diff --git a/src/mips/constants-mips.h b/src/mips/constants-mips.h
index d0fdf88..b20e9a2 100644
--- a/src/mips/constants-mips.h
+++ b/src/mips/constants-mips.h
@@ -28,15 +28,25 @@
 #ifndef  V8_MIPS_CONSTANTS_H_
 #define  V8_MIPS_CONSTANTS_H_
 
-#include "checks.h"
-
 // UNIMPLEMENTED_ macro for MIPS.
+#ifdef DEBUG
 #define UNIMPLEMENTED_MIPS()                                                  \
   v8::internal::PrintF("%s, \tline %d: \tfunction %s not implemented. \n",    \
                        __FILE__, __LINE__, __func__)
+#else
+#define UNIMPLEMENTED_MIPS()
+#endif
+
 #define UNSUPPORTED_MIPS() v8::internal::PrintF("Unsupported instruction.\n")
 
 
+#ifdef _MIPS_ARCH_MIPS32R2
+  #define mips32r2 1
+#else
+  #define mips32r2 0
+#endif
+
+
 // Defines constants and accessor classes to assemble, disassemble and
 // simulate MIPS32 instructions.
 //
@@ -44,8 +54,8 @@
 //      Volume II: The MIPS32 Instruction Set
 // Try www.cs.cornell.edu/courses/cs3410/2008fa/MIPS_Vol2.pdf.
 
-namespace assembler {
-namespace mips {
+namespace v8 {
+namespace internal {
 
 // -----------------------------------------------------------------------------
 // Registers and FPURegister.
@@ -61,9 +71,18 @@
 static const int kPCRegister = 34;
 
 // Number coprocessor registers.
-static const int kNumFPURegister = 32;
+static const int kNumFPURegisters = 32;
 static const int kInvalidFPURegister = -1;
 
+// FPU (coprocessor 1) control registers. Currently only FCSR is implemented.
+static const int kFCSRRegister = 31;
+static const int kInvalidFPUControlRegister = -1;
+static const uint32_t kFPUInvalidResult = (uint32_t) (1 << 31) - 1;
+
+// FCSR constants.
+static const uint32_t kFCSRFlagMask = (1 << 6) - 1;
+static const uint32_t kFCSRFlagShift = 2;
+
 // Helper functions for converting between register numbers and names.
 class Registers {
  public:
@@ -88,7 +107,7 @@
 };
 
 // Helper functions for converting between register numbers and names.
-class FPURegister {
+class FPURegisters {
  public:
   // Return the name of the register.
   static const char* Name(int reg);
@@ -103,7 +122,7 @@
 
  private:
 
-  static const char* names_[kNumFPURegister];
+  static const char* names_[kNumFPURegisters];
   static const RegisterAlias aliases_[];
 };
 
@@ -136,6 +155,7 @@
 static const int kSaBits        = 5;
 static const int kFunctionShift = 0;
 static const int kFunctionBits  = 6;
+static const int kLuiShift      = 16;
 
 static const int kImm16Shift = 0;
 static const int kImm16Bits  = 16;
@@ -146,6 +166,14 @@
 static const int kFsBits        = 5;
 static const int kFtShift       = 16;
 static const int kFtBits        = 5;
+static const int kFdShift       = 6;
+static const int kFdBits        = 5;
+static const int kFCccShift     = 8;
+static const int kFCccBits      = 3;
+static const int kFBccShift     = 18;
+static const int kFBccBits      = 3;
+static const int kFBtrueShift   = 16;
+static const int kFBtrueBits    = 1;
 
 // ----- Miscellianous useful masks.
 // Instruction bit masks.
@@ -159,9 +187,9 @@
 static const int  kFunctionFieldMask =
     ((1 << kFunctionBits) - 1) << kFunctionShift;
 // Misc masks.
-static const int  HIMask        =   0xffff << 16;
-static const int  LOMask        =   0xffff;
-static const int  signMask      =   0x80000000;
+static const int  kHiMask       =   0xffff << 16;
+static const int  kLoMask       =   0xffff;
+static const int  kSignMask     =   0x80000000;
 
