpc_end_masked({{.+}}), !dbg [[DBG_LOC_END:![0-9]+]]
+  // TERM_DEBUG:     [[TERM_LPAD]]
+  // TERM_DEBUG:     call void @__clang_call_terminate
+  // TERM_DEBUG:     unreachable
+  foo();
+
+  int x;
+#pragma omp parallel
+#pragma omp masked filter(x)
+  // TERM_DEBUG-NOT: __kmpc_global_thread_num
+  // TERM_DEBUG:     call i32 @__kmpc_masked({{.+}}), !dbg [[DBG_LOC_START:![0-9]+]]
+  // TERM_DEBUG:     invoke void {{.*}}foo{{.*}}()
+  // TERM_DEBUG:     unwind label %[[TERM_LPAD:.+]],
+  // TERM_DEBUG-NOT: __kmpc_global_thread_num
+  // TERM_DEBUG:     call void @__kmpc_end_masked({{.+}}), !dbg [[DBG_LOC_END:![0-9]+]]
+  // TERM_DEBUG:     [[TERM_LPAD]]
+  // TERM_DEBUG:     call void @__clang_call_terminate
+  // TERM_DEBUG:     unreachable
+  foo();
+}
+// TERM_DEBUG-DAG: [[DBG_LOC_START]] = !DILocation(line: [[@LINE-12]],
+// TERM_DEBUG-DAG: [[DBG_LOC_END]] = !DILocation(line: [[@LINE-3]],
+
+#endif

llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h

public:
   /// \param BodyGenCB Callback that will generate the region code.
   /// \param FiniCB Callback to finalize variable copies.
   ///
   /// \returns The insertion position *after* the master.
   InsertPointTy createMaster(const LocationDescription &Loc,
                              BodyGenCallbackTy BodyGenCB,
                              FinalizeCallbackTy FiniCB);
 
+  /// Generator for '#omp masked'
+  ///
+  /// \param Loc The insert and source location description.
+  /// \param BodyGenCB Callback that will generate the region code.
+  /// \param FiniCB Callback to finialize variable copies.
+  ///
+  /// \returns The insertion position *after* the master.
+  InsertPointTy createMasked(const LocationDescription &Loc,
+                             BodyGenCallbackTy BodyGenCB,
+                             FinalizeCallbackTy FiniCB, Value *Filter);
+
   /// Generator for '#omp critical'
   ///
   /// \param Loc The insert and source location description.
   /// \param BodyGenCB Callback that will generate the region body code.
   /// \param FiniCB Callback to finalize variable copies.
   /// \param CriticalName name of the lock used by the critical directive
   /// \param HintInst Hint Instruction for hint clause associated with critical
   ///

llvm/include/llvm/Frontend/OpenMP/OMPKinds.def

 __OMP_RTL(omp_set_num_threads, false, Void, Int32)
 __OMP_RTL(omp_set_dynamic, false, Void, Int32)
 __OMP_RTL(omp_set_nested, false, Void, Int32)
 __OMP_RTL(omp_set_schedule, false, Void, Int32, Int32)
 __OMP_RTL(omp_set_max_active_levels, false, Void, Int32)
 
 __OMP_RTL(__kmpc_master, false, Int32, IdentPtr, Int32)
 __OMP_RTL(__kmpc_end_master, false, Void, IdentPtr, Int32)
+__OMP_RTL(__kmpc_masked, false, Int32, IdentPtr, Int32, Int32)
+__OMP_RTL(__kmpc_end_masked, false, Void, IdentPtr, Int32)
 __OMP_RTL(__kmpc_critical, false, Void, IdentPtr, Int32, KmpCriticalNamePtrTy)
 __OMP_RTL(__kmpc_critical_with_hint, false, Void, IdentPtr, Int32,
           KmpCriticalNamePtrTy, Int32)
 __OMP_RTL(__kmpc_end_critical, false, Void, IdentPtr, Int32,
           KmpCriticalNamePtrTy)
 
 __OMP_RTL(__kmpc_begin, false, Void, IdentPtr, Int32)
 __OMP_RTL(__kmpc_end, false, Void, IdentPtr)

 __OMP_RTL_ATTRS(omp_set_schedule, SetterAttrs, AttributeSet(), ParamAttrs())
 __OMP_RTL_ATTRS(omp_set_max_active_levels, SetterAttrs, AttributeSet(),
                 ParamAttrs())
 
