diff --git a/include/llvm/Target/TargetRegisterInfo.h b/include/llvm/Target/TargetRegisterInfo.h
index 053168a2a9d..695d5ef8e13 100644
--- a/include/llvm/Target/TargetRegisterInfo.h
+++ b/include/llvm/Target/TargetRegisterInfo.h
@@ -268,6 +268,7 @@ public:
   typedef const TargetRegisterClass * const * regclass_iterator;
 private:
   const TargetRegisterDesc *Desc;             // Pointer to the descriptor array
+  const char *const *SubRegIndexNames;        // Names of subreg indexes.
   unsigned NumRegs;                           // Number of entries in the array
 
   regclass_iterator RegClassBegin, RegClassEnd;   // List of regclasses
@@ -278,6 +279,7 @@ protected:
   TargetRegisterInfo(const TargetRegisterDesc *D, unsigned NR,
                      regclass_iterator RegClassBegin,
                      regclass_iterator RegClassEnd,
+                     const char *const *subregindexnames,
                      int CallFrameSetupOpcode = -1,
                      int CallFrameDestroyOpcode = -1,
                      const unsigned* subregs = 0,
@@ -378,6 +380,13 @@ public:
     return NumRegs;
   }
 
+  /// getSubRegIndexName - Return the human-readable symbolic target-specific
+  /// name for the specified SubRegIndex.
+  const char *getSubRegIndexName(unsigned SubIdx) const {
+    assert(SubIdx && "This is not a subregister index");
+    return SubRegIndexNames[SubIdx-1];
+  }
+
   /// regsOverlap - Returns true if the two registers are equal or alias each
   /// other. The registers may be virtual register.
   bool regsOverlap(unsigned regA, unsigned regB) const {
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 06499db10d0..e54cd5cf949 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -219,8 +219,12 @@ void MachineOperand::print(raw_ostream &OS, const TargetMachine *TM) const {
         OS << "%physreg" << getReg();
     }
 
-    if (getSubReg() != 0)
-      OS << ':' << getSubReg();
+    if (getSubReg() != 0) {
+      if (TM)
+        OS << ':' << TM->getRegisterInfo()->getSubRegIndexName(getSubReg());
+      else
+        OS << ':' << getSubReg();
+    }
 
     if (isDef() || isKill() || isDead() || isImplicit() || isUndef() ||
         isEarlyClobber()) {
diff --git a/lib/Target/TargetRegisterInfo.cpp b/lib/Target/TargetRegisterInfo.cpp
index 52983ffe093..ec2248a6b84 100644
--- a/lib/Target/TargetRegisterInfo.cpp
+++ b/lib/Target/TargetRegisterInfo.cpp
@@ -22,6 +22,7 @@ using namespace llvm;
 
 TargetRegisterInfo::TargetRegisterInfo(const TargetRegisterDesc *D, unsigned NR,
                              regclass_iterator RCB, regclass_iterator RCE,
+                             const char *const *subregindexnames,
                              int CFSO, int CFDO,
                              const unsigned* subregs, const unsigned subregsize,
                          const unsigned* superregs, const unsigned superregsize,
@@ -29,7 +30,8 @@ TargetRegisterInfo::TargetRegisterInfo(const TargetRegisterDesc *D, unsigned NR,
   : SubregHash(subregs), SubregHashSize(subregsize),
     SuperregHash(superregs), SuperregHashSize(superregsize),
     AliasesHash(aliases), AliasesHashSize(aliasessize),
-    Desc(D), NumRegs(NR), RegClassBegin(RCB), RegClassEnd(RCE) {
+    Desc(D), SubRegIndexNames(subregindexnames), NumRegs(NR),
+    RegClassBegin(RCB), RegClassEnd(RCE) {
   assert(NumRegs < FirstVirtualRegister &&
          "Target has too many physical registers!");
 
diff --git a/utils/TableGen/RegisterInfoEmitter.cpp b/utils/TableGen/RegisterInfoEmitter.cpp
index 28429faefa2..baaf044601d 100644
--- a/utils/TableGen/RegisterInfoEmitter.cpp
+++ b/utils/TableGen/RegisterInfoEmitter.cpp
@@ -811,6 +811,16 @@ void RegisterInfoEmitter::run(raw_ostream &OS) {
       OS << "Empty_SuperRegsSet },\n";
   }
   OS << "  };\n";      // End of register descriptors...
+
+  // Emit SubRegIndex names, skipping 0
+  const std::vector<Record*> SubRegIndices = Target.getSubRegIndices();
+  OS << "\n  const char *const SubRegIndexTable[] = { \"";
+  for (unsigned i = 0, e = SubRegIndices.size(); i != e; ++i) {
+    OS << SubRegIndices[i]->getName();
+    if (i+1 != e)
+      OS << "\", \"";
+  }
+  OS << "\" };\n\n";
   OS << "}\n\n";       // End of anonymous namespace...
 
   std::string ClassName = Target.getName() + "GenRegisterInfo";
@@ -876,7 +886,8 @@ void RegisterInfoEmitter::run(raw_ostream &OS) {
   OS << ClassName << "::" << ClassName
      << "(int CallFrameSetupOpcode, int CallFrameDestroyOpcode)\n"
      << "  : TargetRegisterInfo(RegisterDescriptors, " << Registers.size()+1
-     << ", RegisterClasses, RegisterClasses+" << RegisterClasses.size() <<",\n "
+     << ", RegisterClasses, RegisterClasses+" << RegisterClasses.size() <<",\n"
+     << "                 SubRegIndexTable,\n"
      << "                 CallFrameSetupOpcode, CallFrameDestroyOpcode,\n"
      << "                 SubregHashTable, SubregHashTableSize,\n"
      << "                 SuperregHashTable, SuperregHashTableSize,\n"