Index: include/llvm/MC/MCAsmInfo.h
===================================================================
--- include/llvm/MC/MCAsmInfo.h
+++ include/llvm/MC/MCAsmInfo.h
@@ -128,6 +128,10 @@
   /// file.  Defaults to "L"
   const char *PrivateGlobalPrefix;
 
+  /// This prefix is used for labels for basic blocks. Defaults to the same as
+  /// PrivateGlobalPrefix.
+  const char *PrivateLabelPrefix;
+
   /// This prefix is used for symbols that should be passed through the
   /// assembler but be removed by the linker.  This is 'l' on Darwin, currently
   /// used for some ObjC metadata.  The default of "" meast that for this system
@@ -418,6 +422,7 @@
 
   bool useAssignmentForEHBegin() const { return UseAssignmentForEHBegin; }
   const char *getPrivateGlobalPrefix() const { return PrivateGlobalPrefix; }
+  const char *getPrivateLabelPrefix() const { return PrivateLabelPrefix; }
   bool hasLinkerPrivateGlobalPrefix() const {
     return LinkerPrivateGlobalPrefix[0] != '\0';
   }
Index: lib/CodeGen/MachineBasicBlock.cpp
===================================================================
--- lib/CodeGen/MachineBasicBlock.cpp
+++ lib/CodeGen/MachineBasicBlock.cpp
@@ -55,8 +55,7 @@
     const MachineFunction *MF = getParent();
     MCContext &Ctx = MF->getContext();
     const TargetMachine &TM = MF->getTarget();
-    const char *Prefix =
-        TM.getSubtargetImpl()->getDataLayout()->getPrivateGlobalPrefix();
+    const char *Prefix = Ctx.getAsmInfo()->getPrivateLabelPrefix();
     CachedMCSymbol = Ctx.GetOrCreateSymbol(Twine(Prefix) + "BB" +
                                            Twine(MF->getFunctionNumber()) +
                                            "_" + Twine(getNumber()));
Index: lib/MC/MCAsmInfo.cpp
===================================================================
--- lib/MC/MCAsmInfo.cpp
+++ lib/MC/MCAsmInfo.cpp
@@ -41,6 +41,7 @@
   LabelSuffix = ":";
   UseAssignmentForEHBegin = false;
   PrivateGlobalPrefix = "L";
+  PrivateLabelPrefix = PrivateGlobalPrefix;
   LinkerPrivateGlobalPrefix = "";
   InlineAsmStart = "APP";
   InlineAsmEnd = "NO_APP";