[OPENMP] Remove extra sync barriers for 'firstprivate' clause.

Sync barrier will be emitted after generation of firstprivate variables
only if one of the firstprivate vars is used in lastprivate clause.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@260877 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGStmtOpenMP.cpp b/lib/CodeGen/CGStmtOpenMP.cpp
index b378cc6dea5496b07464286df425b68076312473..1a9ff6eacd4ea6c31e4d617579dc1accb27eeb54 100644 (file)
--- a/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/lib/CodeGen/CGStmtOpenMP.cpp
@@ -376,14 +376,23 @@ bool CodeGenFunction::EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
                                                 OMPPrivateScope &PrivateScope) {
   if (!HaveInsertPoint())
     return false;
+  bool FirstprivateIsLastprivate = false;
+  llvm::DenseSet<const VarDecl *> Lastprivates;
+  for (const auto *C : D.getClausesOfKind<OMPLastprivateClause>()) {
+    for (const auto *D : C->varlists())
+      Lastprivates.insert(
+          cast<VarDecl>(cast<DeclRefExpr>(D)->getDecl())->getCanonicalDecl());
+  }
   llvm::DenseSet<const VarDecl *> EmittedAsFirstprivate;
   for (const auto *C : D.getClausesOfKind<OMPFirstprivateClause>()) {
     auto IRef = C->varlist_begin();
     auto InitsRef = C->inits().begin();
     for (auto IInit : C->private_copies()) {
       auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
-      if (EmittedAsFirstprivate.count(OrigVD) == 0) {
-        EmittedAsFirstprivate.insert(OrigVD);
+      FirstprivateIsLastprivate =
+          FirstprivateIsLastprivate ||
+          (Lastprivates.count(OrigVD->getCanonicalDecl()) > 0);
+      if (EmittedAsFirstprivate.insert(OrigVD->getCanonicalDecl()).second) {
         auto *VD = cast<VarDecl>(cast<DeclRefExpr>(IInit)->getDecl());
         auto *VDInit = cast<VarDecl>(cast<DeclRefExpr>(*InitsRef)->getDecl());
         bool IsRegistered;
@@ -443,7 +452,7 @@ bool CodeGenFunction::EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
       ++IRef, ++InitsRef;
     }
   }
-  return !EmittedAsFirstprivate.empty();
+  return FirstprivateIsLastprivate && !EmittedAsFirstprivate.empty();
 }
 
