[OPENMP50]Allow nonmonotonic modifier for all schedule kinds.

[ABataev]

Summary

According to OpenMP 5.0, nonmonotonic modifier can be used with all
schedule kinds, not only dynamic and guided as in OpenMP 4.5.

[jdoerfert]

LGTM

clang/lib/CodeGen/CGStmtOpenMP.cpp

// Emit 'then' code.
       const bool IVSigned = IVExpr->getType()->hasSignedIntegerRepresentation();
       // OpenMP 4.5, 2.7.1 Loop Construct, Description.
       // If the static schedule kind is specified or if the ordered clause is
       // specified, and if no monotonic modifier is specified, the effect will
       // be as if the monotonic modifier was specified.
       bool StaticChunkedOne = RT.isStaticChunked(ScheduleKind.Schedule,
           /* Chunked */ Chunk != nullptr) && HasChunkSizeOne &&
           isOpenMPLoopBoundSharingDirective(S.getDirectiveKind());
+      bool IsMonotonic =
+          Ordered ||
+          ((ScheduleKind.Schedule == OMPC_SCHEDULE_static ||
+            ScheduleKind.Schedule == OMPC_SCHEDULE_unknown) &&
+           !(ScheduleKind.M1 == OMPC_SCHEDULE_MODIFIER_nonmonotonic ||
+             ScheduleKind.M1 == OMPC_SCHEDULE_MODIFIER_nonmonotonic)) ||
+          ScheduleKind.M1 == OMPC_SCHEDULE_MODIFIER_monotonic ||
+          ScheduleKind.M2 == OMPC_SCHEDULE_MODIFIER_monotonic;
       if ((RT.isStaticNonchunked(ScheduleKind.Schedule,
                                  /* Chunked */ Chunk != nullptr) ||
            StaticChunkedOne) &&
           !Ordered) {
         JumpDest LoopExit =
             getJumpDestInCurrentScope(createBasicBlock("omp.loop.exit"));
         emitCommonSimdLoop(
             *this, S,
-            [&S](CodeGenFunction &CGF, PrePostActionTy &) {
+            [&S, IsMonotonic](CodeGenFunction &CGF, PrePostActionTy &) {
               if (isOpenMPSimdDirective(S.getDirectiveKind())) {
-                CGF.EmitOMPSimdInit(S, /*IsMonotonic=*/true);
+                CGF.EmitOMPSimdInit(S, IsMonotonic);
               } else if (const auto *C = S.getSingleClause<OMPOrderClause>()) {
                 if (C->getKind() == OMPC_ORDER_concurrent)
                   CGF.LoopStack.setParallel(/*Enable=*/true);
               }
             },
             [IVSize, IVSigned, Ordered, IL, LB, UB, ST, StaticChunkedOne, Chunk,
              &S, ScheduleKind, LoopExit,
              &LoopScope](CodeGenFunction &CGF, PrePostActionTy &) {
// Emit 'then' code.
         EmitBlock(LoopExit.getBlock());
         // Tell the runtime we are done.
         auto &&CodeGen = [&S](CodeGenFunction &CGF) {
           CGF.CGM.getOpenMPRuntime().emitForStaticFinish(CGF, S.getEndLoc(),
                                                          S.getDirectiveKind());
         };
         OMPCancelStack.emitExit(*this, S.getDirectiveKind(), CodeGen);
       } else {
-        const bool IsMonotonic =
-            Ordered || ScheduleKind.Schedule == OMPC_SCHEDULE_static ||
-            ScheduleKind.Schedule == OMPC_SCHEDULE_unknown ||
-            ScheduleKind.M1 == OMPC_SCHEDULE_MODIFIER_monotonic ||
-            ScheduleKind.M2 == OMPC_SCHEDULE_MODIFIER_monotonic;
         // Emit the outer loop, which requests its work chunk [LB..UB] from
         // runtime and runs the inner loop to process it.
         const OMPLoopArguments LoopArguments(
             LB.getAddress(*this), UB.getAddress(*this), ST.getAddress(*this),
             IL.getAddress(*this), Chunk, EUB);
         EmitOMPForOuterLoop(ScheduleKind, IsMonotonic, S, LoopScope, Ordered,
                             LoopArguments, CGDispatchBounds);
       }

