[OpenMP] Code generation for target exit data directive

[sfantao]

Summary

This patch adds support for the target exit data directive code generation.

Given that, apart from the employed runtime call, target exit data requires the same code generation pattern as target enter data, the OpenMP codegen entry point was renamed and reused for both.

[sfantao]

Rebase.

[ABataev]

lib/CodeGen/CGStmtOpenMP.cpp

2801–2803

Remove extra braces, not required for one line statement

2807–2809

Extra braces

[sfantao]

Remove extra braces.

Waiting on dependency.

[sfantao]

• Rebase.

lib/CodeGen/CGOpenMPRuntime.h

public:
   /// \param Device Expression evaluated in device clause associated with the
   /// target directive, or null if no device clause is used.
   /// \param CodeGen, Function that emits the enclosed region.
   virtual void emitTargetDataCalls(CodeGenFunction &CGF,
                                    const OMPExecutableDirective &D,
                                    const Expr *IfCond, const Expr *Device,
                                    const RegionCodeGenTy &CodeGen);
 
-  /// \brief Emit the target data mapping code associated with \a D.
+  /// \brief Emit the target enter or exit data mapping code associated with
+  /// directive \a D.
   /// \param D Directive to emit.
   /// \param IfCond Expression evaluated in if clause associated with the target
   /// directive, or null if no if clause is used.
   /// \param Device Expression evaluated in device clause associated with the
   /// target directive, or null if no device clause is used.
-  virtual void emitTargetEnterDataCall(CodeGenFunction &CGF,
+  virtual void emitTargetEnterOrExitDataCall(CodeGenFunction &CGF,
                                              const OMPExecutableDirective &D,
-                                       const Expr *IfCond, const Expr *Device);
+                                             const Expr *IfCond,
+                                             const Expr *Device);
 };
 
 } // namespace CodeGen
 } // namespace clang
 
 #endif

lib/CodeGen/CGOpenMPRuntime.cpp

void CGOpenMPRuntime::emitTargetDataCalls(CodeGenFunction &CGF,
   if (IfCond) {
     emitOMPIfClause(CGF, IfCond, EndThenGen, ElseGen);
   } else {
     CodeGenFunction::RunCleanupsScope Scope(CGF);
     EndThenGen(CGF);
   }
 }
 
-void CGOpenMPRuntime::emitTargetEnterDataCall(CodeGenFunction &CGF,
-                                              const OMPExecutableDirective &D,
-                                              const Expr *IfCond,
-                                              const Expr *Device) {
+void CGOpenMPRuntime::emitTargetEnterOrExitDataCall(
+    CodeGenFunction &CGF, const OMPExecutableDirective &D, const Expr *IfCond,
   if (!CGF.HaveInsertPoint())
     return;
 
+  assert((isa<OMPTargetEnterDataDirective>(D) ||
+          isa<OMPTargetExitDataDirective>(D)) &&
+         "Expecting either target enter or exit data directives.");
+
   // Generate the code for the opening of the data environment.
   auto &&ThenGen = [this, &D, &CGF, Device](CodeGenFunction &CGF) {
     // Fill up the arrays with all the mapped variables.
     OpenMPMapClauseHandler::MapValuesArrayTy BasePointers;
     OpenMPMapClauseHandler::MapValuesArrayTy Pointers;
     OpenMPMapClauseHandler::MapValuesArrayTy Sizes;
     OpenMPMapClauseHandler::MapFlagsArrayTy MapTypes;
 
else
       DeviceID = CGF.Builder.getInt32(OMP_DEVICEID_UNDEF);
 
     // Emit the number of elements in the offloading arrays.
     auto *PointerNum = CGF.Builder.getInt32(BasePointers.size());
 
     llvm::Value *OffloadingArgs[] = {
         DeviceID,         PointerNum,    BasePointersArrayArg,
         PointersArrayArg, SizesArrayArg, MapTypesArrayArg};
-    CGF.EmitRuntimeCall(createRuntimeFunction(OMPRTL__tgt_target_data_begin),
-                        OffloadingArgs);
+    CGF.EmitRuntimeCall(
+        createRuntimeFunction(isa<OMPTargetEnterDataDirective>(D)
+                                  ? OMPRTL__tgt_target_data_begin
+                                  : OMPRTL__tgt_target_data_end),
   };
 
