commit 07a3b59279c4f67188b428fb315e1761a04e8116
author Alexey Bataev <a.bataev@hotmail.com> Fri Aug 23 19:52:05 2019 +0000
committer Alexey Bataev <a.bataev@hotmail.com> Fri Aug 23 19:52:05 2019 +0000
tree 87e2b2d0219a3dc5adb28792ae59a425b39aad43
parent 236f8012c942bbf49bd4ff0eb5ea287b0f47f9f2

[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

clang/lib/CodeGen/CGOpenMPRuntime.cpp

diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 84211e3..99fa079 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -3509,7 +3509,7 @@
   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 @@
   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 @@
   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 @@
   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