 void CodeGenFunction::EmitOMPPrivateClause(
@@ -490,7 +499,6 @@ bool CodeGenFunction::EmitOMPCopyinClause(const OMPExecutableDirective &D) {
       auto *VD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
       QualType Type = VD->getType();
       if (CopiedVars.insert(VD->getCanonicalDecl()).second) {
-
         // Get the address of the master variable. If we are emitting code with
         // TLS support, the address is passed from the master as field in the
         // captured declaration.
@@ -964,12 +972,11 @@ void CodeGenFunction::EmitOMPParallelDirective(const OMPParallelDirective &S) {
   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
     OMPPrivateScope PrivateScope(CGF);
     bool Copyins = CGF.EmitOMPCopyinClause(S);
-    bool Firstprivates = CGF.EmitOMPFirstprivateClause(S, PrivateScope);
-    if (Copyins || Firstprivates) {
+    (void)CGF.EmitOMPFirstprivateClause(S, PrivateScope);
+    if (Copyins) {
       // Emit implicit barrier to synchronize threads and avoid data races on
-      // initialization of firstprivate variables or propagation master's thread
-      // values of threadprivate variables to local instances of that variables
-      // of all other implicit threads.
+      // 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.getLocStart(), OMPD_unknown, /*EmitChecks=*/false,
           /*ForceSimpleCall=*/true);
@@ -1605,7 +1612,8 @@ bool CodeGenFunction::EmitOMPWorksharingLoop(const OMPLoopDirective &S) {
       OMPPrivateScope LoopScope(*this);
       if (EmitOMPFirstprivateClause(S, LoopScope)) {
         // Emit implicit barrier to synchronize threads and avoid data races on
-        // initialization of firstprivate variables.
+        // initialization of firstprivate variables and post-update of
+        // lastprivate variables.
         CGM.getOpenMPRuntime().emitBarrierCall(
             *this, S.getLocStart(), OMPD_unknown, /*EmitChecks=*/false,
             /*ForceSimpleCall=*/true);
@@ -1804,7 +1812,8 @@ CodeGenFunction::EmitSections(const OMPExecutableDirective &S) {
     CodeGenFunction::OMPPrivateScope LoopScope(CGF);
     if (CGF.EmitOMPFirstprivateClause(S, LoopScope)) {
       // Emit implicit barrier to synchronize threads and avoid data races on
-      // initialization of firstprivate variables.
+      // initialization of firstprivate variables and post-update of lastprivate
+      // variables.
       CGF.CGM.getOpenMPRuntime().emitBarrierCall(
           CGF, S.getLocStart(), OMPD_unknown, /*EmitChecks=*/false,
           /*ForceSimpleCall=*/true);
@@ -1883,8 +1892,7 @@ void CodeGenFunction::EmitOMPSingleDirective(const OMPSingleDirective &S) {
   llvm::SmallVector<const Expr *, 8> SrcExprs;
   llvm::SmallVector<const Expr *, 8> AssignmentOps;
   // Check if there are any 'copyprivate' clauses associated with this
-  // 'single'
-  // construct.
+  // 'single' construct.
   // Build a list of copyprivate variables along with helper expressions
   // (<source>, <destination>, <destination>=<source> expressions)
   for (const auto *C : S.getClausesOfKind<OMPCopyprivateClause>()) {
@@ -1897,10 +1905,9 @@ void CodeGenFunction::EmitOMPSingleDirective(const OMPSingleDirective &S) {
   }
   LexicalScope Scope(*this, S.getSourceRange());
   // Emit code for 'single' region along with 'copyprivate' clauses
-  bool HasFirstprivates;
-  auto &&CodeGen = [&S, &HasFirstprivates](CodeGenFunction &CGF) {
+  auto &&CodeGen = [&S](CodeGenFunction &CGF) {
     CodeGenFunction::OMPPrivateScope SingleScope(CGF);
-    HasFirstprivates = CGF.EmitOMPFirstprivateClause(S, SingleScope);
+    (void)CGF.EmitOMPFirstprivateClause(S, SingleScope);
     CGF.EmitOMPPrivateClause(S, SingleScope);
     (void)SingleScope.Privatize();
 
@@ -1909,10 +1916,9 @@ void CodeGenFunction::EmitOMPSingleDirective(const OMPSingleDirective &S) {
   CGM.getOpenMPRuntime().emitSingleRegion(*this, CodeGen, S.getLocStart(),
                                           CopyprivateVars, DestExprs, SrcExprs,
                                           AssignmentOps);
-  // Emit an implicit barrier at the end (to avoid data race on firstprivate
-  // init or if no 'nowait' clause was specified and no 'copyprivate' clause).
-  if ((!S.getSingleClause<OMPNowaitClause>() || HasFirstprivates) &&
-      CopyprivateVars.empty()) {
+  // Emit an implicit barrier at the end (to avoid data race if no 'nowait'
+  // clause was specified and no 'copyprivate' clause).
+  if (!S.getSingleClause<OMPNowaitClause>() && CopyprivateVars.empty()) {
     CGM.getOpenMPRuntime().emitBarrierCall(
         *this, S.getLocStart(),
         S.getSingleClause<OMPNowaitClause>() ? OMPD_unknown : OMPD_single);

diff --git a/test/OpenMP/for_firstprivate_codegen.cpp b/test/OpenMP/for_firstprivate_codegen.cpp
index 01a93559451a05d82dcfdfa0ed143393659e55f0..5b1a4069410ac5c969e51e0110f1a4b2a9579779 100644 (file)
--- a/test/OpenMP/for_firstprivate_codegen.cpp
+++ b/test/OpenMP/for_firstprivate_codegen.cpp
@@ -95,7 +95,7 @@ int main() {
     // LAMBDA: [[SIVAR2_VAL:%.+]] = load i{{[0-9]+}}, i{{[0-9]+}}* [[SIVAR2_PRIVATE_ADDR_REF]]
     // LAMBDA: store i{{[0-9]+}} [[SIVAR2_VAL]], i{{[0-9]+}}* [[SIVAR2_PRIVATE_ADDR]]
 
