Submit code-stubs-mips.cc.

src/mips/code-stubs-mips.cc

Index: src/mips/code-stubs-mips.cc
diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index d99f7241a6aa1e78bf0187700104d218b80ffba5..89981fdb193f3abaa76be880be78c463b7b0f2f2 100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -40,24 +40,233 @@ namespace internal {
 
 #define __ ACCESS_MASM(masm)
 
+static void EmitIdenticalObjectComparison(MacroAssembler* masm,
+                                          Label* slow,
+                                          Condition cc,
+                                          bool never_nan_nan);
+static void EmitSmiNonsmiComparison(MacroAssembler* masm,
+                                    Register lhs,
+                                    Register rhs,
+                                    Label* rhs_not_nan,
+                                    Label* slow,
+                                    bool strict);
+static void EmitTwoNonNanDoubleComparison(MacroAssembler* masm, Condition cc);
+static void EmitStrictTwoHeapObjectCompare(MacroAssembler* masm,
+                                           Register lhs,
+                                           Register rhs);
+
+
+// Check if the operand is a heap number.
+static void EmitCheckForHeapNumber(MacroAssembler* masm, Register operand,
+                                   Register scratch1, Register scratch2,
+                                   Label* not_a_heap_number) {
+  __ lw(scratch1, FieldMemOperand(operand, HeapObject::kMapOffset));
+  __ LoadRoot(scratch2, Heap::kHeapNumberMapRootIndex);
+  __ Branch(not_a_heap_number, ne, scratch1, Operand(scratch2));
+}
+
 
 void ToNumberStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // The ToNumber stub takes one argument in a0.
+  Label check_heap_number, call_builtin;
+  __ JumpIfNotSmi(a0, &check_heap_number);
+  __ mov(v0, a0);
+  __ Ret();
+
+  __ bind(&check_heap_number);
+  EmitCheckForHeapNumber(masm, a0, a1, t0, &call_builtin);
+  __ mov(v0, a0);
+  __ Ret();
+
+  __ bind(&call_builtin);
+  __ push(a0);
+  __ InvokeBuiltin(Builtins::TO_NUMBER, JUMP_FUNCTION);
 }
 
 
 void FastNewClosureStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Create a new closure from the given function info in new
+  // space. Set the context to the current context in cp.
+  Label gc;
+
+  // Pop the function info from the stack.
+  __ pop(a3);
+
+  // Attempt to allocate new JSFunction in new space.
+  __ AllocateInNewSpace(JSFunction::kSize,
+                        v0,
+                        a1,
+                        a2,
+                        &gc,
+                        TAG_OBJECT);
+
+  int map_index = strict_mode_ == kStrictMode
+      ? Context::STRICT_MODE_FUNCTION_MAP_INDEX
+      : Context::FUNCTION_MAP_INDEX;
+
+  // Compute the function map in the current global context and set that
+  // as the map of the allocated object.
+  __ lw(a2, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
+  __ lw(a2, FieldMemOperand(a2, GlobalObject::kGlobalContextOffset));
+  __ lw(a2, MemOperand(a2, Context::SlotOffset(map_index)));
+  __ sw(a2, FieldMemOperand(v0, HeapObject::kMapOffset));
+
+  // Initialize the rest of the function. We don't have to update the
+  // write barrier because the allocated object is in new space.
+  __ LoadRoot(a1, Heap::kEmptyFixedArrayRootIndex);
+  __ LoadRoot(a2, Heap::kTheHoleValueRootIndex);
+  __ LoadRoot(t0, Heap::kUndefinedValueRootIndex);
+  __ sw(a1, FieldMemOperand(v0, JSObject::kPropertiesOffset));
+  __ sw(a1, FieldMemOperand(v0, JSObject::kElementsOffset));
+  __ sw(a2, FieldMemOperand(v0, JSFunction::kPrototypeOrInitialMapOffset));
+  __ sw(a3, FieldMemOperand(v0, JSFunction::kSharedFunctionInfoOffset));
+  __ sw(cp, FieldMemOperand(v0, JSFunction::kContextOffset));
+  __ sw(a1, FieldMemOperand(v0, JSFunction::kLiteralsOffset));
+  __ sw(t0, FieldMemOperand(v0, JSFunction::kNextFunctionLinkOffset));
+
+  // Initialize the code pointer in the function to be the one
+  // found in the shared function info object.
+  __ lw(a3, FieldMemOperand(a3, SharedFunctionInfo::kCodeOffset));
+  __ Addu(a3, a3, Operand(Code::kHeaderSize - kHeapObjectTag));
+  __ sw(a3, FieldMemOperand(v0, JSFunction::kCodeEntryOffset));
+
+  // Return result. The argument function info has been popped already.
+  __ Ret();
+
+  // Create a new closure through the slower runtime call.
+  __ bind(&gc);
+  __ LoadRoot(t0, Heap::kFalseValueRootIndex);
+  __ Push(cp, a3, t0);
+  __ TailCallRuntime(Runtime::kNewClosure, 3, 1);
 }
 
 
 void FastNewContextStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Try to allocate the context in new space.
+  Label gc;
+  int length = slots_ + Context::MIN_CONTEXT_SLOTS;
+
+  // Attempt to allocate the context in new space.
+  __ AllocateInNewSpace(FixedArray::SizeFor(length),
+                        v0,
+                        a1,
+                        a2,
+                        &gc,
+                        TAG_OBJECT);
+
+  // Load the function from the stack.
+  __ lw(a3, MemOperand(sp, 0));
+
+  // Setup the object header.
+  __ LoadRoot(a2, Heap::kContextMapRootIndex);
+  __ sw(a2, FieldMemOperand(v0, HeapObject::kMapOffset));
+  __ li(a2, Operand(Smi::FromInt(length)));
+  __ sw(a2, FieldMemOperand(v0, FixedArray::kLengthOffset));
+
+  // Setup the fixed slots.
+  __ li(a1, Operand(Smi::FromInt(0)));
+  __ sw(a3, MemOperand(v0, Context::SlotOffset(Context::CLOSURE_INDEX)));
+  __ sw(v0, MemOperand(v0, Context::SlotOffset(Context::FCONTEXT_INDEX)));
+  __ sw(a1, MemOperand(v0, Context::SlotOffset(Context::PREVIOUS_INDEX)));
+  __ sw(a1, MemOperand(v0, Context::SlotOffset(Context::EXTENSION_INDEX)));
+
+  // Copy the global object from the surrounding context.
+  __ lw(a1, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
+  __ sw(a1, MemOperand(v0, Context::SlotOffset(Context::GLOBAL_INDEX)));
+
+  // Initialize the rest of the slots to undefined.
+  __ LoadRoot(a1, Heap::kUndefinedValueRootIndex);
+  for (int i = Context::MIN_CONTEXT_SLOTS; i < length; i++) {
+    __ sw(a1, MemOperand(v0, Context::SlotOffset(i)));
+  }
+
+  // Remove the on-stack argument and return.
+  __ mov(cp, v0);
+  __ Pop();
+  __ Ret();
+
+  // Need to collect. Call into runtime system.
+  __ bind(&gc);
+  __ TailCallRuntime(Runtime::kNewContext, 1, 1);
 }
 
 
 void FastCloneShallowArrayStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Stack layout on entry:
+  // [sp]: constant elements.
+  // [sp + kPointerSize]: literal index.
+  // [sp + (2 * kPointerSize)]: literals array.
+
+  // All sizes here are multiples of kPointerSize.
+  int elements_size = (length_ > 0) ? FixedArray::SizeFor(length_) : 0;
+  int size = JSArray::kSize + elements_size;
+
+  // Load boilerplate object into r3 and check if we need to create a
+  // boilerplate.
+  Label slow_case;
+  __ lw(a3, MemOperand(sp, 2 * kPointerSize));
+  __ lw(a0, MemOperand(sp, 1 * kPointerSize));
+  __ Addu(a3, a3, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ sll(t0, a0, kPointerSizeLog2 - kSmiTagSize);
+  __ Addu(t0, a3, t0);
+  __ lw(a3, MemOperand(t0));
+  __ LoadRoot(t1, Heap::kUndefinedValueRootIndex);
+  __ Branch(&slow_case, eq, a3, Operand(t1));
+
+  if (FLAG_debug_code) {
+    const char* message;
+    Heap::RootListIndex expected_map_index;
+    if (mode_ == CLONE_ELEMENTS) {
+      message = "Expected (writable) fixed array";
+      expected_map_index = Heap::kFixedArrayMapRootIndex;
+    } else {
+      ASSERT(mode_ == COPY_ON_WRITE_ELEMENTS);
+      message = "Expected copy-on-write fixed array";
+      expected_map_index = Heap::kFixedCOWArrayMapRootIndex;
+    }
+    __ push(a3);
+    __ lw(a3, FieldMemOperand(a3, JSArray::kElementsOffset));
+    __ lw(a3, FieldMemOperand(a3, HeapObject::kMapOffset));
+    __ LoadRoot(at, expected_map_index);
+    __ Assert(eq, message, a3, Operand(at));
+    __ pop(a3);
+  }
+
+  // Allocate both the JS array and the elements array in one big
+  // allocation. This avoids multiple limit checks.
+  // Return new object in v0.
+  __ AllocateInNewSpace(size,
+                        v0,
+                        a1,
+                        a2,
+                        &slow_case,
+                        TAG_OBJECT);
+
+  // Copy the JS array part.
+  for (int i = 0; i < JSArray::kSize; i += kPointerSize) {
+    if ((i != JSArray::kElementsOffset) || (length_ == 0)) {
+      __ lw(a1, FieldMemOperand(a3, i));
+      __ sw(a1, FieldMemOperand(v0, i));
+    }
+  }
+
+  if (length_ > 0) {
+    // Get hold of the elements array of the boilerplate and setup the
+    // elements pointer in the resulting object.
+    __ lw(a3, FieldMemOperand(a3, JSArray::kElementsOffset));
+    __ Addu(a2, v0, Operand(JSArray::kSize));
+    __ sw(a2, FieldMemOperand(v0, JSArray::kElementsOffset));
+
+    // Copy the elements array.
+    __ CopyFields(a2, a3, a1.bit(), elements_size / kPointerSize);
+  }
+
+  // Return and remove the on-stack parameters.
+  __ Addu(sp, sp, Operand(3 * kPointerSize));
+  __ Ret();
+
+  __ bind(&slow_case);
+  __ TailCallRuntime(Runtime::kCreateArrayLiteralShallow, 3, 1);
 }
 
 
@@ -107,7 +316,62 @@ class ConvertToDoubleStub : public CodeStub {
 
 
 void ConvertToDoubleStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+#ifndef BIG_ENDIAN_FLOATING_POINT
+  Register exponent = result1_;
+  Register mantissa = result2_;
+#else
+  Register exponent = result2_;
+  Register mantissa = result1_;
+#endif
+  Label not_special;
+  // Convert from Smi to integer.
+  __ sra(source_, source_, kSmiTagSize);
+  // Move sign bit from source to destination.  This works because the sign bit
+  // in the exponent word of the double has the same position and polarity as
+  // the 2's complement sign bit in a Smi.
+  STATIC_ASSERT(HeapNumber::kSignMask == 0x80000000u);
+  __ And(exponent, source_, Operand(HeapNumber::kSignMask));
+  // Subtract from 0 if source was negative.
+  __ subu(at, zero_reg, source_);
+  __ movn(source_, at, exponent);
+
+  // We have -1, 0 or 1, which we treat specially. Register source_ contains
+  // absolute value: it is either equal to 1 (special case of -1 and 1),
+  // greater than 1 (not a special case) or less than 1 (special case of 0).
+  __ Branch(&not_special, gt, source_, Operand(1));
+
+  // For 1 or -1 we need to or in the 0 exponent (biased to 1023).
+  static const uint32_t exponent_word_for_1 =
+      HeapNumber::kExponentBias << HeapNumber::kExponentShift;
+  // Safe to use 'at' as dest reg here.
+  __ Or(at, exponent, Operand(exponent_word_for_1));
+  __ movn(exponent, at, source_);  // Write exp when source not 0.
+  // 1, 0 and -1 all have 0 for the second word.
+  __ mov(mantissa, zero_reg);
+  __ Ret();
+
+  __ bind(&not_special);
+  // Count leading zeros.
+  // Gets the wrong answer for 0, but we already checked for that case above.
+  __ clz(zeros_, source_);
+  // Compute exponent and or it into the exponent register.
+  // We use mantissa as a scratch register here.
+  __ li(mantissa, Operand(31 + HeapNumber::kExponentBias));
+  __ subu(mantissa, mantissa, zeros_);
+  __ sll(mantissa, mantissa, HeapNumber::kExponentShift);
+  __ Or(exponent, exponent, mantissa);
+
+  // Shift up the source chopping the top bit off.
+  __ Addu(zeros_, zeros_, Operand(1));
+  // This wouldn't work for 1.0 or -1.0 as the shift would be 32 which means 0.
+  __ sllv(source_, source_, zeros_);
+  // Compute lower part of fraction (last 12 bits).
+  __ sll(mantissa, source_, HeapNumber::kMantissaBitsInTopWord);
+  // And the top (top 20 bits).
+  __ srl(source_, source_, 32 - HeapNumber::kMantissaBitsInTopWord);
+  __ or_(exponent, exponent, source_);
+
+  __ Ret();
 }
 
 
@@ -115,7 +379,34 @@ void FloatingPointHelper::LoadSmis(MacroAssembler* masm,
                                    FloatingPointHelper::Destination destination,
                                    Register scratch1,
                                    Register scratch2) {
-  UNIMPLEMENTED_MIPS();
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+    __ sra(scratch1, a0, kSmiTagSize);
+    __ mtc1(scratch1, f14);
+    __ cvt_d_w(f14, f14);
+    __ sra(scratch1, a1, kSmiTagSize);
+    __ mtc1(scratch1, f12);
+    __ cvt_d_w(f12, f12);
+    if (destination == kCoreRegisters) {
+      __ mfc1(a2, f14);
+      __ mfc1(a3, f15);
+
+      __ mfc1(a0, f12);
+      __ mfc1(a1, f13);
+    }
+  } else {
+    ASSERT(destination == kCoreRegisters);
+    // Write Smi from a0 to a3 and a2 in double format.
+    __ mov(scratch1, a0);
+    ConvertToDoubleStub stub1(a3, a2, scratch1, scratch2);
+    __ push(ra);
+    __ Call(stub1.GetCode(), RelocInfo::CODE_TARGET);
+    // Write Smi from a1 to a1 and a0 in double format.
+    __ mov(scratch1, a1);
+    ConvertToDoubleStub stub2(a1, a0, scratch1, scratch2);
+    __ Call(stub2.GetCode(), RelocInfo::CODE_TARGET);
+    __ pop(ra);
+  }
 }
 
 
@@ -126,7 +417,14 @@ void FloatingPointHelper::LoadOperands(
     Register scratch1,
     Register scratch2,
     Label* slow) {
-  UNIMPLEMENTED_MIPS();
+
+  // Load right operand (a0) to f12 or a2/a3.
+  LoadNumber(masm, destination,
+             a0, f14, a2, a3, heap_number_map, scratch1, scratch2, slow);
+
+  // Load left operand (a1) to f14 or a0/a1.
+  LoadNumber(masm, destination,
+             a1, f12, a0, a1, heap_number_map, scratch1, scratch2, slow);
 }
 
 
@@ -140,7 +438,60 @@ void FloatingPointHelper::LoadNumber(MacroAssembler* masm,
                                      Register scratch1,
                                      Register scratch2,
                                      Label* not_number) {
-  UNIMPLEMENTED_MIPS();
+  if (FLAG_debug_code) {
+    __ AbortIfNotRootValue(heap_number_map,
+                           Heap::kHeapNumberMapRootIndex,
+                           "HeapNumberMap register clobbered.");
+  }
+
+  Label is_smi, done;
+
+  __ JumpIfSmi(object, &is_smi);
+  __ JumpIfNotHeapNumber(object, heap_number_map, scratch1, not_number);
+
+  // Handle loading a double from a heap number.
+  if (CpuFeatures::IsSupported(FPU) &&
+      destination == kFPURegisters) {
+    CpuFeatures::Scope scope(FPU);
+    // Load the double from tagged HeapNumber to double register.
+
+    // ARM uses a workaround here because of the unaligned HeapNumber
+    // kValueOffset. On MIPS this workaround is built into ldc1 so there's no
+    // point in generating even more instructions.
+    __ ldc1(dst, FieldMemOperand(object, HeapNumber::kValueOffset));
+  } else {
+    ASSERT(destination == kCoreRegisters);
+    // Load the double from heap number to dst1 and dst2 in double format.
+    __ lw(dst1, FieldMemOperand(object, HeapNumber::kValueOffset));
+    __ lw(dst2, FieldMemOperand(object,
+        HeapNumber::kValueOffset + kPointerSize));
+  }
+  __ Branch(&done);
+
+  // Handle loading a double from a smi.
+  __ bind(&is_smi);
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+    // Convert smi to double using FPU instructions.
+    __ SmiUntag(scratch1, object);
+    __ mtc1(scratch1, dst);
+    __ cvt_d_w(dst, dst);
+    if (destination == kCoreRegisters) {
+      // Load the converted smi to dst1 and dst2 in double format.
+      __ mfc1(dst1, dst);
+      __ mfc1(dst2, FPURegister::from_code(dst.code() + 1));
+    }
+  } else {
+    ASSERT(destination == kCoreRegisters);
+    // Write smi to dst1 and dst2 double format.
+    __ mov(scratch1, object);
+    ConvertToDoubleStub stub(dst2, dst1, scratch1, scratch2);
+    __ push(ra);
+    __ Call(stub.GetCode(), RelocInfo::CODE_TARGET);
+    __ pop(ra);
+  }
+
+  __ bind(&done);
 }
 
 
@@ -153,7 +504,40 @@ void FloatingPointHelper::ConvertNumberToInt32(MacroAssembler* masm,
                                                Register scratch3,
                                                FPURegister double_scratch,
                                                Label* not_number) {
-  UNIMPLEMENTED_MIPS();
+  if (FLAG_debug_code) {
+    __ AbortIfNotRootValue(heap_number_map,
+                           Heap::kHeapNumberMapRootIndex,
+                           "HeapNumberMap register clobbered.");
+  }
+  Label is_smi;
+  Label done;
+  Label not_in_int32_range;
+
+  __ JumpIfSmi(object, &is_smi);
+  __ lw(scratch1, FieldMemOperand(object, HeapNumber::kMapOffset));
+  __ Branch(not_number, ne, scratch1, Operand(heap_number_map));
+  __ ConvertToInt32(object,
+                    dst,
+                    scratch1,
+                    scratch2,
+                    double_scratch,
+                    &not_in_int32_range);
+  __ jmp(&done);
+
+  __ bind(&not_in_int32_range);
+  __ lw(scratch1, FieldMemOperand(object, HeapNumber::kExponentOffset));
+  __ lw(scratch2, FieldMemOperand(object, HeapNumber::kMantissaOffset));
+
+  __ EmitOutOfInt32RangeTruncate(dst,
+                                 scratch1,
+                                 scratch2,
+                                 scratch3);
+
+  __ jmp(&done);
+
+  __ bind(&is_smi);
+  __ SmiUntag(dst, object);
+  __ bind(&done);
 }
 
 
@@ -165,7 +549,76 @@ void FloatingPointHelper::ConvertIntToDouble(MacroAssembler* masm,
                                              Register dst2,
                                              Register scratch2,
                                              FPURegister single_scratch) {
-  UNIMPLEMENTED_MIPS();
+  ASSERT(!int_scratch.is(scratch2));
+
+  Label done;
+
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+    __ mtc1(int_scratch, single_scratch);
+    __ cvt_d_w(double_dst, single_scratch);
+    if (destination == kCoreRegisters) {
+      __ mfc1(dst1, double_dst);
+      __ mfc1(dst2, FPURegister::from_code(double_dst.code() + 1));
+    }
+  } else {
+    Label fewer_than_20_useful_bits;
+    // Expected output:
+    // |         dst2            |         dst1            |
+    // | s |   exp   |              mantissa               |
+
+    // Check for zero.
+    __ mov(dst2, int_scratch);
+    __ mov(dst1, int_scratch);
+    __ Branch(&done, eq, int_scratch, Operand(zero_reg));
+
+    // Preload the sign of the value.
+    __ And(dst2, int_scratch, Operand(HeapNumber::kSignMask));
+    // Get the absolute value of the object (as an unsigned integer).
+    Label skip_sub;
+    __ Branch(&skip_sub, ge, dst2, Operand(zero_reg));
+    __ Subu(int_scratch, zero_reg, int_scratch);
+    __ bind(&skip_sub);
+
+    // Get mantisssa[51:20].
+
+    // Get the position of the first set bit.
+    __ clz(dst1, int_scratch);
+    __ li(scratch2, 31);
+    __ Subu(dst1, scratch2, dst1);
+
+    // Set the exponent.
+    __ Addu(scratch2, dst1, Operand(HeapNumber::kExponentBias));
+    __ Ins(dst2, scratch2,
+        HeapNumber::kExponentShift, HeapNumber::kExponentBits);
+
+    // Clear the first non null bit.
+    __ li(scratch2, Operand(1));
+    __ sllv(scratch2, scratch2, dst1);
+    __ li(at, -1);
+    __ Xor(scratch2, scratch2, at);
+    __ And(int_scratch, int_scratch, scratch2);
+
+    // Get the number of bits to set in the lower part of the mantissa.
+    __ Subu(scratch2, dst1, Operand(HeapNumber::kMantissaBitsInTopWord));
+    __ Branch(&fewer_than_20_useful_bits, lt, scratch2, Operand(zero_reg));
+    // Set the higher 20 bits of the mantissa.
+    __ srlv(at, int_scratch, scratch2);
+    __ or_(dst2, dst2, at);
+    __ li(at, 32);
+    __ subu(scratch2, at, scratch2);
+    __ sllv(dst1, int_scratch, scratch2);
+    __ Branch(&done);
+
+    __ bind(&fewer_than_20_useful_bits);
+    __ li(at, HeapNumber::kMantissaBitsInTopWord);
+    __ subu(scratch2, at, dst1);
+    __ sllv(scratch2, int_scratch, scratch2);
+    __ Or(dst2, dst2, scratch2);
+    // Set dst1 to 0.
+    __ mov(dst1, zero_reg);
+  }
+  __ bind(&done);
 }
 
 
@@ -180,7 +633,81 @@ void FloatingPointHelper::LoadNumberAsInt32Double(MacroAssembler* masm,
                                                   Register scratch2,
                                                   FPURegister single_scratch,
                                                   Label* not_int32) {
-  UNIMPLEMENTED_MIPS();
+  ASSERT(!scratch1.is(object) && !scratch2.is(object));
+  ASSERT(!scratch1.is(scratch2));
+  ASSERT(!heap_number_map.is(object) &&
+         !heap_number_map.is(scratch1) &&
+         !heap_number_map.is(scratch2));
+
+  Label done, obj_is_not_smi;
+
+  __ JumpIfNotSmi(object, &obj_is_not_smi);
+  __ SmiUntag(scratch1, object);
+  ConvertIntToDouble(masm, scratch1, destination, double_dst, dst1, dst2,
+                     scratch2, single_scratch);
+  __ Branch(&done);
+
+  __ bind(&obj_is_not_smi);
+  if (FLAG_debug_code) {
+    __ AbortIfNotRootValue(heap_number_map,
+                           Heap::kHeapNumberMapRootIndex,
+                           "HeapNumberMap register clobbered.");
+  }
+  __ JumpIfNotHeapNumber(object, heap_number_map, scratch1, not_int32);
+
+  // Load the number.
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+    // Load the double value.
+    __ ldc1(double_dst, FieldMemOperand(object, HeapNumber::kValueOffset));
+
+    // NOTE: ARM uses a MacroAssembler function here (EmitVFPTruncate).
+    // On MIPS a lot of things cannot be implemented the same way so right
+    // now it makes a lot more sense to just do things manually.
+
+    // Save FCSR.
+    __ cfc1(scratch1, FCSR);
+    // Disable FPU exceptions.
+    __ ctc1(zero_reg, FCSR);
+    __ trunc_w_d(single_scratch, double_dst);
+    // Retrieve FCSR.
+    __ cfc1(scratch2, FCSR);
+    // Restore FCSR.
+    __ ctc1(scratch1, FCSR);
+
+    // Check for inexact conversion.
+    __ srl(scratch2, scratch2, kFCSRFlagShift);
+    __ And(scratch2, scratch2, (kFCSRFlagMask | kFCSRInexactFlagBit));
+
+    // Jump to not_int32 if the operation did not succeed.
+    __ Branch(not_int32, ne, scratch2, Operand(zero_reg));
+
+    if (destination == kCoreRegisters) {
+      __ mfc1(dst1, double_dst);
+      __ mfc1(dst2, FPURegister::from_code(double_dst.code() + 1));
+    }
+
+  } else {
+    ASSERT(!scratch1.is(object) && !scratch2.is(object));
+    // Load the double value in the destination registers.
+    __ lw(dst2, FieldMemOperand(object, HeapNumber::kExponentOffset));
+    __ lw(dst1, FieldMemOperand(object, HeapNumber::kMantissaOffset));
+
+    // Check for 0 and -0.
+    __ And(scratch1, dst1, Operand(~HeapNumber::kSignMask));
+    __ Or(scratch1, scratch1, Operand(dst2));
+    __ Branch(&done, eq, scratch1, Operand(zero_reg));
+
+    // Check that the value can be exactly represented by a 32-bit integer.
+    // Jump to not_int32 if that's not the case.
+    DoubleIs32BitInteger(masm, dst1, dst2, scratch1, scratch2, not_int32);
+
+    // dst1 and dst2 were trashed. Reload the double value.
+    __ lw(dst2, FieldMemOperand(object, HeapNumber::kExponentOffset));
+    __ lw(dst1, FieldMemOperand(object, HeapNumber::kMantissaOffset));
+  }
+
+  __ bind(&done);
 }
 