 __OMP_RTL_ATTRS(__kmpc_master, InaccessibleArgOnlyAttrs, AttributeSet(),
                 ParamAttrs(ReadOnlyPtrAttrs))
 __OMP_RTL_ATTRS(__kmpc_end_master, InaccessibleArgOnlyAttrs, AttributeSet(),
                 ParamAttrs(ReadOnlyPtrAttrs))
+__OMP_RTL_ATTRS(__kmpc_masked, InaccessibleArgOnlyAttrs, AttributeSet(),
+                ParamAttrs(ReadOnlyPtrAttrs))
+__OMP_RTL_ATTRS(__kmpc_end_masked, InaccessibleArgOnlyAttrs, AttributeSet(),
+                ParamAttrs(ReadOnlyPtrAttrs))
 __OMP_RTL_ATTRS(__kmpc_critical, BarrierAttrs, AttributeSet(),
                 ParamAttrs(ReadOnlyPtrAttrs, AttributeSet(), AttributeSet()))
 __OMP_RTL_ATTRS(__kmpc_critical_with_hint, BarrierAttrs, AttributeSet(),
                 ParamAttrs(ReadOnlyPtrAttrs, AttributeSet(), AttributeSet(),
                            AttributeSet()))
 __OMP_RTL_ATTRS(__kmpc_end_critical, BarrierAttrs, AttributeSet(),
                 ParamAttrs(ReadOnlyPtrAttrs, AttributeSet(), AttributeSet()))
 

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

OpenMPIRBuilder::createMaster(const LocationDescription &Loc,
 
   Function *ExitRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_end_master);
   Instruction *ExitCall = Builder.CreateCall(ExitRTLFn, Args);
 
   return EmitOMPInlinedRegion(OMPD, EntryCall, ExitCall, BodyGenCB, FiniCB,
                               /*Conditional*/ true, /*hasFinalize*/ true);
 }
 
+OpenMPIRBuilder::InsertPointTy
+OpenMPIRBuilder::createMasked(const LocationDescription &Loc,
+                              BodyGenCallbackTy BodyGenCB,
+                              FinalizeCallbackTy FiniCB, Value *Filter) {
+  if (!updateToLocation(Loc))
+    return Loc.IP;
+
+  Directive OMPD = Directive::OMPD_masked;
+  Constant *SrcLocStr = getOrCreateSrcLocStr(Loc);
+  Value *Ident = getOrCreateIdent(SrcLocStr);
+  Value *ThreadId = getOrCreateThreadID(Ident);
+  Value *Args[] = {Ident, ThreadId, Filter};
+  Value *ArgsEnd[] = {Ident, ThreadId};
+
+  Function *EntryRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_masked);
+  Instruction *EntryCall = Builder.CreateCall(EntryRTLFn, Args);
+
+  Function *ExitRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_end_masked);
+  Instruction *ExitCall = Builder.CreateCall(ExitRTLFn, ArgsEnd);
+
+  return EmitOMPInlinedRegion(OMPD, EntryCall, ExitCall, BodyGenCB, FiniCB,
+                              /*Conditional*/ true, /*hasFinalize*/ true);
+}
+
 CanonicalLoopInfo *OpenMPIRBuilder::createLoopSkeleton(
     DebugLoc DL, Value *TripCount, Function *F, BasicBlock *PreInsertBefore,
     BasicBlock *PostInsertBefore, const Twine &Name) {
   Module *M = F->getParent();
   LLVMContext &Ctx = M->getContext();
   Type *IndVarTy = TripCount->getType();
 
   // Create the basic block structure.

llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp

for (auto &FI : *ThenBB) {
     }
   }
   EXPECT_NE(MasterEndCI, nullptr);
   EXPECT_EQ(MasterEndCI->getNumArgOperands(), 2U);
   EXPECT_TRUE(isa<GlobalVariable>(MasterEndCI->getArgOperand(0)));
   EXPECT_EQ(MasterEndCI->getArgOperand(1), MasterEntryCI->getArgOperand(1));
 }
 