 
 // ----- MIPS Opcodes and Function Fields.
@@ -194,12 +222,20 @@
   BGTZL     =   ((2 << 3) + 7) << kOpcodeShift,
 
   SPECIAL2  =   ((3 << 3) + 4) << kOpcodeShift,
+  SPECIAL3  =   ((3 << 3) + 7) << kOpcodeShift,
 
   LB        =   ((4 << 3) + 0) << kOpcodeShift,
+  LH        =   ((4 << 3) + 1) << kOpcodeShift,
+  LWL       =   ((4 << 3) + 2) << kOpcodeShift,
   LW        =   ((4 << 3) + 3) << kOpcodeShift,
   LBU       =   ((4 << 3) + 4) << kOpcodeShift,
+  LHU       =   ((4 << 3) + 5) << kOpcodeShift,
+  LWR       =   ((4 << 3) + 6) << kOpcodeShift,
   SB        =   ((5 << 3) + 0) << kOpcodeShift,
+  SH        =   ((5 << 3) + 1) << kOpcodeShift,
+  SWL       =   ((5 << 3) + 2) << kOpcodeShift,
   SW        =   ((5 << 3) + 3) << kOpcodeShift,
+  SWR       =   ((5 << 3) + 6) << kOpcodeShift,
 
   LWC1      =   ((6 << 3) + 1) << kOpcodeShift,
   LDC1      =   ((6 << 3) + 5) << kOpcodeShift,
@@ -216,9 +252,12 @@
   SLLV      =   ((0 << 3) + 4),
   SRLV      =   ((0 << 3) + 6),
   SRAV      =   ((0 << 3) + 7),
+  MOVCI     =   ((0 << 3) + 1),
 
   JR        =   ((1 << 3) + 0),
   JALR      =   ((1 << 3) + 1),
+  MOVZ      =   ((1 << 3) + 2),
+  MOVN      =   ((1 << 3) + 3),
   BREAK     =   ((1 << 3) + 5),
 
   MFHI      =   ((2 << 3) + 0),
@@ -250,6 +289,12 @@
 
   // SPECIAL2 Encoding of Function Field.
   MUL       =   ((0 << 3) + 2),
+  CLZ       =   ((4 << 3) + 0),
+  CLO       =   ((4 << 3) + 1),
+
+  // SPECIAL3 Encoding of Function Field.
+  EXT       =   ((0 << 3) + 0),
+  INS       =   ((0 << 3) + 4),
 
   // REGIMM  encoding of rt Field.
   BLTZ      =   ((0 << 3) + 0) << 16,
@@ -259,8 +304,10 @@
 
