diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 93445a8c84f..80221d7feb6 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -338,6 +338,9 @@ void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
     return;
 
   GVSym->redefineIfPossible();
+  if (GVSym->isDefined() || GVSym->isVariable())
+    report_fatal_error("symbol '" + Twine(GVSym->getName()) +
+                       "' is already defined");
 
   if (MAI->hasDotTypeDotSizeDirective())
     OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
@@ -547,11 +550,14 @@ void AsmPrinter::EmitFunctionEntryLabel() {
 
   // The function label could have already been emitted if two symbols end up
   // conflicting due to asm renaming.  Detect this and emit an error.
-  if (CurrentFnSym->isUndefined())
-    return OutStreamer.EmitLabel(CurrentFnSym);
+  if (CurrentFnSym->isVariable())
+    report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
+                       "' is a protected alias");
+  if (CurrentFnSym->isDefined())
+    report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
+                       "' label emitted multiple times to assembly file");
 
-  report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
-                     "' label emitted multiple times to assembly file");
+  return OutStreamer.EmitLabel(CurrentFnSym);
 }
 
 /// emitComments - Pretty-print comments for instructions.
diff --git a/test/CodeGen/X86/equiv_with_fndef.ll b/test/CodeGen/X86/equiv_with_fndef.ll
new file mode 100644
index 00000000000..efbb8ab3da6
--- /dev/null
+++ b/test/CodeGen/X86/equiv_with_fndef.ll
@@ -0,0 +1,10 @@
+; RUN: not llc < %s 2>&1 | FileCheck %s
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+module asm ".equiv pselect, __pselect"
+
+define void @pselect() {
+  ret void
+}
+; CHECK: 'pselect' is a protected alias
diff --git a/test/CodeGen/X86/equiv_with_vardef.ll b/test/CodeGen/X86/equiv_with_vardef.ll
new file mode 100644
index 00000000000..29c19a107ec
--- /dev/null
+++ b/test/CodeGen/X86/equiv_with_vardef.ll
@@ -0,0 +1,8 @@
+; RUN: not llc < %s 2>&1 | FileCheck %s
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+module asm ".equiv var, __var"
+
+@var = global i32 0
+; CHECK: symbol 'var' is already defined