   // In the event we get an if clause, we don't have to take any action on the
   // else side.
   auto &&ElseGen = [](CodeGenFunction &CGF) {};
 
   if (IfCond) {
     emitOMPIfClause(CGF, IfCond, ThenGen, ElseGen);
   } else {
     CodeGenFunction::RunCleanupsScope Scope(CGF);
     ThenGen(CGF);
   }
 }

lib/CodeGen/CGStmtOpenMP.cpp

void CodeGenFunction::EmitOMPTargetEnterDataDirective(
   }
 
   // Check if we have any device clause associated with the directive.
   const Expr *Device = nullptr;
   if (auto *C = S.getSingleClause<OMPDeviceClause>()) {
     Device = C->getDevice();
   }
 
-  CGM.getOpenMPRuntime().emitTargetEnterDataCall(*this, S, IfCond, Device);
+  CGM.getOpenMPRuntime().emitTargetEnterOrExitDataCall(*this, S, IfCond,
+                                                       Device);
 }
 
 void CodeGenFunction::EmitOMPTargetExitDataDirective(
     const OMPTargetExitDataDirective &S) {
-  // TODO: codegen for target exit data.
+  // If we don't have target devices, don't bother emitting the data mapping
+  // code.
+  if (CGM.getLangOpts().OMPTargetTriples.empty())
+    return;
+
+  // Check if we have any if clause associated with the directive.
+  const Expr *IfCond = nullptr;
+  if (auto *C = S.getSingleClause<OMPIfClause>()) {
+    IfCond = C->getCondition();
+  }
+
+  // Check if we have any device clause associated with the directive.
+  const Expr *Device = nullptr;
+  if (auto *C = S.getSingleClause<OMPDeviceClause>()) {
+    Device = C->getDevice();
+  }
+
+  CGM.getOpenMPRuntime().emitTargetEnterOrExitDataCall(*this, S, IfCond,
+                                                       Device);
 }
 
 void CodeGenFunction::EmitOMPTargetParallelDirective(
     const OMPTargetParallelDirective &S) {
   // TODO: codegen for target parallel.
 }
 