clang/lib/Sema/SemaOpenMP.cpp

if (Kind == OMPC_SCHEDULE_unknown) {
     }
     Diag(KindLoc, diag::err_omp_unexpected_clause_value)
         << Values << getOpenMPClauseName(OMPC_schedule);
     return nullptr;
   }
   // OpenMP, 2.7.1, Loop Construct, Restrictions
   // The nonmonotonic modifier can only be specified with schedule(dynamic) or
   // schedule(guided).
-  if ((M1 == OMPC_SCHEDULE_MODIFIER_nonmonotonic ||
+  // OpenMP 5.0 does not have this restriction.
+  if (LangOpts.OpenMP < 50 &&
+      (M1 == OMPC_SCHEDULE_MODIFIER_nonmonotonic ||
        M2 == OMPC_SCHEDULE_MODIFIER_nonmonotonic) &&
       Kind != OMPC_SCHEDULE_dynamic && Kind != OMPC_SCHEDULE_guided) {
     Diag(M1 == OMPC_SCHEDULE_MODIFIER_nonmonotonic ? M1Loc : M2Loc,
          diag::err_omp_schedule_nonmonotonic_static);
     return nullptr;
   }
   Expr *ValExpr = ChunkSize;
   Stmt *HelperValStmt = nullptr;

clang/test/OpenMP/for_ast_print.cpp

T tmain(T argc) {
   static T a;
 // CHECK: static T a;
 #pragma omp for schedule(dynamic) linear(a) allocate(a)
   // CHECK-NEXT: #pragma omp for schedule(dynamic) linear(a) allocate(a)
   for (int i = 0; i < 2; ++i)
     a = 2;
 // CHECK-NEXT: for (int i = 0; i < 2; ++i)
 // CHECK-NEXT: a = 2;
+#pragma omp for schedule(nonmonotonic: dynamic)
+  // CHECK-NEXT: #pragma omp for schedule(nonmonotonic: dynamic)
+  for (int i = 0; i < 2; ++i)
+    a = 2;
+// CHECK-NEXT: for (int i = 0; i < 2; ++i)
+// CHECK-NEXT: a = 2;
+#pragma omp for schedule(monotonic : dynamic)
+  // CHECK-NEXT: #pragma omp for schedule(monotonic: dynamic)
+  for (int i = 0; i < 2; ++i)
+    a = 2;
+// CHECK-NEXT: for (int i = 0; i < 2; ++i)
+// CHECK-NEXT: a = 2;
+#pragma omp for schedule(nonmonotonic : guided)
+  // CHECK-NEXT: #pragma omp for schedule(nonmonotonic: guided)
+  for (int i = 0; i < 2; ++i)
+    a = 2;
+// CHECK-NEXT: for (int i = 0; i < 2; ++i)
+// CHECK-NEXT: a = 2;
+#pragma omp for schedule(monotonic : guided)
+  // CHECK-NEXT: #pragma omp for schedule(monotonic: guided)
+  for (int i = 0; i < 2; ++i)
+    a = 2;
+// CHECK-NEXT: for (int i = 0; i < 2; ++i)
+// CHECK-NEXT: a = 2;
+#pragma omp for schedule(nonmonotonic : static)
+  // CHECK-NEXT: #pragma omp for schedule(nonmonotonic: static)
+  for (int i = 0; i < 2; ++i)
+    a = 2;
+// CHECK-NEXT: for (int i = 0; i < 2; ++i)
+// CHECK-NEXT: a = 2;
+#pragma omp for schedule(monotonic :static)
+  // CHECK-NEXT: #pragma omp for schedule(monotonic: static)
+  for (int i = 0; i < 2; ++i)
+    a = 2;
+// CHECK-NEXT: for (int i = 0; i < 2; ++i)
+// CHECK-NEXT: a = 2;
+#pragma omp for schedule(nonmonotonic : auto)
+  // CHECK-NEXT: #pragma omp for schedule(nonmonotonic: auto)
+  for (int i = 0; i < 2; ++i)
+    a = 2;
+// CHECK-NEXT: for (int i = 0; i < 2; ++i)
+// CHECK-NEXT: a = 2;
+#pragma omp for schedule(monotonic : auto)
+  // CHECK-NEXT: #pragma omp for schedule(monotonic: auto)
+  for (int i = 0; i < 2; ++i)
+    a = 2;
+// CHECK-NEXT: for (int i = 0; i < 2; ++i)
+// CHECK-NEXT: a = 2;
+#pragma omp for schedule(nonmonotonic : runtime)
+  // CHECK-NEXT: #pragma omp for schedule(nonmonotonic: runtime)
+  for (int i = 0; i < 2; ++i)
+    a = 2;
+// CHECK-NEXT: for (int i = 0; i < 2; ++i)
+// CHECK-NEXT: a = 2;
+#pragma omp for schedule(monotonic : runtime)
+  // CHECK-NEXT: #pragma omp for schedule(monotonic: runtime)
+  for (int i = 0; i < 2; ++i)
+    a = 2;
+// CHECK-NEXT: for (int i = 0; i < 2; ++i)
+// CHECK-NEXT: a = 2;
 #pragma omp parallel
 #pragma omp for allocate(argc) private(argc, b), firstprivate(c, d), lastprivate(d, f) collapse(N) schedule(static, N) ordered(N) nowait
   for (auto &x : arr) {
     int j, hhh = 0;
     for (int i = 0; i < 2; ++i) {
       int j, hhh = 0;
       for (int j = 0; j < 2; ++j)
         for (int j = 0; j < 2; ++j)