   // COP1 Encoding of rs Field.
   MFC1      =   ((0 << 3) + 0) << 21,
+  CFC1      =   ((0 << 3) + 2) << 21,
   MFHC1     =   ((0 << 3) + 3) << 21,
   MTC1      =   ((0 << 3) + 4) << 21,
+  CTC1      =   ((0 << 3) + 6) << 21,
   MTHC1     =   ((0 << 3) + 7) << 21,
   BC1       =   ((1 << 3) + 0) << 21,
   S         =   ((2 << 3) + 0) << 21,
@@ -269,14 +316,46 @@
   L         =   ((2 << 3) + 5) << 21,
   PS        =   ((2 << 3) + 6) << 21,
   // COP1 Encoding of Function Field When rs=S.
+  ROUND_L_S =   ((1 << 3) + 0),
+  TRUNC_L_S =   ((1 << 3) + 1),
+  CEIL_L_S  =   ((1 << 3) + 2),
+  FLOOR_L_S =   ((1 << 3) + 3),
+  ROUND_W_S =   ((1 << 3) + 4),
+  TRUNC_W_S =   ((1 << 3) + 5),
+  CEIL_W_S  =   ((1 << 3) + 6),
+  FLOOR_W_S =   ((1 << 3) + 7),
   CVT_D_S   =   ((4 << 3) + 1),
   CVT_W_S   =   ((4 << 3) + 4),
   CVT_L_S   =   ((4 << 3) + 5),
   CVT_PS_S  =   ((4 << 3) + 6),
   // COP1 Encoding of Function Field When rs=D.
+  ADD_D     =   ((0 << 3) + 0),
+  SUB_D     =   ((0 << 3) + 1),
+  MUL_D     =   ((0 << 3) + 2),
+  DIV_D     =   ((0 << 3) + 3),
+  SQRT_D    =   ((0 << 3) + 4),
+  ABS_D     =   ((0 << 3) + 5),
+  MOV_D     =   ((0 << 3) + 6),
+  NEG_D     =   ((0 << 3) + 7),
+  ROUND_L_D =   ((1 << 3) + 0),
+  TRUNC_L_D =   ((1 << 3) + 1),
+  CEIL_L_D  =   ((1 << 3) + 2),
+  FLOOR_L_D =   ((1 << 3) + 3),
+  ROUND_W_D =   ((1 << 3) + 4),
+  TRUNC_W_D =   ((1 << 3) + 5),
+  CEIL_W_D  =   ((1 << 3) + 6),
+  FLOOR_W_D =   ((1 << 3) + 7),
   CVT_S_D   =   ((4 << 3) + 0),
   CVT_W_D   =   ((4 << 3) + 4),
   CVT_L_D   =   ((4 << 3) + 5),
+  C_F_D     =   ((6 << 3) + 0),
+  C_UN_D    =   ((6 << 3) + 1),
+  C_EQ_D    =   ((6 << 3) + 2),
+  C_UEQ_D   =   ((6 << 3) + 3),
+  C_OLT_D   =   ((6 << 3) + 4),
+  C_ULT_D   =   ((6 << 3) + 5),
+  C_OLE_D   =   ((6 << 3) + 6),
+  C_ULE_D   =   ((6 << 3) + 7),
   // COP1 Encoding of Function Field When rs=W or L.
   CVT_S_W   =   ((4 << 3) + 0),
   CVT_D_W   =   ((4 << 3) + 1),
@@ -293,7 +372,7 @@
 // the 'U' prefix is used to specify unsigned comparisons.
 enum Condition {
   // Any value < 0 is considered no_condition.
-  no_condition  = -1,
+  kNoCondition  = -1,
 
   overflow      =  0,
   no_overflow   =  1,
@@ -321,12 +400,59 @@
   eq            = equal,
   not_zero      = not_equal,
   ne            = not_equal,
+  nz            = not_equal,
   sign          = negative,
   not_sign      = positive,
+  mi            = negative,
+  pl            = positive,
+  hi            = Ugreater,
+  ls            = Uless_equal,
+  ge            = greater_equal,
+  lt            = less,
+  gt            = greater,
+  le            = less_equal,
+  hs            = Ugreater_equal,
+  lo            = Uless,
+  al            = cc_always,
 
-  cc_default    = no_condition
+  cc_default    = kNoCondition
 };
 
+
+// Returns the equivalent of !cc.
+// Negation of the default kNoCondition (-1) results in a non-default
+// no_condition value (-2). As long as tests for no_condition check
+// for condition < 0, this will work as expected.
+inline Condition NegateCondition(Condition cc) {
+  ASSERT(cc != cc_always);
+  return static_cast<Condition>(cc ^ 1);
+}
+
+
+inline Condition ReverseCondition(Condition cc) {
+  switch (cc) {
+    case Uless:
+      return Ugreater;
+    case Ugreater:
+      return Uless;
+    case Ugreater_equal:
+      return Uless_equal;
+    case Uless_equal:
+      return Ugreater_equal;
+    case less:
+      return greater;
+    case greater:
+      return less;
+    case greater_equal:
+      return less_equal;
+    case less_equal:
+      return greater_equal;
+    default:
+      return cc;
+  };
+}
+
+
 // ----- Coprocessor conditions.
 enum FPUCondition {
   F,    // False
@@ -340,6 +466,46 @@
 };
 