 
@@ -193,7 +720,89 @@ void FloatingPointHelper::LoadNumberAsInt32(MacroAssembler* masm,
                                             Register scratch3,
                                             FPURegister double_scratch,
                                             Label* not_int32) {
-  UNIMPLEMENTED_MIPS();
+  ASSERT(!dst.is(object));
+  ASSERT(!scratch1.is(object) && !scratch2.is(object) && !scratch3.is(object));
+  ASSERT(!scratch1.is(scratch2) &&
+         !scratch1.is(scratch3) &&
+         !scratch2.is(scratch3));
+
+  Label done;
+
+  // Untag the object into the destination register.
+  __ SmiUntag(dst, object);
+  // Just return if the object is a smi.
+  __ JumpIfSmi(object, &done);
+
+  if (FLAG_debug_code) {
+    __ AbortIfNotRootValue(heap_number_map,
+                           Heap::kHeapNumberMapRootIndex,
+                           "HeapNumberMap register clobbered.");
+  }
+  __ JumpIfNotHeapNumber(object, heap_number_map, scratch1, not_int32);
+
+  // Object is a heap number.
+  // Convert the floating point value to a 32-bit integer.
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+    // Load the double value.
+    __ ldc1(double_scratch, FieldMemOperand(object, HeapNumber::kValueOffset));
+
+    // NOTE: ARM uses a MacroAssembler function here (EmitVFPTruncate).
+    // On MIPS a lot of things cannot be implemented the same way so right
+    // now it makes a lot more sense to just do things manually.
+
+    // Save FCSR.
+    __ cfc1(scratch1, FCSR);
+    // Disable FPU exceptions.
+    __ ctc1(zero_reg, FCSR);
+    __ trunc_w_d(double_scratch, double_scratch);
+    // Retrieve FCSR.
+    __ cfc1(scratch2, FCSR);
+    // Restore FCSR.
+    __ ctc1(scratch1, FCSR);
+
+    // Check for inexact conversion.
+    __ srl(scratch2, scratch2, kFCSRFlagShift);
+    __ And(scratch2, scratch2, (kFCSRFlagMask | kFCSRInexactFlagBit));
+
+    // Jump to not_int32 if the operation did not succeed.
+    __ Branch(not_int32, ne, scratch2, Operand(zero_reg));
+    // Get the result in the destination register.
+    __ mfc1(dst, double_scratch);
+
+  } else {
+    // Load the double value in the destination registers.
+    __ lw(scratch2, FieldMemOperand(object, HeapNumber::kExponentOffset));
+    __ lw(scratch1, FieldMemOperand(object, HeapNumber::kMantissaOffset));
+
+    // Check for 0 and -0.
+    __ And(dst, scratch1, Operand(~HeapNumber::kSignMask));
+    __ Or(dst, scratch2, Operand(dst));
+    __ Branch(&done, eq, dst, Operand(zero_reg));
+
+    DoubleIs32BitInteger(masm, scratch1, scratch2, dst, scratch3, not_int32);
+
+    // Registers state after DoubleIs32BitInteger.
+    // dst: mantissa[51:20].
+    // scratch2: 1
+
+    // Shift back the higher bits of the mantissa.
+    __ srlv(dst, dst, scratch3);
+    // Set the implicit first bit.
+    __ li(at, 32);
+    __ subu(scratch3, at, scratch3);
+    __ sllv(scratch2, scratch2, scratch3);
+    __ Or(dst, dst, scratch2);
+    // Set the sign.
+    __ lw(scratch1, FieldMemOperand(object, HeapNumber::kExponentOffset));
+    __ And(scratch1, scratch1, Operand(HeapNumber::kSignMask));
+    Label skip_sub;
+    __ Branch(&skip_sub, ge, scratch1, Operand(zero_reg));
+    __ Subu(dst, zero_reg, dst);
+    __ bind(&skip_sub);
+  }
+
+  __ bind(&done);
 }
 
 
@@ -203,7 +812,57 @@ void FloatingPointHelper::DoubleIs32BitInteger(MacroAssembler* masm,
                                                Register dst,
                                                Register scratch,
                                                Label* not_int32) {
-  UNIMPLEMENTED_MIPS();
+  // Get exponent alone in scratch.
+  __ Ext(scratch,
+         src1,
+         HeapNumber::kExponentShift,
+         HeapNumber::kExponentBits);
+
+  // Substract the bias from the exponent.
+  __ Subu(scratch, scratch, Operand(HeapNumber::kExponentBias));
+
+  // src1: higher (exponent) part of the double value.
+  // src2: lower (mantissa) part of the double value.
+  // scratch: unbiased exponent.
+
+  // Fast cases. Check for obvious non 32-bit integer values.
+  // Negative exponent cannot yield 32-bit integers.
+  __ Branch(not_int32, lt, scratch, Operand(zero_reg));
+  // Exponent greater than 31 cannot yield 32-bit integers.
+  // Also, a positive value with an exponent equal to 31 is outside of the
+  // signed 32-bit integer range.
+  // Another way to put it is that if (exponent - signbit) > 30 then the
+  // number cannot be represented as an int32.
+  Register tmp = dst;
+  __ srl(at, src1, 31);
+  __ subu(tmp, scratch, at);
+  __ Branch(not_int32, gt, tmp, Operand(30));
+  // - Bits [21:0] in the mantissa are not null.
+  __ And(tmp, src2, 0x3fffff);
+  __ Branch(not_int32, ne, tmp, Operand(zero_reg));
+
+  // Otherwise the exponent needs to be big enough to shift left all the
+  // non zero bits left. So we need the (30 - exponent) last bits of the
+  // 31 higher bits of the mantissa to be null.
+  // Because bits [21:0] are null, we can check instead that the
+  // (32 - exponent) last bits of the 32 higher bits of the mantisssa are null.
+
+  // Get the 32 higher bits of the mantissa in dst.
+  __ Ext(dst,
+         src2,
+         HeapNumber::kMantissaBitsInTopWord,
+         32 - HeapNumber::kMantissaBitsInTopWord);
+  __ sll(at, src1, HeapNumber::kNonMantissaBitsInTopWord);
+  __ or_(dst, dst, at);
+
+  // Create the mask and test the lower bits (of the higher bits).
+  __ li(at, 32);
+  __ subu(scratch, at, scratch);
+  __ li(src2, 1);
+  __ sllv(src1, src2, scratch);
+  __ Subu(src1, src1, Operand(1));
+  __ And(src1, dst, src1);
+  __ Branch(not_int32, ne, src1, Operand(zero_reg));
 }
 
 
@@ -212,18 +871,567 @@ void FloatingPointHelper::CallCCodeForDoubleOperation(
     Token::Value op,
     Register heap_number_result,
     Register scratch) {
-  UNIMPLEMENTED_MIPS();
+  // Using core registers:
+  // a0: Left value (least significant part of mantissa).
+  // a1: Left value (sign, exponent, top of mantissa).
+  // a2: Right value (least significant part of mantissa).
+  // a3: Right value (sign, exponent, top of mantissa).
+
+  // Assert that heap_number_result is saved.
+  // We currently always use s0 to pass it.
+  ASSERT(heap_number_result.is(s0));
+
+  // Push the current return address before the C call.
+  __ push(ra);
+  __ PrepareCallCFunction(4, scratch);  // Two doubles are 4 arguments.
+  if (!IsMipsSoftFloatABI) {
+    CpuFeatures::Scope scope(FPU);
+    // We are not using MIPS FPU instructions, and parameters for the runtime
+    // function call are prepaired in a0-a3 registers, but function we are
+    // calling is compiled with hard-float flag and expecting hard float ABI
+    // (parameters in f12/f14 registers). We need to copy parameters from
+    // a0-a3 registers to f12/f14 register pairs.
+    __ mtc1(a0, f12);
+    __ mtc1(a1, f13);
+    __ mtc1(a2, f14);
+    __ mtc1(a3, f15);
+  }
+  // Call C routine that may not cause GC or other trouble.
+  __ CallCFunction(ExternalReference::double_fp_operation(op, masm->isolate()),
+                   4);
+  // Store answer in the overwritable heap number.
+  if (!IsMipsSoftFloatABI) {
+    CpuFeatures::Scope scope(FPU);
+    // Double returned in register f0.
+    __ sdc1(f0, FieldMemOperand(heap_number_result, HeapNumber::kValueOffset));
+  } else {
+    // Double returned in registers v0 and v1.
+    __ sw(v1, FieldMemOperand(heap_number_result, HeapNumber::kExponentOffset));
+    __ sw(v0, FieldMemOperand(heap_number_result, HeapNumber::kMantissaOffset));
+  }
+  // Place heap_number_result in v0 and return to the pushed return address.
+  __ mov(v0, heap_number_result);
+  __ pop(ra);
+  __ Ret();
 }
 
 
 // See comment for class, this does NOT work for int32's that are in Smi range.
 void WriteInt32ToHeapNumberStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label max_negative_int;
+  // the_int_ has the answer which is a signed int32 but not a Smi.
+  // We test for the special value that has a different exponent.
+  STATIC_ASSERT(HeapNumber::kSignMask == 0x80000000u);
+  // Test sign, and save for later conditionals.
+  __ And(sign_, the_int_, Operand(0x80000000u));
+  __ Branch(&max_negative_int, eq, the_int_, Operand(0x80000000u));
+
+  // Set up the correct exponent in scratch_.  All non-Smi int32s have the same.
+  // A non-Smi integer is 1.xxx * 2^30 so the exponent is 30 (biased).
+  uint32_t non_smi_exponent =
+      (HeapNumber::kExponentBias + 30) << HeapNumber::kExponentShift;
+  __ li(scratch_, Operand(non_smi_exponent));
+  // Set the sign bit in scratch_ if the value was negative.
+  __ or_(scratch_, scratch_, sign_);
+  // Subtract from 0 if the value was negative.
+  __ subu(at, zero_reg, the_int_);
+  __ movn(the_int_, at, sign_);
+  // We should be masking the implict first digit of the mantissa away here,
+  // but it just ends up combining harmlessly with the last digit of the
+  // exponent that happens to be 1.  The sign bit is 0 so we shift 10 to get
+  // the most significant 1 to hit the last bit of the 12 bit sign and exponent.
+  ASSERT(((1 << HeapNumber::kExponentShift) & non_smi_exponent) != 0);
+  const int shift_distance = HeapNumber::kNonMantissaBitsInTopWord - 2;
+  __ srl(at, the_int_, shift_distance);
+  __ or_(scratch_, scratch_, at);
+  __ sw(scratch_, FieldMemOperand(the_heap_number_,
+                                   HeapNumber::kExponentOffset));
+  __ sll(scratch_, the_int_, 32 - shift_distance);
+  __ sw(scratch_, FieldMemOperand(the_heap_number_,
+                                   HeapNumber::kMantissaOffset));
+  __ Ret();
+
+  __ bind(&max_negative_int);
+  // The max negative int32 is stored as a positive number in the mantissa of
+  // a double because it uses a sign bit instead of using two's complement.
+  // The actual mantissa bits stored are all 0 because the implicit most
+  // significant 1 bit is not stored.
+  non_smi_exponent += 1 << HeapNumber::kExponentShift;
+  __ li(scratch_, Operand(HeapNumber::kSignMask | non_smi_exponent));
+  __ sw(scratch_,
+        FieldMemOperand(the_heap_number_, HeapNumber::kExponentOffset));
+  __ mov(scratch_, zero_reg);
+  __ sw(scratch_,
+        FieldMemOperand(the_heap_number_, HeapNumber::kMantissaOffset));
+  __ Ret();
+}
+
+
+// Handle the case where the lhs and rhs are the same object.
+// Equality is almost reflexive (everything but NaN), so this is a test
+// for "identity and not NaN".
+static void EmitIdenticalObjectComparison(MacroAssembler* masm,
+                                          Label* slow,
+                                          Condition cc,
+                                          bool never_nan_nan) {
+  Label not_identical;
+  Label heap_number, return_equal;
+  Register exp_mask_reg = t5;
+
+  __ Branch(&not_identical, ne, a0, Operand(a1));
+
+  // The two objects are identical. If we know that one of them isn't NaN then
+  // we now know they test equal.
+  if (cc != eq || !never_nan_nan) {
+    __ li(exp_mask_reg, Operand(HeapNumber::kExponentMask));
+
+    // Test for NaN. Sadly, we can't just compare to factory->nan_value(),
+    // so we do the second best thing - test it ourselves.
+    // They are both equal and they are not both Smis so both of them are not
+    // Smis. If it's not a heap number, then return equal.
+    if (cc == less || cc == greater) {
+      __ GetObjectType(a0, t4, t4);
+      __ Branch(slow, greater, t4, Operand(FIRST_JS_OBJECT_TYPE));
+    } else {
+      __ GetObjectType(a0, t4, t4);
+      __ Branch(&heap_number, eq, t4, Operand(HEAP_NUMBER_TYPE));
+      // Comparing JS objects with <=, >= is complicated.
+      if (cc != eq) {
+      __ Branch(slow, greater, t4, Operand(FIRST_JS_OBJECT_TYPE));
+        // Normally here we fall through to return_equal, but undefined is
+        // special: (undefined == undefined) == true, but
+        // (undefined <= undefined) == false!  See ECMAScript 11.8.5.
+        if (cc == less_equal || cc == greater_equal) {
+          __ Branch(&return_equal, ne, t4, Operand(ODDBALL_TYPE));
+          __ LoadRoot(t2, Heap::kUndefinedValueRootIndex);
+          __ Branch(&return_equal, ne, a0, Operand(t2));
+          if (cc == le) {
+            // undefined <= undefined should fail.
+            __ li(v0, Operand(GREATER));
+          } else  {
+            // undefined >= undefined should fail.
+            __ li(v0, Operand(LESS));
+          }
+          __ Ret();
+        }
+      }
+    }
+  }
+
+  __ bind(&return_equal);
+  if (cc == less) {
+    __ li(v0, Operand(GREATER));  // Things aren't less than themselves.
+  } else if (cc == greater) {
+    __ li(v0, Operand(LESS));     // Things aren't greater than themselves.
+  } else {
+    __ mov(v0, zero_reg);         // Things are <=, >=, ==, === themselves.
+  }
+  __ Ret();
+
+  if (cc != eq || !never_nan_nan) {
+    // For less and greater we don't have to check for NaN since the result of
+    // x < x is false regardless.  For the others here is some code to check
+    // for NaN.
+    if (cc != lt && cc != gt) {
+      __ bind(&heap_number);
+      // It is a heap number, so return non-equal if it's NaN and equal if it's
+      // not NaN.
+
+      // The representation of NaN values has all exponent bits (52..62) set,
+      // and not all mantissa bits (0..51) clear.
+      // Read top bits of double representation (second word of value).
+      __ lw(t2, FieldMemOperand(a0, HeapNumber::kExponentOffset));
+      // Test that exponent bits are all set.
+      __ And(t3, t2, Operand(exp_mask_reg));
+      // If all bits not set (ne cond), then not a NaN, objects are equal.
+      __ Branch(&return_equal, ne, t3, Operand(exp_mask_reg));
+
+      // Shift out flag and all exponent bits, retaining only mantissa.
+      __ sll(t2, t2, HeapNumber::kNonMantissaBitsInTopWord);
+      // Or with all low-bits of mantissa.
+      __ lw(t3, FieldMemOperand(a0, HeapNumber::kMantissaOffset));
+      __ Or(v0, t3, Operand(t2));
+      // For equal we already have the right value in v0:  Return zero (equal)
+      // if all bits in mantissa are zero (it's an Infinity) and non-zero if
+      // not (it's a NaN).  For <= and >= we need to load v0 with the failing
+      // value if it's a NaN.
+      if (cc != eq) {
+        // All-zero means Infinity means equal.
+        __ Ret(eq, v0, Operand(zero_reg));
+        if (cc == le) {
+          __ li(v0, Operand(GREATER));  // NaN <= NaN should fail.
+        } else {
+          __ li(v0, Operand(LESS));     // NaN >= NaN should fail.
+        }
+      }
+      __ Ret();
+    }
+    // No fall through here.
+  }
+
+  __ bind(&not_identical);
+}
+
+
+static void EmitSmiNonsmiComparison(MacroAssembler* masm,
+                                    Register lhs,
+                                    Register rhs,
+                                    Label* both_loaded_as_doubles,
+                                    Label* slow,
+                                    bool strict) {
+  ASSERT((lhs.is(a0) && rhs.is(a1)) ||
+         (lhs.is(a1) && rhs.is(a0)));
+
+  Label lhs_is_smi;
+  __ And(t0, lhs, Operand(kSmiTagMask));
+  __ Branch(&lhs_is_smi, eq, t0, Operand(zero_reg));
+  // Rhs is a Smi.
+  // Check whether the non-smi is a heap number.
+  __ GetObjectType(lhs, t4, t4);
+  if (strict) {
+    // If lhs was not a number and rhs was a Smi then strict equality cannot
+    // succeed. Return non-equal (lhs is already not zero).
+    __ mov(v0, lhs);
+    __ Ret(ne, t4, Operand(HEAP_NUMBER_TYPE));
+  } else {
+    // Smi compared non-strictly with a non-Smi non-heap-number. Call
+    // the runtime.
+    __ Branch(slow, ne, t4, Operand(HEAP_NUMBER_TYPE));
+  }
+
+  // Rhs is a smi, lhs is a number.
+  // Convert smi rhs to double.
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+    __ sra(at, rhs, kSmiTagSize);
+    __ mtc1(at, f14);
+    __ cvt_d_w(f14, f14);
+    __ ldc1(f12, FieldMemOperand(lhs, HeapNumber::kValueOffset));
+  } else {
+    // Load lhs to a double in a2, a3.
+    __ lw(a3, FieldMemOperand(lhs, HeapNumber::kValueOffset + 4));
+    __ lw(a2, FieldMemOperand(lhs, HeapNumber::kValueOffset));
+
+    // Write Smi from rhs to a1 and a0 in double format. t5 is scratch.
+    __ mov(t6, rhs);
+    ConvertToDoubleStub stub1(a1, a0, t6, t5);
+    __ push(ra);
+    __ Call(stub1.GetCode(), RelocInfo::CODE_TARGET);
+
+    __ pop(ra);
+  }
+
+  // We now have both loaded as doubles.
+  __ jmp(both_loaded_as_doubles);
+
+  __ bind(&lhs_is_smi);
+  // Lhs is a Smi.  Check whether the non-smi is a heap number.
+  __ GetObjectType(rhs, t4, t4);
+  if (strict) {
+    // If lhs was not a number and rhs was a Smi then strict equality cannot
+    // succeed. Return non-equal.
+    __ li(v0, Operand(1));
+    __ Ret(ne, t4, Operand(HEAP_NUMBER_TYPE));
+  } else {
+    // Smi compared non-strictly with a non-Smi non-heap-number. Call
+    // the runtime.
+    __ Branch(slow, ne, t4, Operand(HEAP_NUMBER_TYPE));
+  }
+
+  // Lhs is a smi, rhs is a number.
+  // Convert smi lhs to double.
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+    __ sra(at, lhs, kSmiTagSize);
+    __ mtc1(at, f12);
+    __ cvt_d_w(f12, f12);
+    __ ldc1(f14, FieldMemOperand(rhs, HeapNumber::kValueOffset));
+  } else {
+    // Convert lhs to a double format. t5 is scratch.
+    __ mov(t6, lhs);
+    ConvertToDoubleStub stub2(a3, a2, t6, t5);
+    __ push(ra);
+    __ Call(stub2.GetCode(), RelocInfo::CODE_TARGET);
+    __ pop(ra);
+    // Load rhs to a double in a1, a0.
+    if (rhs.is(a0)) {
+      __ lw(a1, FieldMemOperand(rhs, HeapNumber::kValueOffset + 4));
+      __ lw(a0, FieldMemOperand(rhs, HeapNumber::kValueOffset));
+    } else {
+      __ lw(a0, FieldMemOperand(rhs, HeapNumber::kValueOffset));
+      __ lw(a1, FieldMemOperand(rhs, HeapNumber::kValueOffset + 4));
+    }
+  }
+  // Fall through to both_loaded_as_doubles.
 }
 
 
 void EmitNanCheck(MacroAssembler* masm, Condition cc) {
-  UNIMPLEMENTED_MIPS();
+  bool exp_first = (HeapNumber::kExponentOffset == HeapNumber::kValueOffset);
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+    // Lhs and rhs are already loaded to f12 and f14 register pairs.
+    __ mfc1(t0, f14);  // f14 has LS 32 bits of rhs.
+    __ mfc1(t1, f15);  // f15 has MS 32 bits of rhs.
+    __ mfc1(t2, f12);  // f12 has LS 32 bits of lhs.
+    __ mfc1(t3, f13);  // f13 has MS 32 bits of lhs.
+  } else {
+    // Lhs and rhs are already loaded to GP registers.
+    __ mov(t0, a0);  // a0 has LS 32 bits of rhs.
+    __ mov(t1, a1);  // a1 has MS 32 bits of rhs.
+    __ mov(t2, a2);  // a2 has LS 32 bits of lhs.
+    __ mov(t3, a3);  // a3 has MS 32 bits of lhs.
+  }
+  Register rhs_exponent = exp_first ? t0 : t1;
+  Register lhs_exponent = exp_first ? t2 : t3;
+  Register rhs_mantissa = exp_first ? t1 : t0;
+  Register lhs_mantissa = exp_first ? t3 : t2;
+  Label one_is_nan, neither_is_nan;
+  Label lhs_not_nan_exp_mask_is_loaded;
+
+  Register exp_mask_reg = t4;
+  __ li(exp_mask_reg, HeapNumber::kExponentMask);
+  __ and_(t5, lhs_exponent, exp_mask_reg);
+  __ Branch(&lhs_not_nan_exp_mask_is_loaded, ne, t5, Operand(exp_mask_reg));
+
+  __ sll(t5, lhs_exponent, HeapNumber::kNonMantissaBitsInTopWord);
+  __ Branch(&one_is_nan, ne, t5, Operand(zero_reg));
+
+  __ Branch(&one_is_nan, ne, lhs_mantissa, Operand(zero_reg));
+
+  __ li(exp_mask_reg, HeapNumber::kExponentMask);
+  __ bind(&lhs_not_nan_exp_mask_is_loaded);
+  __ and_(t5, rhs_exponent, exp_mask_reg);
+
+  __ Branch(&neither_is_nan, ne, t5, Operand(exp_mask_reg));
+
+  __ sll(t5, rhs_exponent, HeapNumber::kNonMantissaBitsInTopWord);
+  __ Branch(&one_is_nan, ne, t5, Operand(zero_reg));
+
+  __ Branch(&neither_is_nan, eq, rhs_mantissa, Operand(zero_reg));
+
+  __ bind(&one_is_nan);
+  // NaN comparisons always fail.
+  // Load whatever we need in v0 to make the comparison fail.
+  if (cc == lt || cc == le) {
+    __ li(v0, Operand(GREATER));
+  } else {
+    __ li(v0, Operand(LESS));
+  }
+  __ Ret();  // Return.
+
+  __ bind(&neither_is_nan);
+}
+
+
+static void EmitTwoNonNanDoubleComparison(MacroAssembler* masm, Condition cc) {
+  // f12 and f14 have the two doubles.  Neither is a NaN.
+  // Call a native function to do a comparison between two non-NaNs.
+  // Call C routine that may not cause GC or other trouble.
+  // We use a call_was and return manually because we need arguments slots to
+  // be freed.
+
+  Label return_result_not_equal, return_result_equal;
+  if (cc == eq) {
+    // Doubles are not equal unless they have the same bit pattern.
+    // Exception: 0 and -0.
+    bool exp_first = (HeapNumber::kExponentOffset == HeapNumber::kValueOffset);
+    if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+      // Lhs and rhs are already loaded to f12 and f14 register pairs.
+      __ mfc1(t0, f14);  // f14 has LS 32 bits of rhs.
+      __ mfc1(t1, f15);  // f15 has MS 32 bits of rhs.
+      __ mfc1(t2, f12);  // f12 has LS 32 bits of lhs.
+      __ mfc1(t3, f13);  // f13 has MS 32 bits of lhs.
+    } else {
+      // Lhs and rhs are already loaded to GP registers.
+      __ mov(t0, a0);  // a0 has LS 32 bits of rhs.
+      __ mov(t1, a1);  // a1 has MS 32 bits of rhs.
+      __ mov(t2, a2);  // a2 has LS 32 bits of lhs.
+      __ mov(t3, a3);  // a3 has MS 32 bits of lhs.
+    }
+    Register rhs_exponent = exp_first ? t0 : t1;
+    Register lhs_exponent = exp_first ? t2 : t3;
+    Register rhs_mantissa = exp_first ? t1 : t0;
+    Register lhs_mantissa = exp_first ? t3 : t2;
+
+    __ xor_(v0, rhs_mantissa, lhs_mantissa);
+    __ Branch(&return_result_not_equal, ne, v0, Operand(zero_reg));
+
+    __ subu(v0, rhs_exponent, lhs_exponent);
+    __ Branch(&return_result_equal, eq, v0, Operand(zero_reg));
+    // 0, -0 case.
+    __ sll(rhs_exponent, rhs_exponent, kSmiTagSize);
+    __ sll(lhs_exponent, lhs_exponent, kSmiTagSize);
+    __ or_(t4, rhs_exponent, lhs_exponent);
+    __ or_(t4, t4, rhs_mantissa);
+
+    __ Branch(&return_result_not_equal, ne, t4, Operand(zero_reg));
+
+    __ bind(&return_result_equal);
+    __ li(v0, Operand(EQUAL));
+    __ Ret();
+  }
+
+  __ bind(&return_result_not_equal);
+
+  if (!CpuFeatures::IsSupported(FPU)) {
+    __ push(ra);
+    __ PrepareCallCFunction(4, t4);  // Two doubles count as 4 arguments.
+    if (!IsMipsSoftFloatABI) {
+      // We are not using MIPS FPU instructions, and parameters for the runtime
+      // function call are prepaired in a0-a3 registers, but function we are
+      // calling is compiled with hard-float flag and expecting hard float ABI
+      // (parameters in f12/f14 registers). We need to copy parameters from
+      // a0-a3 registers to f12/f14 register pairs.
+      __ mtc1(a0, f12);
+      __ mtc1(a1, f13);
+      __ mtc1(a2, f14);
+      __ mtc1(a3, f15);
+    }
+    __ CallCFunction(ExternalReference::compare_doubles(masm->isolate()), 4);
+    __ pop(ra);  // Because this function returns int, result is in v0.
+    __ Ret();
+  } else {
+    CpuFeatures::Scope scope(FPU);
+    Label equal, less_than;
+    __ c(EQ, D, f12, f14);
+    __ bc1t(&equal);
+    __ nop();
+
+    __ c(OLT, D, f12, f14);
+    __ bc1t(&less_than);
+    __ nop();
+
+    // Not equal, not less, not NaN, must be greater.
+    __ li(v0, Operand(GREATER));
+    __ Ret();
+
+    __ bind(&equal);
+    __ li(v0, Operand(EQUAL));
+    __ Ret();
+
+    __ bind(&less_than);
+    __ li(v0, Operand(LESS));
+    __ Ret();
+  }
+}
+
+
+static void EmitStrictTwoHeapObjectCompare(MacroAssembler* masm,
+                                           Register lhs,
+                                           Register rhs) {
+    // If either operand is a JSObject or an oddball value, then they are
+    // not equal since their pointers are different.
+    // There is no test for undetectability in strict equality.
+    STATIC_ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);
+    Label first_non_object;
+    // Get the type of the first operand into a2 and compare it with
+    // FIRST_JS_OBJECT_TYPE.
+    __ GetObjectType(lhs, a2, a2);
+    __ Branch(&first_non_object, less, a2, Operand(FIRST_JS_OBJECT_TYPE));
+
+    // Return non-zero.
+    Label return_not_equal;
+    __ bind(&return_not_equal);
+    __ li(v0, Operand(1));
+    __ Ret();
+
+    __ bind(&first_non_object);
+    // Check for oddballs: true, false, null, undefined.
+    __ Branch(&return_not_equal, eq, a2, Operand(ODDBALL_TYPE));
+
+    __ GetObjectType(rhs, a3, a3);
+    __ Branch(&return_not_equal, greater, a3, Operand(FIRST_JS_OBJECT_TYPE));
+
+    // Check for oddballs: true, false, null, undefined.
+    __ Branch(&return_not_equal, eq, a3, Operand(ODDBALL_TYPE));
+
+    // Now that we have the types we might as well check for symbol-symbol.
+    // Ensure that no non-strings have the symbol bit set.
+    STATIC_ASSERT(LAST_TYPE < kNotStringTag + kIsSymbolMask);
+    STATIC_ASSERT(kSymbolTag != 0);
+    __ And(t2, a2, Operand(a3));
+    __ And(t0, t2, Operand(kIsSymbolMask));
+    __ Branch(&return_not_equal, ne, t0, Operand(zero_reg));
+}
+
+
+static void EmitCheckForTwoHeapNumbers(MacroAssembler* masm,
+                                       Register lhs,
+                                       Register rhs,
+                                       Label* both_loaded_as_doubles,
+                                       Label* not_heap_numbers,
+                                       Label* slow) {
+  __ GetObjectType(lhs, a3, a2);
+  __ Branch(not_heap_numbers, ne, a2, Operand(HEAP_NUMBER_TYPE));
+  __ lw(a2, FieldMemOperand(rhs, HeapObject::kMapOffset));
+  // If first was a heap number & second wasn't, go to slow case.
+  __ Branch(slow, ne, a3, Operand(a2));
+
+  // Both are heap numbers. Load them up then jump to the code we have
+  // for that.
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+    __ ldc1(f12, FieldMemOperand(lhs, HeapNumber::kValueOffset));
+    __ ldc1(f14, FieldMemOperand(rhs, HeapNumber::kValueOffset));
+  } else {
+    __ lw(a2, FieldMemOperand(lhs, HeapNumber::kValueOffset));
+    __ lw(a3, FieldMemOperand(lhs, HeapNumber::kValueOffset + 4));
+    if (rhs.is(a0)) {
+      __ lw(a1, FieldMemOperand(rhs, HeapNumber::kValueOffset + 4));
+      __ lw(a0, FieldMemOperand(rhs, HeapNumber::kValueOffset));
+    } else {
+      __ lw(a0, FieldMemOperand(rhs, HeapNumber::kValueOffset));
+      __ lw(a1, FieldMemOperand(rhs, HeapNumber::kValueOffset + 4));
+    }
+  }
+  __ jmp(both_loaded_as_doubles);
+}
+
+
+// Fast negative check for symbol-to-symbol equality.
+static void EmitCheckForSymbolsOrObjects(MacroAssembler* masm,
+                                         Register lhs,
+                                         Register rhs,
+                                         Label* possible_strings,
+                                         Label* not_both_strings) {
+  ASSERT((lhs.is(a0) && rhs.is(a1)) ||
+         (lhs.is(a1) && rhs.is(a0)));
+
+  // a2 is object type of lhs.
+  // Ensure that no non-strings have the symbol bit set.
+  Label object_test;
+  STATIC_ASSERT(kSymbolTag != 0);
+  __ And(at, a2, Operand(kIsNotStringMask));
+  __ Branch(&object_test, ne, at, Operand(zero_reg));
+  __ And(at, a2, Operand(kIsSymbolMask));
+  __ Branch(possible_strings, eq, at, Operand(zero_reg));
+  __ GetObjectType(rhs, a3, a3);
+  __ Branch(not_both_strings, ge, a3, Operand(FIRST_NONSTRING_TYPE));
+  __ And(at, a3, Operand(kIsSymbolMask));
+  __ Branch(possible_strings, eq, at, Operand(zero_reg));
+
+  // Both are symbols. We already checked they weren't the same pointer
+  // so they are not equal.
+  __ li(v0, Operand(1));   // Non-zero indicates not equal.
+  __ Ret();
+
+  __ bind(&object_test);
+  __ Branch(not_both_strings, lt, a2, Operand(FIRST_JS_OBJECT_TYPE));
+  __ GetObjectType(rhs, a2, a3);
+  __ Branch(not_both_strings, lt, a3, Operand(FIRST_JS_OBJECT_TYPE));
+
+  // If both objects are undetectable, they are equal.  Otherwise, they
+  // are not equal, since they are different objects and an object is not
+  // equal to undefined.
+  __ lw(a3, FieldMemOperand(lhs, HeapObject::kMapOffset));
+  __ lbu(a2, FieldMemOperand(a2, Map::kBitFieldOffset));
+  __ lbu(a3, FieldMemOperand(a3, Map::kBitFieldOffset));
+  __ and_(a0, a2, a3);
+  __ And(a0, a0, Operand(1 << Map::kIsUndetectable));
+  __ Xor(v0, a0, Operand(1 << Map::kIsUndetectable));
+  __ Ret();
 }
 
