reapply r98656 unmodified, which exposed the asmprinter not

handling constant unions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98680 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 26 insertions, 3 deletions

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 2636e2c..1d4f7f7 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1138,6 +1138,21 @@ static void EmitGlobalConstantStruct(const ConstantStruct *CS,
          "Layout of constant struct may be incorrect!");
 }
 
+static void EmitGlobalConstantUnion(const ConstantUnion *CU, 
+                                    unsigned AddrSpace, AsmPrinter &AP) {
+  const TargetData *TD = AP.TM.getTargetData();
+  unsigned Size = TD->getTypeAllocSize(CU->getType());
+
+  const Constant *Contents = CU->getOperand(0);
+  unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
+    
+  // Print the actually filled part
+  AP.EmitGlobalConstant(Contents, AddrSpace);
+
+  // And pad with enough zeroes
+  AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
+}
+
 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
                                  AsmPrinter &AP) {
   // FP Constants are printed as integer constants to avoid losing
@@ -1257,9 +1272,6 @@ void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
 
   if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
     return EmitGlobalConstantFP(CFP, AddrSpace, *this);
-  
-  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
-    return EmitGlobalConstantVector(V, AddrSpace, *this);
 
   if (isa<ConstantPointerNull>(CV)) {
     unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
@@ -1267,6 +1279,12 @@ void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
     return;
   }
   
+  if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
+    return EmitGlobalConstantUnion(CVU, AddrSpace, *this);
+  
+  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
+    return EmitGlobalConstantVector(V, AddrSpace, *this);
+  
   // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
   // thread the streamer with EmitValue.
   OutStreamer.EmitValue(LowerConstant(CV, *this),
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 3d9a4d5..11293e4 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -2592,6 +2592,11 @@ void SelectionDAGBuilder::visitGetElementPtr(User &I) {
       }
 
       Ty = StTy->getElementType(Field);
+    } else if (const UnionType *UnTy = dyn_cast<UnionType>(Ty)) {
+      unsigned Field = cast<ConstantInt>(Idx)->getZExtValue();
+      
+      // Offset canonically 0 for unions, but type changes
+      Ty = UnTy->getElementType(Field);
     } else {
       Ty = cast<SequentialType>(Ty)->getElementType();