[OPENMP 4.1] Improved codegen for 'uval' qualifier of 'linear' clause.

According to standard the 'uval' modifier declares the address of the original list item to have an invariant value for all iterations of the associated loop(s). Patch improves codegen for this qualifier by removing usage of the original reference variable and replacing by referenced l-value.

llvm-svn: 245674

1 files changed, 15 insertions, 5 deletions

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index d2653b7cb90..5d86cc23f00 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -6423,7 +6423,12 @@ OMPClause *Sema::ActOnOpenMPLinearClause(
         *this, Private, DE->getType().getUnqualifiedType(), DE->getExprLoc());
     // Build var to save initial value.
     VarDecl *Init = buildVarDecl(*this, ELoc, QType, ".linear.start");
-    AddInitializerToDecl(Init, DefaultLvalueConversion(DE).get(),
+    Expr *InitExpr;
+    if (LinKind == OMPC_LINEAR_uval)
+      InitExpr = VD->getInit();
+    else
+      InitExpr = DE;
+    AddInitializerToDecl(Init, DefaultLvalueConversion(InitExpr).get(),
                          /*DirectInit*/ false, /*TypeMayContainAuto*/ false);
     auto InitRef = buildDeclRefExpr(
         *this, Init, DE->getType().getUnqualifiedType(), DE->getExprLoc());
@@ -6491,15 +6496,20 @@ static bool FinishOpenMPLinearClause(OMPLinearClause &Clause, DeclRefExpr *IV,
   bool HasErrors = false;
   auto CurInit = Clause.inits().begin();
   auto CurPrivate = Clause.privates().begin();
+  auto LinKind = Clause.getModifier();
   for (auto &RefExpr : Clause.varlists()) {
     Expr *InitExpr = *CurInit;
 
     // Build privatized reference to the current linear var.
     auto DE = cast<DeclRefExpr>(RefExpr);
-    auto CapturedRef =
-        buildDeclRefExpr(SemaRef, cast<VarDecl>(DE->getDecl()),
-                         DE->getType().getUnqualifiedType(), DE->getExprLoc(),
-                         /*RefersToCapture=*/true);
+    Expr *CapturedRef;
+    if (LinKind == OMPC_LINEAR_uval)
+      CapturedRef = cast<VarDecl>(DE->getDecl())->getInit();
+    else
+      CapturedRef =
+          buildDeclRefExpr(SemaRef, cast<VarDecl>(DE->getDecl()),
+                           DE->getType().getUnqualifiedType(), DE->getExprLoc(),
+                           /*RefersToCapture=*/true);
 
     // Build update: Var = InitExpr + IV * Step
     ExprResult Update =