[OPENMP]Do not crash for const firstprivates.

If the variable is a firstprivate variable and it was not emitted beause
this a constant variable with the constant initializer, we can use the
initial value instead of the variable itself. It also fixes the problem
with the compiler crash in this case.

llvm-svn: 361564

1 files changed, 19 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 01194e3a60f..6a973cdb57e 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -758,7 +758,25 @@ bool CodeGenFunction::EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
         DeclRefExpr DRE(getContext(), const_cast<VarDecl *>(OrigVD),
                         /*RefersToEnclosingVariableOrCapture=*/FD != nullptr,
                         (*IRef)->getType(), VK_LValue, (*IRef)->getExprLoc());
-        LValue OriginalLVal = EmitLValue(&DRE);
+        LValue OriginalLVal;
+        if (!FD) {
+          // Check if the firstprivate variable is just a constant value.
+          ConstantEmission CE = tryEmitAsConstant(&DRE);
+          if (CE && !CE.isReference()) {
+            // Constant value, no need to create a copy.
+            ++IRef;
+            ++InitsRef;
+            continue;
+          }
+          if (CE && CE.isReference()) {
+            OriginalLVal = CE.getReferenceLValue(*this, &DRE);
+          } else {
+            assert(!CE && "Expected non-constant firstprivate.");
+            OriginalLVal = EmitLValue(&DRE);
+          }
+        } else {
+          OriginalLVal = EmitLValue(&DRE);
+        }
         QualType Type = VD->getType();
         if (Type->isArrayType()) {
           // Emit VarDecl with copy init for arrays.