[OPENMP] Fixed support for 'schedule' clause with non-constant chunk size.

'schedule' clause for combined directives requires additional processing. Special helper variable is generated, that is captured in the outlined parallel region for 'parallel for' region. This captured variable is used to store chunk expression from the 'schedule' clause in this 'parallel for' region.

llvm-svn: 237100

1 files changed, 39 insertions, 11 deletions

diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 70db0091938..130f080ef08 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -951,6 +951,38 @@ static LValue EmitOMPHelperVar(CodeGenFunction &CGF,
   return CGF.EmitLValue(Helper);
 }
 
+static std::pair<llvm::Value * /*Chunk*/, OpenMPScheduleClauseKind>
+emitScheduleClause(CodeGenFunction &CGF, const OMPLoopDirective &S,
+                   bool OuterRegion) {
+  // Detect the loop schedule kind and chunk.
+  auto ScheduleKind = OMPC_SCHEDULE_unknown;
+  llvm::Value *Chunk = nullptr;
+  if (auto *C =
+          cast_or_null<OMPScheduleClause>(S.getSingleClause(OMPC_schedule))) {
+    ScheduleKind = C->getScheduleKind();
+    if (const auto *Ch = C->getChunkSize()) {
+      if (auto *ImpRef = cast_or_null<DeclRefExpr>(C->getHelperChunkSize())) {
+        if (OuterRegion) {
+          const VarDecl *ImpVar = cast<VarDecl>(ImpRef->getDecl());
+          CGF.EmitVarDecl(*ImpVar);
+          CGF.EmitStoreThroughLValue(
+              CGF.EmitAnyExpr(Ch),
+              CGF.MakeNaturalAlignAddrLValue(CGF.GetAddrOfLocalVar(ImpVar),
+                                             ImpVar->getType()));
+        } else {
+          Ch = ImpRef;
+        }
+      }
+      if (!C->getHelperChunkSize() || !OuterRegion) {
+        Chunk = CGF.EmitScalarExpr(Ch);
+        Chunk = CGF.EmitScalarConversion(Chunk, Ch->getType(),
+                                         S.getIterationVariable()->getType());
+      }
+    }
+  }
+  return std::make_pair(Chunk, ScheduleKind);
+}
+
 bool CodeGenFunction::EmitOMPWorksharingLoop(const OMPLoopDirective &S) {
   // Emit the loop iteration variable.
   auto IVExpr = cast<DeclRefExpr>(S.getIterationVariable());
@@ -1013,17 +1045,12 @@ bool CodeGenFunction::EmitOMPWorksharingLoop(const OMPLoopDirective &S) {
       (void)LoopScope.Privatize();
 
       // Detect the loop schedule kind and chunk.
-      auto ScheduleKind = OMPC_SCHEDULE_unknown;
-      llvm::Value *Chunk = nullptr;
-      if (auto C = cast_or_null<OMPScheduleClause>(
-              S.getSingleClause(OMPC_schedule))) {
-        ScheduleKind = C->getScheduleKind();
-        if (auto Ch = C->getChunkSize()) {
-          Chunk = EmitScalarExpr(Ch);
-          Chunk = EmitScalarConversion(Chunk, Ch->getType(),
-                                       S.getIterationVariable()->getType());
-        }
-      }
+      llvm::Value *Chunk;
+      OpenMPScheduleClauseKind ScheduleKind;
+      auto ScheduleInfo =
+          emitScheduleClause(*this, S, /*OuterRegion=*/false);
+      Chunk = ScheduleInfo.first;
+      ScheduleKind = ScheduleInfo.second;
       const unsigned IVSize = getContext().getTypeSize(IVExpr->getType());
       const bool IVSigned = IVExpr->getType()->hasSignedIntegerRepresentation();
       if (RT.isStaticNonchunked(ScheduleKind,
@@ -1329,6 +1356,7 @@ void CodeGenFunction::EmitOMPParallelForDirective(
   // Emit directive as a combined directive that consists of two implicit
   // directives: 'parallel' with 'for' directive.
   LexicalScope Scope(*this, S.getSourceRange());
+  (void)emitScheduleClause(*this, S, /*OuterRegion=*/true);
   auto &&CodeGen = [&S](CodeGenFunction &CGF) {
     CGF.EmitOMPWorksharingLoop(S);
     // Emit implicit barrier at the end of parallel region, but this barrier