-    // LAMBDA: call void @__kmpc_barrier(
+    // LAMBDA-NOT: call void @__kmpc_barrier(
     g = 1;
     g1 = 1;
     sivar = 2;
@@ -158,7 +158,7 @@ int main() {
     // BLOCKS: [[SIVAR2_VAL:%.+]] = load i{{[0-9]+}}, i{{[0-9]+}}* [[SIVAR_REF_ADDRR]]
     // BLOCKS: store i{{[0-9]+}} {{.+}}, i{{[0-9]+}}* [[SIVAR2_PRIVATE_ADDR]]
 
-    // BLOCKS: call void @__kmpc_barrier(
+    // BLOCKS-NOT: call void @__kmpc_barrier(
     g = 1;
     g1 =1;
     sivar = 2;
@@ -246,7 +246,7 @@ int main() {
 // CHECK: store i{{[0-9]+}} [[SIVAR_VAL]], i{{[0-9]+}}* [[SIVAR_PRIV]]
 
 // Synchronization for initialization.
-// CHECK: call void @__kmpc_barrier(%{{.+}}* [[IMPLICIT_BARRIER_LOC]], i{{[0-9]+}} [[GTID]])
+// CHECK-NOT: call void @__kmpc_barrier(
 
 // CHECK: call void @__kmpc_for_static_init_4(
 // CHECK: call void @__kmpc_for_static_fini(
@@ -310,10 +310,8 @@ int main() {
 // CHECK: call {{.*}} [[S_INT_TY_COPY_CONSTR]]([[S_INT_TY]]* [[VAR_PRIV]], [[S_INT_TY]]* {{.*}} [[VAR_REF]], [[ST_TY]]* [[ST_TY_TEMP]])
 // CHECK: call {{.*}} [[ST_TY_DESTR]]([[ST_TY]]* [[ST_TY_TEMP]])
 
-// Synchronization for initialization.
-// CHECK: [[GTID_REF:%.+]] = load i{{[0-9]+}}*, i{{[0-9]+}}** [[GTID_ADDR_ADDR]]
-// CHECK: [[GTID:%.+]] = load i{{[0-9]+}}, i{{[0-9]+}}* [[GTID_REF]]
-// CHECK: call void @__kmpc_barrier(%{{.+}}* [[IMPLICIT_BARRIER_LOC]], i{{[0-9]+}} [[GTID]])
+// No synchronization for initialization.
+// CHECK-NOT: call void @__kmpc_barrier(
 
 // CHECK: call void @__kmpc_for_static_init_4(
 // CHECK: call void @__kmpc_for_static_fini(

diff --git a/test/OpenMP/parallel_firstprivate_codegen.cpp b/test/OpenMP/parallel_firstprivate_codegen.cpp
index d0da8cea87ac0ce34c55649fcb542cf20ae8c4f4..cd50a0cb0e8bf10aba95d5b7c99d7a7e4754cce2 100644 (file)
--- a/test/OpenMP/parallel_firstprivate_codegen.cpp
+++ b/test/OpenMP/parallel_firstprivate_codegen.cpp
@@ -31,7 +31,6 @@ struct S {
 // CHECK-DAG: [[S_FLOAT_TY:%.+]] = type { float }
 // CHECK-DAG: [[S_INT_TY:%.+]] = type { i{{[0-9]+}} }
 // CHECK-DAG: [[ST_TY:%.+]] = type { i{{[0-9]+}}, i{{[0-9]+}} }
-// CHECK-DAG: [[IMPLICIT_BARRIER_LOC:@.+]] = private unnamed_addr constant %{{.+}} { i32 0, i32 66, i32 0, i32 0, i8*
 
