diff --git a/src/code-stubs.h b/src/code-stubs.h
index e5a222f..c2dd0a7 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -29,6 +29,7 @@
 #define V8_CODE_STUBS_H_
 
 #include "globals.h"
+#include "macro-assembler.h"
 
 namespace v8 {
 namespace internal {
@@ -80,6 +81,14 @@
   CODE_STUB_LIST_ALL_PLATFORMS(V)    \
   CODE_STUB_LIST_ARM(V)
 
+// Types of uncatchable exceptions.
+enum UncatchableExceptionType { OUT_OF_MEMORY, TERMINATION };
+
+// Mode to overwrite BinaryExpression values.
+enum OverwriteMode { NO_OVERWRITE, OVERWRITE_LEFT, OVERWRITE_RIGHT };
+enum UnaryOverwriteMode { UNARY_OVERWRITE, UNARY_NO_OVERWRITE };
+
+
 // Stub is base classes of all stubs.
 class CodeStub BASE_EMBEDDED {
  public:
@@ -105,6 +114,12 @@
   static int MinorKeyFromKey(uint32_t key) {
     return MinorKeyBits::decode(key);
   };
+
+  // Gets the major key from a code object that is a code stub or binary op IC.
+  static Major GetMajorKey(Code* code_stub) {
+    return static_cast<Major>(code_stub->major_key());
+  }
+
   static const char* MajorName(Major major_key, bool allow_unknown_keys);
 
   virtual ~CodeStub() {}
@@ -172,6 +187,609 @@
   friend class BreakPointIterator;
 };
 
+
+// Helper interface to prepare to/restore after making runtime calls.
+class RuntimeCallHelper {
+ public:
+  virtual ~RuntimeCallHelper() {}
+
+  virtual void BeforeCall(MacroAssembler* masm) const = 0;
+
+  virtual void AfterCall(MacroAssembler* masm) const = 0;
+
+ protected:
+  RuntimeCallHelper() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(RuntimeCallHelper);
+};
+
+} }  // namespace v8::internal
+
+#if V8_TARGET_ARCH_IA32
+#include "ia32/code-stubs-ia32.h"
+#elif V8_TARGET_ARCH_X64
+#include "x64/code-stubs-x64.h"
+#elif V8_TARGET_ARCH_ARM
+#include "arm/code-stubs-arm.h"
+#elif V8_TARGET_ARCH_MIPS
+#include "mips/code-stubs-mips.h"
+#else
+#error Unsupported target architecture.
+#endif
+
+namespace v8 {
+namespace internal {
+
+
+// RuntimeCallHelper implementation used in IC stubs: enters/leaves a
+// newly created internal frame before/after the runtime call.
+class ICRuntimeCallHelper : public RuntimeCallHelper {
+ public:
+  ICRuntimeCallHelper() {}
+
+  virtual void BeforeCall(MacroAssembler* masm) const;
+
+  virtual void AfterCall(MacroAssembler* masm) const;
+};
+
+
+// Trivial RuntimeCallHelper implementation.
+class NopRuntimeCallHelper : public RuntimeCallHelper {
+ public:
+  NopRuntimeCallHelper() {}
+
+  virtual void BeforeCall(MacroAssembler* masm) const {}
+
+  virtual void AfterCall(MacroAssembler* masm) const {}
+};
+
+
+class StackCheckStub : public CodeStub {
+ public:
+  StackCheckStub() { }
+
+  void Generate(MacroAssembler* masm);
+
+ private:
+
+  const char* GetName() { return "StackCheckStub"; }
+
+  Major MajorKey() { return StackCheck; }
+  int MinorKey() { return 0; }
+};
+
+
+class FastNewClosureStub : public CodeStub {
+ public:
+  void Generate(MacroAssembler* masm);
+
+ private:
+  const char* GetName() { return "FastNewClosureStub"; }
+  Major MajorKey() { return FastNewClosure; }
+  int MinorKey() { return 0; }
+};
+
+
+class FastNewContextStub : public CodeStub {
+ public:
+  static const int kMaximumSlots = 64;
+
+  explicit FastNewContextStub(int slots) : slots_(slots) {
+    ASSERT(slots_ > 0 && slots <= kMaximumSlots);
+  }
+
+  void Generate(MacroAssembler* masm);
+
+ private:
+  int slots_;
+
+  const char* GetName() { return "FastNewContextStub"; }
+  Major MajorKey() { return FastNewContext; }
+  int MinorKey() { return slots_; }
+};
+
+
+class FastCloneShallowArrayStub : public CodeStub {
+ public:
+  // Maximum length of copied elements array.