 
@@ -235,12 +1443,109 @@ void NumberToStringStub::GenerateLookupNumberStringCache(MacroAssembler* masm,
                                                          Register scratch3,
                                                          bool object_is_smi,
                                                          Label* not_found) {
-  UNIMPLEMENTED_MIPS();
+  // Use of registers. Register result is used as a temporary.
+  Register number_string_cache = result;
+  Register mask = scratch3;
+
+  // Load the number string cache.
+  __ LoadRoot(number_string_cache, Heap::kNumberStringCacheRootIndex);
+
+  // Make the hash mask from the length of the number string cache. It
+  // contains two elements (number and string) for each cache entry.
+  __ lw(mask, FieldMemOperand(number_string_cache, FixedArray::kLengthOffset));
+  // Divide length by two (length is a smi).
+  __ sra(mask, mask, kSmiTagSize + 1);
+  __ Addu(mask, mask, -1);  // Make mask.
+
+  // Calculate the entry in the number string cache. The hash value in the
+  // number string cache for smis is just the smi value, and the hash for
+  // doubles is the xor of the upper and lower words. See
+  // Heap::GetNumberStringCache.
+  Isolate* isolate = masm->isolate();
+  Label is_smi;
+  Label load_result_from_cache;
+  if (!object_is_smi) {
+    __ JumpIfSmi(object, &is_smi);
+    if (CpuFeatures::IsSupported(FPU)) {
+      CpuFeatures::Scope scope(FPU);
+      __ CheckMap(object,
+                  scratch1,
+                  Heap::kHeapNumberMapRootIndex,
+                  not_found,
+                  true);
+
+      STATIC_ASSERT(8 == kDoubleSize);
+      __ Addu(scratch1,
+              object,
+              Operand(HeapNumber::kValueOffset - kHeapObjectTag));
+      __ lw(scratch2, MemOperand(scratch1, kPointerSize));
+      __ lw(scratch1, MemOperand(scratch1, 0));
+      __ Xor(scratch1, scratch1, Operand(scratch2));
+      __ And(scratch1, scratch1, Operand(mask));
+
+      // Calculate address of entry in string cache: each entry consists
+      // of two pointer sized fields.
+      __ sll(scratch1, scratch1, kPointerSizeLog2 + 1);
+      __ Addu(scratch1, number_string_cache, scratch1);
+
+      Register probe = mask;
+      __ lw(probe,
+             FieldMemOperand(scratch1, FixedArray::kHeaderSize));
+      __ JumpIfSmi(probe, not_found);
+      __ ldc1(f12, FieldMemOperand(object, HeapNumber::kValueOffset));
+      __ ldc1(f14, FieldMemOperand(probe, HeapNumber::kValueOffset));
+      __ c(EQ, D, f12, f14);
+      __ bc1t(&load_result_from_cache);
+      __ nop();   // bc1t() requires explicit fill of branch delay slot.
+      __ Branch(not_found);
+    } else {
+      // Note that there is no cache check for non-FPU case, even though
+      // it seems there could be. May be a tiny opimization for non-FPU
+      // cores.
+      __ Branch(not_found);
+    }
+  }
+
+  __ bind(&is_smi);
+  Register scratch = scratch1;
+  __ sra(scratch, object, 1);   // Shift away the tag.
+  __ And(scratch, mask, Operand(scratch));
+
+  // Calculate address of entry in string cache: each entry consists
+  // of two pointer sized fields.
+  __ sll(scratch, scratch, kPointerSizeLog2 + 1);
+  __ Addu(scratch, number_string_cache, scratch);
+
+  // Check if the entry is the smi we are looking for.
+  Register probe = mask;
+  __ lw(probe, FieldMemOperand(scratch, FixedArray::kHeaderSize));
+  __ Branch(not_found, ne, object, Operand(probe));
+
+  // Get the result from the cache.
+  __ bind(&load_result_from_cache);
+  __ lw(result,
+         FieldMemOperand(scratch, FixedArray::kHeaderSize + kPointerSize));
+
+  __ IncrementCounter(isolate->counters()->number_to_string_native(),
+                      1,
+                      scratch1,
+                      scratch2);
 }
 
 
 void NumberToStringStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label runtime;
+
+  __ lw(a1, MemOperand(sp, 0));
+
+  // Generate code to lookup number in the number string cache.
+  GenerateLookupNumberStringCache(masm, a1, v0, a2, a3, t0, false, &runtime);
+  __ Addu(sp, sp, Operand(1 * kPointerSize));
+  __ Ret();
+
+  __ bind(&runtime);
+  // Handle number to string in the runtime system if not found in the cache.
+  __ TailCallRuntime(Runtime::kNumberToString, 1, 1);
 }
 
 
@@ -248,14 +1553,254 @@ void NumberToStringStub::Generate(MacroAssembler* masm) {
 // On exit, v0 is 0, positive, or negative (smi) to indicate the result
 // of the comparison.
 void CompareStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label slow;  // Call builtin.
+  Label not_smis, both_loaded_as_doubles;
+
+
+  if (include_smi_compare_) {
+    Label not_two_smis, smi_done;
+    __ Or(a2, a1, a0);
+    __ JumpIfNotSmi(a2, &not_two_smis);
+    __ sra(a1, a1, 1);
+    __ sra(a0, a0, 1);
+    __ Subu(v0, a1, a0);
+    __ Ret();
+    __ bind(&not_two_smis);
+  } else if (FLAG_debug_code) {
+    __ Or(a2, a1, a0);
+    __ And(a2, a2, kSmiTagMask);
+    __ Assert(ne, "CompareStub: unexpected smi operands.",
+        a2, Operand(zero_reg));
+  }
+
+
+  // NOTICE! This code is only reached after a smi-fast-case check, so
+  // it is certain that at least one operand isn't a smi.
+
+  // Handle the case where the objects are identical.  Either returns the answer
+  // or goes to slow.  Only falls through if the objects were not identical.
+  EmitIdenticalObjectComparison(masm, &slow, cc_, never_nan_nan_);
+
+  // If either is a Smi (we know that not both are), then they can only
+  // be strictly equal if the other is a HeapNumber.
+  STATIC_ASSERT(kSmiTag == 0);
+  ASSERT_EQ(0, Smi::FromInt(0));
+  __ And(t2, lhs_, Operand(rhs_));
+  __ JumpIfNotSmi(t2, &not_smis, t0);
+  // One operand is a smi. EmitSmiNonsmiComparison generates code that can:
+  // 1) Return the answer.
+  // 2) Go to slow.
+  // 3) Fall through to both_loaded_as_doubles.
+  // 4) Jump to rhs_not_nan.
+  // In cases 3 and 4 we have found out we were dealing with a number-number
+  // comparison and the numbers have been loaded into f12 and f14 as doubles,
+  // or in GP registers (a0, a1, a2, a3) depending on the presence of the FPU.
+  EmitSmiNonsmiComparison(masm, lhs_, rhs_,
+                          &both_loaded_as_doubles, &slow, strict_);
+
+  __ bind(&both_loaded_as_doubles);
+  // f12, f14 are the double representations of the left hand side
+  // and the right hand side if we have FPU. Otherwise a2, a3 represent
+  // left hand side and a0, a1 represent right hand side.
+
+  Isolate* isolate = masm->isolate();
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+    Label nan;
+    __ li(t0, Operand(LESS));
+    __ li(t1, Operand(GREATER));
+    __ li(t2, Operand(EQUAL));
+
+    // Check if either rhs or lhs is NaN.
+    __ c(UN, D, f12, f14);
+    __ bc1t(&nan);
+    __ nop();
+
+    // Check if LESS condition is satisfied. If true, move conditionally
+    // result to v0.
+    __ c(OLT, D, f12, f14);
+    __ movt(v0, t0);
+    // Use previous check to store conditionally to v0 oposite condition
+    // (GREATER). If rhs is equal to lhs, this will be corrected in next
+    // check.
+    __ movf(v0, t1);
+    // Check if EQUAL condition is satisfied. If true, move conditionally
+    // result to v0.
+    __ c(EQ, D, f12, f14);
+    __ movt(v0, t2);
+
+    __ Ret();
+
+    __ bind(&nan);
+    // NaN comparisons always fail.
+    // Load whatever we need in v0 to make the comparison fail.
+    if (cc_ == lt || cc_ == le) {
+      __ li(v0, Operand(GREATER));
+    } else {
+      __ li(v0, Operand(LESS));
+    }
+    __ Ret();
+  } else {
+    // Checks for NaN in the doubles we have loaded.  Can return the answer or
+    // fall through if neither is a NaN.  Also binds rhs_not_nan.
+    EmitNanCheck(masm, cc_);
+
+    // Compares two doubles that are not NaNs. Returns the answer.
+    // Never falls through.
+    EmitTwoNonNanDoubleComparison(masm, cc_);
+  }
+
+  __ bind(&not_smis);
+  // At this point we know we are dealing with two different objects,
+  // and neither of them is a Smi. The objects are in lhs_ and rhs_.
+  if (strict_) {
+    // This returns non-equal for some object types, or falls through if it
+    // was not lucky.
+    EmitStrictTwoHeapObjectCompare(masm, lhs_, rhs_);
+  }
+
+  Label check_for_symbols;
+  Label flat_string_check;
+  // Check for heap-number-heap-number comparison. Can jump to slow case,
+  // or load both doubles and jump to the code that handles
+  // that case. If the inputs are not doubles then jumps to check_for_symbols.
+  // In this case a2 will contain the type of lhs_.
+  EmitCheckForTwoHeapNumbers(masm,
+                             lhs_,
+                             rhs_,
+                             &both_loaded_as_doubles,
+                             &check_for_symbols,
+                             &flat_string_check);
+
+  __ bind(&check_for_symbols);
+  if (cc_ == eq && !strict_) {
+    // Returns an answer for two symbols or two detectable objects.
+    // Otherwise jumps to string case or not both strings case.
+    // Assumes that a2 is the type of lhs_ on entry.
+    EmitCheckForSymbolsOrObjects(masm, lhs_, rhs_, &flat_string_check, &slow);
+  }
+
+  // Check for both being sequential ASCII strings, and inline if that is the
+  // case.
+  __ bind(&flat_string_check);
+
+  __ JumpIfNonSmisNotBothSequentialAsciiStrings(lhs_, rhs_, a2, a3, &slow);
+
+  __ IncrementCounter(isolate->counters()->string_compare_native(), 1, a2, a3);
+  if (cc_ == eq) {
+    StringCompareStub::GenerateFlatAsciiStringEquals(masm,
+                                                     lhs_,
+                                                     rhs_,
+                                                     a2,
+                                                     a3,
+                                                     t0);
+  } else {
+    StringCompareStub::GenerateCompareFlatAsciiStrings(masm,
+                                                       lhs_,
+                                                       rhs_,
+                                                       a2,
+                                                       a3,
+                                                       t0,
+                                                       t1);
+  }
+  // Never falls through to here.
+
+  __ bind(&slow);
+  // Prepare for call to builtin. Push object pointers, a0 (lhs) first,
+  // a1 (rhs) second.
+  __ Push(lhs_, rhs_);
+  // Figure out which native to call and setup the arguments.
+  Builtins::JavaScript native;
+  if (cc_ == eq) {
+    native = strict_ ? Builtins::STRICT_EQUALS : Builtins::EQUALS;
+  } else {
+    native = Builtins::COMPARE;
+    int ncr;  // NaN compare result.
+    if (cc_ == lt || cc_ == le) {
+      ncr = GREATER;
+    } else {
+      ASSERT(cc_ == gt || cc_ == ge);  // Remaining cases.
+      ncr = LESS;
+    }
+    __ li(a0, Operand(Smi::FromInt(ncr)));
+    __ push(a0);
+  }
+
+  // Call the native; it returns -1 (less), 0 (equal), or 1 (greater)
+  // tagged as a small integer.
+  __ InvokeBuiltin(native, JUMP_FUNCTION);
 }
 
 
 // This stub does not handle the inlined cases (Smis, Booleans, undefined).
 // The stub returns zero for false, and a non-zero value for true.
 void ToBooleanStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // This stub uses FPU instructions.
+  ASSERT(CpuFeatures::IsEnabled(FPU));
+
+  Label false_result;
+  Label not_heap_number;
+  Register scratch0 = t5.is(tos_) ? t3 : t5;
+
+  __ LoadRoot(scratch0, Heap::kNullValueRootIndex);
+  __ Branch(&false_result, eq, tos_, Operand(scratch0));
+
+  // HeapNumber => false if +0, -0, or NaN.
+  __ lw(scratch0, FieldMemOperand(tos_, HeapObject::kMapOffset));
+  __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
+  __ Branch(&not_heap_number, ne, scratch0, Operand(at));
+
+  __ Subu(at, tos_, Operand(kHeapObjectTag));
+  __ ldc1(f12, MemOperand(at, HeapNumber::kValueOffset));
+  __ fcmp(f12, 0.0, UEQ);
+
+  // "tos_" is a register, and contains a non zero value by default.
+  // Hence we only need to overwrite "tos_" with zero to return false for
+  // FP_ZERO or FP_NAN cases. Otherwise, by default it returns true.
+  __ movt(tos_, zero_reg);
+  __ Ret();
+
+  __ bind(&not_heap_number);
+
+  // Check if the value is 'null'.
+  // 'null' => false.
+  __ LoadRoot(at, Heap::kNullValueRootIndex);
+  __ Branch(&false_result, eq, tos_, Operand(at));
+
+  // It can be an undetectable object.
+  // Undetectable => false.
+  __ lw(at, FieldMemOperand(tos_, HeapObject::kMapOffset));
+  __ lbu(scratch0, FieldMemOperand(at, Map::kBitFieldOffset));
+  __ And(scratch0, scratch0, Operand(1 << Map::kIsUndetectable));
+  __ Branch(&false_result, eq, scratch0, Operand(1 << Map::kIsUndetectable));
+
+  // JavaScript object => true.
+  __ lw(scratch0, FieldMemOperand(tos_, HeapObject::kMapOffset));
+  __ lbu(scratch0, FieldMemOperand(scratch0, Map::kInstanceTypeOffset));
+
+  // "tos_" is a register and contains a non-zero value.
+  // Hence we implicitly return true if the greater than
+  // condition is satisfied.
+  __ Ret(gt, scratch0, Operand(FIRST_JS_OBJECT_TYPE));
+
+  // Check for string.
+  __ lw(scratch0, FieldMemOperand(tos_, HeapObject::kMapOffset));
+  __ lbu(scratch0, FieldMemOperand(scratch0, Map::kInstanceTypeOffset));
+  // "tos_" is a register and contains a non-zero value.
+  // Hence we implicitly return true if the greater than
+  // condition is satisfied.
+  __ Ret(gt, scratch0, Operand(FIRST_NONSTRING_TYPE));
+
+  // String value => false iff empty, i.e., length is zero.
+  __ lw(tos_, FieldMemOperand(tos_, String::kLengthOffset));
+  // If length is zero, "tos_" contains zero ==> false.
+  // If length is not zero, "tos_" contains a non-zero value ==> true.
+  __ Ret();
+
+  // Return 0 in "tos_" for false.
+  __ bind(&false_result);
+  __ mov(tos_, zero_reg);
+  __ Ret();
 }
 
 
@@ -267,99 +1812,288 @@ Handle<Code> GetTypeRecordingUnaryOpStub(int key,
 
 
 const char* TypeRecordingUnaryOpStub::GetName() {
-  UNIMPLEMENTED_MIPS();
-  return NULL;
+  if (name_ != NULL) return name_;
+  const int kMaxNameLength = 100;
+  name_ = Isolate::Current()->bootstrapper()->AllocateAutoDeletedArray(
+      kMaxNameLength);
+  if (name_ == NULL) return "OOM";
+  const char* op_name = Token::Name(op_);
+  const char* overwrite_name = NULL;  // Make g++ happy.
+  switch (mode_) {
+    case UNARY_NO_OVERWRITE: overwrite_name = "Alloc"; break;
+    case UNARY_OVERWRITE: overwrite_name = "Overwrite"; break;
+  }
+
+  OS::SNPrintF(Vector<char>(name_, kMaxNameLength),
+               "TypeRecordingUnaryOpStub_%s_%s_%s",
+               op_name,
+               overwrite_name,
+               TRUnaryOpIC::GetName(operand_type_));
+  return name_;
 }
 
 
 // TODO(svenpanne): Use virtual functions instead of switch.
 void TypeRecordingUnaryOpStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  switch (operand_type_) {
+    case TRUnaryOpIC::UNINITIALIZED:
+      GenerateTypeTransition(masm);
+      break;
+    case TRUnaryOpIC::SMI:
+      GenerateSmiStub(masm);
+      break;
+    case TRUnaryOpIC::HEAP_NUMBER:
+      GenerateHeapNumberStub(masm);
+      break;
+    case TRUnaryOpIC::GENERIC:
+      GenerateGenericStub(masm);
+      break;
+  }
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateTypeTransition(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Argument is in a0 and v0 at this point, so we can overwrite a0.
+  // Push this stub's key. Although the operation and the type info are
+  // encoded into the key, the encoding is opaque, so push them too.
+  __ li(a2, Operand(Smi::FromInt(MinorKey())));
+  __ li(a1, Operand(Smi::FromInt(op_)));
+  __ li(a0, Operand(Smi::FromInt(operand_type_)));
+
+  __ Push(v0, a2, a1, a0);
+
+  __ TailCallExternalReference(
+      ExternalReference(IC_Utility(IC::kTypeRecordingUnaryOp_Patch),
+                        masm->isolate()),
+      4,
+      1);
 }
 
 
 // TODO(svenpanne): Use virtual functions instead of switch.
 void TypeRecordingUnaryOpStub::GenerateSmiStub(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  switch (op_) {
+    case Token::SUB:
+      GenerateSmiStubSub(masm);
+      break;
+    case Token::BIT_NOT:
+      GenerateSmiStubBitNot(masm);
+      break;
+    default:
+      UNREACHABLE();
+  }
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateSmiStubSub(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label non_smi, slow;
+  GenerateSmiCodeSub(masm, &non_smi, &slow);
+  __ bind(&non_smi);
+  __ bind(&slow);
+  GenerateTypeTransition(masm);
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateSmiStubBitNot(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label non_smi;
+  GenerateSmiCodeBitNot(masm, &non_smi);
+  __ bind(&non_smi);
+  GenerateTypeTransition(masm);
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateSmiCodeSub(MacroAssembler* masm,
                                                   Label* non_smi,
                                                   Label* slow) {
-  UNIMPLEMENTED_MIPS();
+  __ JumpIfNotSmi(a0, non_smi);
+
+  // The result of negating zero or the smallest negative smi is not a smi.
+  __ And(t0, a0, ~0x80000000);
+  __ Branch(slow, eq, t0, Operand(zero_reg));
+
+  // Return '0 - value'.
+  __ Subu(v0, zero_reg, a0);
+  __ Ret();
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateSmiCodeBitNot(MacroAssembler* masm,
                                                      Label* non_smi) {
-  UNIMPLEMENTED_MIPS();
+  __ JumpIfNotSmi(a0, non_smi);
+
+  // Flip bits and revert inverted smi-tag.
+  __ Neg(v0, a0);
+  __ And(v0, v0, ~kSmiTagMask);
+  __ Ret();
 }
 
 
 // TODO(svenpanne): Use virtual functions instead of switch.
 void TypeRecordingUnaryOpStub::GenerateHeapNumberStub(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  switch (op_) {
+    case Token::SUB:
+      GenerateHeapNumberStubSub(masm);
+      break;
+    case Token::BIT_NOT:
+      GenerateHeapNumberStubBitNot(masm);
+      break;
+    default:
+      UNREACHABLE();
+  }
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateHeapNumberStubSub(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label non_smi, slow;
+  GenerateSmiCodeSub(masm, &non_smi, &slow);
+  __ bind(&non_smi);
+  GenerateHeapNumberCodeSub(masm, &slow);
+  __ bind(&slow);
+  GenerateTypeTransition(masm);
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateHeapNumberStubBitNot(
     MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label non_smi, slow;
+  GenerateSmiCodeBitNot(masm, &non_smi);
+  __ bind(&non_smi);
+  GenerateHeapNumberCodeBitNot(masm, &slow);
+  __ bind(&slow);
+  GenerateTypeTransition(masm);
 }
 
