Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -6579,6 +6579,11 @@
   Args.AddAllArgs(CmdArgs, options::OPT_dylinker__install__name);
   Args.AddLastArg(CmdArgs, options::OPT_dylinker);
   Args.AddLastArg(CmdArgs, options::OPT_Mach);
+
+  if (D.IsUsingLTO(Args))
+    if (!Args.hasFlag(options::OPT_fzero_initialized_in_bss,
+                      options::OPT_fno_zero_initialized_in_bss))
+      CmdArgs.push_back("-mllvm -nozero-initialized-in-bss");
 }
 
 void darwin::Linker::ConstructJob(Compilation &C, const JobAction &JA,
Index: test/Driver/no-zero-initialized-in-bss.c
===================================================================
--- /dev/null
+++ test/Driver/no-zero-initialized-in-bss.c
@@ -0,0 +1,11 @@
+// RUN: %clang -### -c -fno-zero-initialized-in-bss %s 2>&1 | FileCheck -check-prefix CHECK-NO-ZERO %s
+// RUN: %clang -### -c -fzero-initialized-in-bss %s 2>&1 | FileCheck -check-prefix CHECK-ZERO %s
+// RUN: %clang -### -c %s 2>&1 | FileCheck -check-prefix CHECK-ZERO %s
+// RUN: %clang -### -flto -fzero-initialized-in-bss -fno-zero-initialized-in-bss -target x86_64-apple-darwin %s 2>&1 | FileCheck -check-prefix CHECK-NO-ZERO-LTO-DARWIN %s
+// RUN: %clang -### -flto -fno-zero-initialized-in-bss -fzero-initialized-in-bss -target x86_64-apple-darwin %s 2>&1 | FileCheck -check-prefix CHECK-ZERO-LTO-DARWIN %s
+// RUN: %clang -### -flto -target x86_64-apple-darwin %s 2>&1 | FileCheck -check-prefix CHECK-ZERO-LTO-DARWIN %s
+
+// CHECK-NO-ZERO: -mno-zero-initialized-in-bss
+// CHECK-ZERO-NOT: -mno-zero-initialized-in-bss
+// CHECK-NO-ZERO-LTO-DARWIN: -mllvm -nozero-initialized-in-bss
+// CHECK-ZERO-LTO-DARWIN-NOT: -mllvm -nozero-initialized-in-bss