clang/test/OpenMP/for_schedule_messages.cpp

-// RUN: %clang_cc1 -verify -fopenmp %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp45 -fopenmp -fopenmp-version=45 %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp50 -fopenmp -fopenmp-version=50 %s -Wuninitialized
 
-// RUN: %clang_cc1 -verify -fopenmp-simd %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp45 -fopenmp-simd -fopenmp-version=45 %s -Wuninitialized
+// RUN: %clang_cc1 -verify=expected,omp50 -fopenmp-simd -fopenmp-version=50 %s -Wuninitialized
 
 void foo() {
 }
 
 bool foobool(int argc) {
   return argc;
 }
 
T tmain(T argc, S **argv) {
   #pragma omp for schedule (auto_dynamic // expected-error {{expected 'static', 'dynamic', 'guided', 'auto', 'runtime', 'monotonic', 'nonmonotonic' or 'simd' in OpenMP clause 'schedule'}} expected-error {{expected ')'}} expected-note {{to match this '('}}
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (nonmonotonic, // expected-error {{expected ')'}} expected-error {{expected 'simd' in OpenMP clause 'schedule'}} expected-warning {{missing ':' after schedule modifier - ignoring}} expected-note {{to match this '('}}
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (simd: // expected-error {{expected ')'}} expected-error {{expected 'static', 'dynamic', 'guided', 'auto' or 'runtime' in OpenMP clause 'schedule'}} expected-note {{to match this '('}}
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (monotonic, auto // expected-error {{expected ')'}} expected-warning {{missing ':' after schedule modifier - ignoring}} expected-error {{expected 'simd' in OpenMP clause 'schedule'}} expected-note {{to match this '('}}
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
-  #pragma omp for schedule (nonmonotonic: auto, // expected-error {{expected ')'}} expected-error {{'nonmonotonic' modifier can only be specified with 'dynamic' or 'guided' schedule kind}} expected-note {{to match this '('}}
+  #pragma omp for schedule (nonmonotonic: auto, // expected-error {{expected ')'}} omp45-error {{'nonmonotonic' modifier can only be specified with 'dynamic' or 'guided' schedule kind}} expected-note {{to match this '('}}
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (auto,  // expected-error {{expected ')'}} expected-note {{to match this '('}}
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (runtime, 3)  // expected-error {{expected ')'}} expected-note {{to match this '('}}
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   // expected-error@+1 {{expected ')'}} expected-note@+1 {{to match this '('}}
   #pragma omp for schedule (guided argc
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
T tmain(T argc, S **argv) {
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   // expected-error@+1 2 {{expression must have integral or unscoped enumeration type, not 'char *'}}
   #pragma omp for schedule (guided, argv[1]=2) // expected-error {{expected ')'}} expected-note {{to match this '('}}
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (dynamic, 1)
   for (int i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (static, N) // expected-error {{argument to 'schedule' clause must be a strictly positive integer value}}
   for (T i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
-  #pragma omp for schedule (nonmonotonic: static) // expected-error {{'nonmonotonic' modifier can only be specified with 'dynamic' or 'guided' schedule kind}}
+  #pragma omp for schedule (nonmonotonic: static) // omp45-error {{'nonmonotonic' modifier can only be specified with 'dynamic' or 'guided' schedule kind}}
   for (T i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
-  #pragma omp for schedule (nonmonotonic: auto) // expected-error {{'nonmonotonic' modifier can only be specified with 'dynamic' or 'guided' schedule kind}}
+  #pragma omp for schedule (nonmonotonic: auto) // omp45-error {{'nonmonotonic' modifier can only be specified with 'dynamic' or 'guided' schedule kind}}
   for (T i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
-  #pragma omp for schedule (nonmonotonic: runtime) // expected-error {{'nonmonotonic' modifier can only be specified with 'dynamic' or 'guided' schedule kind}}
+  #pragma omp for schedule (nonmonotonic: runtime) // omp45-error {{'nonmonotonic' modifier can only be specified with 'dynamic' or 'guided' schedule kind}}
   for (T i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (monotonic, nonmonotonic: auto) // expected-error {{modifier 'nonmonotonic' cannot be used along with modifier 'monotonic'}}
   for (T i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (nonmonotonic, monotonic: auto) // expected-error {{modifier 'monotonic' cannot be used along with modifier 'nonmonotonic'}}
   for (T i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (nonmonotonic, nonmonotonic: auto) // expected-error {{modifier 'nonmonotonic' cannot be used along with modifier 'nonmonotonic'}}
   for (T i = ST; i < N; i++) argv[0][i] = argv[0][i] - argv[0][i-ST];
   #pragma omp for schedule (monotonic, monotonic: auto) // expected-error {{modifier 'monotonic' cannot be used along with modifier 'monotonic'}}