-
 void TypeRecordingUnaryOpStub::GenerateHeapNumberCodeSub(MacroAssembler* masm,
                                                          Label* slow) {
-  UNIMPLEMENTED_MIPS();
+  EmitCheckForHeapNumber(masm, a0, a1, t2, slow);
+  // a0 is a heap number.  Get a new heap number in a1.
+  if (mode_ == UNARY_OVERWRITE) {
+    __ lw(a2, FieldMemOperand(a0, HeapNumber::kExponentOffset));
+    __ Xor(a2, a2, Operand(HeapNumber::kSignMask));  // Flip sign.
+    __ sw(a2, FieldMemOperand(a0, HeapNumber::kExponentOffset));
+  } else {
+    Label slow_allocate_heapnumber, heapnumber_allocated;
+    __ AllocateHeapNumber(a1, a2, a3, t2, &slow_allocate_heapnumber);
+    __ jmp(&heapnumber_allocated);
+
+    __ bind(&slow_allocate_heapnumber);
+    __ EnterInternalFrame();
+    __ push(a0);
+    __ CallRuntime(Runtime::kNumberAlloc, 0);
+    __ mov(a1, v0);
+    __ pop(a0);
+    __ LeaveInternalFrame();
+
+    __ bind(&heapnumber_allocated);
+    __ lw(a3, FieldMemOperand(a0, HeapNumber::kMantissaOffset));
+    __ lw(a2, FieldMemOperand(a0, HeapNumber::kExponentOffset));
+    __ sw(a3, FieldMemOperand(a1, HeapNumber::kMantissaOffset));
+    __ Xor(a2, a2, Operand(HeapNumber::kSignMask));  // Flip sign.
+    __ sw(a2, FieldMemOperand(a1, HeapNumber::kExponentOffset));
+    __ mov(v0, a1);
+  }
+  __ Ret();
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateHeapNumberCodeBitNot(
     MacroAssembler* masm, Label* slow) {
-  UNIMPLEMENTED_MIPS();
+  EmitCheckForHeapNumber(masm, a0, a1, t2, slow);
+  // Convert the heap number in a0 to an untagged integer in a1.
+  __ ConvertToInt32(a0, a1, a2, a3, f0, slow);
+
+  // Do the bitwise operation and check if the result fits in a smi.
+  Label try_float;
+  __ Neg(a1, a1);
+  __ Addu(a2, a1, Operand(0x40000000));
+  __ Branch(&try_float, lt, a2, Operand(zero_reg));
+
+  // Tag the result as a smi and we're done.
+  __ SmiTag(v0, a1);
+  __ Ret();
+
+  // Try to store the result in a heap number.
+  __ bind(&try_float);
+  if (mode_ == UNARY_NO_OVERWRITE) {
+    Label slow_allocate_heapnumber, heapnumber_allocated;
+    __ AllocateHeapNumber(v0, a2, a3, t2, &slow_allocate_heapnumber);
+    __ jmp(&heapnumber_allocated);
+
+    __ bind(&slow_allocate_heapnumber);
+    __ EnterInternalFrame();
+    __ push(a1);
+    __ CallRuntime(Runtime::kNumberAlloc, 0);
+    __ pop(a1);
+    __ LeaveInternalFrame();
+
+    __ bind(&heapnumber_allocated);
+  }
+
+  if (CpuFeatures::IsSupported(FPU)) {
+    // Convert the int32 in a1 to the heap number in v0. a2 is corrupted.
+    CpuFeatures::Scope scope(FPU);
+    __ mtc1(a1, f0);
+    __ cvt_d_w(f0, f0);
+    __ sdc1(f0, FieldMemOperand(v0, HeapNumber::kValueOffset));
+    __ Ret();
+  } else {
+    // WriteInt32ToHeapNumberStub does not trigger GC, so we do not
+    // have to set up a frame.
+    WriteInt32ToHeapNumberStub stub(a1, v0, a2, a3);
+    __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
+  }
 }
 
 
 // TODO(svenpanne): Use virtual functions instead of switch.
 void TypeRecordingUnaryOpStub::GenerateGenericStub(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  switch (op_) {
+    case Token::SUB:
+      GenerateGenericStubSub(masm);
+      break;
+    case Token::BIT_NOT:
+      GenerateGenericStubBitNot(masm);
+      break;
+    default:
+      UNREACHABLE();
+  }
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateGenericStubSub(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label non_smi, slow;
+  GenerateSmiCodeSub(masm, &non_smi, &slow);
+  __ bind(&non_smi);
+  GenerateHeapNumberCodeSub(masm, &slow);
+  __ bind(&slow);
+  GenerateGenericCodeFallback(masm);
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateGenericStubBitNot(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label non_smi, slow;
+  GenerateSmiCodeBitNot(masm, &non_smi);
+  __ bind(&non_smi);
+  GenerateHeapNumberCodeBitNot(masm, &slow);
+  __ bind(&slow);
+  GenerateGenericCodeFallback(masm);
 }
 
 
 void TypeRecordingUnaryOpStub::GenerateGenericCodeFallback(
     MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Handle the slow case by jumping to the JavaScript builtin.
+  __ push(a0);
+  switch (op_) {
+    case Token::SUB:
+      __ InvokeBuiltin(Builtins::UNARY_MINUS, JUMP_FUNCTION);
+      break;
+    case Token::BIT_NOT:
+      __ InvokeBuiltin(Builtins::BIT_NOT, JUMP_FUNCTION);
+      break;
+    default:
+      UNREACHABLE();
+  }
 }
 
 
@@ -372,7 +2106,20 @@ Handle<Code> GetTypeRecordingBinaryOpStub(int key,
 
 
 void TypeRecordingBinaryOpStub::GenerateTypeTransition(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label get_result;
+
+  __ Push(a1, a0);
+
+  __ li(a2, Operand(Smi::FromInt(MinorKey())));
+  __ li(a1, Operand(Smi::FromInt(op_)));
+  __ li(a0, Operand(Smi::FromInt(operands_type_)));
+  __ Push(a2, a1, a0);
+
+  __ TailCallExternalReference(
+      ExternalReference(IC_Utility(IC::kTypeRecordingBinaryOp_Patch),
+                        masm->isolate()),
+      5,
+      1);
 }
 
 
@@ -383,12 +2130,57 @@ void TypeRecordingBinaryOpStub::GenerateTypeTransitionWithSavedArgs(
 
 
 void TypeRecordingBinaryOpStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  switch (operands_type_) {
+    case TRBinaryOpIC::UNINITIALIZED:
+      GenerateTypeTransition(masm);
+      break;
+    case TRBinaryOpIC::SMI:
+      GenerateSmiStub(masm);
+      break;
+    case TRBinaryOpIC::INT32:
+      GenerateInt32Stub(masm);
+      break;
+    case TRBinaryOpIC::HEAP_NUMBER:
+      GenerateHeapNumberStub(masm);
+      break;
+    case TRBinaryOpIC::ODDBALL:
+      GenerateOddballStub(masm);
+      break;
+    case TRBinaryOpIC::BOTH_STRING:
+      GenerateBothStringStub(masm);
+      break;
+    case TRBinaryOpIC::STRING:
+      GenerateStringStub(masm);
+      break;
+    case TRBinaryOpIC::GENERIC:
+      GenerateGeneric(masm);
+      break;
+    default:
+      UNREACHABLE();
+  }
 }
 
 
 const char* TypeRecordingBinaryOpStub::GetName() {
-  UNIMPLEMENTED_MIPS();
+  if (name_ != NULL) return name_;
+  const int kMaxNameLength = 100;
+  name_ = Isolate::Current()->bootstrapper()->AllocateAutoDeletedArray(
+      kMaxNameLength);
+  if (name_ == NULL) return "OOM";
+  const char* op_name = Token::Name(op_);
+  const char* overwrite_name;
+  switch (mode_) {
+    case NO_OVERWRITE: overwrite_name = "Alloc"; break;
+    case OVERWRITE_RIGHT: overwrite_name = "OverwriteRight"; break;
+    case OVERWRITE_LEFT: overwrite_name = "OverwriteLeft"; break;
+    default: overwrite_name = "UnknownOverwrite"; break;
+  }
+
+  OS::SNPrintF(Vector<char>(name_, kMaxNameLength),
+               "TypeRecordingBinaryOpStub_%s_%s_%s",
+               op_name,
+               overwrite_name,
+               TRBinaryOpIC::GetName(operands_type_));
   return name_;
 }
 
@@ -396,7 +2188,156 @@ const char* TypeRecordingBinaryOpStub::GetName() {
 
 void TypeRecordingBinaryOpStub::GenerateSmiSmiOperation(
     MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Register left = a1;
+  Register right = a0;
+
+  Register scratch1 = t0;
+  Register scratch2 = t1;
+
+  ASSERT(right.is(a0));
+  STATIC_ASSERT(kSmiTag == 0);
+
+  Label not_smi_result;
+  switch (op_) {
+    case Token::ADD:
+      __ AdduAndCheckForOverflow(v0, left, right, scratch1);
+      __ RetOnNoOverflow(scratch1);
+      // No need to revert anything - right and left are intact.
+      break;
+    case Token::SUB:
+      __ SubuAndCheckForOverflow(v0, left, right, scratch1);
+      __ RetOnNoOverflow(scratch1);
+      // No need to revert anything - right and left are intact.
+      break;
+    case Token::MUL: {
+      // Remove tag from one of the operands. This way the multiplication result
+      // will be a smi if it fits the smi range.
+      __ SmiUntag(scratch1, right);
+      // Do multiplication.
+      // lo = lower 32 bits of scratch1 * left.
+      // hi = higher 32 bits of scratch1 * left.
+      __ Mult(left, scratch1);
+      // Check for overflowing the smi range - no overflow if higher 33 bits of
+      // the result are identical.
+      __ mflo(scratch1);
+      __ mfhi(scratch2);
+      __ sra(scratch1, scratch1, 31);
+      __ Branch(&not_smi_result, ne, scratch1, Operand(scratch2));
+      // Go slow on zero result to handle -0.
+      __ mflo(v0);
+      __ Ret(ne, v0, Operand(zero_reg));
+      // We need -0 if we were multiplying a negative number with 0 to get 0.
+      // We know one of them was zero.
+      __ Addu(scratch2, right, left);
+      Label skip;
+      // ARM uses the 'pl' condition, which is 'ge'.
+      // Negating it results in 'lt'.
+      __ Branch(&skip, lt, scratch2, Operand(zero_reg));
+      ASSERT(Smi::FromInt(0) == 0);
+      __ mov(v0, zero_reg);
+      __ Ret();  // Return smi 0 if the non-zero one was positive.
+      __ bind(&skip);
+      // We fall through here if we multiplied a negative number with 0, because
+      // that would mean we should produce -0.
+      }
+      break;
+    case Token::DIV: {
+      Label done;
+      __ SmiUntag(scratch2, right);
+      __ SmiUntag(scratch1, left);
+      __ Div(scratch1, scratch2);
+      // A minor optimization: div may be calculated asynchronously, so we check
+      // for division by zero before getting the result.
+      __ Branch(&not_smi_result, eq, scratch2, Operand(zero_reg));
+      // If the result is 0, we need to make sure the dividsor (right) is
+      // positive, otherwise it is a -0 case.
+      // Quotient is in 'lo', remainder is in 'hi'.
+      // Check for no remainder first.
+      __ mfhi(scratch1);
+      __ Branch(&not_smi_result, ne, scratch1, Operand(zero_reg));
+      __ mflo(scratch1);
+      __ Branch(&done, ne, scratch1, Operand(zero_reg));
+      __ Branch(&not_smi_result, lt, scratch2, Operand(zero_reg));
+      __ bind(&done);
+      // Check that the signed result fits in a Smi.
+      __ Addu(scratch2, scratch1, Operand(0x40000000));
+      __ Branch(&not_smi_result, lt, scratch2, Operand(zero_reg));
+      __ SmiTag(v0, scratch1);
+      __ Ret();
+      }
+      break;
+    case Token::MOD: {
+      Label done;
+      __ SmiUntag(scratch2, right);
+      __ SmiUntag(scratch1, left);
+      __ Div(scratch1, scratch2);
+      // A minor optimization: div may be calculated asynchronously, so we check
+      // for division by 0 before calling mfhi.
+      // Check for zero on the right hand side.
+      __ Branch(&not_smi_result, eq, scratch2, Operand(zero_reg));
+      // If the result is 0, we need to make sure the dividend (left) is
+      // positive (or 0), otherwise it is a -0 case.
+      // Remainder is in 'hi'.
+      __ mfhi(scratch2);
+      __ Branch(&done, ne, scratch2, Operand(zero_reg));
+      __ Branch(&not_smi_result, lt, scratch1, Operand(zero_reg));
+      __ bind(&done);
+      // Check that the signed result fits in a Smi.
+      __ Addu(scratch1, scratch2, Operand(0x40000000));
+      __ Branch(&not_smi_result, lt, scratch1, Operand(zero_reg));
+      __ SmiTag(v0, scratch2);
+      __ Ret();
+      }
+      break;
+    case Token::BIT_OR:
+      __ Or(v0, left, Operand(right));
+      __ Ret();
+      break;
+    case Token::BIT_AND:
+      __ And(v0, left, Operand(right));
+      __ Ret();
+      break;
+    case Token::BIT_XOR:
+      __ Xor(v0, left, Operand(right));
+      __ Ret();
+      break;
+    case Token::SAR:
+      // Remove tags from right operand.
+      __ GetLeastBitsFromSmi(scratch1, right, 5);
+      __ srav(scratch1, left, scratch1);
+      // Smi tag result.
+      __ And(v0, scratch1, Operand(~kSmiTagMask));
+      __ Ret();
+      break;
+    case Token::SHR:
+      // Remove tags from operands. We can't do this on a 31 bit number
+      // because then the 0s get shifted into bit 30 instead of bit 31.
+      __ SmiUntag(scratch1, left);
+      __ GetLeastBitsFromSmi(scratch2, right, 5);
+      __ srlv(v0, scratch1, scratch2);
+      // Unsigned shift is not allowed to produce a negative number, so
+      // check the sign bit and the sign bit after Smi tagging.
+      __ And(scratch1, v0, Operand(0xc0000000));
+      __ Branch(&not_smi_result, ne, scratch1, Operand(zero_reg));
+      // Smi tag result.
+      __ SmiTag(v0);
+      __ Ret();
+      break;
+    case Token::SHL:
+      // Remove tags from operands.
+      __ SmiUntag(scratch1, left);
+      __ GetLeastBitsFromSmi(scratch2, right, 5);
+      __ sllv(scratch1, scratch1, scratch2);
+      // Check that the signed result fits in a Smi.
+      __ Addu(scratch2, scratch1, Operand(0x40000000));
+      __ Branch(&not_smi_result, lt, scratch2, Operand(zero_reg));
+      __ SmiTag(v0, scratch1);
+      __ Ret();
+      break;
+    default:
+      UNREACHABLE();
+  }
+  __ bind(&not_smi_result);
 }
 
 
@@ -404,7 +2345,211 @@ void TypeRecordingBinaryOpStub::GenerateFPOperation(MacroAssembler* masm,
                                                     bool smi_operands,
                                                     Label* not_numbers,
                                                     Label* gc_required) {
-  UNIMPLEMENTED_MIPS();
+  Register left = a1;
+  Register right = a0;
+  Register scratch1 = t3;
+  Register scratch2 = t5;
+  Register scratch3 = t0;
+
+  ASSERT(smi_operands || (not_numbers != NULL));
+  if (smi_operands && FLAG_debug_code) {
+    __ AbortIfNotSmi(left);
+    __ AbortIfNotSmi(right);
+  }
+
+  Register heap_number_map = t2;
+  __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
+
+  switch (op_) {
+    case Token::ADD:
+    case Token::SUB:
+    case Token::MUL:
+    case Token::DIV:
+    case Token::MOD: {
+      // Load left and right operands into f12 and f14 or a0/a1 and a2/a3
+      // depending on whether FPU is available or not.
+      FloatingPointHelper::Destination destination =
+          CpuFeatures::IsSupported(FPU) &&
+          op_ != Token::MOD ?
+              FloatingPointHelper::kFPURegisters :
+              FloatingPointHelper::kCoreRegisters;
+
+      // Allocate new heap number for result.
+      Register result = s0;
+      GenerateHeapResultAllocation(
+          masm, result, heap_number_map, scratch1, scratch2, gc_required);
+
+      // Load the operands.
+      if (smi_operands) {
+        FloatingPointHelper::LoadSmis(masm, destination, scratch1, scratch2);
+      } else {
+        FloatingPointHelper::LoadOperands(masm,
+                                          destination,
+                                          heap_number_map,
+                                          scratch1,
+                                          scratch2,
+                                          not_numbers);
+      }
+
+      // Calculate the result.
+      if (destination == FloatingPointHelper::kFPURegisters) {
+        // Using FPU registers:
+        // f12: Left value.
+        // f14: Right value.
+        CpuFeatures::Scope scope(FPU);
+        switch (op_) {
+        case Token::ADD:
+          __ add_d(f10, f12, f14);
+          break;
+        case Token::SUB:
+          __ sub_d(f10, f12, f14);
+          break;
+        case Token::MUL:
+          __ mul_d(f10, f12, f14);
+          break;
+        case Token::DIV:
+          __ div_d(f10, f12, f14);
+          break;
+        default:
+          UNREACHABLE();
+        }
+
+        // ARM uses a workaround here because of the unaligned HeapNumber
+        // kValueOffset. On MIPS this workaround is built into sdc1 so
+        // there's no point in generating even more instructions.
+        __ sdc1(f10, FieldMemOperand(result, HeapNumber::kValueOffset));
+        __ mov(v0, result);
+        __ Ret();
+      } else {
+        // Call the C function to handle the double operation.
+        FloatingPointHelper::CallCCodeForDoubleOperation(masm,
+                                                         op_,
+                                                         result,
+                                                         scratch1);
+        if (FLAG_debug_code) {
+          __ stop("Unreachable code.");
+        }
+      }
+      break;
+    }
+    case Token::BIT_OR:
+    case Token::BIT_XOR:
+    case Token::BIT_AND:
+    case Token::SAR:
+    case Token::SHR:
+    case Token::SHL: {
+      if (smi_operands) {
+        __ SmiUntag(a3, left);
+        __ SmiUntag(a2, right);
+      } else {
+        // Convert operands to 32-bit integers. Right in a2 and left in a3.
+        FloatingPointHelper::ConvertNumberToInt32(masm,
+                                                  left,
+                                                  a3,
+                                                  heap_number_map,
+                                                  scratch1,
+                                                  scratch2,
+                                                  scratch3,
+                                                  f0,
+                                                  not_numbers);
+        FloatingPointHelper::ConvertNumberToInt32(masm,
+                                                  right,
+                                                  a2,
+                                                  heap_number_map,
+                                                  scratch1,
+                                                  scratch2,
+                                                  scratch3,
+                                                  f0,
+                                                  not_numbers);
+      }
+      Label result_not_a_smi;
+      switch (op_) {
+        case Token::BIT_OR:
+          __ Or(a2, a3, Operand(a2));
+          break;
+        case Token::BIT_XOR:
+          __ Xor(a2, a3, Operand(a2));
+          break;
+        case Token::BIT_AND:
+          __ And(a2, a3, Operand(a2));
+          break;
+        case Token::SAR:
+          // Use only the 5 least significant bits of the shift count.
+          __ GetLeastBitsFromInt32(a2, a2, 5);
+          __ srav(a2, a3, a2);
+          break;
+        case Token::SHR:
+          // Use only the 5 least significant bits of the shift count.
+          __ GetLeastBitsFromInt32(a2, a2, 5);
+          __ srlv(a2, a3, a2);
+          // SHR is special because it is required to produce a positive answer.
+          // The code below for writing into heap numbers isn't capable of
+          // writing the register as an unsigned int so we go to slow case if we
+          // hit this case.
+          if (CpuFeatures::IsSupported(FPU)) {
+            __ Branch(&result_not_a_smi, lt, a2, Operand(zero_reg));
+          } else {
+            __ Branch(not_numbers, lt, a2, Operand(zero_reg));
+          }
+          break;
+        case Token::SHL:
+          // Use only the 5 least significant bits of the shift count.
+          __ GetLeastBitsFromInt32(a2, a2, 5);
+          __ sllv(a2, a3, a2);
+          break;
+        default:
+          UNREACHABLE();
+      }
+      // Check that the *signed* result fits in a smi.
+      __ Addu(a3, a2, Operand(0x40000000));
+      __ Branch(&result_not_a_smi, lt, a3, Operand(zero_reg));
+      __ SmiTag(v0, a2);
+      __ Ret();
+
+      // Allocate new heap number for result.
+      __ bind(&result_not_a_smi);
+      Register result = t1;
+      if (smi_operands) {
+        __ AllocateHeapNumber(
+            result, scratch1, scratch2, heap_number_map, gc_required);
+      } else {
+        GenerateHeapResultAllocation(
+            masm, result, heap_number_map, scratch1, scratch2, gc_required);
+      }
+
+      // a2: Answer as signed int32.
+      // t1: Heap number to write answer into.
+
+      // Nothing can go wrong now, so move the heap number to v0, which is the
+      // result.
+      __ mov(v0, t1);
+
+      if (CpuFeatures::IsSupported(FPU)) {
+        // Convert the int32 in a2 to the heap number in a0. As
+        // mentioned above SHR needs to always produce a positive result.
+        CpuFeatures::Scope scope(FPU);
+        __ mtc1(a2, f0);
+        if (op_ == Token::SHR) {
+          __ Cvt_d_uw(f0, f0);
+        } else {
+          __ cvt_d_w(f0, f0);
+        }
+        // ARM uses a workaround here because of the unaligned HeapNumber
+        // kValueOffset. On MIPS this workaround is built into sdc1 so
+        // there's no point in generating even more instructions.
+        __ sdc1(f0, FieldMemOperand(v0, HeapNumber::kValueOffset));
+        __ Ret();
+      } else {
+        // Tail call that writes the int32 in a2 to the heap number in v0, using
+        // a3 and a0 as scratch. v0 is preserved and returned.
+        WriteInt32ToHeapNumberStub stub(a2, v0, a3, a0);
+        __ TailCallStub(&stub);
+      }
+      break;
+    }
+    default:
+      UNREACHABLE();
+  }
 }
 
 
@@ -416,42 +2561,549 @@ void TypeRecordingBinaryOpStub::GenerateSmiCode(MacroAssembler* masm,
     Label* use_runtime,
     Label* gc_required,
     SmiCodeGenerateHeapNumberResults allow_heapnumber_results) {
-  UNIMPLEMENTED_MIPS();
+  Label not_smis;
+
+  Register left = a1;
+  Register right = a0;
+  Register scratch1 = t3;
+  Register scratch2 = t5;
+
+  // Perform combined smi check on both operands.
+  __ Or(scratch1, left, Operand(right));
+  STATIC_ASSERT(kSmiTag == 0);
+  __ JumpIfNotSmi(scratch1, &not_smis);
+
+  // If the smi-smi operation results in a smi return is generated.
+  GenerateSmiSmiOperation(masm);
+
+  // If heap number results are possible generate the result in an allocated
+  // heap number.
+  if (allow_heapnumber_results == ALLOW_HEAPNUMBER_RESULTS) {
+    GenerateFPOperation(masm, true, use_runtime, gc_required);
+  }
+  __ bind(&not_smis);
 }
 
 
 void TypeRecordingBinaryOpStub::GenerateSmiStub(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label not_smis, call_runtime;
+
+  if (result_type_ == TRBinaryOpIC::UNINITIALIZED ||
+      result_type_ == TRBinaryOpIC::SMI) {
+    // Only allow smi results.
+    GenerateSmiCode(masm, &call_runtime, NULL, NO_HEAPNUMBER_RESULTS);
+  } else {
+    // Allow heap number result and don't make a transition if a heap number
+    // cannot be allocated.
+    GenerateSmiCode(masm,
+                    &call_runtime,
+                    &call_runtime,
+                    ALLOW_HEAPNUMBER_RESULTS);
+  }
+
+  // Code falls through if the result is not returned as either a smi or heap
+  // number.
+  GenerateTypeTransition(masm);
+
+  __ bind(&call_runtime);
+  GenerateCallRuntime(masm);
 }
 
 
 void TypeRecordingBinaryOpStub::GenerateStringStub(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  ASSERT(operands_type_ == TRBinaryOpIC::STRING);
+  // Try to add arguments as strings, otherwise, transition to the generic
+  // TRBinaryOpIC type.
+  GenerateAddStrings(masm);
+  GenerateTypeTransition(masm);
+}
+
+
+void TypeRecordingBinaryOpStub::GenerateBothStringStub(MacroAssembler* masm) {
+  Label call_runtime;
+  ASSERT(operands_type_ == TRBinaryOpIC::BOTH_STRING);
+  ASSERT(op_ == Token::ADD);
+  // If both arguments are strings, call the string add stub.
+  // Otherwise, do a transition.
+
+  // Registers containing left and right operands respectively.
+  Register left = a1;
+  Register right = a0;
+
+  // Test if left operand is a string.
+  __ JumpIfSmi(left, &call_runtime);
+  __ GetObjectType(left, a2, a2);
+  __ Branch(&call_runtime, ge, a2, Operand(FIRST_NONSTRING_TYPE));
+
+  // Test if right operand is a string.
+  __ JumpIfSmi(right, &call_runtime);
+  __ GetObjectType(right, a2, a2);
+  __ Branch(&call_runtime, ge, a2, Operand(FIRST_NONSTRING_TYPE));
+
+  StringAddStub string_add_stub(NO_STRING_CHECK_IN_STUB);
+  GenerateRegisterArgsPush(masm);
+  __ TailCallStub(&string_add_stub);
+
+  __ bind(&call_runtime);
+  GenerateTypeTransition(masm);
 }
 
