Fix wrong-code bug: __imag on a scalar lvalue should produce a zero rvalue,

rather than an lvalue referring to the scalar.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150889 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 8 insertions, 4 deletions

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 3871f33a26..060841d507 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -1465,9 +1465,10 @@ LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
     assert(LV.isSimple() && "real/imag on non-ordinary l-value");
     llvm::Value *Addr = LV.getAddress();
 
-    // real and imag are valid on scalars.  This is a faster way of
-    // testing that.
-    if (!cast<llvm::PointerType>(Addr->getType())
+    // __real is valid on scalars.  This is a faster way of testing that.
+    // __imag can only produce an rvalue on scalars.
+    if (E->getOpcode() == UO_Real &&
+        !cast<llvm::PointerType>(Addr->getType())
            ->getElementType()->isStructTy()) {
       assert(E->getSubExpr()->getType()->isArithmeticType());
       return LV;
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index 8bd4c2b5aa..6eed2ed346 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -1642,7 +1642,10 @@ Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) {
 
   // __imag on a scalar returns zero.  Emit the subexpr to ensure side
   // effects are evaluated, but not the actual value.
-  CGF.EmitScalarExpr(Op, true);
+  if (Op->isGLValue())
+    CGF.EmitLValue(Op);
+  else
+    CGF.EmitScalarExpr(Op, true);
   return llvm::Constant::getNullValue(ConvertType(E->getType()));
 }