+  static const int kMaximumClonedLength = 8;
+
+  enum Mode {
+    CLONE_ELEMENTS,
+    COPY_ON_WRITE_ELEMENTS
+  };
+
+  FastCloneShallowArrayStub(Mode mode, int length)
+      : mode_(mode),
+        length_((mode == COPY_ON_WRITE_ELEMENTS) ? 0 : length) {
+    ASSERT(length_ >= 0);
+    ASSERT(length_ <= kMaximumClonedLength);
+  }
+
+  void Generate(MacroAssembler* masm);
+
+ private:
+  Mode mode_;
+  int length_;
+
+  const char* GetName() { return "FastCloneShallowArrayStub"; }
+  Major MajorKey() { return FastCloneShallowArray; }
+  int MinorKey() {
+    ASSERT(mode_ == 0 || mode_ == 1);
+    return (length_ << 1) | mode_;
+  }
+};
+
+
+class InstanceofStub: public CodeStub {
+ public:
+  InstanceofStub() { }
+
+  void Generate(MacroAssembler* masm);
+
+ private:
+  Major MajorKey() { return Instanceof; }
+  int MinorKey() { return 0; }
+};
+
+
+enum NegativeZeroHandling {
+  kStrictNegativeZero,
+  kIgnoreNegativeZero
+};
+
+
+class GenericUnaryOpStub : public CodeStub {
+ public:
+  GenericUnaryOpStub(Token::Value op,
+                     UnaryOverwriteMode overwrite,
+                     NegativeZeroHandling negative_zero = kStrictNegativeZero)
+      : op_(op), overwrite_(overwrite), negative_zero_(negative_zero) { }
+
+ private:
+  Token::Value op_;
+  UnaryOverwriteMode overwrite_;
+  NegativeZeroHandling negative_zero_;
+
+  class OverwriteField: public BitField<UnaryOverwriteMode, 0, 1> {};
+  class NegativeZeroField: public BitField<NegativeZeroHandling, 1, 1> {};
+  class OpField: public BitField<Token::Value, 2, kMinorBits - 2> {};
+
+  Major MajorKey() { return GenericUnaryOp; }
+  int MinorKey() {
+    return OpField::encode(op_) |
+           OverwriteField::encode(overwrite_) |
+           NegativeZeroField::encode(negative_zero_);
+  }
+
+  void Generate(MacroAssembler* masm);
+
+  const char* GetName();
+};
+
+
+enum NaNInformation {
+  kBothCouldBeNaN,
+  kCantBothBeNaN
+};
+
+
+class CompareStub: public CodeStub {
+ public:
+  CompareStub(Condition cc,
+              bool strict,
+              NaNInformation nan_info = kBothCouldBeNaN,
+              bool include_number_compare = true,
+              Register lhs = no_reg,
+              Register rhs = no_reg) :
+      cc_(cc),
+      strict_(strict),
+      never_nan_nan_(nan_info == kCantBothBeNaN),
+      include_number_compare_(include_number_compare),
+      lhs_(lhs),
+      rhs_(rhs),
+      name_(NULL) { }
+
+  void Generate(MacroAssembler* masm);
+
+ private:
+  Condition cc_;
+  bool strict_;
+  // Only used for 'equal' comparisons.  Tells the stub that we already know
+  // that at least one side of the comparison is not NaN.  This allows the
+  // stub to use object identity in the positive case.  We ignore it when
+  // generating the minor key for other comparisons to avoid creating more
+  // stubs.
+  bool never_nan_nan_;
+  // Do generate the number comparison code in the stub. Stubs without number
+  // comparison code is used when the number comparison has been inlined, and
+  // the stub will be called if one of the operands is not a number.
+  bool include_number_compare_;
+  // Register holding the left hand side of the comparison if the stub gives
+  // a choice, no_reg otherwise.