+TEST_F(OpenMPIRBuilderTest, MaskedDirective) {
+  using InsertPointTy = OpenMPIRBuilder::InsertPointTy;
+  OpenMPIRBuilder OMPBuilder(*M);
+  OMPBuilder.initialize();
+  F->setName("func");
+  IRBuilder<> Builder(BB);
+
+  OpenMPIRBuilder::LocationDescription Loc({Builder.saveIP(), DL});
+
+  AllocaInst *PrivAI = nullptr;
+
+  BasicBlock *EntryBB = nullptr;
+  BasicBlock *ExitBB = nullptr;
+  BasicBlock *ThenBB = nullptr;
+
+  auto BodyGenCB = [&](InsertPointTy AllocaIP, InsertPointTy CodeGenIP,
+                       BasicBlock &FiniBB) {
+    if (AllocaIP.isSet())
+      Builder.restoreIP(AllocaIP);
+    else
+      Builder.SetInsertPoint(&*(F->getEntryBlock().getFirstInsertionPt()));
+    PrivAI = Builder.CreateAlloca(F->arg_begin()->getType());
+    Builder.CreateStore(F->arg_begin(), PrivAI);
+
+    llvm::BasicBlock *CodeGenIPBB = CodeGenIP.getBlock();
+    llvm::Instruction *CodeGenIPInst = &*CodeGenIP.getPoint();
+    EXPECT_EQ(CodeGenIPBB->getTerminator(), CodeGenIPInst);
+
+    Builder.restoreIP(CodeGenIP);
+
+    // collect some info for checks later
+    ExitBB = FiniBB.getUniqueSuccessor();
+    ThenBB = Builder.GetInsertBlock();
+    EntryBB = ThenBB->getUniquePredecessor();
+
+    // simple instructions for body
+    Value *PrivLoad =
+        Builder.CreateLoad(PrivAI->getAllocatedType(), PrivAI, "local.use");
+    Builder.CreateICmpNE(F->arg_begin(), PrivLoad);
+  };
+
+  auto FiniCB = [&](InsertPointTy IP) {
+    BasicBlock *IPBB = IP.getBlock();
+    EXPECT_NE(IPBB->end(), IP.getPoint());
+  };
+
+  Constant *Filter = ConstantInt::get(Type::getInt32Ty(M->getContext()), 0);
+  Builder.restoreIP(
+      OMPBuilder.createMasked(Builder, BodyGenCB, FiniCB, Filter));
+  Value *EntryBBTI = EntryBB->getTerminator();
+  EXPECT_NE(EntryBBTI, nullptr);
+  EXPECT_TRUE(isa<BranchInst>(EntryBBTI));
+  BranchInst *EntryBr = cast<BranchInst>(EntryBB->getTerminator());
+  EXPECT_TRUE(EntryBr->isConditional());
+  EXPECT_EQ(EntryBr->getSuccessor(0), ThenBB);
+  EXPECT_EQ(ThenBB->getUniqueSuccessor(), ExitBB);
+  EXPECT_EQ(EntryBr->getSuccessor(1), ExitBB);
+
+  CmpInst *CondInst = cast<CmpInst>(EntryBr->getCondition());
+  EXPECT_TRUE(isa<CallInst>(CondInst->getOperand(0)));
+
+  CallInst *MaskedEntryCI = cast<CallInst>(CondInst->getOperand(0));
+  EXPECT_EQ(MaskedEntryCI->getNumArgOperands(), 3U);
+  EXPECT_EQ(MaskedEntryCI->getCalledFunction()->getName(), "__kmpc_masked");
+  EXPECT_TRUE(isa<GlobalVariable>(MaskedEntryCI->getArgOperand(0)));
+
+  CallInst *MaskedEndCI = nullptr;
+  for (auto &FI : *ThenBB) {
+    Instruction *cur = &FI;
+    if (isa<CallInst>(cur)) {
+      MaskedEndCI = cast<CallInst>(cur);
+      if (MaskedEndCI->getCalledFunction()->getName() == "__kmpc_end_masked")
+        break;
+      MaskedEndCI = nullptr;
+    }
+  }
+  EXPECT_NE(MaskedEndCI, nullptr);
+  EXPECT_EQ(MaskedEndCI->getNumArgOperands(), 2U);
+  EXPECT_TRUE(isa<GlobalVariable>(MaskedEndCI->getArgOperand(0)));
+  EXPECT_EQ(MaskedEndCI->getArgOperand(1), MaskedEntryCI->getArgOperand(1));
+}
+
 TEST_F(OpenMPIRBuilderTest, CriticalDirective) {
   using InsertPointTy = OpenMPIRBuilder::InsertPointTy;
   OpenMPIRBuilder OMPBuilder(*M);
   OMPBuilder.initialize();
   F->setName("func");
   IRBuilder<> Builder(BB);
 
   OpenMPIRBuilder::LocationDescription Loc({Builder.saveIP(), DL});