Adding basic runtime support

Author: Ritanya-B-Bharadwaj

clang/lib/CodeGen/CGOpenMPRuntime.cpp

@@ -3691,7 +3691,7 @@ CGOpenMPRuntime::emitTaskInit(CodeGenFunction &CGF, SourceLocation Loc,
     DestructorsFlag = 0x8,
     PriorityFlag = 0x20,
     DetachableFlag = 0x40,
-    PoolFlag = 0x80,
+    FreeAgentFlag = 0x100,
   };
   unsigned Flags = Data.Tied ? TiedFlag : 0;
   bool NeedsCleanup = false;
@@ -3704,7 +3704,7 @@ CGOpenMPRuntime::emitTaskInit(CodeGenFunction &CGF, SourceLocation Loc,
   if (const auto *Clause = D.getSingleClause<OMPThreadsetClause>()) {
     OpenMPThreadsetKind Kind = Clause->getThreadsetKind();
     if (Kind == OMPC_THREADSET_omp_pool)
-      Flags = Flags | PoolFlag;
+      Flags = Flags | FreeAgentFlag;
   }
   if (Data.Priority.getInt())
     Flags = Flags | PriorityFlag;

clang/test/OpenMP/task_codegen.cpp

@@ -10271,7 +10271,7 @@ void test_threadset()
 // CHECK6-NEXT:       call i32 @__kmpc_global_thread_num(ptr @[[GLOB_PTR:[0-9]+]])
 // CHECK6-NEXT:       call i32 @__kmpc_omp_task(ptr @1, i32 %omp_global_thread_num1, ptr %0)
 // CHECK6-NEXT:       call i32 @__kmpc_global_thread_num(ptr @[[GLOB_PTR2:[0-9]+]])
-// CHECK6-NEXT:       [[TMP3:%.*]] = call ptr @__kmpc_omp_task_alloc(ptr @1, i32 %omp_global_thread_num3, i32 129, i64 40, i64 1, ptr @.omp_task_entry..[[ENTRY2:[0-9]+]])
+// CHECK6-NEXT:       [[TMP3:%.*]] = call ptr @__kmpc_omp_task_alloc(ptr @1, i32 %omp_global_thread_num3, i32 257, i64 40, i64 1, ptr @.omp_task_entry..[[ENTRY2:[0-9]+]])
 // CHECK6-NEXT:       getelementptr inbounds nuw %struct.kmp_task_t_with_privates{{.*}}, ptr %3, i32 0, i32 0
 // CHECK6-NEXT:       call i32 @__kmpc_global_thread_num(ptr @[[GLOB_PTR2:[0-9]+]])
 // CHECK6-NEXT:       call i32 @__kmpc_omp_task(ptr @1, i32 %omp_global_thread_num4, ptr %3)

clang/test/OpenMP/taskloop_codegen.cpp

@@ -279,7 +279,7 @@ void test_threadset()
 // CHECK6-NEXT:       call void @__kmpc_taskloop(ptr @1, i32 %[[TID0:.*]], ptr %[[TID1:.*]], i32 1, ptr %[[TID3:.*]], ptr %4, i64 %[[TID7:.*]], i32 1, i32 0, i64 0, ptr null)
 // CHECK6-NEXT:       call void @__kmpc_end_taskgroup(ptr @1, i32 %[[TID0:.*]])
 // CHECK6-NEXT:       call void @__kmpc_taskgroup(ptr @1, i32 %[[TID0:.*]])
-// CHECK6-NEXT:       %[[TID8:.*]] = call ptr @__kmpc_omp_task_alloc(ptr @1, i32 %[[TID0:.*]], i32 129, i64 80, i64 1, ptr @.omp_task_entry..[[ENTRY1:[0-9]+]])
+// CHECK6-NEXT:       %[[TID8:.*]] = call ptr @__kmpc_omp_task_alloc(ptr @1, i32 %[[TID0:.*]], i32 257, i64 80, i64 1, ptr @.omp_task_entry..[[ENTRY1:[0-9]+]])
 // CHECK6-NEXT:       %[[TID9:.*]] = getelementptr inbounds nuw %struct.kmp_task_t_with_privates{{.*}}, ptr %[[TID8:.*]], i32 0, i32 0
 // CHECK6-NEXT:       %[[TID10:.*]] = getelementptr inbounds nuw %struct.kmp_task_t{{.*}}, ptr %[[TID9:.*]], i32 0, i32 5
 // CHECK6-NEXT:       store i64 0, ptr %[[TID10:.*]], align 8

openmp/runtime/src/kmp.h

@@ -2740,7 +2740,8 @@ typedef struct kmp_tasking_flags { /* Total struct must be exactly 32 bits */
   unsigned tasking_ser : 1;
   unsigned task_serial : 1;
   unsigned tasktype : 1;
-  unsigned reserved : 8;
+  unsigned reserved : 7;
+  unsigned free_agent_eligible : 1;
   unsigned hidden_helper : 1;
   unsigned detachable : 1;
   unsigned priority_specified : 1;
@@ -2763,7 +2764,8 @@ typedef struct kmp_tasking_flags { /* Total struct must be exactly 32 bits */
                                       setting for the task */
   unsigned detachable : 1; /* 1 == can detach */
   unsigned hidden_helper : 1; /* 1 == hidden helper task */
-  unsigned reserved : 8; /* reserved for compiler use */
+  unsigned free_agent_eligible : 1; /* set if task can be executed by a free-agent thread */
+  unsigned reserved : 7; /* reserved for compiler use */
 
   /* Library flags */ /* Total library flags must be 16 bits */
   unsigned tasktype : 1; /* task is either explicit(1) or implicit (0) */