 
+// -----------------------------------------------------------------------------
+// Hints.
+
+// Branch hints are not used on the MIPS.  They are defined so that they can
+// appear in shared function signatures, but will be ignored in MIPS
+// implementations.
+enum Hint {
+  no_hint = 0
+};
+
+
+inline Hint NegateHint(Hint hint) {
+  return no_hint;
+}
+
+
+// -----------------------------------------------------------------------------
+// Specific instructions, constants, and masks.
+// These constants are declared in assembler-mips.cc, as they use named
+// registers and other constants.
+
+// addiu(sp, sp, 4) aka Pop() operation or part of Pop(r)
+// operations as post-increment of sp.
+extern const Instr kPopInstruction;
+// addiu(sp, sp, -4) part of Push(r) operation as pre-decrement of sp.
+extern const Instr kPushInstruction;
+// sw(r, MemOperand(sp, 0))
+extern const Instr kPushRegPattern;
+//  lw(r, MemOperand(sp, 0))
+extern const Instr kPopRegPattern;
+extern const Instr kLwRegFpOffsetPattern;
+extern const Instr kSwRegFpOffsetPattern;
+extern const Instr kLwRegFpNegOffsetPattern;
+extern const Instr kSwRegFpNegOffsetPattern;
+// A mask for the Rt register for push, pop, lw, sw instructions.
+extern const Instr kRtMask;
+extern const Instr kLwSwInstrTypeMask;
+extern const Instr kLwSwInstrArgumentMask;
+extern const Instr kLwSwOffsetMask;
+
 // Break 0xfffff, reserved for redirected real time call.
 const Instr rtCallRedirInstr = SPECIAL | BREAK | call_rt_redirected << 6;
 // A nop instruction. (Encoding of sll 0 0 0).
@@ -348,10 +514,10 @@
 class Instruction {
  public:
   enum {
-    kInstructionSize = 4,
-    kInstructionSizeLog2 = 2,
+    kInstrSize = 4,
+    kInstrSizeLog2 = 2,
     // On MIPS PC cannot actually be directly accessed. We behave as if PC was
-    // always the value of the current instruction being exectued.
+    // always the value of the current instruction being executed.
     kPCReadOffset = 0
   };
 
@@ -388,45 +554,64 @@
 
 
   // Accessors for the different named fields used in the MIPS encoding.
-  inline Opcode OpcodeField() const {
+  inline Opcode OpcodeValue() const {
     return static_cast<Opcode>(
         Bits(kOpcodeShift + kOpcodeBits - 1, kOpcodeShift));
   }
 
-  inline int RsField() const {
+  inline int RsValue() const {
     ASSERT(InstructionType() == kRegisterType ||
            InstructionType() == kImmediateType);
     return Bits(kRsShift + kRsBits - 1, kRsShift);
   }
 
-  inline int RtField() const {
+  inline int RtValue() const {
     ASSERT(InstructionType() == kRegisterType ||
            InstructionType() == kImmediateType);
     return Bits(kRtShift + kRtBits - 1, kRtShift);
   }
 
-  inline int RdField() const {
+  inline int RdValue() const {
     ASSERT(InstructionType() == kRegisterType);
     return Bits(kRdShift + kRdBits - 1, kRdShift);
   }
 
-  inline int SaField() const {
+  inline int SaValue() const {
     ASSERT(InstructionType() == kRegisterType);
     return Bits(kSaShift + kSaBits - 1, kSaShift);
   }
 
-  inline int FunctionField() const {
+  inline int FunctionValue() const {
     ASSERT(InstructionType() == kRegisterType ||
            InstructionType() == kImmediateType);
     return Bits(kFunctionShift + kFunctionBits - 1, kFunctionShift);
   }
 
-  inline int FsField() const {
-    return Bits(kFsShift + kRsBits - 1, kFsShift);
+  inline int FdValue() const {
+    return Bits(kFdShift + kFdBits - 1, kFdShift);
   }
 