+  Register lhs_;
+  // Register holding the right hand side of the comparison if the stub gives
+  // a choice, no_reg otherwise.
+  Register rhs_;
+
+  // Encoding of the minor key CCCCCCCCCCCCRCNS.
+  class StrictField: public BitField<bool, 0, 1> {};
+  class NeverNanNanField: public BitField<bool, 1, 1> {};
+  class IncludeNumberCompareField: public BitField<bool, 2, 1> {};
+  class RegisterField: public BitField<bool, 3, 1> {};
+  class ConditionField: public BitField<int, 4, 12> {};
+
+  Major MajorKey() { return Compare; }
+
+  int MinorKey();
+
+  // Branch to the label if the given object isn't a symbol.
+  void BranchIfNonSymbol(MacroAssembler* masm,
+                         Label* label,
+                         Register object,
+                         Register scratch);
+
+  // Unfortunately you have to run without snapshots to see most of these
+  // names in the profile since most compare stubs end up in the snapshot.
+  char* name_;
+  const char* GetName();
+#ifdef DEBUG
+  void Print() {
+    PrintF("CompareStub (cc %d), (strict %s), "
+           "(never_nan_nan %s), (number_compare %s) ",
+           static_cast<int>(cc_),
+           strict_ ? "true" : "false",
+           never_nan_nan_ ? "true" : "false",
+           include_number_compare_ ? "included" : "not included");
+
+    if (!lhs_.is(no_reg) && !rhs_.is(no_reg)) {
+      PrintF("(lhs r%d), (rhs r%d)\n", lhs_.code(), rhs_.code());
+    } else {
+      PrintF("\n");
+    }
+  }
+#endif
+};
+
+
+class CEntryStub : public CodeStub {
+ public:
+  explicit CEntryStub(int result_size) : result_size_(result_size) { }
+
+  void Generate(MacroAssembler* masm);
+
+ private:
+  void GenerateCore(MacroAssembler* masm,
+                    Label* throw_normal_exception,
+                    Label* throw_termination_exception,
+                    Label* throw_out_of_memory_exception,
+                    bool do_gc,
+                    bool always_allocate_scope,
+                    int alignment_skew = 0);
+  void GenerateThrowTOS(MacroAssembler* masm);
+  void GenerateThrowUncatchable(MacroAssembler* masm,
+                                UncatchableExceptionType type);
+
+  // Number of pointers/values returned.
+  const int result_size_;
+
+  Major MajorKey() { return CEntry; }
+  // Minor key must differ if different result_size_ values means different
+  // code is generated.
+  int MinorKey();
+
+  const char* GetName() { return "CEntryStub"; }
+};
+
+
+class ApiGetterEntryStub : public CodeStub {
+ public:
+  ApiGetterEntryStub(Handle<AccessorInfo> info,
+                     ApiFunction* fun)
+      : info_(info),
+        fun_(fun) { }
+  void Generate(MacroAssembler* masm);
+  virtual bool has_custom_cache() { return true; }
+  virtual bool GetCustomCache(Code** code_out);
+  virtual void SetCustomCache(Code* value);
+
+  static const int kStackSpace = 5;
+  static const int kArgc = 4;
+ private:
+  Handle<AccessorInfo> info() { return info_; }
+  ApiFunction* fun() { return fun_; }
+  Major MajorKey() { return NoCache; }
+  int MinorKey() { return 0; }
+  const char* GetName() { return "ApiEntryStub"; }
+  // The accessor info associated with the function.
+  Handle<AccessorInfo> info_;
+  // The function to be called.
