Index: lib/CodeGen/GlobalMerge.cpp
===================================================================
--- lib/CodeGen/GlobalMerge.cpp
+++ lib/CodeGen/GlobalMerge.cpp
@@ -577,7 +577,8 @@
   for (auto &GV : M.globals()) {
     // Merge is safe for "normal" internal or external globals only
     if (GV.isDeclaration() || GV.isThreadLocal() ||
-        GV.hasSection() || GV.hasImplicitSection())
+        GV.hasSection() || GV.hasImplicitSection() ||
+        GV.hasDLLExportStorageClass())
       continue;
 
     // It's not safe to merge globals that may be preempted
Index: test/CodeGen/ARM/global-merge-dllexport.ll
===================================================================
--- /dev/null
+++ test/CodeGen/ARM/global-merge-dllexport.ll
@@ -0,0 +1,15 @@
+; RUN: llc < %s -mtriple=thumbv7-win32 -arm-global-merge | FileCheck %s
+
+@x = global i32 0, align 4
+@y = dllexport global i32 0, align 4
+
+define void @f1(i32 %a1, i32 %a2) {
+; CHECK: f1:
+; CHECK: movw [[REG1:r[0-9]+]], :lower16:x
+; CHECK: movt [[REG1]], :upper16:x
+  store i32 %a1, i32* @x, align 4
+  store i32 %a2, i32* @y, align 4
+  ret void
+}
+
+; CHECK-NOT: .L_MergedGlobals