diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -3564,6 +3564,7 @@
 
 /// printBasicBlock - This member is called for each basic block in a method.
 void AssemblyWriter::printBasicBlock(const BasicBlock *BB) {
+  assert(BB && BB->getParent() && "block without parent!");
   bool IsEntryBlock = BB == &BB->getParent()->getEntryBlock();
   if (BB->hasName()) {              // Print out the label if it exists...
     Out << "\n";
@@ -3578,10 +3579,7 @@
       Out << "<badref>:";
   }
 
-  if (!BB->getParent()) {
-    Out.PadToColumn(50);
-    Out << "; Error: Block without parent!";
-  } else if (!IsEntryBlock) {
+  if (!IsEntryBlock) {
     // Output predecessors for the block.
     Out.PadToColumn(50);
     Out << ";";