 template <typename T>
 T tmain() {
@@ -70,7 +69,7 @@ int main() {
     // LAMBDA: store i{{[0-9]+}} [[G_VAL]], i{{[0-9]+}}* [[G_PRIVATE_ADDR]], align 128
     // LAMBDA: [[SIVAR_VAL:%.+]] = load i{{[0-9]+}}, i{{[0-9]+}}* [[SIVAR_REF]]
     // LAMBDA: store i{{[0-9]+}} [[SIVAR_VAL]], i{{[0-9]+}}* [[SIVAR_PRIVATE_ADDR]]
-    // LAMBDA: call {{.*}}void @__kmpc_barrier(
+    // LAMBDA-NOT: call {{.*}}void @__kmpc_barrier(
     g = 1;
     sivar = 2;
     // LAMBDA: store i{{[0-9]+}} 1, i{{[0-9]+}}* [[G_PRIVATE_ADDR]],
@@ -115,7 +114,7 @@ int main() {
     // BLOCK: [[SIVAR_REF:%.+]] = load i{{[0-9]+}}*, i{{[0-9]+}}** [[SIVAR_REF_ADDR]]
     // BLOCKS: [[SIVAR_VAL:%.+]] = load i{{[0-9]+}}, i{{[0-9]+}}* [[SIVAR_REF]],
     // BLOCKS: store i{{[0-9]+}} [[SIVAR_VAL]], i{{[0-9]+}}* [[SIVAR_PRIVATE_ADDR]],
-    // BLOCKS: call {{.*}}void @__kmpc_barrier(
+    // BLOCKS-NOT: call {{.*}}void @__kmpc_barrier(
     g = 1;
     sivar = 2;
     // BLOCKS: store i{{[0-9]+}} 1, i{{[0-9]+}}* [[G_PRIVATE_ADDR]],
@@ -244,9 +243,7 @@ int main() {
 // CHECK: call {{.*}} [[ST_TY_DEFAULT_CONSTR]]([[ST_TY]]* [[ST_TY_TEMP:%.+]])
 // CHECK: call {{.*}} [[S_INT_TY_COPY_CONSTR]]([[S_INT_TY]]* [[VAR_PRIV]], [[S_INT_TY]]* {{.*}} [[VAR_REF]], [[ST_TY]]* [[ST_TY_TEMP]])
 // CHECK: call {{.*}} [[ST_TY_DESTR]]([[ST_TY]]* [[ST_TY_TEMP]])
-// CHECK: [[GTID_REF:%.+]] = load i{{[0-9]+}}*, i{{[0-9]+}}** [[GTID_ADDR_ADDR]]
-// CHECK: [[GTID:%.+]] = load i{{[0-9]+}}, i{{[0-9]+}}* [[GTID_REF]]
-// CHECK: call {{.*}}void @__kmpc_barrier(%{{.+}}* [[IMPLICIT_BARRIER_LOC]], i{{[0-9]+}} [[GTID]])
+// CHECK-NOT: call {{.*}}void @__kmpc_barrier(
 // CHECK-DAG: call {{.*}} [[S_INT_TY_DESTR]]([[S_INT_TY]]* [[VAR_PRIV]])
 // CHECK-DAG: call {{.*}} [[S_INT_TY_DESTR]]([[S_INT_TY]]*
 // CHECK: ret void

diff --git a/test/OpenMP/sections_firstprivate_codegen.cpp b/test/OpenMP/sections_firstprivate_codegen.cpp
index 0e9273f52ca7730b1e9617ab87630ef6dfdd2362..dd854b57b1205c0c6d6c9bb47d4a5f9097e594fe 100644 (file)
--- a/test/OpenMP/sections_firstprivate_codegen.cpp
+++ b/test/OpenMP/sections_firstprivate_codegen.cpp
@@ -59,7 +59,6 @@ S<float> s_arr[] = {1, 2};
 // CHECK-DAG: [[VAR:@.+]] = global [[S_FLOAT_TY]] zeroinitializer,
 S<float> var(3);
 // CHECK-DAG: [[SIVAR:@.+]] = internal global i{{[0-9]+}} 0,
-// CHECK-DAG: [[IMPLICIT_BARRIER_LOC:@.+]] = private unnamed_addr constant %{{.+}} { i32 0, i32 66, i32 0, i32 0, i8*
 // CHECK-DAG: [[SECTIONS_BARRIER_LOC:@.+]] = private unnamed_addr constant %{{.+}} { i32 0, i32 194, i32 0, i32 0, i8*
 
 // CHECK: call {{.*}} [[S_FLOAT_TY_DEF_CONSTR:@.+]]([[S_FLOAT_TY]]* [[TEST]])
@@ -94,7 +93,7 @@ int main() {
     // LAMBDA: [[SIVAR1_VAL:%.+]] = load i{{[0-9]+}}, i{{[0-9]+}}* [[SIVAR1_REF]]
     // LAMBDA: store i{{[0-9]+}} [[SIVAR1_VAL]], i{{[0-9]+}}* [[SIVAR1_PRIVATE_ADDR]]
 
-    // LAMBDA: call void @__kmpc_barrier(
+    // LAMBDA-NOT: call void @__kmpc_barrier(
     {
       g = 1;
       sivar = 10;
@@ -154,7 +153,7 @@ int main() {
 