clang/test/OpenMP/schedule_codegen.cpp

-// RUN: %clang_cc1 -fopenmp -x c++ -triple x86_64-unknown-unknown -emit-llvm -fexceptions -fcxx-exceptions -o - %s | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -fopenmp-version=50 -x c++ -triple x86_64-unknown-unknown -emit-llvm -fexceptions -fcxx-exceptions -o - %s | FileCheck %s
 
-// RUN: %clang_cc1 -fopenmp-simd -x c++ -triple x86_64-unknown-unknown -emit-llvm -fexceptions -fcxx-exceptions -o - %s | FileCheck --check-prefix SIMD-ONLY0 %s
+// RUN: %clang_cc1 -fopenmp-simd -fopenmp-version=50 -x c++ -triple x86_64-unknown-unknown -emit-llvm -fexceptions -fcxx-exceptions -o - %s | FileCheck --check-prefix SIMD-ONLY0 %s
 // SIMD-ONLY0-NOT: {{__kmpc|__tgt}}
 
 int main() {
 // CHECK: @__kmpc_for_static_init
 // CHECK-NOT: !llvm.access.group
 // CHECK: @__kmpc_for_static_fini
 #pragma omp for
   for(int i = 0; i < 10; ++i);

 // CHECK: @__kmpc_dispatch_init
 // CHECK: !llvm.access.group
 #pragma omp for schedule(nonmonotonic: dynamic)
   for(int i = 0; i < 10; ++i);
 // CHECK: @__kmpc_dispatch_init
 // CHECK: !llvm.access.group
 #pragma omp for simd schedule(nonmonotonic: dynamic)
   for(int i = 0; i < 10; ++i);
+// CHECK: call void @__kmpc_for_static_init_4(%struct.ident_t* {{.+}}, i32 %{{.+}}, i32 1073741858,
+// CHECK: !llvm.access.group
+#pragma omp for simd schedule(nonmonotonic: static)
+  for(int i = 0; i < 10; ++i);
+// CHECK: call void @__kmpc_dispatch_init_4(%struct.ident_t* {{.+}}, i32 %{{.+}}, i32 1073741862,
+// CHECK: !llvm.access.group
+#pragma omp for schedule(nonmonotonic: auto)
+  for(int i = 0; i < 10; ++i);
+// CHECK: call void @__kmpc_dispatch_init_4(%struct.ident_t* {{.+}}, i32 %{{.+}}, i32 1073741861,
+// CHECK: !llvm.access.group
+#pragma omp for simd schedule(nonmonotonic: runtime)
+  for(int i = 0; i < 10; ++i);
 // CHECK: @__kmpc_dispatch_init
 // CHECK-NOT: !llvm.access.group
 // CHECK: @__kmpc_dispatch_next
 #pragma omp for schedule(static) ordered
   for(int i = 0; i < 10; ++i);
 // CHECK: @__kmpc_dispatch_init
 // CHECK-NOT: !llvm.access.group
 // CHECK: @__kmpc_dispatch_next