[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, 26 insertions, 8 deletions

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 43211bf9f58..db238c02d5c 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -1280,15 +1280,24 @@ StmtResult Sema::ActOnOpenMPRegionEnd(StmtResult S,
     ActOnCapturedRegionError();
     return StmtError();
   }
-  // Mark all variables in private list clauses as used in inner region. This is
-  // required for proper codegen.
+  // This is required for proper codegen.
   for (auto *Clause : Clauses) {
     if (isOpenMPPrivate(Clause->getClauseKind())) {
+      // Mark all variables in private list clauses as used in inner region.
       for (auto *VarRef : Clause->children()) {
         if (auto *E = cast_or_null<Expr>(VarRef)) {
           MarkDeclarationsReferencedInExpr(E);
         }
       }
+    } else if (isParallelOrTaskRegion(DSAStack->getCurrentDirective()) &&
+               Clause->getClauseKind() == OMPC_schedule) {
+      // Mark all variables in private list clauses as used in inner region.
+      // Required for proper codegen of combined directives.
+      // TODO: add processing for other clauses.
+      if (auto *E = cast_or_null<Expr>(
+              cast<OMPScheduleClause>(Clause)->getHelperChunkSize())) {
+          MarkDeclarationsReferencedInExpr(E);
+        }
     }
   }
   return ActOnCapturedRegionEnd(S.get());
@@ -4511,6 +4520,7 @@ OMPClause *Sema::ActOnOpenMPScheduleClause(
     return nullptr;
   }
   Expr *ValExpr = ChunkSize;
+  Expr *HelperValExpr = nullptr;
   if (ChunkSize) {
     if (!ChunkSize->isValueDependent() && !ChunkSize->isTypeDependent() &&
         !ChunkSize->isInstantiationDependent() &&
@@ -4527,17 +4537,25 @@ OMPClause *Sema::ActOnOpenMPScheduleClause(
       //  chunk_size must be a loop invariant integer expression with a positive
       //  value.
       llvm::APSInt Result;
-      if (ValExpr->isIntegerConstantExpr(Result, Context) &&
-          Result.isSigned() && !Result.isStrictlyPositive()) {
-        Diag(ChunkSizeLoc, diag::err_omp_negative_expression_in_clause)
-            << "schedule" << ChunkSize->getSourceRange();
-        return nullptr;
+      if (ValExpr->isIntegerConstantExpr(Result, Context)) {
+        if (Result.isSigned() && !Result.isStrictlyPositive()) {
+          Diag(ChunkSizeLoc, diag::err_omp_negative_expression_in_clause)
+              << "schedule" << ChunkSize->getSourceRange();
+          return nullptr;
+        }
+      } else if (isParallelOrTaskRegion(DSAStack->getCurrentDirective())) {
+        auto *ImpVar = buildVarDecl(*this, ChunkSize->getExprLoc(),
+                                    ChunkSize->getType(), ".chunk.");
+        auto *ImpVarRef = buildDeclRefExpr(*this, ImpVar, ChunkSize->getType(),
+                                           ChunkSize->getExprLoc(),
+                                           /*RefersToCapture=*/true);
+        HelperValExpr = ImpVarRef;
       }
     }
   }
 
   return new (Context) OMPScheduleClause(StartLoc, LParenLoc, KindLoc, CommaLoc,
-                                         EndLoc, Kind, ValExpr);
+                                         EndLoc, Kind, ValExpr, HelperValExpr);
 }
 
 OMPClause *Sema::ActOnOpenMPClause(OpenMPClauseKind Kind,