 
 void TypeRecordingBinaryOpStub::GenerateInt32Stub(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  ASSERT(operands_type_ == TRBinaryOpIC::INT32);
+
+  Register left = a1;
+  Register right = a0;
+  Register scratch1 = t3;
+  Register scratch2 = t5;
+  FPURegister double_scratch = f0;
+  FPURegister single_scratch = f6;
+
+  Register heap_number_result = no_reg;
+  Register heap_number_map = t2;
+  __ LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
+
+  Label call_runtime;
+  // Labels for type transition, used for wrong input or output types.
+  // Both label are currently actually bound to the same position. We use two
+  // different label to differentiate the cause leading to type transition.
+  Label transition;
+
+  // Smi-smi fast case.
+  Label skip;
+  __ Or(scratch1, left, right);
+  __ JumpIfNotSmi(scratch1, &skip);
+  GenerateSmiSmiOperation(masm);
+  // Fall through if the result is not a smi.
+  __ bind(&skip);
+
+  switch (op_) {
+    case Token::ADD:
+    case Token::SUB:
+    case Token::MUL:
+    case Token::DIV:
+    case Token::MOD: {
+    // Load both operands and check that they are 32-bit integer.
+    // Jump to type transition if they are not. The registers a0 and a1 (right
+    // and left) are preserved for the runtime call.
+    FloatingPointHelper::Destination destination =
+        CpuFeatures::IsSupported(FPU) &&
+        op_ != Token::MOD ?
+        FloatingPointHelper::kFPURegisters :
+        FloatingPointHelper::kCoreRegisters;
+
+    FloatingPointHelper::LoadNumberAsInt32Double(masm,
+                                                 right,
+                                                 destination,
+                                                 f14,
+                                                 a2,
+                                                 a3,
+                                                 heap_number_map,
+                                                 scratch1,
+                                                 scratch2,
+                                                 f2,
+                                                 &transition);
+    FloatingPointHelper::LoadNumberAsInt32Double(masm,
+                                                 left,
+                                                 destination,
+                                                 f12,
+                                                 t0,
+                                                 t1,
+                                                 heap_number_map,
+                                                 scratch1,
+                                                 scratch2,
+                                                 f2,
+                                                 &transition);
+
+      if (destination == FloatingPointHelper::kFPURegisters) {
+        CpuFeatures::Scope scope(FPU);
+        Label return_heap_number;
+        switch (op_) {
+          case Token::ADD:
+            __ add_d(f10, f12, f14);
+            break;
+          case Token::SUB:
+            __ sub_d(f10, f12, f14);
+            break;
+          case Token::MUL:
+            __ mul_d(f10, f12, f14);
+            break;
+          case Token::DIV:
+            __ div_d(f10, f12, f14);
+            break;
+          default:
+            UNREACHABLE();
+        }
+
+        if (op_ != Token::DIV) {
+          // These operations produce an integer result.
+          // Try to return a smi if we can.
+          // Otherwise return a heap number if allowed, or jump to type
+          // transition.
+
+          // NOTE: ARM uses a MacroAssembler function here (EmitVFPTruncate).
+          // On MIPS a lot of things cannot be implemented the same way so right
+          // now it makes a lot more sense to just do things manually.
+
+          // Save FCSR.
+          __ cfc1(scratch1, FCSR);
+          // Disable FPU exceptions.
+          __ ctc1(zero_reg, FCSR);
+          __ trunc_w_d(single_scratch, f10);
+          // Retrieve FCSR.
+          __ cfc1(scratch2, FCSR);
+          // Restore FCSR.
+          __ ctc1(scratch1, FCSR);
+
+          // Check for inexact conversion.
+          __ srl(scratch2, scratch2, kFCSRFlagShift);
+          __ And(scratch2, scratch2, kFCSRFlagMask);
+
+          if (result_type_ <= TRBinaryOpIC::INT32) {
+            // If scratch2 != 0, result does not fit in a 32-bit integer.
+            __ Branch(&transition, ne, scratch2, Operand(zero_reg));
+          }
+
+          // Check if the result fits in a smi.
+          __ mfc1(scratch1, single_scratch);
+          __ Addu(scratch2, scratch1, Operand(0x40000000));
+          // If not try to return a heap number.
+          __ Branch(&return_heap_number, lt, scratch2, Operand(zero_reg));
+          // Check for minus zero. Return heap number for minus zero.
+          Label not_zero;
+          __ Branch(&not_zero, ne, scratch1, Operand(zero_reg));
+          __ mfc1(scratch2, f11);
+          __ And(scratch2, scratch2, HeapNumber::kSignMask);
+          __ Branch(&return_heap_number, ne, scratch2, Operand(zero_reg));
+          __ bind(&not_zero);
+
+          // Tag the result and return.
+          __ SmiTag(v0, scratch1);
+          __ Ret();
+        } else {
+          // DIV just falls through to allocating a heap number.
+        }
+
+        if (result_type_ >= (op_ == Token::DIV) ? TRBinaryOpIC::HEAP_NUMBER
+                                                : TRBinaryOpIC::INT32) {
+          __ bind(&return_heap_number);
+          // We are using FPU registers so s0 is available.
+          heap_number_result = s0;
+          GenerateHeapResultAllocation(masm,
+                                       heap_number_result,
+                                       heap_number_map,
+                                       scratch1,
+                                       scratch2,
+                                       &call_runtime);
+          __ mov(v0, heap_number_result);
+          __ sdc1(f10, FieldMemOperand(v0, HeapNumber::kValueOffset));
+          __ Ret();
+        }
+
+        // A DIV operation expecting an integer result falls through
+        // to type transition.
+
+      } else {
+        // We preserved a0 and a1 to be able to call runtime.
+        // Save the left value on the stack.
+        __ Push(t1, t0);
+
+        Label pop_and_call_runtime;
+
+        // Allocate a heap number to store the result.
+        heap_number_result = s0;
+        GenerateHeapResultAllocation(masm,
+                                     heap_number_result,
+                                     heap_number_map,
+                                     scratch1,
+                                     scratch2,
+                                     &pop_and_call_runtime);
+
+        // Load the left value from the value saved on the stack.
+        __ Pop(a1, a0);
+
+        // Call the C function to handle the double operation.
+        FloatingPointHelper::CallCCodeForDoubleOperation(
+            masm, op_, heap_number_result, scratch1);
+        if (FLAG_debug_code) {
+          __ stop("Unreachable code.");
+        }
+
+        __ bind(&pop_and_call_runtime);
+        __ Drop(2);
+        __ Branch(&call_runtime);
+      }
+
+      break;
+    }
+
+    case Token::BIT_OR:
+    case Token::BIT_XOR:
+    case Token::BIT_AND:
+    case Token::SAR:
+    case Token::SHR:
+    case Token::SHL: {
+      Label return_heap_number;
+      Register scratch3 = t1;
+      // Convert operands to 32-bit integers. Right in a2 and left in a3. The
+      // registers a0 and a1 (right and left) are preserved for the runtime
+      // call.
+      FloatingPointHelper::LoadNumberAsInt32(masm,
+                                             left,
+                                             a3,
+                                             heap_number_map,
+                                             scratch1,
+                                             scratch2,
+                                             scratch3,
+                                             f0,
+                                             &transition);
+      FloatingPointHelper::LoadNumberAsInt32(masm,
+                                             right,
+                                             a2,
+                                             heap_number_map,
+                                             scratch1,
+                                             scratch2,
+                                             scratch3,
+                                             f0,
+                                             &transition);
+
+      // The ECMA-262 standard specifies that, for shift operations, only the
+      // 5 least significant bits of the shift value should be used.
+      switch (op_) {
+        case Token::BIT_OR:
+          __ Or(a2, a3, Operand(a2));
+          break;
+        case Token::BIT_XOR:
+          __ Xor(a2, a3, Operand(a2));
+          break;
+        case Token::BIT_AND:
+          __ And(a2, a3, Operand(a2));
+          break;
+        case Token::SAR:
+          __ And(a2, a2, Operand(0x1f));
+          __ srav(a2, a3, a2);
+          break;
+        case Token::SHR:
+          __ And(a2, a2, Operand(0x1f));
+          __ srlv(a2, a3, a2);
+          // SHR is special because it is required to produce a positive answer.
+          // We only get a negative result if the shift value (a2) is 0.
+          // This result cannot be respresented as a signed 32-bit integer, try
+          // to return a heap number if we can.
+          // The non FPU code does not support this special case, so jump to
+          // runtime if we don't support it.
+          if (CpuFeatures::IsSupported(FPU)) {
+            __ Branch((result_type_ <= TRBinaryOpIC::INT32)
+                        ? &transition
+                        : &return_heap_number,
+                       lt,
+                       a2,
+                       Operand(zero_reg));
+          } else {
+            __ Branch((result_type_ <= TRBinaryOpIC::INT32)
+                        ? &transition
+                        : &call_runtime,
+                       lt,
+                       a2,
+                       Operand(zero_reg));
+          }
+          break;
+        case Token::SHL:
+          __ And(a2, a2, Operand(0x1f));
+          __ sllv(a2, a3, a2);
+          break;
+        default:
+          UNREACHABLE();
+      }
+
+      // Check if the result fits in a smi.
+      __ Addu(scratch1, a2, Operand(0x40000000));
+      // If not try to return a heap number. (We know the result is an int32.)
+      __ Branch(&return_heap_number, lt, scratch1, Operand(zero_reg));
+      // Tag the result and return.
+      __ SmiTag(v0, a2);
+      __ Ret();
+
+      __ bind(&return_heap_number);
+      heap_number_result = t1;
+      GenerateHeapResultAllocation(masm,
+                                   heap_number_result,
+                                   heap_number_map,
+                                   scratch1,
+                                   scratch2,
+                                   &call_runtime);
+
+      if (CpuFeatures::IsSupported(FPU)) {
+        CpuFeatures::Scope scope(FPU);
+
+        if (op_ != Token::SHR) {
+          // Convert the result to a floating point value.
+          __ mtc1(a2, double_scratch);
+          __ cvt_d_w(double_scratch, double_scratch);
+        } else {
+          // The result must be interpreted as an unsigned 32-bit integer.
+          __ mtc1(a2, double_scratch);
+          __ Cvt_d_uw(double_scratch, double_scratch);
+        }
+
+        // Store the result.
+        __ mov(v0, heap_number_result);
+        __ sdc1(double_scratch, FieldMemOperand(v0, HeapNumber::kValueOffset));
+        __ Ret();
+      } else {
+        // Tail call that writes the int32 in a2 to the heap number in v0, using
+        // a3 and a1 as scratch. v0 is preserved and returned.
+        __ mov(a0, t1);
+        WriteInt32ToHeapNumberStub stub(a2, v0, a3, a1);
+        __ TailCallStub(&stub);
+      }
+
+      break;
+    }
+
+    default:
+      UNREACHABLE();
+  }
+
+  if (transition.is_linked()) {
+    __ bind(&transition);
+    GenerateTypeTransition(masm);
+  }
+
+  __ bind(&call_runtime);
+  GenerateCallRuntime(masm);
+}
+
+
+void TypeRecordingBinaryOpStub::GenerateOddballStub(MacroAssembler* masm) {
+  Label call_runtime;
+
+  if (op_ == Token::ADD) {
+    // Handle string addition here, because it is the only operation
+    // that does not do a ToNumber conversion on the operands.
+    GenerateAddStrings(masm);
+  }
+
+  // Convert oddball arguments to numbers.
+  Label check, done;
+  __ LoadRoot(t0, Heap::kUndefinedValueRootIndex);
+  __ Branch(&check, ne, a1, Operand(t0));
+  if (Token::IsBitOp(op_)) {
+    __ li(a1, Operand(Smi::FromInt(0)));
+  } else {
+    __ LoadRoot(a1, Heap::kNanValueRootIndex);
+  }
+  __ jmp(&done);
+  __ bind(&check);
+  __ LoadRoot(t0, Heap::kUndefinedValueRootIndex);
+  __ Branch(&done, ne, a0, Operand(t0));
+  if (Token::IsBitOp(op_)) {
+    __ li(a0, Operand(Smi::FromInt(0)));
+  } else {
+    __ LoadRoot(a0, Heap::kNanValueRootIndex);
+  }
+  __ bind(&done);
+
+  GenerateHeapNumberStub(masm);
 }
 
 
 void TypeRecordingBinaryOpStub::GenerateHeapNumberStub(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label call_runtime;
+  GenerateFPOperation(masm, false, &call_runtime, &call_runtime);
+
+  __ bind(&call_runtime);
+  GenerateCallRuntime(masm);
 }
 
 
 void TypeRecordingBinaryOpStub::GenerateGeneric(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label call_runtime, call_string_add_or_runtime;
+
+  GenerateSmiCode(masm, &call_runtime, &call_runtime, ALLOW_HEAPNUMBER_RESULTS);
+
+  GenerateFPOperation(masm, false, &call_string_add_or_runtime, &call_runtime);
+
+  __ bind(&call_string_add_or_runtime);
+  if (op_ == Token::ADD) {
+    GenerateAddStrings(masm);
+  }
+
+  __ bind(&call_runtime);
+  GenerateCallRuntime(masm);
 }
 
 
 void TypeRecordingBinaryOpStub::GenerateAddStrings(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  ASSERT(op_ == Token::ADD);
+  Label left_not_string, call_runtime;
+
+  Register left = a1;
+  Register right = a0;
+
+  // Check if left argument is a string.
+  __ JumpIfSmi(left, &left_not_string);
+  __ GetObjectType(left, a2, a2);
+  __ Branch(&left_not_string, ge, a2, Operand(FIRST_NONSTRING_TYPE));
+
+  StringAddStub string_add_left_stub(NO_STRING_CHECK_LEFT_IN_STUB);
+  GenerateRegisterArgsPush(masm);
+  __ TailCallStub(&string_add_left_stub);
+
+  // Left operand is not a string, test right.
+  __ bind(&left_not_string);
+  __ JumpIfSmi(right, &call_runtime);
+  __ GetObjectType(right, a2, a2);
+  __ Branch(&call_runtime, ge, a2, Operand(FIRST_NONSTRING_TYPE));
+
+  StringAddStub string_add_right_stub(NO_STRING_CHECK_RIGHT_IN_STUB);
+  GenerateRegisterArgsPush(masm);
+  __ TailCallStub(&string_add_right_stub);
+
+  // At least one argument is not a string.
+  __ bind(&call_runtime);
 }
 
 
 void TypeRecordingBinaryOpStub::GenerateCallRuntime(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  GenerateRegisterArgsPush(masm);
+  switch (op_) {
+    case Token::ADD:
+      __ InvokeBuiltin(Builtins::ADD, JUMP_FUNCTION);
+      break;
+    case Token::SUB:
+      __ InvokeBuiltin(Builtins::SUB, JUMP_FUNCTION);
+      break;
+    case Token::MUL:
+      __ InvokeBuiltin(Builtins::MUL, JUMP_FUNCTION);
+      break;
+    case Token::DIV:
+      __ InvokeBuiltin(Builtins::DIV, JUMP_FUNCTION);
+      break;
+    case Token::MOD:
+      __ InvokeBuiltin(Builtins::MOD, JUMP_FUNCTION);
+      break;
+    case Token::BIT_OR:
+      __ InvokeBuiltin(Builtins::BIT_OR, JUMP_FUNCTION);
+      break;
+    case Token::BIT_AND:
+      __ InvokeBuiltin(Builtins::BIT_AND, JUMP_FUNCTION);
+      break;
+    case Token::BIT_XOR:
+      __ InvokeBuiltin(Builtins::BIT_XOR, JUMP_FUNCTION);
+      break;
+    case Token::SAR:
+      __ InvokeBuiltin(Builtins::SAR, JUMP_FUNCTION);
+      break;
+    case Token::SHR:
+      __ InvokeBuiltin(Builtins::SHR, JUMP_FUNCTION);
+      break;
+    case Token::SHL:
+      __ InvokeBuiltin(Builtins::SHL, JUMP_FUNCTION);
+      break;
+    default:
+      UNREACHABLE();
+  }
 }
 
 
@@ -462,34 +3114,382 @@ void TypeRecordingBinaryOpStub::GenerateHeapResultAllocation(
     Register scratch1,
     Register scratch2,
     Label* gc_required) {
-  UNIMPLEMENTED_MIPS();
+
+  // Code below will scratch result if allocation fails. To keep both arguments
+  // intact for the runtime call result cannot be one of these.
+  ASSERT(!result.is(a0) && !result.is(a1));
+
+  if (mode_ == OVERWRITE_LEFT || mode_ == OVERWRITE_RIGHT) {
+    Label skip_allocation, allocated;
+    Register overwritable_operand = mode_ == OVERWRITE_LEFT ? a1 : a0;
+    // If the overwritable operand is already an object, we skip the
+    // allocation of a heap number.
+    __ JumpIfNotSmi(overwritable_operand, &skip_allocation);
+    // Allocate a heap number for the result.
+    __ AllocateHeapNumber(
+        result, scratch1, scratch2, heap_number_map, gc_required);
+    __ Branch(&allocated);
+    __ bind(&skip_allocation);
+    // Use object holding the overwritable operand for result.
+    __ mov(result, overwritable_operand);
+    __ bind(&allocated);
+  } else {
+    ASSERT(mode_ == NO_OVERWRITE);
+    __ AllocateHeapNumber(
+        result, scratch1, scratch2, heap_number_map, gc_required);
+  }
 }
 
 
 void TypeRecordingBinaryOpStub::GenerateRegisterArgsPush(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  __ Push(a1, a0);
 }
 
 
 
 void TranscendentalCacheStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Untagged case: double input in f4, double result goes
+  //   into f4.
+  // Tagged case: tagged input on top of stack and in a0,
+  //   tagged result (heap number) goes into v0.
+
+  Label input_not_smi;
+  Label loaded;
+  Label calculate;
+  Label invalid_cache;
+  const Register scratch0 = t5;
+  const Register scratch1 = t3;
+  const Register cache_entry = a0;
+  const bool tagged = (argument_type_ == TAGGED);
+
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+
+    if (tagged) {
+      // Argument is a number and is on stack and in a0.
+      // Load argument and check if it is a smi.
+      __ JumpIfNotSmi(a0, &input_not_smi);
+
+      // Input is a smi. Convert to double and load the low and high words
+      // of the double into a2, a3.
+      __ sra(t0, a0, kSmiTagSize);
+      __ mtc1(t0, f4);
+      __ cvt_d_w(f4, f4);
+      __ mfc1(a2, f4);
+      __ mfc1(a3, f5);
+      __ Branch(&loaded);
+
+      __ bind(&input_not_smi);
+      // Check if input is a HeapNumber.
+      __ CheckMap(a0,
+                  a1,
+                  Heap::kHeapNumberMapRootIndex,
+                  &calculate,
+                  true);
+      // Input is a HeapNumber. Store the
+      // low and high words into a2, a3.
+      __ lw(a2, FieldMemOperand(a0, HeapNumber::kValueOffset));
+      __ lw(a3, FieldMemOperand(a0, HeapNumber::kValueOffset + 4));
+    } else {
+      // Input is untagged double in f4. Output goes to f4.
+      __ mfc1(a2, f4);
+      __ mfc1(a3, f5);
+    }
+    __ bind(&loaded);
+    // a2 = low 32 bits of double value.
+    // a3 = high 32 bits of double value.
+    // Compute hash (the shifts are arithmetic):
+    //   h = (low ^ high); h ^= h >> 16; h ^= h >> 8; h = h & (cacheSize - 1);
+    __ Xor(a1, a2, a3);
+    __ sra(t0, a1, 16);
+    __ Xor(a1, a1, t0);
+    __ sra(t0, a1, 8);
+    __ Xor(a1, a1, t0);
+    ASSERT(IsPowerOf2(TranscendentalCache::SubCache::kCacheSize));
+    __ And(a1, a1, Operand(TranscendentalCache::SubCache::kCacheSize - 1));
+
+    // a2 = low 32 bits of double value.
+    // a3 = high 32 bits of double value.
+    // a1 = TranscendentalCache::hash(double value).
+    __ li(cache_entry, Operand(
+        ExternalReference::transcendental_cache_array_address(
+            masm->isolate())));
+    // a0 points to cache array.
+    __ lw(cache_entry, MemOperand(cache_entry, type_ * sizeof(
+        Isolate::Current()->transcendental_cache()->caches_[0])));
+    // a0 points to the cache for the type type_.
+    // If NULL, the cache hasn't been initialized yet, so go through runtime.
+    __ Branch(&invalid_cache, eq, cache_entry, Operand(zero_reg));
+
+#ifdef DEBUG
+    // Check that the layout of cache elements match expectations.
+    { TranscendentalCache::SubCache::Element test_elem[2];
+      char* elem_start = reinterpret_cast<char*>(&test_elem[0]);
+      char* elem2_start = reinterpret_cast<char*>(&test_elem[1]);
+      char* elem_in0 = reinterpret_cast<char*>(&(test_elem[0].in[0]));
+      char* elem_in1 = reinterpret_cast<char*>(&(test_elem[0].in[1]));
+      char* elem_out = reinterpret_cast<char*>(&(test_elem[0].output));
+      CHECK_EQ(12, elem2_start - elem_start);  // Two uint_32's and a pointer.
+      CHECK_EQ(0, elem_in0 - elem_start);
+      CHECK_EQ(kIntSize, elem_in1 - elem_start);
+      CHECK_EQ(2 * kIntSize, elem_out - elem_start);
+    }
+#endif
+
+    // Find the address of the a1'st entry in the cache, i.e., &a0[a1*12].
+    __ sll(t0, a1, 1);
+    __ Addu(a1, a1, t0);
+    __ sll(t0, a1, 2);
+    __ Addu(cache_entry, cache_entry, t0);
+
+    // Check if cache matches: Double value is stored in uint32_t[2] array.
+    __ lw(t0, MemOperand(cache_entry, 0));
+    __ lw(t1, MemOperand(cache_entry, 4));
+    __ lw(t2, MemOperand(cache_entry, 8));
+    __ Addu(cache_entry, cache_entry, 12);
+    __ Branch(&calculate, ne, a2, Operand(t0));
+    __ Branch(&calculate, ne, a3, Operand(t1));
+    // Cache hit. Load result, cleanup and return.
+    if (tagged) {
+      // Pop input value from stack and load result into v0.
+      __ Drop(1);
+      __ mov(v0, t2);
+    } else {
+      // Load result into f4.
+      __ ldc1(f4, FieldMemOperand(t2, HeapNumber::kValueOffset));
+    }
+    __ Ret();
+  }  // if (CpuFeatures::IsSupported(FPU))
+
+  __ bind(&calculate);
+  if (tagged) {
+    __ bind(&invalid_cache);
+    __ TailCallExternalReference(ExternalReference(RuntimeFunction(),
+                                                   masm->isolate()),
+                                 1,
+                                 1);
+  } else {
+    if (!CpuFeatures::IsSupported(FPU)) UNREACHABLE();
+    CpuFeatures::Scope scope(FPU);
+
+    Label no_update;
+    Label skip_cache;
+    const Register heap_number_map = t2;
+
+    // Call C function to calculate the result and update the cache.
+    // Register a0 holds precalculated cache entry address; preserve
+    // it on the stack and pop it into register cache_entry after the
+    // call.
+    __ push(cache_entry);
+    GenerateCallCFunction(masm, scratch0);
+    __ GetCFunctionDoubleResult(f4);
+
+    // Try to update the cache. If we cannot allocate a
+    // heap number, we return the result without updating.
+    __ pop(cache_entry);
+    __ LoadRoot(t1, Heap::kHeapNumberMapRootIndex);
+    __ AllocateHeapNumber(t2, scratch0, scratch1, t1, &no_update);
+    __ sdc1(f4, FieldMemOperand(t2, HeapNumber::kValueOffset));
+
+    __ sw(a2, MemOperand(cache_entry, 0 * kPointerSize));
+    __ sw(a3, MemOperand(cache_entry, 1 * kPointerSize));
+    __ sw(t2, MemOperand(cache_entry, 2 * kPointerSize));
+
+    __ mov(v0, cache_entry);
+    __ Ret();
+
+    __ bind(&invalid_cache);
+    // The cache is invalid. Call runtime which will recreate the
+    // cache.
+    __ LoadRoot(t1, Heap::kHeapNumberMapRootIndex);
+    __ AllocateHeapNumber(a0, scratch0, scratch1, t1, &skip_cache);
+    __ sdc1(f4, FieldMemOperand(a0, HeapNumber::kValueOffset));
+    __ EnterInternalFrame();
+    __ push(a0);
+    __ CallRuntime(RuntimeFunction(), 1);
+    __ LeaveInternalFrame();
+    __ ldc1(f4, FieldMemOperand(v0, HeapNumber::kValueOffset));
+    __ Ret();
+
+    __ bind(&skip_cache);
+    // Call C function to calculate the result and answer directly
+    // without updating the cache.
+    GenerateCallCFunction(masm, scratch0);
+    __ GetCFunctionDoubleResult(f4);
+    __ bind(&no_update);
+
+    // We return the value in f4 without adding it to the cache, but
+    // we cause a scavenging GC so that future allocations will succeed.
+    __ EnterInternalFrame();
+
+    // Allocate an aligned object larger than a HeapNumber.
+    ASSERT(4 * kPointerSize >= HeapNumber::kSize);
+    __ li(scratch0, Operand(4 * kPointerSize));
+    __ push(scratch0);
+    __ CallRuntimeSaveDoubles(Runtime::kAllocateInNewSpace);
+    __ LeaveInternalFrame();
+    __ Ret();
+  }
+}
+
+
+void TranscendentalCacheStub::GenerateCallCFunction(MacroAssembler* masm,
+                                                    Register scratch) {
+  __ push(ra);
+  __ PrepareCallCFunction(2, scratch);
+  __ mfc1(v0, f4);
+  __ mfc1(v1, f5);
+  switch (type_) {
+    case TranscendentalCache::SIN:
+      __ CallCFunction(
+          ExternalReference::math_sin_double_function(masm->isolate()), 2);
+      break;
+    case TranscendentalCache::COS:
+      __ CallCFunction(
+          ExternalReference::math_cos_double_function(masm->isolate()), 2);
+      break;
+    case TranscendentalCache::LOG:
+      __ CallCFunction(
+          ExternalReference::math_log_double_function(masm->isolate()), 2);
+      break;
+    default:
+      UNIMPLEMENTED();
+      break;
+  }
+  __ pop(ra);
 }
 