     // BLOCKS: [[SIVAR1_VAL:%.+]] = load i{{[0-9]+}}, i{{[0-9]+}}* [[SIVAR1_REF]],
     // BLOCKS: store i{{[0-9]+}} [[SIVAR1_VAL]], i{{[0-9]+}}* [[SIVAR1_PRIVATE_ADDR]],
-    // BLOCKS: call void @__kmpc_barrier(
+    // BLOCKS-NOT: call void @__kmpc_barrier(
     {
       g = 1;
       sivar = 10;
@@ -242,7 +241,7 @@ int main() {
 // CHECK: [[SIVAR_VAL:%.+]] = load i{{[0-9]+}}, i{{[0-9]+}}* [[SIVAR]],
 // CHECK: store i{{[0-9]+}} [[SIVAR_VAL]], i{{[0-9]+}}* [[SIVAR_PRIV]],
 
-// CHECK: call void @__kmpc_barrier(%{{.+}}* [[IMPLICIT_BARRIER_LOC]], i{{[0-9]+}} [[GTID]])
+// CHECK-NOT: call void @__kmpc_barrier(
 // CHECK: call void @__kmpc_for_static_init_4(
 // CHECK: call void @__kmpc_for_static_fini(
 
@@ -304,10 +303,8 @@ int main() {
 // CHECK: call {{.*}} [[S_INT_TY_COPY_CONSTR]]([[S_INT_TY]]* [[VAR_PRIV]], [[S_INT_TY]]* {{.*}} [[VAR_REF]], [[ST_TY]]* [[ST_TY_TEMP]])
 // CHECK: call {{.*}} [[ST_TY_DESTR]]([[ST_TY]]* [[ST_TY_TEMP]])
 
-// Synchronization for initialization.
-// CHECK: [[GTID_REF:%.+]] = load i{{[0-9]+}}*, i{{[0-9]+}}** [[GTID_ADDR_ADDR]]
-// CHECK: [[GTID:%.+]] = load i{{[0-9]+}}, i{{[0-9]+}}* [[GTID_REF]]
-// CHECK: call void @__kmpc_barrier(%{{.+}}* [[IMPLICIT_BARRIER_LOC]], i{{[0-9]+}} [[GTID]])
+// No synchronization for initialization.
+// CHECK-NOT: call void @__kmpc_barrier(
 
 // CHECK: call void @__kmpc_for_static_init_4(
 // CHECK: call void @__kmpc_for_static_fini(

diff --git a/test/OpenMP/single_firstprivate_codegen.cpp b/test/OpenMP/single_firstprivate_codegen.cpp
index cc72addb5f453839c3cd475e32eb7ec5e9004fe9..8407f77243c507b68f72ee2327fd5fe28dea0010 100644 (file)
--- a/test/OpenMP/single_firstprivate_codegen.cpp
+++ b/test/OpenMP/single_firstprivate_codegen.cpp
@@ -57,7 +57,6 @@ int vec[] = {1, 2};
 S<float> s_arr[] = {1, 2};
 // CHECK-DAG: [[VAR:@.+]] = global [[S_FLOAT_TY]] zeroinitializer,
 S<float> var(3);
-// CHECK-DAG: [[IMPLICIT_BARRIER_LOC:@.+]] = private unnamed_addr constant %{{.+}} { i32 0, i32 66, i32 0, i32 0, i8*
 // CHECK-DAG: [[SINGLE_BARRIER_LOC:@.+]] = private unnamed_addr constant %{{.+}} { i32 0, i32 322, i32 0, i32 0, i8*
 
 // CHECK: call {{.*}} [[S_FLOAT_TY_DEF_CONSTR:@.+]]([[S_FLOAT_TY]]* [[TEST]])
@@ -215,7 +214,7 @@ int main() {
 // CHECK-DAG: call {{.*}} [[S_FLOAT_TY_DESTR]]([[S_FLOAT_TY]]*
 // CHECK: call void @__kmpc_end_single(
 
-// CHECK: call void @__kmpc_barrier(%{{.+}}* [[IMPLICIT_BARRIER_LOC]], i{{[0-9]+}} [[GTID]])
+// CHECK-NOT: call void @__kmpc_barrier(
 
 // CHECK: = call {{.*}}i{{.+}} [[TMAIN_INT:@.+]]()