+  ApiFunction* fun_;
+};
+
+
+class JSEntryStub : public CodeStub {
+ public:
+  JSEntryStub() { }
+
+  void Generate(MacroAssembler* masm) { GenerateBody(masm, false); }
+
+ protected:
+  void GenerateBody(MacroAssembler* masm, bool is_construct);
+
+ private:
+  Major MajorKey() { return JSEntry; }
+  int MinorKey() { return 0; }
+
+  const char* GetName() { return "JSEntryStub"; }
+};
+
+
+class JSConstructEntryStub : public JSEntryStub {
+ public:
+  JSConstructEntryStub() { }
+
+  void Generate(MacroAssembler* masm) { GenerateBody(masm, true); }
+
+ private:
+  int MinorKey() { return 1; }
+
+  const char* GetName() { return "JSConstructEntryStub"; }
+};
+
+
+class ArgumentsAccessStub: public CodeStub {
+ public:
+  enum Type {
+    READ_ELEMENT,
+    NEW_OBJECT
+  };
+
+  explicit ArgumentsAccessStub(Type type) : type_(type) { }
+
+ private:
+  Type type_;
+
+  Major MajorKey() { return ArgumentsAccess; }
+  int MinorKey() { return type_; }
+
+  void Generate(MacroAssembler* masm);
+  void GenerateReadElement(MacroAssembler* masm);
+  void GenerateNewObject(MacroAssembler* masm);
+
+  const char* GetName() { return "ArgumentsAccessStub"; }
+
+#ifdef DEBUG
+  void Print() {
+    PrintF("ArgumentsAccessStub (type %d)\n", type_);
+  }
+#endif
+};
+
+
+class RegExpExecStub: public CodeStub {
+ public:
+  RegExpExecStub() { }
+
+ private:
+  Major MajorKey() { return RegExpExec; }
+  int MinorKey() { return 0; }
+
+  void Generate(MacroAssembler* masm);
+
+  const char* GetName() { return "RegExpExecStub"; }
+
+#ifdef DEBUG
+  void Print() {
+    PrintF("RegExpExecStub\n");
+  }
+#endif
+};
+
+
+class CallFunctionStub: public CodeStub {
+ public:
+  CallFunctionStub(int argc, InLoopFlag in_loop, CallFunctionFlags flags)
+      : argc_(argc), in_loop_(in_loop), flags_(flags) { }
+
+  void Generate(MacroAssembler* masm);
+
+ private:
+  int argc_;
+  InLoopFlag in_loop_;
+  CallFunctionFlags flags_;
+
+#ifdef DEBUG
+  void Print() {
+    PrintF("CallFunctionStub (args %d, in_loop %d, flags %d)\n",
+           argc_,
+           static_cast<int>(in_loop_),
+           static_cast<int>(flags_));
+  }
+#endif
+
+  // Minor key encoding in 32 bits with Bitfield <Type, shift, size>.
+  class InLoopBits: public BitField<InLoopFlag, 0, 1> {};
+  class FlagBits: public BitField<CallFunctionFlags, 1, 1> {};
+  class ArgcBits: public BitField<int, 2, 32 - 2> {};
+
+  Major MajorKey() { return CallFunction; }
+  int MinorKey() {
+    // Encode the parameters in a unique 32 bit value.
+    return InLoopBits::encode(in_loop_)
+           | FlagBits::encode(flags_)
+           | ArgcBits::encode(argc_);
+  }
+
+  InLoopFlag InLoop() { return in_loop_; }
+  bool ReceiverMightBeValue() {
+    return (flags_ & RECEIVER_MIGHT_BE_VALUE) != 0;
+  }
+
+ public:
+  static int ExtractArgcFromMinorKey(int minor_key) {
+    return ArgcBits::decode(minor_key);
+  }
+};
+
+
+enum StringIndexFlags {
+  // Accepts smis or heap numbers.
+  STRING_INDEX_IS_NUMBER,
+
+  // Accepts smis or heap numbers that are valid array indices
+  // (ECMA-262 15.4). Invalid indices are reported as being out of
+  // range.
+  STRING_INDEX_IS_ARRAY_INDEX
+};
+
+
+// Generates code implementing String.prototype.charCodeAt.
+//
+// Only supports the case when the receiver is a string and the index
+// is a number (smi or heap number) that is a valid index into the
+// string. Additional index constraints are specified by the
+// flags. Otherwise, bails out to the provided labels.
+//
+// Register usage: |object| may be changed to another string in a way
+// that doesn't affect charCodeAt/charAt semantics, |index| is
+// preserved, |scratch| and |result| are clobbered.