 
 Runtime::FunctionId TranscendentalCacheStub::RuntimeFunction() {
-  UNIMPLEMENTED_MIPS();
-  return Runtime::kAbort;
+  switch (type_) {
+    // Add more cases when necessary.
+    case TranscendentalCache::SIN: return Runtime::kMath_sin;
+    case TranscendentalCache::COS: return Runtime::kMath_cos;
+    case TranscendentalCache::LOG: return Runtime::kMath_log;
+    default:
+      UNIMPLEMENTED();
+      return Runtime::kAbort;
+  }
 }
 
 
 void StackCheckStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  __ TailCallRuntime(Runtime::kStackGuard, 0, 1);
 }
 
 
 void MathPowStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label call_runtime;
+
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+
+    Label base_not_smi;
+    Label exponent_not_smi;
+    Label convert_exponent;
+
+    const Register base = a0;
+    const Register exponent = a2;
+    const Register heapnumbermap = t1;
+    const Register heapnumber = s0;  // Callee-saved register.
+    const Register scratch = t2;
+    const Register scratch2 = t3;
+
+    // Alocate FP values in the ABI-parameter-passing regs.
+    const DoubleRegister double_base = f12;
+    const DoubleRegister double_exponent = f14;
+    const DoubleRegister double_result = f0;
+    const DoubleRegister double_scratch = f2;
+
+    __ LoadRoot(heapnumbermap, Heap::kHeapNumberMapRootIndex);
+    __ lw(base, MemOperand(sp, 1 * kPointerSize));
+    __ lw(exponent, MemOperand(sp, 0 * kPointerSize));
+
+    // Convert base to double value and store it in f0.
+    __ JumpIfNotSmi(base, &base_not_smi);
+    // Base is a Smi. Untag and convert it.
+    __ SmiUntag(base);
+    __ mtc1(base, double_scratch);
+    __ cvt_d_w(double_base, double_scratch);
+    __ Branch(&convert_exponent);
+
+    __ bind(&base_not_smi);
+    __ lw(scratch, FieldMemOperand(base, JSObject::kMapOffset));
+    __ Branch(&call_runtime, ne, scratch, Operand(heapnumbermap));
+    // Base is a heapnumber. Load it into double register.
+    __ ldc1(double_base, FieldMemOperand(base, HeapNumber::kValueOffset));
+
+    __ bind(&convert_exponent);
+    __ JumpIfNotSmi(exponent, &exponent_not_smi);
+    __ SmiUntag(exponent);
+
+    // The base is in a double register and the exponent is
+    // an untagged smi. Allocate a heap number and call a
+    // C function for integer exponents. The register containing
+    // the heap number is callee-saved.
+    __ AllocateHeapNumber(heapnumber,
+                          scratch,
+                          scratch2,
+                          heapnumbermap,
+                          &call_runtime);
+    __ push(ra);
+    __ PrepareCallCFunction(3, scratch);
+    // ABI (o32) for func(double d, int x): d in f12, x in a2.
+    ASSERT(double_base.is(f12));
+    ASSERT(exponent.is(a2));
+    if (IsMipsSoftFloatABI) {
+      // Simulator case, supports FPU, but with soft-float passing.
+      __ mfc1(a0, double_base);
+      __ mfc1(a1, FPURegister::from_code(double_base.code() + 1));
+    }
+    __ CallCFunction(
+        ExternalReference::power_double_int_function(masm->isolate()), 3);
+    __ pop(ra);
+    __ GetCFunctionDoubleResult(double_result);
+    __ sdc1(double_result,
+            FieldMemOperand(heapnumber, HeapNumber::kValueOffset));
+    __ mov(v0, heapnumber);
+    __ DropAndRet(2 * kPointerSize);
+
+    __ bind(&exponent_not_smi);
+    __ lw(scratch, FieldMemOperand(exponent, JSObject::kMapOffset));
+    __ Branch(&call_runtime, ne, scratch, Operand(heapnumbermap));
+    // Exponent is a heapnumber. Load it into double register.
+    __ ldc1(double_exponent,
+            FieldMemOperand(exponent, HeapNumber::kValueOffset));
+
+    // The base and the exponent are in double registers.
+    // Allocate a heap number and call a C function for
+    // double exponents. The register containing
+    // the heap number is callee-saved.
+    __ AllocateHeapNumber(heapnumber,
+                          scratch,
+                          scratch2,
+                          heapnumbermap,
+                          &call_runtime);
+    __ push(ra);
+    __ PrepareCallCFunction(4, scratch);
+    // ABI (o32) for func(double a, double b): a in f12, b in f14.
+    ASSERT(double_base.is(f12));
+    ASSERT(double_exponent.is(f14));
+    if (IsMipsSoftFloatABI) {
+      __ mfc1(a0, double_base);
+      __ mfc1(a1, FPURegister::from_code(double_base.code() + 1));
+      __ mfc1(a2, double_exponent);
+      __ mfc1(a3, FPURegister::from_code(double_exponent.code() + 1));
+    }
+    __ CallCFunction(
+        ExternalReference::power_double_double_function(masm->isolate()), 4);
+    __ pop(ra);
+    __ GetCFunctionDoubleResult(double_result);
+    __ sdc1(double_result,
+            FieldMemOperand(heapnumber, HeapNumber::kValueOffset));
+    __ mov(v0, heapnumber);
+    __ DropAndRet(2 * kPointerSize);
+  }
+
+  __ bind(&call_runtime);
+  __ TailCallRuntime(Runtime::kMath_pow_cfunction, 2, 1);
 }
 
 
@@ -499,13 +3499,13 @@ bool CEntryStub::NeedsImmovableCode() {
 
 
 void CEntryStub::GenerateThrowTOS(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  __ Throw(v0);
 }
 
 
 void CEntryStub::GenerateThrowUncatchable(MacroAssembler* masm,
                                           UncatchableExceptionType type) {
-  UNIMPLEMENTED_MIPS();
+  __ ThrowUncatchable(type, v0);
 }
 
 
@@ -515,17 +3515,369 @@ void CEntryStub::GenerateCore(MacroAssembler* masm,
                               Label* throw_out_of_memory_exception,
                               bool do_gc,
                               bool always_allocate) {
-  UNIMPLEMENTED_MIPS();
+  // v0: result parameter for PerformGC, if any
+  // s0: number of arguments including receiver (C callee-saved)
+  // s1: pointer to the first argument          (C callee-saved)
+  // s2: pointer to builtin function            (C callee-saved)
+
+  if (do_gc) {
+    // Move result passed in v0 into a0 to call PerformGC.
+    __ mov(a0, v0);
+    __ PrepareCallCFunction(1, a1);
+    __ CallCFunction(
+        ExternalReference::perform_gc_function(masm->isolate()), 1);
+  }
+
+  ExternalReference scope_depth =
+      ExternalReference::heap_always_allocate_scope_depth(masm->isolate());
+  if (always_allocate) {
+    __ li(a0, Operand(scope_depth));
+    __ lw(a1, MemOperand(a0));
+    __ Addu(a1, a1, Operand(1));
+    __ sw(a1, MemOperand(a0));
+  }
+
+  // Prepare arguments for C routine: a0 = argc, a1 = argv
+  __ mov(a0, s0);
+  __ mov(a1, s1);
+
+  // We are calling compiled C/C++ code. a0 and a1 hold our two arguments. We
+  // also need to reserve the 4 argument slots on the stack.
+
+  __ AssertStackIsAligned();
+
+  __ li(a2, Operand(ExternalReference::isolate_address()));
+
+  // From arm version of this function:
+  // TODO(1242173): To let the GC traverse the return address of the exit
+  // frames, we need to know where the return address is. Right now,
+  // we push it on the stack to be able to find it again, but we never
+  // restore from it in case of changes, which makes it impossible to
+  // support moving the C entry code stub. This should be fixed, but currently
+  // this is OK because the CEntryStub gets generated so early in the V8 boot
+  // sequence that it is not moving ever.
+
+  { Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm);
+    // This branch-and-link sequence is needed to find the current PC on mips,
+    // saved to the ra register.
+    // Use masm-> here instead of the double-underscore macro since extra
+    // coverage code can interfere with the proper calculation of ra.
+    Label find_ra;
+    masm->bal(&find_ra);  // bal exposes branch delay slot.
+    masm->nop();  // Branch delay slot nop.
+    masm->bind(&find_ra);
+
+    // Adjust the value in ra to point to the correct return location, 2nd
+    // instruction past the real call into C code (the jalr(t9)), and push it.
+    // This is the return address of the exit frame.
+    const int kNumInstructionsToJump = 6;
+    masm->Addu(ra, ra, kNumInstructionsToJump * kPointerSize);
+    masm->sw(ra, MemOperand(sp));  // This spot was reserved in EnterExitFrame.
+    masm->Subu(sp, sp, StandardFrameConstants::kCArgsSlotsSize);
+    // Stack is still aligned.
+
+    // Call the C routine.
+    masm->mov(t9, s2);  // Function pointer to t9 to conform to ABI for PIC.
+    masm->jalr(t9);
+    masm->nop();    // Branch delay slot nop.
+    // Make sure the stored 'ra' points to this position.
+    ASSERT_EQ(kNumInstructionsToJump,
+              masm->InstructionsGeneratedSince(&find_ra));
+  }
+
+  // Restore stack (remove arg slots).
+  __ Addu(sp, sp, StandardFrameConstants::kCArgsSlotsSize);
+
+  if (always_allocate) {
+    // It's okay to clobber a2 and a3 here. v0 & v1 contain result.
+    __ li(a2, Operand(scope_depth));
+    __ lw(a3, MemOperand(a2));
+    __ Subu(a3, a3, Operand(1));
+    __ sw(a3, MemOperand(a2));
+  }
+
+  // Check for failure result.
+  Label failure_returned;
+  STATIC_ASSERT(((kFailureTag + 1) & kFailureTagMask) == 0);
+  __ addiu(a2, v0, 1);
+  __ andi(t0, a2, kFailureTagMask);
+  __ Branch(&failure_returned, eq, t0, Operand(zero_reg));
+
+  // Exit C frame and return.
+  // v0:v1: result
+  // sp: stack pointer
+  // fp: frame pointer
+  __ LeaveExitFrame(save_doubles_, s0);
+  __ Ret();
+
+  // Check if we should retry or throw exception.
+  Label retry;
+  __ bind(&failure_returned);
+  STATIC_ASSERT(Failure::RETRY_AFTER_GC == 0);
+  __ andi(t0, v0, ((1 << kFailureTypeTagSize) - 1) << kFailureTagSize);
+  __ Branch(&retry, eq, t0, Operand(zero_reg));
+
+  // Special handling of out of memory exceptions.
+  Failure* out_of_memory = Failure::OutOfMemoryException();
+  __ Branch(throw_out_of_memory_exception, eq,
+            v0, Operand(reinterpret_cast<int32_t>(out_of_memory)));
+
+  // Retrieve the pending exception and clear the variable.
+  __ li(t0,
+        Operand(ExternalReference::the_hole_value_location(masm->isolate())));
+  __ lw(a3, MemOperand(t0));
+  __ li(t0, Operand(ExternalReference(Isolate::k_pending_exception_address,
+                                      masm->isolate())));
+  __ lw(v0, MemOperand(t0));
+  __ sw(a3, MemOperand(t0));
+
+  // Special handling of termination exceptions which are uncatchable
+  // by javascript code.
+  __ Branch(throw_termination_exception, eq,
+            v0, Operand(masm->isolate()->factory()->termination_exception()));
+
+  // Handle normal exception.
+  __ jmp(throw_normal_exception);
+
+  __ bind(&retry);
+  // Last failure (v0) will be moved to (a0) for parameter when retrying.
 }
 
 
 void CEntryStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Called from JavaScript; parameters are on stack as if calling JS function
+  // a0: number of arguments including receiver
+  // a1: pointer to builtin function
+  // fp: frame pointer    (restored after C call)
+  // sp: stack pointer    (restored as callee's sp after C call)
+  // cp: current context  (C callee-saved)
+
+  // NOTE: Invocations of builtins may return failure objects
+  // instead of a proper result. The builtin entry handles
+  // this by performing a garbage collection and retrying the
+  // builtin once.
+
+  // Compute the argv pointer in a callee-saved register.
+  __ sll(s1, a0, kPointerSizeLog2);
+  __ Addu(s1, sp, s1);
+  __ Subu(s1, s1, Operand(kPointerSize));
+
+  // Enter the exit frame that transitions from JavaScript to C++.
+  __ EnterExitFrame(save_doubles_);
+
+  // Setup argc and the builtin function in callee-saved registers.
+  __ mov(s0, a0);
+  __ mov(s2, a1);
+
+  // s0: number of arguments (C callee-saved)
+  // s1: pointer to first argument (C callee-saved)
+  // s2: pointer to builtin function (C callee-saved)
+
+  Label throw_normal_exception;
+  Label throw_termination_exception;
+  Label throw_out_of_memory_exception;
+
+  // Call into the runtime system.
+  GenerateCore(masm,
+               &throw_normal_exception,
+               &throw_termination_exception,
+               &throw_out_of_memory_exception,
+               false,
+               false);
+
+  // Do space-specific GC and retry runtime call.
+  GenerateCore(masm,
+               &throw_normal_exception,
+               &throw_termination_exception,
+               &throw_out_of_memory_exception,
+               true,
+               false);
+
+  // Do full GC and retry runtime call one final time.
+  Failure* failure = Failure::InternalError();
+  __ li(v0, Operand(reinterpret_cast<int32_t>(failure)));
+  GenerateCore(masm,
+               &throw_normal_exception,
+               &throw_termination_exception,
+               &throw_out_of_memory_exception,
+               true,
+               true);
+
+  __ bind(&throw_out_of_memory_exception);
+  GenerateThrowUncatchable(masm, OUT_OF_MEMORY);
+
+  __ bind(&throw_termination_exception);
+  GenerateThrowUncatchable(masm, TERMINATION);
+
+  __ bind(&throw_normal_exception);
+  GenerateThrowTOS(masm);
 }
 
 
 void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
-  UNIMPLEMENTED_MIPS();
+  Label invoke, exit;
+
+  // Registers:
+  // a0: entry address
+  // a1: function
+  // a2: reveiver
+  // a3: argc
+  //
+  // Stack:
+  // 4 args slots
+  // args
+
+  // Save callee saved registers on the stack.
+  __ MultiPush((kCalleeSaved | ra.bit()) & ~sp.bit());
+
+  // Load argv in s0 register.
+  __ lw(s0, MemOperand(sp, kNumCalleeSaved * kPointerSize +
+                           StandardFrameConstants::kCArgsSlotsSize));
+
+  // We build an EntryFrame.
+  __ li(t3, Operand(-1));  // Push a bad frame pointer to fail if it is used.
+  int marker = is_construct ? StackFrame::ENTRY_CONSTRUCT : StackFrame::ENTRY;
+  __ li(t2, Operand(Smi::FromInt(marker)));
+  __ li(t1, Operand(Smi::FromInt(marker)));
+  __ li(t0, Operand(ExternalReference(Isolate::k_c_entry_fp_address,
+                                      masm->isolate())));
+  __ lw(t0, MemOperand(t0));
+  __ Push(t3, t2, t1, t0);
+  // Setup frame pointer for the frame to be pushed.
+  __ addiu(fp, sp, -EntryFrameConstants::kCallerFPOffset);
+
+  // Registers:
+  // a0: entry_address
+  // a1: function
+  // a2: reveiver_pointer
+  // a3: argc
+  // s0: argv
+  //
+  // Stack:
+  // caller fp          |
+  // function slot      | entry frame
+  // context slot       |
+  // bad fp (0xff...f)  |
+  // callee saved registers + ra
+  // 4 args slots
+  // args
+
+  #ifdef ENABLE_LOGGING_AND_PROFILING
+    // If this is the outermost JS call, set js_entry_sp value.
+    ExternalReference js_entry_sp(Isolate::k_js_entry_sp_address,
+                                  masm->isolate());
+    __ li(t1, Operand(ExternalReference(js_entry_sp)));
+    __ lw(t2, MemOperand(t1));
+    {
+      Label skip;
+      __ Branch(&skip, ne, t2, Operand(zero_reg));
+      __ sw(fp, MemOperand(t1));
+      __ bind(&skip);
+    }
+  #endif
+
+  // Call a faked try-block that does the invoke.
+  __ bal(&invoke);  // bal exposes branch delay slot.
+  __ nop();   // Branch delay slot nop.
+
+  // Caught exception: Store result (exception) in the pending
+  // exception field in the JSEnv and return a failure sentinel.
+  // Coming in here the fp will be invalid because the PushTryHandler below
+  // sets it to 0 to signal the existence of the JSEntry frame.
+  __ li(t0, Operand(ExternalReference(Isolate::k_pending_exception_address,
+                                      masm->isolate())));
+  __ sw(v0, MemOperand(t0));  // We come back from 'invoke'. result is in v0.
+  __ li(v0, Operand(reinterpret_cast<int32_t>(Failure::Exception())));
+  __ b(&exit);  // b exposes branch delay slot.
+  __ nop();   // Branch delay slot nop.
+
+  // Invoke: Link this frame into the handler chain.
+  __ bind(&invoke);
+  __ PushTryHandler(IN_JS_ENTRY, JS_ENTRY_HANDLER);
+  // If an exception not caught by another handler occurs, this handler
+  // returns control to the code after the bal(&invoke) above, which
+  // restores all kCalleeSaved registers (including cp and fp) to their
+  // saved values before returning a failure to C.
+
+  // Clear any pending exceptions.
+  __ li(t0,
+        Operand(ExternalReference::the_hole_value_location(masm->isolate())));
+  __ lw(t1, MemOperand(t0));
+  __ li(t0, Operand(ExternalReference(Isolate::k_pending_exception_address,
+                                      masm->isolate())));
+  __ sw(t1, MemOperand(t0));
+
+  // Invoke the function by calling through JS entry trampoline builtin.
+  // Notice that we cannot store a reference to the trampoline code directly in
+  // this stub, because runtime stubs are not traversed when doing GC.
+
+  // Registers:
+  // a0: entry_address
+  // a1: function
+  // a2: reveiver_pointer
+  // a3: argc
+  // s0: argv
+  //
+  // Stack:
+  // handler frame
+  // entry frame
+  // callee saved registers + ra
+  // 4 args slots
+  // args
+
+  if (is_construct) {
+    ExternalReference construct_entry(Builtins::kJSConstructEntryTrampoline,
+                                      masm->isolate());
+    __ li(t0, Operand(construct_entry));
+  } else {
+    ExternalReference entry(Builtins::kJSEntryTrampoline, masm->isolate());
+    __ li(t0, Operand(entry));
+  }
+  __ lw(t9, MemOperand(t0));  // Deref address.
+
+  // Call JSEntryTrampoline.
+  __ addiu(t9, t9, Code::kHeaderSize - kHeapObjectTag);
+  __ Call(t9);
+
+  // Unlink this frame from the handler chain. When reading the
+  // address of the next handler, there is no need to use the address
+  // displacement since the current stack pointer (sp) points directly
+  // to the stack handler.
+  __ lw(t1, MemOperand(sp, StackHandlerConstants::kNextOffset));
+  __ li(t0, Operand(ExternalReference(Isolate::k_handler_address,
+                                      masm->isolate())));
+  __ sw(t1, MemOperand(t0));
+
+  // This restores sp to its position before PushTryHandler.
+  __ addiu(sp, sp, StackHandlerConstants::kSize);
+
+#ifdef ENABLE_LOGGING_AND_PROFILING
+  // If current FP value is the same as js_entry_sp value, it means that
+  // the current function is the outermost.
+  __ li(t1, Operand(ExternalReference(js_entry_sp)));
+  __ lw(t2, MemOperand(t1));
+  {
+    Label skip;
+    __ Branch(&skip, ne, fp, Operand(t2));
+    __ sw(zero_reg, MemOperand(t1));
+    __ bind(&skip);
+  }
+#endif
+
+  __ bind(&exit);  // v0 holds result.
+  // Restore the top frame descriptors from the stack.
+  __ pop(t1);
+  __ li(t0, Operand(ExternalReference(Isolate::k_c_entry_fp_address,
+                                      masm->isolate())));
+  __ sw(t1, MemOperand(t0));
+
+  // Reset the stack to the callee saved registers.
+  __ addiu(sp, sp, -EntryFrameConstants::kCallerFPOffset);
+
+  // Restore callee saved registers from the stack.
+  __ MultiPop((kCalleeSaved | ra.bit()) & ~sp.bit());
+  // Return.
+  __ Jump(ra);
 }
 
 
@@ -534,58 +3886,1008 @@ void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
 // a1 (or at sp), depending on whether or not
 // args_in_registers() is true.
 void InstanceofStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Fixed register usage throughout the stub:
+  const Register object = a0;  // Object (lhs).
+  const Register map = a3;  // Map of the object.
+  const Register function = a1;  // Function (rhs).
+  const Register prototype = t0;  // Prototype of the function.
+  const Register scratch = a2;
+  Label slow, loop, is_instance, is_not_instance, not_js_object;
+  if (!HasArgsInRegisters()) {
+    __ lw(object, MemOperand(sp, 1 * kPointerSize));
+    __ lw(function, MemOperand(sp, 0));
+  }
+
+  // Check that the left hand is a JS object and load map.
+  __ JumpIfSmi(object, &not_js_object);
+  __ IsObjectJSObjectType(object, map, scratch, &not_js_object);
+
+  // Look up the function and the map in the instanceof cache.
+  Label miss;
+  __ LoadRoot(t1, Heap::kInstanceofCacheFunctionRootIndex);
+  __ Branch(&miss, ne, function, Operand(t1));
+  __ LoadRoot(t1, Heap::kInstanceofCacheMapRootIndex);
+  __ Branch(&miss, ne, map, Operand(t1));
+  __ LoadRoot(v0, Heap::kInstanceofCacheAnswerRootIndex);
+  __ DropAndRet(HasArgsInRegisters() ? 0 : 2);
+
+  __ bind(&miss);
+  __ TryGetFunctionPrototype(function, prototype, scratch, &slow);
+
+  // Check that the function prototype is a JS object.
+  __ JumpIfSmi(prototype, &slow);
+  __ IsObjectJSObjectType(prototype, scratch, scratch, &slow);
+
+  __ StoreRoot(function, Heap::kInstanceofCacheFunctionRootIndex);
+  __ StoreRoot(map, Heap::kInstanceofCacheMapRootIndex);
+
+  // Register mapping: a3 is object map and t0 is function prototype.
+  // Get prototype of object into a2.
+  __ lw(scratch, FieldMemOperand(map, Map::kPrototypeOffset));
+
+  // Loop through the prototype chain looking for the function prototype.
+  __ bind(&loop);
+  __ Branch(&is_instance, eq, scratch, Operand(prototype));
+  __ LoadRoot(t1, Heap::kNullValueRootIndex);
+  __ Branch(&is_not_instance, eq, scratch, Operand(t1));
+  __ lw(scratch, FieldMemOperand(scratch, HeapObject::kMapOffset));
+  __ lw(scratch, FieldMemOperand(scratch, Map::kPrototypeOffset));
+  __ Branch(&loop);
+
+  __ bind(&is_instance);
+  ASSERT(Smi::FromInt(0) == 0);
+  __ mov(v0, zero_reg);
+  __ StoreRoot(v0, Heap::kInstanceofCacheAnswerRootIndex);
+  __ DropAndRet(HasArgsInRegisters() ? 0 : 2);
+
+  __ bind(&is_not_instance);
+  __ li(v0, Operand(Smi::FromInt(1)));
+  __ StoreRoot(v0, Heap::kInstanceofCacheAnswerRootIndex);
+  __ DropAndRet(HasArgsInRegisters() ? 0 : 2);
+
+  Label object_not_null, object_not_null_or_smi;
+  __ bind(&not_js_object);
+  // Before null, smi and string value checks, check that the rhs is a function
+  // as for a non-function rhs an exception needs to be thrown.
+  __ JumpIfSmi(function, &slow);
+  __ GetObjectType(function, map, scratch);
+  __ Branch(&slow, ne, scratch, Operand(JS_FUNCTION_TYPE));
+
+  // Null is not instance of anything.
+  __ Branch(&object_not_null, ne, scratch,
+      Operand(masm->isolate()->factory()->null_value()));
+  __ li(v0, Operand(Smi::FromInt(1)));
+  __ DropAndRet(HasArgsInRegisters() ? 0 : 2);
+
+  __ bind(&object_not_null);
+  // Smi values are not instances of anything.
+  __ JumpIfNotSmi(object, &object_not_null_or_smi);
+  __ li(v0, Operand(Smi::FromInt(1)));
+  __ DropAndRet(HasArgsInRegisters() ? 0 : 2);
+
+  __ bind(&object_not_null_or_smi);
+  // String values are not instances of anything.
+  __ IsObjectJSStringType(object, scratch, &slow);
+  __ li(v0, Operand(Smi::FromInt(1)));
+  __ DropAndRet(HasArgsInRegisters() ? 0 : 2);
+
+  // Slow-case.  Tail call builtin.
+  __ bind(&slow);
+  if (HasArgsInRegisters()) {
+    __ Push(a0, a1);
+  }
+  __ InvokeBuiltin(Builtins::INSTANCE_OF, JUMP_FUNCTION);
 }
 
 
 void ArgumentsAccessStub::GenerateReadElement(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // The displacement is the offset of the last parameter (if any)
+  // relative to the frame pointer.
+  static const int kDisplacement =
+      StandardFrameConstants::kCallerSPOffset - kPointerSize;
+
+  // Check that the key is a smiGenerateReadElement.
+  Label slow;
+  __ JumpIfNotSmi(a1, &slow);
+
+  // Check if the calling frame is an arguments adaptor frame.
+  Label adaptor;
+  __ lw(a2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ lw(a3, MemOperand(a2, StandardFrameConstants::kContextOffset));
+  __ Branch(&adaptor,
+            eq,
+            a3,
+            Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+
+  // Check index (a1) against formal parameters count limit passed in
+  // through register a0. Use unsigned comparison to get negative
+  // check for free.
+  __ Branch(&slow, hs, a1, Operand(a0));
+
+  // Read the argument from the stack and return it.
+  __ subu(a3, a0, a1);
+  __ sll(t3, a3, kPointerSizeLog2 - kSmiTagSize);
+  __ Addu(a3, fp, Operand(t3));
+  __ lw(v0, MemOperand(a3, kDisplacement));
+  __ Ret();
+
+  // Arguments adaptor case: Check index (a1) against actual arguments
+  // limit found in the arguments adaptor frame. Use unsigned
+  // comparison to get negative check for free.
+  __ bind(&adaptor);
+  __ lw(a0, MemOperand(a2, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ Branch(&slow, Ugreater_equal, a1, Operand(a0));
+
+  // Read the argument from the adaptor frame and return it.
+  __ subu(a3, a0, a1);
+  __ sll(t3, a3, kPointerSizeLog2 - kSmiTagSize);
+  __ Addu(a3, a2, Operand(t3));
+  __ lw(v0, MemOperand(a3, kDisplacement));
+  __ Ret();
+
+  // Slow-case: Handle non-smi or out-of-bounds access to arguments
+  // by calling the runtime system.
+  __ bind(&slow);
+  __ push(a1);
+  __ TailCallRuntime(Runtime::kGetArgumentsProperty, 1, 1);
 }
 