-  inline int FtField() const {
-    return Bits(kFtShift + kRsBits - 1, kFtShift);
+  inline int FsValue() const {
+    return Bits(kFsShift + kFsBits - 1, kFsShift);
+  }
+
+  inline int FtValue() const {
+    return Bits(kFtShift + kFtBits - 1, kFtShift);
+  }
+
+  // Float Compare condition code instruction bits.
+  inline int FCccValue() const {
+    return Bits(kFCccShift + kFCccBits - 1, kFCccShift);
+  }
+
+  // Float Branch condition code instruction bits.
+  inline int FBccValue() const {
+    return Bits(kFBccShift + kFBccBits - 1, kFBccShift);
+  }
+
+  // Float Branch true/false instruction bit.
+  inline int FBtrueValue() const {
+    return Bits(kFBtrueShift + kFBtrueBits - 1, kFBtrueShift);
   }
 
   // Return the fields at their original place in the instruction encoding.
@@ -440,6 +625,11 @@
     return InstructionBits() & kRsFieldMask;
   }
 
+  // Same as above function, but safe to call within InstructionType().
+  inline int RsFieldRawNoAssert() const {
+    return InstructionBits() & kRsFieldMask;
+  }
+
   inline int RtFieldRaw() const {
     ASSERT(InstructionType() == kRegisterType ||
            InstructionType() == kImmediateType);
@@ -461,37 +651,37 @@
   }
 
   // Get the secondary field according to the opcode.
-  inline int SecondaryField() const {
+  inline int SecondaryValue() const {
     Opcode op = OpcodeFieldRaw();
     switch (op) {
       case SPECIAL:
       case SPECIAL2:
-        return FunctionField();
+        return FunctionValue();
       case COP1:
-        return RsField();
+        return RsValue();
       case REGIMM:
-        return RtField();
+        return RtValue();
       default:
         return NULLSF;
     }
   }
 
-  inline int32_t Imm16Field() const {
+  inline int32_t Imm16Value() const {
     ASSERT(InstructionType() == kImmediateType);
     return Bits(kImm16Shift + kImm16Bits - 1, kImm16Shift);
   }
 
-  inline int32_t Imm26Field() const {
+  inline int32_t Imm26Value() const {
     ASSERT(InstructionType() == kJumpType);
     return Bits(kImm16Shift + kImm26Bits - 1, kImm26Shift);
   }
 
   // Say if the instruction should not be used in a branch delay slot.
-  bool IsForbiddenInBranchDelay();
+  bool IsForbiddenInBranchDelay() const;
   // Say if the instruction 'links'. eg: jal, bal.
-  bool IsLinkingInstruction();
+  bool IsLinkingInstruction() const;
   // Say if the instruction is a break or a trap.
-  bool IsTrap();
+  bool IsTrap() const;
 
   // Instructions are read of out a code stream. The only way to get a
   // reference to an instruction is to convert a pointer. There is no way
@@ -510,16 +700,24 @@
 // -----------------------------------------------------------------------------
 // MIPS assembly various constants.
 
-static const int kArgsSlotsSize  = 4 * Instruction::kInstructionSize;
+
+static const int kArgsSlotsSize  = 4 * Instruction::kInstrSize;
 static const int kArgsSlotsNum   = 4;
+// C/C++ argument slots size.
+static const int kCArgsSlotsSize = 4 * Instruction::kInstrSize;
+// JS argument slots size.
+static const int kJSArgsSlotsSize = 0 * Instruction::kInstrSize;
+// Assembly builtins argument slots size.
+static const int kBArgsSlotsSize = 0 * Instruction::kInstrSize;
 
-static const int kBranchReturnOffset = 2 * Instruction::kInstructionSize;
+static const int kBranchReturnOffset = 2 * Instruction::kInstrSize;
 
-static const int kDoubleAlignment = 2 * 8;
-static const int kDoubleAlignmentMask = kDoubleAlignmentMask - 1;
+static const int kDoubleAlignmentBits = 3;
+static const int kDoubleAlignment = (1 << kDoubleAlignmentBits);
+static const int kDoubleAlignmentMask = kDoubleAlignment - 1;
 
 
-} }   // namespace assembler::mips
+} }   // namespace v8::internal
 
 #endif    // #ifndef V8_MIPS_CONSTANTS_H_