+class StringCharCodeAtGenerator {
+ public:
+  StringCharCodeAtGenerator(Register object,
+                            Register index,
+                            Register scratch,
+                            Register result,
+                            Label* receiver_not_string,
+                            Label* index_not_number,
+                            Label* index_out_of_range,
+                            StringIndexFlags index_flags)
+      : object_(object),
+        index_(index),
+        scratch_(scratch),
+        result_(result),
+        receiver_not_string_(receiver_not_string),
+        index_not_number_(index_not_number),
+        index_out_of_range_(index_out_of_range),
+        index_flags_(index_flags) {
+    ASSERT(!scratch_.is(object_));
+    ASSERT(!scratch_.is(index_));
+    ASSERT(!scratch_.is(result_));
+    ASSERT(!result_.is(object_));
+    ASSERT(!result_.is(index_));
+  }
+
+  // Generates the fast case code. On the fallthrough path |result|
+  // register contains the result.
+  void GenerateFast(MacroAssembler* masm);
+
+  // Generates the slow case code. Must not be naturally
+  // reachable. Expected to be put after a ret instruction (e.g., in
+  // deferred code). Always jumps back to the fast case.
+  void GenerateSlow(MacroAssembler* masm,
+                    const RuntimeCallHelper& call_helper);
+
+ private:
+  Register object_;
+  Register index_;
+  Register scratch_;
+  Register result_;
+
+  Label* receiver_not_string_;
+  Label* index_not_number_;
+  Label* index_out_of_range_;
+
+  StringIndexFlags index_flags_;
+
+  Label call_runtime_;
+  Label index_not_smi_;
+  Label got_smi_index_;
+  Label exit_;
+
+  DISALLOW_COPY_AND_ASSIGN(StringCharCodeAtGenerator);
+};
+
+
+// Generates code for creating a one-char string from a char code.
+class StringCharFromCodeGenerator {
+ public:
+  StringCharFromCodeGenerator(Register code,
+                              Register result)
+      : code_(code),
+        result_(result) {
+    ASSERT(!code_.is(result_));
+  }
+
+  // Generates the fast case code. On the fallthrough path |result|
+  // register contains the result.
+  void GenerateFast(MacroAssembler* masm);
+
+  // Generates the slow case code. Must not be naturally
+  // reachable. Expected to be put after a ret instruction (e.g., in
+  // deferred code). Always jumps back to the fast case.
+  void GenerateSlow(MacroAssembler* masm,
+                    const RuntimeCallHelper& call_helper);
+
+ private:
+  Register code_;
+  Register result_;
+
+  Label slow_case_;
+  Label exit_;
+
+  DISALLOW_COPY_AND_ASSIGN(StringCharFromCodeGenerator);
+};
+
+
+// Generates code implementing String.prototype.charAt.
+//
+// Only supports the case when the receiver is a string and the index
+// is a number (smi or heap number) that is a valid index into the
+// string. Additional index constraints are specified by the
+// flags. Otherwise, bails out to the provided labels.
+//
+// Register usage: |object| may be changed to another string in a way
+// that doesn't affect charCodeAt/charAt semantics, |index| is
+// preserved, |scratch1|, |scratch2|, and |result| are clobbered.
+class StringCharAtGenerator {
+ public:
+  StringCharAtGenerator(Register object,
+                        Register index,
+                        Register scratch1,
+                        Register scratch2,
+                        Register result,
+                        Label* receiver_not_string,
+                        Label* index_not_number,
+                        Label* index_out_of_range,
+                        StringIndexFlags index_flags)
+      : char_code_at_generator_(object,
+                                index,
+                                scratch1,
+                                scratch2,
+                                receiver_not_string,
+                                index_not_number,
+                                index_out_of_range,
+                                index_flags),
+        char_from_code_generator_(scratch2, result) {}
+
+  // Generates the fast case code. On the fallthrough path |result|
+  // register contains the result.
+  void GenerateFast(MacroAssembler* masm);
+
+  // Generates the slow case code. Must not be naturally
+  // reachable. Expected to be put after a ret instruction (e.g., in
+  // deferred code). Always jumps back to the fast case.
+  void GenerateSlow(MacroAssembler* masm,
+                    const RuntimeCallHelper& call_helper);
+
+ private:
+  StringCharCodeAtGenerator char_code_at_generator_;
+  StringCharFromCodeGenerator char_from_code_generator_;
+
+  DISALLOW_COPY_AND_ASSIGN(StringCharAtGenerator);
+};
+
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_