[OPENMP5]Use nonmonotonic modifier by default for non-static and

non-ordered loops.

According to OpenMP 5.0, 2.9.2 Worksharing-Loop Construct, Desription, If the static schedule kind is specified or if the ordered clause is specified, and if the nonmonotonic modifier is not specified, the effect is as if the monotonic modifier is specified. Otherwise, unless the monotonic modifier is specified, the effect is as if the nonmonotonic modifier is specified.
The first part of this requirement is implemented in runtime. Patch adds
support for the second, nonmonotonic, part of this requirement.

llvm-svn: 369801

1 files changed, 21 insertions, 8 deletions

diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 84211e33b87..99fa0790e90 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -3509,7 +3509,7 @@ bool CGOpenMPRuntime::isDynamic(OpenMPScheduleClauseKind ScheduleKind) const {
   return Schedule != OMP_sch_static;
 }
 
-static int addMonoNonMonoModifier(OpenMPSchedType Schedule,
+static int addMonoNonMonoModifier(CodeGenModule &CGM, OpenMPSchedType Schedule,
                                   OpenMPScheduleClauseModifier M1,
                                   OpenMPScheduleClauseModifier M2) {
   int Modifier = 0;
@@ -3543,6 +3543,18 @@ static int addMonoNonMonoModifier(OpenMPSchedType Schedule,
   case OMPC_SCHEDULE_MODIFIER_unknown:
     break;
   }
+  // OpenMP 5.0, 2.9.2 Worksharing-Loop Construct, Desription.
+  // If the static schedule kind is specified or if the ordered clause is
+  // specified, and if the nonmonotonic modifier is not specified, the effect is
+  // as if the monotonic modifier is specified. Otherwise, unless the monotonic
+  // modifier is specified, the effect is as if the nonmonotonic modifier is
+  // specified.
+  if (CGM.getLangOpts().OpenMP >= 50 && Modifier == 0) {
+    if (!(Schedule == OMP_sch_static_chunked || Schedule == OMP_sch_static ||
+          Schedule == OMP_sch_static_balanced_chunked ||
+          Schedule == OMP_ord_static_chunked || Schedule == OMP_ord_static))
+      Modifier = OMP_sch_modifier_nonmonotonic;
+  }
   return Schedule | Modifier;
 }
 
@@ -3567,13 +3579,14 @@ void CGOpenMPRuntime::emitForDispatchInit(
   llvm::Value *Chunk = DispatchValues.Chunk ? DispatchValues.Chunk
                                             : CGF.Builder.getIntN(IVSize, 1);
   llvm::Value *Args[] = {
-      emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc),
+      emitUpdateLocation(CGF, Loc),
+      getThreadID(CGF, Loc),
       CGF.Builder.getInt32(addMonoNonMonoModifier(
-          Schedule, ScheduleKind.M1, ScheduleKind.M2)), // Schedule type
-      DispatchValues.LB,                                // Lower
-      DispatchValues.UB,                                // Upper
-      CGF.Builder.getIntN(IVSize, 1),                   // Stride
-      Chunk                                             // Chunk
+          CGM, Schedule, ScheduleKind.M1, ScheduleKind.M2)), // Schedule type
+      DispatchValues.LB,                                     // Lower
+      DispatchValues.UB,                                     // Upper
+      CGF.Builder.getIntN(IVSize, 1),                        // Stride
+      Chunk                                                  // Chunk
   };
   CGF.EmitRuntimeCall(createDispatchInitFunction(IVSize, IVSigned), Args);
 }
@@ -3615,7 +3628,7 @@ static void emitForStaticInitCall(
   llvm::Value *Args[] = {
       UpdateLocation,
       ThreadId,
-      CGF.Builder.getInt32(addMonoNonMonoModifier(Schedule, M1,
+      CGF.Builder.getInt32(addMonoNonMonoModifier(CGF.CGM, Schedule, M1,
                                                   M2)), // Schedule type
       Values.IL.getPointer(),                           // &isLastIter
       Values.LB.getPointer(),                           // &LB