 void CodeGenFunction::EmitOMPTargetParallelForDirective(

test/OpenMP/target_exit_data_codegen.cpp

+// expected-no-diagnostics
+#ifndef HEADER
+#define HEADER
+
+///==========================================================================///
+// RUN: %clang_cc1 -DCK1 -verify -fopenmp -omptargets=powerpc64le-ibm-linux-gnu -x c++ -triple powerpc64le-unknown-unknown -emit-llvm %s -o - | FileCheck %s --check-prefix CK1 --check-prefix CK1-64
+// RUN: %clang_cc1 -DCK1 -fopenmp -omptargets=powerpc64le-ibm-linux-gnu -x c++ -std=c++11 -triple powerpc64le-unknown-unknown -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -omptargets=powerpc64le-ibm-linux-gnu -x c++ -triple powerpc64le-unknown-unknown -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s  --check-prefix CK1 --check-prefix CK1-64
+// RUN: %clang_cc1 -DCK1 -verify -fopenmp -omptargets=i386-pc-linux-gnu -x c++ -triple i386-unknown-unknown -emit-llvm %s -o - | FileCheck %s  --check-prefix CK1 --check-prefix CK1-32
+// RUN: %clang_cc1 -DCK1 -fopenmp -omptargets=i386-pc-linux-gnu -x c++ -std=c++11 -triple i386-unknown-unknown -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -omptargets=i386-pc-linux-gnu -x c++ -triple i386-unknown-unknown -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s  --check-prefix CK1 --check-prefix CK1-32
+#ifdef CK1
+
+// CK1: [[ST:%.+]] = type { i32, double* }
+template <typename T>
+struct ST {
+  T a;
+  double *b;
+};
+
+ST<int> gb;
+double gc[100];
+
+// CK1: [[SIZE00:@.+]] = {{.+}}constant [1 x i[[sz:64|32]]] [i{{64|32}} 800]
+// CK1: [[MTYPE00:@.+]] = {{.+}}constant [1 x i32] [i32 2]
+
+// CK1: [[SIZE02:@.+]] = {{.+}}constant [1 x i[[sz]]] [i[[sz]] 4]
+// CK1: [[MTYPE02:@.+]] = {{.+}}constant [1 x i32] [i32 8]
+
+// CK1: [[MTYPE03:@.+]] = {{.+}}constant [1 x i32] [i32 6]
+
+// CK1: [[SIZE04:@.+]] = {{.+}}constant [2 x i[[sz]]] [i[[sz]] {{8|4}}, i[[sz]] 24]
+// CK1: [[MTYPE04:@.+]] = {{.+}}constant [2 x i32] [i32 8, i32 104]
+
+// CK1-LABEL: _Z3fooi
+void foo(int arg) {
+  int la;
+  float lb[arg];
+
+  // Region 00
+  // CK1-NOT: __tgt_target_data_begin
+  // CK1-DAG: call void @__tgt_target_data_end(i32 [[DEV:%[^,]+]], i32 1, i8** [[GEPBP:%.+]], i8** [[GEPP:%.+]], {{.+}}getelementptr {{.+}}[1 x i{{.+}}]* [[SIZE00]], {{.+}}getelementptr {{.+}}[1 x i{{.+}}]* [[MTYPE00]]{{.+}})
+  // CK1-DAG: [[DEV]] = load i32, i32* %{{[^,]+}},
+  // CK1-DAG: [[GEPBP]] = getelementptr inbounds {{.+}}[[BP:%[^,]+]]
+  // CK1-DAG: [[GEPP]] = getelementptr inbounds {{.+}}[[P:%[^,]+]]
+
+  // CK1-DAG: [[BP0:%.+]] = getelementptr inbounds {{.+}}[[BP]], i{{.+}} 0, i{{.+}} 0
+  // CK1-DAG: [[P0:%.+]] = getelementptr inbounds {{.+}}[[P]], i{{.+}} 0, i{{.+}} 0
+  // CK1-DAG: store i8* bitcast ([100 x double]* @gc to i8*), i8** [[BP0]]
+  // CK1-DAG: store i8* bitcast ([100 x double]* @gc to i8*), i8** [[P0]]
+
+  // CK1: %{{.+}} = add nsw i32 %{{[^,]+}}, 1
+  #pragma omp target exit data if(1+3-5) device(arg) map(from: gc)
+  {++arg;}
+
+  // Region 01
