Index: src/Unwind/DwarfParser.hpp
===================================================================
--- src/Unwind/DwarfParser.hpp	(revision 207169)
+++ src/Unwind/DwarfParser.hpp	(working copy)
@@ -45,6 +45,7 @@
     uint8_t   personalityEncoding;
     uint8_t   personalityOffsetInCIE;
     pint_t    personality;
+    uint32_t  returnAddressRegister;
     uint32_t  codeAlignFactor;
     int       dataAlignFactor;
     bool      isSignalFrame;
@@ -295,7 +296,8 @@
   // parse data alignment factor
   cieInfo->dataAlignFactor = (int)addressSpace.getSLEB128(p, cieContentEnd);
   // parse return address register
-  addressSpace.getULEB128(p, cieContentEnd);
+  cieInfo->returnAddressRegister = (uint32_t)addressSpace.getULEB128(p,
+                                                                 cieContentEnd);
   // parse augmentation data based on augmentation string
   const char *result = NULL;
   if (addressSpace.get8(strStart) == 'z') {
Index: src/Unwind/DwarfInstructions.hpp
===================================================================
--- src/Unwind/DwarfInstructions.hpp	(revision 207061)
+++ src/Unwind/DwarfInstructions.hpp	(working copy)
@@ -63,33 +63,6 @@
   static v128 getSavedVectorRegister(A &addressSpace, const R &registers,
                                   pint_t cfa, const RegisterLocation &savedReg);
 
-  // x86 specific variants
-  static int lastRestoreReg(const Registers_x86 &);
-  static bool isReturnAddressRegister(int regNum, const Registers_x86 &);
-  static pint_t getCFA(A &addressSpace, const PrologInfo &prolog,
-                       const Registers_x86 &);
-
-  // x86_64 specific variants
-  static int lastRestoreReg(const Registers_x86_64 &);
-  static bool isReturnAddressRegister(int regNum, const Registers_x86_64 &);
-  static pint_t getCFA(A &addressSpace,
-                       const PrologInfo &prolog,
-                       const Registers_x86_64 &);
-
-  // ppc specific variants
-  static int lastRestoreReg(const Registers_ppc &);
-  static bool isReturnAddressRegister(int regNum, const Registers_ppc &);
-  static pint_t getCFA(A &addressSpace,
-                       const PrologInfo &prolog,
-                       const Registers_ppc &);
-
-  // arm64 specific variants
-  static bool isReturnAddressRegister(int regNum, const Registers_arm64 &);
-  static int lastRestoreReg(const Registers_arm64 &);
-  static pint_t getCFA(A &addressSpace,
-                       const PrologInfo &prolog,
-                       const Registers_arm64 &);
-
 };
 
 
@@ -177,14 +150,26 @@
     PrologInfo prolog;
     if (CFI_Parser<A>::parseFDEInstructions(addressSpace, fdeInfo, cieInfo, pc,
                                                                      &prolog)) {
-      R newRegisters = registers;
+      // get pointer to cfa
+      pint_t cfa;;
+      if (prolog.cfaRegister != 0)
+        cfa = (pint_t)((sint_t)registers.getRegister((int)prolog.cfaRegister)
+                                                  + prolog.cfaRegisterOffset);
+      else if (prolog.cfaExpression != 0)
+        cfa = evaluateExpression((pint_t)prolog.cfaExpression, addressSpace, 
+                                                                registers, 0);
+      else
+        _LIBUNWIND_ABORT("stepWithDwarf(): unknown location for cfa");
 
-      // get pointer to cfa (architecture specific)
-      pint_t cfa = getCFA(addressSpace, prolog, registers);
-
       // restore registers that dwarf says were saved
+      R newRegisters = registers;
       pint_t returnAddress = 0;
-      for (int i = 0; i <= lastRestoreReg(newRegisters); ++i) {
+      const int lastReg = R::lastDwarfRegNum();
+      assert((int)CFI_Parser<A>::kMaxRegisterNumber > lastReg
+                                                && "register range too large");
+      assert(lastReg <= (int)cieInfo.returnAddressRegister
+                 && "register range does not contain return address register");
+      for (int i = 0; i <= lastReg; ++i) {
         if (prolog.savedRegisters[i].location !=
             CFI_Parser<A>::kRegisterUnused) {
           if (registers.validFloatRegister(i))
@@ -195,7 +180,7 @@
             newRegisters.setVectorRegister(
                 i, getSavedVectorRegister(addressSpace, registers, cfa,
                                           prolog.savedRegisters[i]));
-          else if (isReturnAddressRegister(i, registers))
+          else if (i == (int)cieInfo.returnAddressRegister)
             returnAddress = getSavedRegister(addressSpace, registers, cfa,
                                              prolog.savedRegisters[i]);
           else if (registers.validRegister(i))
@@ -764,125 +749,7 @@
   return *sp;
 }
 
-//
-//  x86_64 specific functions
-//
-template <typename A, typename R>
-int DwarfInstructions<A, R>::lastRestoreReg(const Registers_x86_64 &) {
-  static_assert((int)CFI_Parser<A>::kMaxRegisterNumber
-              > (int)DW_X86_64_RET_ADDR, "register number out of range");
-  return DW_X86_64_RET_ADDR;
-}
 
