don't send null pointers through the constantexpr codepath unneededly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94010 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 4c5e079..32e9036 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1247,6 +1247,12 @@
   if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
     return EmitGlobalConstantVector(V, AddrSpace, *this);
 
+  if (isa<ConstantPointerNull>(CV)) {
+    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
+    OutStreamer.EmitIntValue(0, Size, AddrSpace);
+    return;
+  }
+  
   // Otherwise, it must be a ConstantExpr.  Emit the data directive, then emit
   // the expression value.
   switch (TM.getTargetData()->getTypeAllocSize(CV->getType())) {