+  // CK1: %{{.+}} = add nsw i32 %{{[^,]+}}, 1
+  #pragma omp target exit data map(release: la) if(1+3-4)
+  {++arg;}
+
+  // Region 02
+  // CK1-NOT: __tgt_target_data_begin
+  // CK1: br i1 %{{[^,]+}}, label %[[IFTHEN:[^,]+]], label %[[IFELSE:[^,]+]]
+  // CK1: [[IFTHEN]]
+  // CK1-DAG: call void @__tgt_target_data_end(i32 4, i32 1, i8** [[GEPBP:%.+]], i8** [[GEPP:%.+]], {{.+}}getelementptr {{.+}}[1 x i{{.+}}]* [[SIZE02]], {{.+}}getelementptr {{.+}}[1 x i{{.+}}]* [[MTYPE02]]{{.+}})
+  // CK1-DAG: [[GEPBP]] = getelementptr inbounds {{.+}}[[BP:%[^,]+]]
+  // CK1-DAG: [[GEPP]] = getelementptr inbounds {{.+}}[[P:%[^,]+]]
+
+  // CK1-DAG: [[BP0:%.+]] = getelementptr inbounds {{.+}}[[BP]], i{{.+}} 0, i{{.+}} 0
+  // CK1-DAG: [[P0:%.+]] = getelementptr inbounds {{.+}}[[P]], i{{.+}} 0, i{{.+}} 0
+  // CK1-DAG: store i8* [[CBPVAL0:%[^,]+]], i8** [[BP0]]
+  // CK1-DAG: store i8* [[CPVAL0:%[^,]+]], i8** [[P0]]
+  // CK1-DAG: [[CBPVAL0]] = bitcast i32* [[VAR0:%.+]] to i8*
+  // CK1-DAG: [[CPVAL0]] = bitcast i32* [[VAR0]] to i8*
+  // CK1: br label %[[IFEND:[^,]+]]
+
+  // CK1: [[IFELSE]]
+  // CK1: br label %[[IFEND]]
+  // CK1: [[IFEND]]
+  // CK1: %{{.+}} = add nsw i32 %{{[^,]+}}, 1
+  #pragma omp target exit data map(release: arg) if(arg) device(4)
+  {++arg;}
+
+  // CK1: %{{.+}} = add nsw i32 %{{[^,]+}}, 1
+  {++arg;}
+
+  // Region 03
+  // CK1-NOT: __tgt_target_data_begin
+  // CK1-DAG: call void @__tgt_target_data_end(i32 -1, i32 1, i8** [[GEPBP:%.+]], i8** [[GEPP:%.+]], i[[sz]]* [[GEPS:%.+]], {{.+}}getelementptr {{.+}}[1 x i{{.+}}]* [[MTYPE03]]{{.+}})
+  // CK1-DAG: [[GEPBP]] = getelementptr inbounds {{.+}}[[BP:%[^,]+]]
+  // CK1-DAG: [[GEPP]] = getelementptr inbounds {{.+}}[[P:%[^,]+]]
+  // CK1-DAG: [[GEPS]] = getelementptr inbounds {{.+}}[[S:%[^,]+]]
+
+  // CK1-DAG: [[BP0:%.+]] = getelementptr inbounds {{.+}}[[BP]], i{{.+}} 0, i{{.+}} 0
+  // CK1-DAG: [[P0:%.+]] = getelementptr inbounds {{.+}}[[P]], i{{.+}} 0, i{{.+}} 0
+  // CK1-DAG: [[S0:%.+]] = getelementptr inbounds {{.+}}[[S]], i{{.+}} 0, i{{.+}} 0
+  // CK1-DAG: store i8* [[CBPVAL0:%[^,]+]], i8** [[BP0]]
+  // CK1-DAG: store i8* [[CPVAL0:%[^,]+]], i8** [[P0]]
+  // CK1-DAG: store i[[sz]] [[CSVAL0:%[^,]+]], i[[sz]]* [[S0]]
+  // CK1-DAG: [[CBPVAL0]] = bitcast float* [[VAR0:%.+]] to i8*
+  // CK1-DAG: [[CPVAL0]] = bitcast float* [[VAR0]] to i8*
+  // CK1-DAG: [[CSVAL0]] = mul nuw i[[sz]] %{{[^,]+}}, 4
+  // CK1: %{{.+}} = add nsw i32 %{{[^,]+}}, 1
+  #pragma omp target exit data map(always, from: lb)
+  {++arg;}
+
+  // CK1: %{{.+}} = add nsw i32 %{{[^,]+}}, 1
+  {++arg;}
+
+  // Region 04
+  // CK1-NOT: __tgt_target_data_begin
+  // CK1-DAG: call void @__tgt_target_data_end(i32 -1, i32 2, i8** [[GEPBP:%.+]], i8** [[GEPP:%.+]], {{.+}}getelementptr {{.+}}[2 x i{{.+}}]* [[SIZE04]], {{.+}}getelementptr {{.+}}[2 x i{{.+}}]* [[MTYPE04]]{{.+}})
+  // CK1-DAG: [[GEPBP]] = getelementptr inbounds {{.+}}[[BP:%[^,]+]]
+  // CK1-DAG: [[GEPP]] = getelementptr inbounds {{.+}}[[P:%[^,]+]]