-template <typename A, typename R>
-bool
-DwarfInstructions<A, R>::isReturnAddressRegister(int regNum,
-                                                 const Registers_x86_64 &) {
-  return (regNum == DW_X86_64_RET_ADDR);
-}
-
-template <typename A, typename R>
-typename A::pint_t DwarfInstructions<A, R>::getCFA(
-    A &addressSpace, const PrologInfo &prolog,
-    const Registers_x86_64 &registers) {
-  if (prolog.cfaRegister != 0)
-    return (pint_t)((sint_t)registers.getRegister((int)prolog.cfaRegister)
-                                                    + prolog.cfaRegisterOffset);
-  else if (prolog.cfaExpression != 0)
-    return evaluateExpression((pint_t)prolog.cfaExpression, addressSpace, registers, 0);
-  else
-    _LIBUNWIND_ABORT("getCFA(): unknown location for x86_64 cfa");
-}
-
-
-//
-//  x86 specific functions
-//
-template <typename A, typename R>
-int DwarfInstructions<A, R>::lastRestoreReg(const Registers_x86 &) {
-  static_assert((int)CFI_Parser<A>::kMaxRegisterNumber
-              > (int)DW_X86_RET_ADDR, "register number out of range");
-  return DW_X86_RET_ADDR;
-}
-
-template <typename A, typename R>
-bool DwarfInstructions<A, R>::isReturnAddressRegister(int regNum,
-                                                      const Registers_x86 &) {
-  return (regNum == DW_X86_RET_ADDR);
-}
-
-template <typename A, typename R>
-typename A::pint_t DwarfInstructions<A, R>::getCFA(
-    A &addressSpace, const PrologInfo &prolog,
-    const Registers_x86 &registers) {
-  if (prolog.cfaRegister != 0)
-    return (pint_t)((sint_t)registers.getRegister((int)prolog.cfaRegister)
-                                                    + prolog.cfaRegisterOffset);
-  else if (prolog.cfaExpression != 0)
-    return evaluateExpression((pint_t)prolog.cfaExpression, addressSpace,
-                                                                  registers, 0);
-  else
-    _LIBUNWIND_ABORT("getCFA(): unknown location for x86 cfa");
-}
-
-
-//
-//  ppc specific functions
-//
-template <typename A, typename R>
-int DwarfInstructions<A, R>::lastRestoreReg(const Registers_ppc &) {
-  static_assert((int)CFI_Parser<A>::kMaxRegisterNumber
-              > (int)UNW_PPC_SPEFSCR, "register number out of range");
-  return UNW_PPC_SPEFSCR;
-}
-
-template <typename A, typename R>
-bool DwarfInstructions<A, R>::isReturnAddressRegister(int regNum,
-                                                      const Registers_ppc &) {
-  return (regNum == UNW_PPC_LR);
-}
-
-template <typename A, typename R>
-typename A::pint_t DwarfInstructions<A, R>::getCFA(
-    A &addressSpace, const PrologInfo &prolog,
-    const Registers_ppc &registers) {
-  if (prolog.cfaRegister != 0)
-    return registers.getRegister(prolog.cfaRegister) + prolog.cfaRegisterOffset;
-  else if (prolog.cfaExpression != 0)
-    return evaluateExpression((pint_t)prolog.cfaExpression, addressSpace,
-                                                                  registers, 0);
-  else
-    _LIBUNWIND_ABORT("getCFA(): unknown location for ppc cfa");
-}
-
-
-
-//
-// arm64 specific functions
-//
-template <typename A, typename R>
-bool DwarfInstructions<A, R>::isReturnAddressRegister(int regNum,
-                                                      const Registers_arm64 &) {
-  return (regNum == UNW_ARM64_LR);
-}
-
-template <typename A, typename R>
-int DwarfInstructions<A, R>::lastRestoreReg(const Registers_arm64 &) {
-  static_assert((int)CFI_Parser<A>::kMaxRegisterNumber
-              > (int)UNW_ARM64_D31, "register number out of range");
-  return UNW_ARM64_D31;
-}
-
-template <typename A, typename R>
-typename A::pint_t DwarfInstructions<A, R>::getCFA(A&, const PrologInfo &prolog,
-                                             const Registers_arm64 &registers) {
-  if (prolog.cfaRegister != 0)
-    return registers.getRegister(prolog.cfaRegister) + prolog.cfaRegisterOffset;
-  else
-    _LIBUNWIND_ABORT("getCFA(): unsupported location for arm64 cfa");
-}
-
-
 } // namespace libunwind
 
 #endif // __DWARF_INSTRUCTIONS_HPP__
Index: src/Unwind/Registers.hpp
===================================================================
--- src/Unwind/Registers.hpp	(revision 207061)
+++ src/Unwind/Registers.hpp	(working copy)
@@ -44,6 +44,7 @@
   void        setVectorRegister(int num, v128 value);
   const char *getRegisterName(int num);
   void        jumpto();
+  static int  lastDwarfRegNum() { return 8; }
 
   uint32_t  getSP() const          { return _registers.__esp; }
   void      setSP(uint32_t value)  { _registers.__esp = value; }
@@ -231,6 +232,7 @@
   void        setVectorRegister(int num, v128 value);
   const char *getRegisterName(int num);
   void        jumpto();
+  static int  lastDwarfRegNum() { return 16; }
 
   uint64_t  getSP() const          { return _registers.__rsp; }
   void      setSP(uint64_t value)  { _registers.__rsp = value; }
@@ -478,6 +480,7 @@
   void        setVectorRegister(int num, v128 value);
   const char *getRegisterName(int num);
   void        jumpto();
+  static int  lastDwarfRegNum() { return 112; }
 
   uint64_t  getSP() const         { return _registers.__r1; }
   void      setSP(uint32_t value) { _registers.__r1 = value; }
@@ -1031,6 +1034,7 @@
   void        setVectorRegister(int num, v128 value);
   const char *getRegisterName(int num);
   void        jumpto();
+  static int  lastDwarfRegNum() { return 95; }
 
   uint64_t  getSP() const         { return _registers.__sp; }
   void      setSP(uint64_t value) { _registers.__sp = value; }