 
 void ArgumentsAccessStub::GenerateNewObject(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // sp[0] : number of parameters
+  // sp[4] : receiver displacement
+  // sp[8] : function
+
+  // Check if the calling frame is an arguments adaptor frame.
+  Label adaptor_frame, try_allocate, runtime;
+  __ lw(a2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ lw(a3, MemOperand(a2, StandardFrameConstants::kContextOffset));
+  __ Branch(&adaptor_frame,
+            eq,
+            a3,
+            Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+
+  // Get the length from the frame.
+  __ lw(a1, MemOperand(sp, 0));
+  __ Branch(&try_allocate);
+
+  // Patch the arguments.length and the parameters pointer.
+  __ bind(&adaptor_frame);
+  __ lw(a1, MemOperand(a2, ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ sw(a1, MemOperand(sp, 0));
+  __ sll(at, a1, kPointerSizeLog2 - kSmiTagSize);
+  __ Addu(a3, a2, Operand(at));
+
+  __ Addu(a3, a3, Operand(StandardFrameConstants::kCallerSPOffset));
+  __ sw(a3, MemOperand(sp, 1 * kPointerSize));
+
+  // Try the new space allocation. Start out with computing the size
+  // of the arguments object and the elements array in words.
+  Label add_arguments_object;
+  __ bind(&try_allocate);
+  __ Branch(&add_arguments_object, eq, a1, Operand(zero_reg));
+  __ srl(a1, a1, kSmiTagSize);
+
+  __ Addu(a1, a1, Operand(FixedArray::kHeaderSize / kPointerSize));
+  __ bind(&add_arguments_object);
+  __ Addu(a1, a1, Operand(GetArgumentsObjectSize() / kPointerSize));
+
+  // Do the allocation of both objects in one go.
+  __ AllocateInNewSpace(
+      a1,
+      v0,
+      a2,
+      a3,
+      &runtime,
+      static_cast<AllocationFlags>(TAG_OBJECT | SIZE_IN_WORDS));
+
+  // Get the arguments boilerplate from the current (global) context.
+  __ lw(t0, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
+  __ lw(t0, FieldMemOperand(t0, GlobalObject::kGlobalContextOffset));
+  __ lw(t0, MemOperand(t0,
+                       Context::SlotOffset(GetArgumentsBoilerplateIndex())));
+
+  // Copy the JS object part.
+  __ CopyFields(v0, t0, a3.bit(), JSObject::kHeaderSize / kPointerSize);
+
+  if (type_ == NEW_NON_STRICT) {
+    // Setup the callee in-object property.
+    STATIC_ASSERT(Heap::kArgumentsCalleeIndex == 1);
+    __ lw(a3, MemOperand(sp, 2 * kPointerSize));
+    const int kCalleeOffset = JSObject::kHeaderSize +
+                              Heap::kArgumentsCalleeIndex * kPointerSize;
+    __ sw(a3, FieldMemOperand(v0, kCalleeOffset));
+  }
+
+  // Get the length (smi tagged) and set that as an in-object property too.
+  STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
+  __ lw(a1, MemOperand(sp, 0 * kPointerSize));
+  __ sw(a1, FieldMemOperand(v0, JSObject::kHeaderSize +
+                                Heap::kArgumentsLengthIndex * kPointerSize));
+
+  Label done;
+  __ Branch(&done, eq, a1, Operand(zero_reg));
+
+  // Get the parameters pointer from the stack.
+  __ lw(a2, MemOperand(sp, 1 * kPointerSize));
+
+  // Setup the elements pointer in the allocated arguments object and
+  // initialize the header in the elements fixed array.
+  __ Addu(t0, v0, Operand(GetArgumentsObjectSize()));
+  __ sw(t0, FieldMemOperand(v0, JSObject::kElementsOffset));
+  __ LoadRoot(a3, Heap::kFixedArrayMapRootIndex);
+  __ sw(a3, FieldMemOperand(t0, FixedArray::kMapOffset));
+  __ sw(a1, FieldMemOperand(t0, FixedArray::kLengthOffset));
+  __ srl(a1, a1, kSmiTagSize);  // Untag the length for the loop.
+
+  // Copy the fixed array slots.
+  Label loop;
+  // Setup t0 to point to the first array slot.
+  __ Addu(t0, t0, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  __ bind(&loop);
+  // Pre-decrement a2 with kPointerSize on each iteration.
+  // Pre-decrement in order to skip receiver.
+  __ Addu(a2, a2, Operand(-kPointerSize));
+  __ lw(a3, MemOperand(a2));
+  // Post-increment t0 with kPointerSize on each iteration.
+  __ sw(a3, MemOperand(t0));
+  __ Addu(t0, t0, Operand(kPointerSize));
+  __ Subu(a1, a1, Operand(1));
+  __ Branch(&loop, ne, a1, Operand(zero_reg));
+
+  // Return and remove the on-stack parameters.
+  __ bind(&done);
+  __ Addu(sp, sp, Operand(3 * kPointerSize));
+  __ Ret();
+
+  // Do the runtime call to allocate the arguments object.
+  __ bind(&runtime);
+  __ TailCallRuntime(Runtime::kNewArgumentsFast, 3, 1);
 }
 
 
 void RegExpExecStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Just jump directly to runtime if native RegExp is not selected at compile
+  // time or if regexp entry in generated code is turned off runtime switch or
+  // at compilation.
+#ifdef V8_INTERPRETED_REGEXP
+  __ TailCallRuntime(Runtime::kRegExpExec, 4, 1);
+#else  // V8_INTERPRETED_REGEXP
+  if (!FLAG_regexp_entry_native) {
+    __ TailCallRuntime(Runtime::kRegExpExec, 4, 1);
+    return;
+  }
+
+  // Stack frame on entry.
+  //  sp[0]: last_match_info (expected JSArray)
+  //  sp[4]: previous index
+  //  sp[8]: subject string
+  //  sp[12]: JSRegExp object
+
+  static const int kLastMatchInfoOffset = 0 * kPointerSize;
+  static const int kPreviousIndexOffset = 1 * kPointerSize;
+  static const int kSubjectOffset = 2 * kPointerSize;
+  static const int kJSRegExpOffset = 3 * kPointerSize;
+
+  Label runtime, invoke_regexp;
+
+  // Allocation of registers for this function. These are in callee save
+  // registers and will be preserved by the call to the native RegExp code, as
+  // this code is called using the normal C calling convention. When calling
+  // directly from generated code the native RegExp code will not do a GC and
+  // therefore the content of these registers are safe to use after the call.
+  // MIPS - using s0..s2, since we are not using CEntry Stub.
+  Register subject = s0;
+  Register regexp_data = s1;
+  Register last_match_info_elements = s2;
+
+  // Ensure that a RegExp stack is allocated.
+  ExternalReference address_of_regexp_stack_memory_address =
+      ExternalReference::address_of_regexp_stack_memory_address(
+          masm->isolate());
+  ExternalReference address_of_regexp_stack_memory_size =
+      ExternalReference::address_of_regexp_stack_memory_size(masm->isolate());
+  __ li(a0, Operand(address_of_regexp_stack_memory_size));
+  __ lw(a0, MemOperand(a0, 0));
+  __ Branch(&runtime, eq, a0, Operand(zero_reg));
+
+  // Check that the first argument is a JSRegExp object.
+  __ lw(a0, MemOperand(sp, kJSRegExpOffset));
+  STATIC_ASSERT(kSmiTag == 0);
+  __ JumpIfSmi(a0, &runtime);
+  __ GetObjectType(a0, a1, a1);
+  __ Branch(&runtime, ne, a1, Operand(JS_REGEXP_TYPE));
+
+  // Check that the RegExp has been compiled (data contains a fixed array).
+  __ lw(regexp_data, FieldMemOperand(a0, JSRegExp::kDataOffset));
+  if (FLAG_debug_code) {
+    __ And(t0, regexp_data, Operand(kSmiTagMask));
+    __ Check(nz,
+             "Unexpected type for RegExp data, FixedArray expected",
+             t0,
+             Operand(zero_reg));
+    __ GetObjectType(regexp_data, a0, a0);
+    __ Check(eq,
+             "Unexpected type for RegExp data, FixedArray expected",
+             a0,
+             Operand(FIXED_ARRAY_TYPE));
+  }
+
+  // regexp_data: RegExp data (FixedArray)
+  // Check the type of the RegExp. Only continue if type is JSRegExp::IRREGEXP.
+  __ lw(a0, FieldMemOperand(regexp_data, JSRegExp::kDataTagOffset));
+  __ Branch(&runtime, ne, a0, Operand(Smi::FromInt(JSRegExp::IRREGEXP)));
+
+  // regexp_data: RegExp data (FixedArray)
+  // Check that the number of captures fit in the static offsets vector buffer.
+  __ lw(a2,
+         FieldMemOperand(regexp_data, JSRegExp::kIrregexpCaptureCountOffset));
+  // Calculate number of capture registers (number_of_captures + 1) * 2. This
+  // uses the asumption that smis are 2 * their untagged value.
+  STATIC_ASSERT(kSmiTag == 0);
+  STATIC_ASSERT(kSmiTagSize + kSmiShiftSize == 1);
+  __ Addu(a2, a2, Operand(2));  // a2 was a smi.
+  // Check that the static offsets vector buffer is large enough.
+  __ Branch(&runtime, hi, a2, Operand(OffsetsVector::kStaticOffsetsVectorSize));
+
+  // a2: Number of capture registers
+  // regexp_data: RegExp data (FixedArray)
+  // Check that the second argument is a string.
+  __ lw(subject, MemOperand(sp, kSubjectOffset));
+  __ JumpIfSmi(subject, &runtime);
+  __ GetObjectType(subject, a0, a0);
+  __ And(a0, a0, Operand(kIsNotStringMask));
+  STATIC_ASSERT(kStringTag == 0);
+  __ Branch(&runtime, ne, a0, Operand(zero_reg));
+
+  // Get the length of the string to r3.
+  __ lw(a3, FieldMemOperand(subject, String::kLengthOffset));
+
+  // a2: Number of capture registers
+  // a3: Length of subject string as a smi
+  // subject: Subject string
+  // regexp_data: RegExp data (FixedArray)
+  // Check that the third argument is a positive smi less than the subject
+  // string length. A negative value will be greater (unsigned comparison).
+  __ lw(a0, MemOperand(sp, kPreviousIndexOffset));
+  __ And(at, a0, Operand(kSmiTagMask));
+  __ Branch(&runtime, ne, at, Operand(zero_reg));
+  __ Branch(&runtime, ls, a3, Operand(a0));
+
+  // a2: Number of capture registers
+  // subject: Subject string
+  // regexp_data: RegExp data (FixedArray)
+  // Check that the fourth object is a JSArray object.
+  __ lw(a0, MemOperand(sp, kLastMatchInfoOffset));
+  __ JumpIfSmi(a0, &runtime);
+  __ GetObjectType(a0, a1, a1);
+  __ Branch(&runtime, ne, a1, Operand(JS_ARRAY_TYPE));
+  // Check that the JSArray is in fast case.
+  __ lw(last_match_info_elements,
+         FieldMemOperand(a0, JSArray::kElementsOffset));
+  __ lw(a0, FieldMemOperand(last_match_info_elements, HeapObject::kMapOffset));
+  __ Branch(&runtime, ne, a0, Operand(
+      masm->isolate()->factory()->fixed_array_map()));
+  // Check that the last match info has space for the capture registers and the
+  // additional information.
+  __ lw(a0,
+         FieldMemOperand(last_match_info_elements, FixedArray::kLengthOffset));
+  __ Addu(a2, a2, Operand(RegExpImpl::kLastMatchOverhead));
+  __ sra(at, a0, kSmiTagSize);  // Untag length for comparison.
+  __ Branch(&runtime, gt, a2, Operand(at));
+  // subject: Subject string
+  // regexp_data: RegExp data (FixedArray)
+  // Check the representation and encoding of the subject string.
+  Label seq_string;
+  __ lw(a0, FieldMemOperand(subject, HeapObject::kMapOffset));
+  __ lbu(a0, FieldMemOperand(a0, Map::kInstanceTypeOffset));
+  // First check for flat string.
+  __ And(at, a0, Operand(kIsNotStringMask | kStringRepresentationMask));
+  STATIC_ASSERT((kStringTag | kSeqStringTag) == 0);
+  __ Branch(&seq_string, eq, at, Operand(zero_reg));
+
+  // subject: Subject string
+  // a0: instance type if Subject string
+  // regexp_data: RegExp data (FixedArray)
+  // Check for flat cons string.
+  // A flat cons string is a cons string where the second part is the empty
+  // string. In that case the subject string is just the first part of the cons
+  // string. Also in this case the first part of the cons string is known to be
+  // a sequential string or an external string.
+  STATIC_ASSERT(kExternalStringTag != 0);
+  STATIC_ASSERT((kConsStringTag & kExternalStringTag) == 0);
+  __ And(at, a0, Operand(kIsNotStringMask | kExternalStringTag));
+  __ Branch(&runtime, ne, at, Operand(zero_reg));
+  __ lw(a0, FieldMemOperand(subject, ConsString::kSecondOffset));
+  __ LoadRoot(a1, Heap::kEmptyStringRootIndex);
+  __ Branch(&runtime, ne, a0, Operand(a1));
+  __ lw(subject, FieldMemOperand(subject, ConsString::kFirstOffset));
+  __ lw(a0, FieldMemOperand(subject, HeapObject::kMapOffset));
+  __ lbu(a0, FieldMemOperand(a0, Map::kInstanceTypeOffset));
+  // Is first part a flat string?
+  STATIC_ASSERT(kSeqStringTag == 0);
+  __ And(at, a0, Operand(kStringRepresentationMask));
+  __ Branch(&runtime, ne, at, Operand(zero_reg));
+
+  __ bind(&seq_string);
+  // subject: Subject string
+  // regexp_data: RegExp data (FixedArray)
+  // a0: Instance type of subject string
+  STATIC_ASSERT(kStringEncodingMask == 4);
+  STATIC_ASSERT(kAsciiStringTag == 4);
+  STATIC_ASSERT(kTwoByteStringTag == 0);
+  // Find the code object based on the assumptions above.
+  __ And(a0, a0, Operand(kStringEncodingMask));  // Non-zero for ascii.
+  __ lw(t9, FieldMemOperand(regexp_data, JSRegExp::kDataAsciiCodeOffset));
+  __ sra(a3, a0, 2);  // a3 is 1 for ascii, 0 for UC16 (usyed below).
+  __ lw(t0, FieldMemOperand(regexp_data, JSRegExp::kDataUC16CodeOffset));
+  __ movz(t9, t0, a0);  // If UC16 (a0 is 0), replace t9 w/kDataUC16CodeOffset.
+
+  // Check that the irregexp code has been generated for the actual string
+  // encoding. If it has, the field contains a code object otherwise it
+  // contains the hole.
+  __ GetObjectType(t9, a0, a0);
+  __ Branch(&runtime, ne, a0, Operand(CODE_TYPE));
+
+  // a3: encoding of subject string (1 if ASCII, 0 if two_byte);
+  // t9: code
+  // subject: Subject string
+  // regexp_data: RegExp data (FixedArray)
+  // Load used arguments before starting to push arguments for call to native
+  // RegExp code to avoid handling changing stack height.
+  __ lw(a1, MemOperand(sp, kPreviousIndexOffset));
+  __ sra(a1, a1, kSmiTagSize);  // Untag the Smi.
+
+  // a1: previous index
+  // a3: encoding of subject string (1 if ASCII, 0 if two_byte);
+  // t9: code
+  // subject: Subject string
+  // regexp_data: RegExp data (FixedArray)
+  // All checks done. Now push arguments for native regexp code.
+  __ IncrementCounter(masm->isolate()->counters()->regexp_entry_native(),
+                      1, a0, a2);
+
+  // Isolates: note we add an additional parameter here (isolate pointer).
+  static const int kRegExpExecuteArguments = 8;
+  static const int kParameterRegisters = 4;
+  __ EnterExitFrame(false, kRegExpExecuteArguments - kParameterRegisters);
+
+  // Stack pointer now points to cell where return address is to be written.
+  // Arguments are before that on the stack or in registers, meaning we
+  // treat the return address as argument 5. Thus every argument after that
+  // needs to be shifted back by 1. Since DirectCEntryStub will handle
+  // allocating space for the c argument slots, we don't need to calculate
+  // that into the argument positions on the stack. This is how the stack will
+  // look (sp meaning the value of sp at this moment):
+  // [sp + 4] - Argument 8
+  // [sp + 3] - Argument 7
+  // [sp + 2] - Argument 6
+  // [sp + 1] - Argument 5
+  // [sp + 0] - saved ra
+
+  // Argument 8: Pass current isolate address.
+  // CFunctionArgumentOperand handles MIPS stack argument slots.
+  __ li(a0, Operand(ExternalReference::isolate_address()));
+  __ sw(a0, MemOperand(sp, 4 * kPointerSize));
+
+  // Argument 7: Indicate that this is a direct call from JavaScript.
+  __ li(a0, Operand(1));
+  __ sw(a0, MemOperand(sp, 3 * kPointerSize));
+
+  // Argument 6: Start (high end) of backtracking stack memory area.
+  __ li(a0, Operand(address_of_regexp_stack_memory_address));
+  __ lw(a0, MemOperand(a0, 0));
+  __ li(a2, Operand(address_of_regexp_stack_memory_size));
+  __ lw(a2, MemOperand(a2, 0));
+  __ addu(a0, a0, a2);
+  __ sw(a0, MemOperand(sp, 2 * kPointerSize));
+
+  // Argument 5: static offsets vector buffer.
+  __ li(a0, Operand(
+        ExternalReference::address_of_static_offsets_vector(masm->isolate())));
+  __ sw(a0, MemOperand(sp, 1 * kPointerSize));
+
+  // For arguments 4 and 3 get string length, calculate start of string data
+  // and calculate the shift of the index (0 for ASCII and 1 for two byte).
+  __ lw(a0, FieldMemOperand(subject, String::kLengthOffset));
+  __ sra(a0, a0, kSmiTagSize);
+  STATIC_ASSERT(SeqAsciiString::kHeaderSize == SeqTwoByteString::kHeaderSize);
+  __ Addu(t0, subject, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+  __ Xor(a3, a3, Operand(1));  // 1 for 2-byte str, 0 for 1-byte.
+  // Argument 4 (a3): End of string data
+  // Argument 3 (a2): Start of string data
+  __ sllv(t1, a1, a3);
+  __ addu(a2, t0, t1);
+  __ sllv(t1, a0, a3);
+  __ addu(a3, t0, t1);
+
+  // Argument 2 (a1): Previous index.
+  // Already there
+
+  // Argument 1 (a0): Subject string.
+  __ mov(a0, subject);
+
+  // Locate the code entry and call it.
+  __ Addu(t9, t9, Operand(Code::kHeaderSize - kHeapObjectTag));
+  DirectCEntryStub stub;
+  stub.GenerateCall(masm, t9);
+
+  __ LeaveExitFrame(false, no_reg);
+
+  // v0: result
+  // subject: subject string (callee saved)
+  // regexp_data: RegExp data (callee saved)
+  // last_match_info_elements: Last match info elements (callee saved)
+
+  // Check the result.
+
+  Label success;
+  __ Branch(&success, eq, v0, Operand(NativeRegExpMacroAssembler::SUCCESS));
+  Label failure;
+  __ Branch(&failure, eq, v0, Operand(NativeRegExpMacroAssembler::FAILURE));
+  // If not exception it can only be retry. Handle that in the runtime system.
+  __ Branch(&runtime, ne, v0, Operand(NativeRegExpMacroAssembler::EXCEPTION));
+  // Result must now be exception. If there is no pending exception already a
+  // stack overflow (on the backtrack stack) was detected in RegExp code but
+  // haven't created the exception yet. Handle that in the runtime system.
+  // TODO(592): Rerunning the RegExp to get the stack overflow exception.
+  __ li(a1, Operand(
+      ExternalReference::the_hole_value_location(masm->isolate())));
+  __ lw(a1, MemOperand(a1, 0));
+  __ li(a2, Operand(ExternalReference(Isolate::k_pending_exception_address,
+                                      masm->isolate())));
+  __ lw(v0, MemOperand(a2, 0));
+  __ Branch(&runtime, eq, v0, Operand(a1));
+
+  __ sw(a1, MemOperand(a2, 0));  // Clear pending exception.
+
+  // Check if the exception is a termination. If so, throw as uncatchable.
+  __ LoadRoot(a0, Heap::kTerminationExceptionRootIndex);
+  Label termination_exception;
+  __ Branch(&termination_exception, eq, v0, Operand(a0));
+
+  __ Throw(a0);  // Expects thrown value in v0.
+
+  __ bind(&termination_exception);
+  __ ThrowUncatchable(TERMINATION, v0);  // Expects thrown value in v0.
+
+  __ bind(&failure);
+  // For failure and exception return null.
+  __ li(v0, Operand(masm->isolate()->factory()->null_value()));
+  __ Addu(sp, sp, Operand(4 * kPointerSize));
+  __ Ret();
+
+  // Process the result from the native regexp code.
+  __ bind(&success);
+  __ lw(a1,
+         FieldMemOperand(regexp_data, JSRegExp::kIrregexpCaptureCountOffset));
+  // Calculate number of capture registers (number_of_captures + 1) * 2.
+  STATIC_ASSERT(kSmiTag == 0);
+  STATIC_ASSERT(kSmiTagSize + kSmiShiftSize == 1);
+  __ Addu(a1, a1, Operand(2));  // a1 was a smi.
+
+  // a1: number of capture registers
+  // subject: subject string
+  // Store the capture count.
+  __ sll(a2, a1, kSmiTagSize + kSmiShiftSize);  // To smi.
+  __ sw(a2, FieldMemOperand(last_match_info_elements,
+                             RegExpImpl::kLastCaptureCountOffset));
+  // Store last subject and last input.
+  __ mov(a3, last_match_info_elements);  // Moved up to reduce latency.
+  __ sw(subject,
+         FieldMemOperand(last_match_info_elements,
+                         RegExpImpl::kLastSubjectOffset));
+  __ RecordWrite(a3, Operand(RegExpImpl::kLastSubjectOffset), a2, t0);
+  __ sw(subject,
+         FieldMemOperand(last_match_info_elements,
+                         RegExpImpl::kLastInputOffset));
+  __ mov(a3, last_match_info_elements);
+  __ RecordWrite(a3, Operand(RegExpImpl::kLastInputOffset), a2, t0);
+
+  // Get the static offsets vector filled by the native regexp code.
+  ExternalReference address_of_static_offsets_vector =
+      ExternalReference::address_of_static_offsets_vector(masm->isolate());
+  __ li(a2, Operand(address_of_static_offsets_vector));
+
+  // a1: number of capture registers
+  // a2: offsets vector
+  Label next_capture, done;
+  // Capture register counter starts from number of capture registers and
+  // counts down until wrapping after zero.
+  __ Addu(a0,
+         last_match_info_elements,
+         Operand(RegExpImpl::kFirstCaptureOffset - kHeapObjectTag));
+  __ bind(&next_capture);
+  __ Subu(a1, a1, Operand(1));
+  __ Branch(&done, lt, a1, Operand(zero_reg));
+  // Read the value from the static offsets vector buffer.
+  __ lw(a3, MemOperand(a2, 0));
+  __ addiu(a2, a2, kPointerSize);
+  // Store the smi value in the last match info.
+  __ sll(a3, a3, kSmiTagSize);  // Convert to Smi.
+  __ sw(a3, MemOperand(a0, 0));
+  __ Branch(&next_capture, USE_DELAY_SLOT);
+  __ addiu(a0, a0, kPointerSize);   // In branch delay slot.
+
+  __ bind(&done);
+
+  // Return last match info.
+  __ lw(v0, MemOperand(sp, kLastMatchInfoOffset));
+  __ Addu(sp, sp, Operand(4 * kPointerSize));
+  __ Ret();
+
+  // Do the runtime call to execute the regexp.
+  __ bind(&runtime);
+  __ TailCallRuntime(Runtime::kRegExpExec, 4, 1);
+#endif  // V8_INTERPRETED_REGEXP
 }
 