+
+  // CK1-DAG: [[BP0:%.+]] = getelementptr inbounds {{.+}}[[BP]], i{{.+}} 0, i{{.+}} 0
+  // CK1-DAG: [[P0:%.+]] = getelementptr inbounds {{.+}}[[P]], i{{.+}} 0, i{{.+}} 0
+  // CK1-DAG: store i8* bitcast ([[ST]]* @gb to i8*), i8** [[BP0]]
+  // CK1-DAG: store i8* bitcast (double** getelementptr inbounds ([[ST]], [[ST]]* @gb, i32 0, i32 1) to i8*), i8** [[P0]]
+
+
+  // CK1-DAG: [[BP1:%.+]] = getelementptr inbounds {{.+}}[[BP]], i{{.+}} 0, i{{.+}} 1
+  // CK1-DAG: [[P1:%.+]] = getelementptr inbounds {{.+}}[[P]], i{{.+}} 0, i{{.+}} 1
+  // CK1-DAG: store i8* bitcast (double** getelementptr inbounds ([[ST]], [[ST]]* @gb, i32 0, i32 1) to i8*), i8** [[BP1]]
+  // CK1-DAG: store i8* [[CPVAL1:%[^,]+]], i8** [[P1]]
+  // CK1-DAG: [[CPVAL1]] = bitcast double* [[SEC1:%.+]] to i8*
+  // CK1-DAG: [[SEC1]] = getelementptr inbounds {{.+}}double* [[SEC11:%[^,]+]], i{{.+}} 0
+  // CK1-DAG: [[SEC11]] = load double*, double** getelementptr inbounds ([[ST]], [[ST]]* @gb, i32 0, i32 1),
+
+  // CK1: %{{.+}} = add nsw i32 %{{[^,]+}}, 1
+  #pragma omp target exit data map(release: gb.b[:3])
+  {++arg;}
+}
+#endif
+///==========================================================================///
+// RUN: %clang_cc1 -DCK2 -verify -fopenmp -omptargets=powerpc64le-ibm-linux-gnu -x c++ -triple powerpc64le-unknown-unknown -emit-llvm %s -o - | FileCheck %s --check-prefix CK2 --check-prefix CK2-64
+// RUN: %clang_cc1 -DCK2 -fopenmp -omptargets=powerpc64le-ibm-linux-gnu -x c++ -std=c++11 -triple powerpc64le-unknown-unknown -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -omptargets=powerpc64le-ibm-linux-gnu -x c++ -triple powerpc64le-unknown-unknown -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s  --check-prefix CK2 --check-prefix CK2-64
+// RUN: %clang_cc1 -DCK2 -verify -fopenmp -omptargets=i386-pc-linux-gnu -x c++ -triple i386-unknown-unknown -emit-llvm %s -o - | FileCheck %s  --check-prefix CK2 --check-prefix CK2-32
+// RUN: %clang_cc1 -DCK2 -fopenmp -omptargets=i386-pc-linux-gnu -x c++ -std=c++11 -triple i386-unknown-unknown -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -omptargets=i386-pc-linux-gnu -x c++ -triple i386-unknown-unknown -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s  --check-prefix CK2 --check-prefix CK2-32
+#ifdef CK2
+
+// CK2: [[ST:%.+]] = type { i32, double* }
+template <typename T>
+struct ST {
+  T a;
+  double *b;
+
+  T foo(T arg) {
+    // Region 00
+    #pragma omp target exit data map(always, release: b[1:3]) if(a>123) device(arg)
+    {arg++;}
+    return arg;
+  }
+};
+
+// CK2: [[SIZE00:@.+]] = {{.+}}constant [2 x i[[sz:64|32]]] [i{{64|32}} {{8|4}}, i{{64|32}} 24]
+// CK2: [[MTYPE00:@.+]] = {{.+}}constant [2 x i32] [i32 12, i32 108]
+
+// CK2-LABEL: _Z3bari
+int bar(int arg){
+  ST<int> A;
+  return A.foo(arg);
+}
+
+// Region 00
+// CK2-NOT: __tgt_target_data_begin
+// CK2: br i1 %{{[^,]+}}, label %[[IFTHEN:[^,]+]], label %[[IFELSE:[^,]+]]
+// CK2: [[IFTHEN]]
+// CK2-DAG: call void @__tgt_target_data_end(i32 [[DEV:%[^,]+]], i32 2, i8** [[GEPBP:%.+]], i8** [[GEPP:%.+]], {{.+}}getelementptr {{.+}}[2 x i{{.+}}]* [[SIZE00]], {{.+}}getelementptr {{.+}}[2 x i{{.+}}]* [[MTYPE00]]{{.+}})
+// CK2-DAG: [[DEV]] = load i32, i32* %{{[^,]+}},
+// CK2-DAG: [[GEPBP]] = getelementptr inbounds {{.+}}[[BP:%[^,]+]]
+// CK2-DAG: [[GEPP]] = getelementptr inbounds {{.+}}[[P:%[^,]+]]
+
+// CK2-DAG: [[BP0:%.+]] = getelementptr inbounds {{.+}}[[BP]], i{{.+}} 0, i{{.+}} 0
+// CK2-DAG: [[P0:%.+]] = getelementptr inbounds {{.+}}[[P]], i{{.+}} 0, i{{.+}} 0
+// CK2-DAG: store i8* [[CBPVAL0:%[^,]+]], i8** [[BP0]]
+// CK2-DAG: store i8* [[CPVAL0:%[^,]+]], i8** [[P0]]
+// CK2-DAG: [[CBPVAL0]] = bitcast [[ST]]* [[VAR0:%.+]] to i8*
+// CK2-DAG: [[CPVAL0]] = bitcast double** [[SEC0:%[^,]+]] to i8*
+// CK2-DAG: [[SEC0]] = getelementptr inbounds {{.*}}[[ST]]* [[VAR0]], i32 0, i32 1
+
+
+// CK2-DAG: [[BP1:%.+]] = getelementptr inbounds {{.+}}[[BP]], i{{.+}} 0, i{{.+}} 1
+// CK2-DAG: [[P1:%.+]] = getelementptr inbounds {{.+}}[[P]], i{{.+}} 0, i{{.+}} 1
+// CK2-DAG: store i8* [[CBPVAL1:%[^,]+]], i8** [[BP1]]
+// CK2-DAG: store i8* [[CPVAL1:%[^,]+]], i8** [[P1]]
+// CK2-DAG: [[CBPVAL1]] = bitcast double** [[SEC0]] to i8*
+// CK2-DAG: [[CPVAL1]] = bitcast double* [[SEC1:%[^,]+]] to i8*
+// CK2-DAG: [[SEC1]] = getelementptr inbounds {{.*}}double* [[SEC11:%[^,]+]], i{{.+}} 1
+// CK2-DAG: [[SEC11]] = load double*, double** [[SEC111:%[^,]+]],
+// CK2-DAG: [[SEC111]] = getelementptr inbounds {{.*}}[[ST]]* [[VAR0]], i32 0, i32 1
+
+// CK2: br label %[[IFEND:[^,]+]]
+
+// CK2: [[IFELSE]]
+// CK2: br label %[[IFEND]]
+// CK2: [[IFEND]]
+// CK2: %{{.+}} = add nsw i32 %{{[^,]+}}, 1
+#endif
+///==========================================================================///
+// RUN: %clang_cc1 -DCK3 -verify -fopenmp -x c++ -triple powerpc64le-unknown-unknown -emit-llvm %s -o - | FileCheck %s --check-prefix CK3 --check-prefix CK3-64
+// RUN: %clang_cc1 -DCK3 -fopenmp -x c++ -std=c++11 -triple powerpc64le-unknown-unknown -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -x c++ -triple powerpc64le-unknown-unknown -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s  --check-prefix CK3 --check-prefix CK3-64
+// RUN: %clang_cc1 -DCK3 -verify -x c++ -triple i386-unknown-unknown -emit-llvm %s -o - | FileCheck %s  --check-prefix CK3 --check-prefix CK3-32
+// RUN: %clang_cc1 -DCK3 -fopenmp -x c++ -std=c++11 -triple i386-unknown-unknown -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -x c++ -triple i386-unknown-unknown -std=c++11 -include-pch %t -verify %s -emit-llvm -o - | FileCheck %s  --check-prefix CK3 --check-prefix CK3-32
+#ifdef CK3
+
+// CK3-LABEL: no_target_devices
+void no_target_devices(int arg) {
+  // CK3-NOT: tgt_target_data_begin
+  // CK3: %{{.+}} = add nsw i32 %{{[^,]+}}, 1
+  // CK3-NOT: tgt_target_data_end
+  // CK3: ret
+  #pragma omp target exit data map(from: arg) if(arg) device(4)
+  {++arg;}
+}
+#endif
+#endif