 
 void RegExpConstructResultStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  const int kMaxInlineLength = 100;
+  Label slowcase;
+  Label done;
+  __ lw(a1, MemOperand(sp, kPointerSize * 2));
+  STATIC_ASSERT(kSmiTag == 0);
+  STATIC_ASSERT(kSmiTagSize == 1);
+  __ JumpIfNotSmi(a1, &slowcase);
+  __ Branch(&slowcase, hi, a1, Operand(Smi::FromInt(kMaxInlineLength)));
+  // Smi-tagging is equivalent to multiplying by 2.
+  // Allocate RegExpResult followed by FixedArray with size in ebx.
+  // JSArray:   [Map][empty properties][Elements][Length-smi][index][input]
+  // Elements:  [Map][Length][..elements..]
+  // Size of JSArray with two in-object properties and the header of a
+  // FixedArray.
+  int objects_size =
+      (JSRegExpResult::kSize + FixedArray::kHeaderSize) / kPointerSize;
+  __ srl(t1, a1, kSmiTagSize + kSmiShiftSize);
+  __ Addu(a2, t1, Operand(objects_size));
+  __ AllocateInNewSpace(
+      a2,  // In: Size, in words.
+      v0,  // Out: Start of allocation (tagged).
+      a3,  // Scratch register.
+      t0,  // Scratch register.
+      &slowcase,
+      static_cast<AllocationFlags>(TAG_OBJECT | SIZE_IN_WORDS));
+  // v0: Start of allocated area, object-tagged.
+  // a1: Number of elements in array, as smi.
+  // t1: Number of elements, untagged.
+
+  // Set JSArray map to global.regexp_result_map().
+  // Set empty properties FixedArray.
+  // Set elements to point to FixedArray allocated right after the JSArray.
+  // Interleave operations for better latency.
+  __ lw(a2, ContextOperand(cp, Context::GLOBAL_INDEX));
+  __ Addu(a3, v0, Operand(JSRegExpResult::kSize));
+  __ li(t0, Operand(masm->isolate()->factory()->empty_fixed_array()));
+  __ lw(a2, FieldMemOperand(a2, GlobalObject::kGlobalContextOffset));
+  __ sw(a3, FieldMemOperand(v0, JSObject::kElementsOffset));
+  __ lw(a2, ContextOperand(a2, Context::REGEXP_RESULT_MAP_INDEX));
+  __ sw(t0, FieldMemOperand(v0, JSObject::kPropertiesOffset));
+  __ sw(a2, FieldMemOperand(v0, HeapObject::kMapOffset));
+
+  // Set input, index and length fields from arguments.
+  __ lw(a1, MemOperand(sp, kPointerSize * 0));
+  __ sw(a1, FieldMemOperand(v0, JSRegExpResult::kInputOffset));
+  __ lw(a1, MemOperand(sp, kPointerSize * 1));
+  __ sw(a1, FieldMemOperand(v0, JSRegExpResult::kIndexOffset));
+  __ lw(a1, MemOperand(sp, kPointerSize * 2));
+  __ sw(a1, FieldMemOperand(v0, JSArray::kLengthOffset));
+
+  // Fill out the elements FixedArray.
+  // v0: JSArray, tagged.
+  // a3: FixedArray, tagged.
+  // t1: Number of elements in array, untagged.
+
+  // Set map.
+  __ li(a2, Operand(masm->isolate()->factory()->fixed_array_map()));
+  __ sw(a2, FieldMemOperand(a3, HeapObject::kMapOffset));
+  // Set FixedArray length.
+  __ sll(t2, t1, kSmiTagSize);
+  __ sw(t2, FieldMemOperand(a3, FixedArray::kLengthOffset));
+  // Fill contents of fixed-array with the-hole.
+  __ li(a2, Operand(masm->isolate()->factory()->the_hole_value()));
+  __ Addu(a3, a3, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
+  // Fill fixed array elements with hole.
+  // v0: JSArray, tagged.
+  // a2: the hole.
+  // a3: Start of elements in FixedArray.
+  // t1: Number of elements to fill.
+  Label loop;
+  __ sll(t1, t1, kPointerSizeLog2);  // Convert num elements to num bytes.
+  __ addu(t1, t1, a3);  // Point past last element to store.
+  __ bind(&loop);
+  __ Branch(&done, ge, a3, Operand(t1));  // Break when a3 past end of elem.
+  __ sw(a2, MemOperand(a3));
+  __ Branch(&loop, USE_DELAY_SLOT);
+  __ addiu(a3, a3, kPointerSize);  // In branch delay slot.
+
+  __ bind(&done);
+  __ Addu(sp, sp, Operand(3 * kPointerSize));
+  __ Ret();
+
+  __ bind(&slowcase);
+  __ TailCallRuntime(Runtime::kRegExpConstructResult, 3, 1);
 }
 
 
 void CallFunctionStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label slow;
+
+  // If the receiver might be a value (string, number or boolean) check
+  // for this and box it if it is.
+  if (ReceiverMightBeValue()) {
+    // Get the receiver from the stack.
+    // function, receiver [, arguments]
+    Label receiver_is_value, receiver_is_js_object;
+    __ lw(a1, MemOperand(sp, argc_ * kPointerSize));
+
+    // Check if receiver is a smi (which is a number value).
+    __ JumpIfSmi(a1, &receiver_is_value);
+
+    // Check if the receiver is a valid JS object.
+    __ GetObjectType(a1, a2, a2);
+    __ Branch(&receiver_is_js_object,
+              ge,
+              a2,
+              Operand(FIRST_JS_OBJECT_TYPE));
+
+    // Call the runtime to box the value.
+    __ bind(&receiver_is_value);
+    // We need natives to execute this.
+    __ EnterInternalFrame();
+    __ push(a1);
+    __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
+    __ LeaveInternalFrame();
+    __ sw(v0, MemOperand(sp, argc_ * kPointerSize));
+
+    __ bind(&receiver_is_js_object);
+  }
+
+  // Get the function to call from the stack.
+  // function, receiver [, arguments]
+  __ lw(a1, MemOperand(sp, (argc_ + 1) * kPointerSize));
+
+  // Check that the function is really a JavaScript function.
+  // a1: pushed function (to be verified)
+  __ JumpIfSmi(a1, &slow);
+  // Get the map of the function object.
+  __ GetObjectType(a1, a2, a2);
+  __ Branch(&slow, ne, a2, Operand(JS_FUNCTION_TYPE));
+
+  // Fast-case: Invoke the function now.
+  // a1: pushed function
+  ParameterCount actual(argc_);
+  __ InvokeFunction(a1, actual, JUMP_FUNCTION);
+
+  // Slow-case: Non-function called.
+  __ bind(&slow);
+  // CALL_NON_FUNCTION expects the non-function callee as receiver (instead
+  // of the original receiver from the call site).
+  __ sw(a1, MemOperand(sp, argc_ * kPointerSize));
+  __ li(a0, Operand(argc_));  // Setup the number of arguments.
+  __ mov(a2, zero_reg);
+  __ GetBuiltinEntry(a3, Builtins::CALL_NON_FUNCTION);
+  __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
+          RelocInfo::CODE_TARGET);
 }
 
 
 // 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.
 const char* CompareStub::GetName() {
-  UNIMPLEMENTED_MIPS();
+  ASSERT((lhs_.is(a0) && rhs_.is(a1)) ||
+         (lhs_.is(a1) && rhs_.is(a0)));
+
+  if (name_ != NULL) return name_;
+  const int kMaxNameLength = 100;
+  name_ = Isolate::Current()->bootstrapper()->AllocateAutoDeletedArray(
+      kMaxNameLength);
+  if (name_ == NULL) return "OOM";
+
+  const char* cc_name;
+  switch (cc_) {
+    case lt: cc_name = "LT"; break;
+    case gt: cc_name = "GT"; break;
+    case le: cc_name = "LE"; break;
+    case ge: cc_name = "GE"; break;
+    case eq: cc_name = "EQ"; break;
+    case ne: cc_name = "NE"; break;
+    default: cc_name = "UnknownCondition"; break;
+  }
+
+  const char* lhs_name = lhs_.is(a0) ? "_a0" : "_a1";
+  const char* rhs_name = rhs_.is(a0) ? "_a0" : "_a1";
+
+  const char* strict_name = "";
+  if (strict_ && (cc_ == eq || cc_ == ne)) {
+    strict_name = "_STRICT";
+  }
+
+  const char* never_nan_nan_name = "";
+  if (never_nan_nan_ && (cc_ == eq || cc_ == ne)) {
+    never_nan_nan_name = "_NO_NAN";
+  }
+
+  const char* include_number_compare_name = "";
+  if (!include_number_compare_) {
+    include_number_compare_name = "_NO_NUMBER";
+  }
+
+  const char* include_smi_compare_name = "";
+  if (!include_smi_compare_) {
+    include_smi_compare_name = "_NO_SMI";
+  }
+
+  OS::SNPrintF(Vector<char>(name_, kMaxNameLength),
+               "CompareStub_%s%s%s%s%s%s",
+               cc_name,
+               lhs_name,
+               rhs_name,
+               strict_name,
+               never_nan_nan_name,
+               include_number_compare_name,
+               include_smi_compare_name);
   return name_;
 }
 
 
 int CompareStub::MinorKey() {
-  UNIMPLEMENTED_MIPS();
-  return 0;
+  // Encode the two parameters in a unique 16 bit value.
+  ASSERT(static_cast<unsigned>(cc_) < (1 << 14));
+  ASSERT((lhs_.is(a0) && rhs_.is(a1)) ||
+         (lhs_.is(a1) && rhs_.is(a0)));
+  return ConditionField::encode(static_cast<unsigned>(cc_))
+         | RegisterField::encode(lhs_.is(a0))
+         | StrictField::encode(strict_)
+         | NeverNanNanField::encode(cc_ == eq ? never_nan_nan_ : false)
+         | IncludeSmiCompareField::encode(include_smi_compare_);
 }
 
 
 // StringCharCodeAtGenerator.
 void StringCharCodeAtGenerator::GenerateFast(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label flat_string;
+  Label ascii_string;
+  Label got_char_code;
+
+  ASSERT(!t0.is(scratch_));
+  ASSERT(!t0.is(index_));
+  ASSERT(!t0.is(result_));
+  ASSERT(!t0.is(object_));
+
+  // If the receiver is a smi trigger the non-string case.
+  __ JumpIfSmi(object_, receiver_not_string_);
+
+  // Fetch the instance type of the receiver into result register.
+  __ lw(result_, FieldMemOperand(object_, HeapObject::kMapOffset));
+  __ lbu(result_, FieldMemOperand(result_, Map::kInstanceTypeOffset));
+  // If the receiver is not a string trigger the non-string case.
+  __ And(t0, result_, Operand(kIsNotStringMask));
+  __ Branch(receiver_not_string_, ne, t0, Operand(zero_reg));
+
+  // If the index is non-smi trigger the non-smi case.
+  __ JumpIfNotSmi(index_, &index_not_smi_);
+
+  // Put smi-tagged index into scratch register.
+  __ mov(scratch_, index_);
+  __ bind(&got_smi_index_);
+
+  // Check for index out of range.
+  __ lw(t0, FieldMemOperand(object_, String::kLengthOffset));
+  __ Branch(index_out_of_range_, ls, t0, Operand(scratch_));
+
+  // We need special handling for non-flat strings.
+  STATIC_ASSERT(kSeqStringTag == 0);
+  __ And(t0, result_, Operand(kStringRepresentationMask));
+  __ Branch(&flat_string, eq, t0, Operand(zero_reg));
+
+  // Handle non-flat strings.
+  __ And(t0, result_, Operand(kIsConsStringMask));
+  __ Branch(&call_runtime_, eq, t0, Operand(zero_reg));
+
+  // ConsString.
+  // Check whether the right hand side is the empty string (i.e. if
+  // this is really a flat string in a cons string). If that is not
+  // the case we would rather go to the runtime system now to flatten
+  // the string.
+  __ lw(result_, FieldMemOperand(object_, ConsString::kSecondOffset));
+  __ LoadRoot(t0, Heap::kEmptyStringRootIndex);
+  __ Branch(&call_runtime_, ne, result_, Operand(t0));
+
+  // Get the first of the two strings and load its instance type.
+  __ lw(object_, FieldMemOperand(object_, ConsString::kFirstOffset));
+  __ lw(result_, FieldMemOperand(object_, HeapObject::kMapOffset));
+  __ lbu(result_, FieldMemOperand(result_, Map::kInstanceTypeOffset));
+  // If the first cons component is also non-flat, then go to runtime.
+  STATIC_ASSERT(kSeqStringTag == 0);
+
+  __ And(t0, result_, Operand(kStringRepresentationMask));
+  __ Branch(&call_runtime_, ne, t0, Operand(zero_reg));
+
+  // Check for 1-byte or 2-byte string.
+  __ bind(&flat_string);
+  STATIC_ASSERT(kAsciiStringTag != 0);
+  __ And(t0, result_, Operand(kStringEncodingMask));
+  __ Branch(&ascii_string, ne, t0, Operand(zero_reg));
+
+  // 2-byte string.
+  // Load the 2-byte character code into the result register. We can
+  // add without shifting since the smi tag size is the log2 of the
+  // number of bytes in a two-byte character.
+  STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize == 1 && kSmiShiftSize == 0);
+  __ Addu(scratch_, object_, Operand(scratch_));
+  __ lhu(result_, FieldMemOperand(scratch_, SeqTwoByteString::kHeaderSize));
+  __ Branch(&got_char_code);
+
+  // ASCII string.
+  // Load the byte into the result register.
+  __ bind(&ascii_string);
+
+  __ srl(t0, scratch_, kSmiTagSize);
+  __ Addu(scratch_, object_, t0);
+
+  __ lbu(result_, FieldMemOperand(scratch_, SeqAsciiString::kHeaderSize));
+
+  __ bind(&got_char_code);
+  __ sll(result_, result_, kSmiTagSize);
+  __ bind(&exit_);
 }
 
 
 void StringCharCodeAtGenerator::GenerateSlow(
     MacroAssembler* masm, const RuntimeCallHelper& call_helper) {
-  UNIMPLEMENTED_MIPS();
+  __ Abort("Unexpected fallthrough to CharCodeAt slow case");
+
+  // Index is not a smi.
+  __ bind(&index_not_smi_);
+  // If index is a heap number, try converting it to an integer.
+  __ CheckMap(index_,
+              scratch_,
+              Heap::kHeapNumberMapRootIndex,
+              index_not_number_,
+              true);
+  call_helper.BeforeCall(masm);
+  // Consumed by runtime conversion function:
+  __ Push(object_, index_, index_);
+  if (index_flags_ == STRING_INDEX_IS_NUMBER) {
+    __ CallRuntime(Runtime::kNumberToIntegerMapMinusZero, 1);
+  } else {
+    ASSERT(index_flags_ == STRING_INDEX_IS_ARRAY_INDEX);
+    // NumberToSmi discards numbers that are not exact integers.
+    __ CallRuntime(Runtime::kNumberToSmi, 1);
+  }
+
+  // Save the conversion result before the pop instructions below
+  // have a chance to overwrite it.
+
+  __ Move(scratch_, v0);
+
+  __ pop(index_);
+  __ pop(object_);
+  // Reload the instance type.
+  __ lw(result_, FieldMemOperand(object_, HeapObject::kMapOffset));
+  __ lbu(result_, FieldMemOperand(result_, Map::kInstanceTypeOffset));
+  call_helper.AfterCall(masm);
+  // If index is still not a smi, it must be out of range.
+  __ JumpIfNotSmi(scratch_, index_out_of_range_);
+  // Otherwise, return to the fast path.
+  __ Branch(&got_smi_index_);
+
+  // Call runtime. We get here when the receiver is a string and the
+  // index is a number, but the code of getting the actual character
+  // is too complex (e.g., when the string needs to be flattened).
+  __ bind(&call_runtime_);
+  call_helper.BeforeCall(masm);
+  __ Push(object_, index_);
+  __ CallRuntime(Runtime::kStringCharCodeAt, 2);
+
+  __ Move(result_, v0);
+
+  call_helper.AfterCall(masm);
+  __ jmp(&exit_);
+
+  __ Abort("Unexpected fallthrough from CharCodeAt slow case");
 }
 
 
@@ -593,13 +4895,46 @@ void StringCharCodeAtGenerator::GenerateSlow(
 // StringCharFromCodeGenerator
 
 void StringCharFromCodeGenerator::GenerateFast(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Fast case of Heap::LookupSingleCharacterStringFromCode.
+
+  ASSERT(!t0.is(result_));
+  ASSERT(!t0.is(code_));
+
+  STATIC_ASSERT(kSmiTag == 0);
+  STATIC_ASSERT(kSmiShiftSize == 0);
+  ASSERT(IsPowerOf2(String::kMaxAsciiCharCode + 1));
+  __ And(t0,
+         code_,
+         Operand(kSmiTagMask |
+                 ((~String::kMaxAsciiCharCode) << kSmiTagSize)));
+  __ Branch(&slow_case_, ne, t0, Operand(zero_reg));
+
+  __ LoadRoot(result_, Heap::kSingleCharacterStringCacheRootIndex);
+  // At this point code register contains smi tagged ASCII char code.
+  STATIC_ASSERT(kSmiTag == 0);
+  __ sll(t0, code_, kPointerSizeLog2 - kSmiTagSize);
+  __ Addu(result_, result_, t0);
+  __ lw(result_, FieldMemOperand(result_, FixedArray::kHeaderSize));
+  __ LoadRoot(t0, Heap::kUndefinedValueRootIndex);
+  __ Branch(&slow_case_, eq, result_, Operand(t0));
+  __ bind(&exit_);
 }
 
 
 void StringCharFromCodeGenerator::GenerateSlow(
     MacroAssembler* masm, const RuntimeCallHelper& call_helper) {
-  UNIMPLEMENTED_MIPS();
+  __ Abort("Unexpected fallthrough to CharFromCode slow case");
+
+  __ bind(&slow_case_);
+  call_helper.BeforeCall(masm);
+  __ push(code_);
+  __ CallRuntime(Runtime::kCharFromCode, 1);
+  __ Move(result_, v0);
+
+  call_helper.AfterCall(masm);
+  __ Branch(&exit_);
+
+  __ Abort("Unexpected fallthrough from CharFromCode slow case");
 }
 
 
@@ -607,13 +4942,15 @@ void StringCharFromCodeGenerator::GenerateSlow(
 // StringCharAtGenerator
 
 void StringCharAtGenerator::GenerateFast(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  char_code_at_generator_.GenerateFast(masm);
+  char_from_code_generator_.GenerateFast(masm);
 }
 
 
 void StringCharAtGenerator::GenerateSlow(
     MacroAssembler* masm, const RuntimeCallHelper& call_helper) {
-  UNIMPLEMENTED_MIPS();
+  char_code_at_generator_.GenerateSlow(masm, call_helper);
+  char_from_code_generator_.GenerateSlow(masm, call_helper);
 }
 
 
@@ -687,7 +5024,24 @@ void StringHelper::GenerateCopyCharacters(MacroAssembler* masm,
                                           Register count,
                                           Register scratch,
                                           bool ascii) {
-  UNIMPLEMENTED_MIPS();
+  Label loop;
+  Label done;
+  // This loop just copies one character at a time, as it is only used for
+  // very short strings.
+  if (!ascii) {
+    __ addu(count, count, count);
+  }
+  __ Branch(&done, eq, count, Operand(zero_reg));
+  __ addu(count, dest, count);  // Count now points to the last dest byte.
+
+  __ bind(&loop);
+  __ lbu(scratch, MemOperand(src));
+  __ addiu(src, src, 1);
+  __ sb(scratch, MemOperand(dest));
+  __ addiu(dest, dest, 1);
+  __ Branch(&loop, lt, dest, Operand(count));
+
+  __ bind(&done);
 }
 
 
@@ -707,7 +5061,105 @@ void StringHelper::GenerateCopyCharactersLong(MacroAssembler* masm,
                                               Register scratch4,
                                               Register scratch5,
                                               int flags) {
-  UNIMPLEMENTED_MIPS();
+  bool ascii = (flags & COPY_ASCII) != 0;
+  bool dest_always_aligned = (flags & DEST_ALWAYS_ALIGNED) != 0;
+
+  if (dest_always_aligned && FLAG_debug_code) {
+    // Check that destination is actually word aligned if the flag says
+    // that it is.
+    __ And(scratch4, dest, Operand(kPointerAlignmentMask));
+    __ Check(eq,
+             "Destination of copy not aligned.",
+             scratch4,
+             Operand(zero_reg));
+  }
+
+  const int kReadAlignment = 4;
+  const int kReadAlignmentMask = kReadAlignment - 1;
+  // Ensure that reading an entire aligned word containing the last character
+  // of a string will not read outside the allocated area (because we pad up
+  // to kObjectAlignment).
+  STATIC_ASSERT(kObjectAlignment >= kReadAlignment);
+  // Assumes word reads and writes are little endian.
+  // Nothing to do for zero characters.
+  Label done;
+
+  if (!ascii) {
+    __ addu(count, count, count);
+  }
+  __ Branch(&done, eq, count, Operand(zero_reg));
+
+  Label byte_loop;
+  // Must copy at least eight bytes, otherwise just do it one byte at a time.
+  __ Subu(scratch1, count, Operand(8));
+  __ Addu(count, dest, Operand(count));
+  Register limit = count;  // Read until src equals this.
+  __ Branch(&byte_loop, lt, scratch1, Operand(zero_reg));
+
+  if (!dest_always_aligned) {
+    // Align dest by byte copying. Copies between zero and three bytes.
+    __ And(scratch4, dest, Operand(kReadAlignmentMask));
+    Label dest_aligned;
+    __ Branch(&dest_aligned, eq, scratch4, Operand(zero_reg));
+    Label aligned_loop;
+    __ bind(&aligned_loop);
+    __ lbu(scratch1, MemOperand(src));
+    __ addiu(src, src, 1);
+    __ sb(scratch1, MemOperand(dest));
+    __ addiu(dest, dest, 1);
+    __ addiu(scratch4, scratch4, 1);
+    __ Branch(&aligned_loop, le, scratch4, Operand(kReadAlignmentMask));
+    __ bind(&dest_aligned);
+  }
+
+  Label simple_loop;
+
+  __ And(scratch4, src, Operand(kReadAlignmentMask));
+  __ Branch(&simple_loop, eq, scratch4, Operand(zero_reg));
+
+  // Loop for src/dst that are not aligned the same way.
+  // This loop uses lwl and lwr instructions. These instructions
+  // depend on the endianness, and the implementation assumes little-endian.
+  {
+    Label loop;
+    __ bind(&loop);
+    __ lwr(scratch1, MemOperand(src));
+    __ Addu(src, src, Operand(kReadAlignment));
+    __ lwl(scratch1, MemOperand(src, -1));
+    __ sw(scratch1, MemOperand(dest));
+    __ Addu(dest, dest, Operand(kReadAlignment));
+    __ Subu(scratch2, limit, dest);
+    __ Branch(&loop, ge, scratch2, Operand(kReadAlignment));
+  }
+
+  __ Branch(&byte_loop);
+
+  // Simple loop.
+  // Copy words from src to dest, until less than four bytes left.
+  // Both src and dest are word aligned.
+  __ bind(&simple_loop);
+  {
+    Label loop;
+    __ bind(&loop);
+    __ lw(scratch1, MemOperand(src));
+    __ Addu(src, src, Operand(kReadAlignment));
+    __ sw(scratch1, MemOperand(dest));
+    __ Addu(dest, dest, Operand(kReadAlignment));
+    __ Subu(scratch2, limit, dest);
+    __ Branch(&loop, ge, scratch2, Operand(kReadAlignment));
+  }
+
+  // Copy bytes from src to dest until dest hits limit.
+  __ bind(&byte_loop);
+  // Test if dest has already reached the limit.
+  __ Branch(&done, ge, dest, Operand(limit));
+  __ lbu(scratch1, MemOperand(src));
+  __ addiu(src, src, 1);
+  __ sb(scratch1, MemOperand(dest));
+  __ addiu(dest, dest, 1);
+  __ Branch(&byte_loop);
+
+  __ bind(&done);
 }
 
 
@@ -720,32 +5172,434 @@ void StringHelper::GenerateTwoCharacterSymbolTableProbe(MacroAssembler* masm,
                                                         Register scratch4,
                                                         Register scratch5,
                                                         Label* not_found) {
-  UNIMPLEMENTED_MIPS();
+  // Register scratch3 is the general scratch register in this function.
+  Register scratch = scratch3;
+
+  // Make sure that both characters are not digits as such strings has a
+  // different hash algorithm. Don't try to look for these in the symbol table.
+  Label not_array_index;
+  __ Subu(scratch, c1, Operand(static_cast<int>('0')));
+  __ Branch(&not_array_index,
+            Ugreater,
+            scratch,
+            Operand(static_cast<int>('9' - '0')));
+  __ Subu(scratch, c2, Operand(static_cast<int>('0')));
+
+  // If check failed combine both characters into single halfword.
+  // This is required by the contract of the method: code at the
+  // not_found branch expects this combination in c1 register.
+  Label tmp;
+  __ sll(scratch1, c2, kBitsPerByte);
+  __ Branch(&tmp, Ugreater, scratch, Operand(static_cast<int>('9' - '0')));
+  __ Or(c1, c1, scratch1);
+  __ bind(&tmp);
+  __ Branch(not_found,
+            Uless_equal,
+            scratch,
+            Operand(static_cast<int>('9' - '0')));
+
+  __ bind(&not_array_index);
+  // Calculate the two character string hash.
+  Register hash = scratch1;
+  StringHelper::GenerateHashInit(masm, hash, c1);
+  StringHelper::GenerateHashAddCharacter(masm, hash, c2);
+  StringHelper::GenerateHashGetHash(masm, hash);
+
+  // Collect the two characters in a register.
+  Register chars = c1;
+  __ sll(scratch, c2, kBitsPerByte);
+  __ Or(chars, chars, scratch);
+
+  // chars: two character string, char 1 in byte 0 and char 2 in byte 1.
+  // hash:  hash of two character string.
+
+  // Load symbol table.
+  // Load address of first element of the symbol table.
+  Register symbol_table = c2;
+  __ LoadRoot(symbol_table, Heap::kSymbolTableRootIndex);
+
+  Register undefined = scratch4;
+  __ LoadRoot(undefined, Heap::kUndefinedValueRootIndex);
+
+  // Calculate capacity mask from the symbol table capacity.
+  Register mask = scratch2;
+  __ lw(mask, FieldMemOperand(symbol_table, SymbolTable::kCapacityOffset));
+  __ sra(mask, mask, 1);
+  __ Addu(mask, mask, -1);
+
+  // Calculate untagged address of the first element of the symbol table.
+  Register first_symbol_table_element = symbol_table;
+  __ Addu(first_symbol_table_element, symbol_table,
+         Operand(SymbolTable::kElementsStartOffset - kHeapObjectTag));
+
+  // Registers.
+  // chars: two character string, char 1 in byte 0 and char 2 in byte 1.
+  // hash:  hash of two character string
+  // mask:  capacity mask
+  // first_symbol_table_element: address of the first element of
+  //                             the symbol table
+  // undefined: the undefined object
+  // scratch: -
+
+  // Perform a number of probes in the symbol table.
+  static const int kProbes = 4;
+  Label found_in_symbol_table;
+  Label next_probe[kProbes];
+  Register candidate = scratch5;  // Scratch register contains candidate.
+  for (int i = 0; i < kProbes; i++) {
+    // Calculate entry in symbol table.
+    if (i > 0) {
+      __ Addu(candidate, hash, Operand(SymbolTable::GetProbeOffset(i)));
+    } else {
+      __ mov(candidate, hash);
+    }
+
+    __ And(candidate, candidate, Operand(mask));
+
+    // Load the entry from the symble table.
+    STATIC_ASSERT(SymbolTable::kEntrySize == 1);
+    __ sll(scratch, candidate, kPointerSizeLog2);
+    __ Addu(scratch, scratch, first_symbol_table_element);
+    __ lw(candidate, MemOperand(scratch));
+
+    // If entry is undefined no string with this hash can be found.
+    Label is_string;
+    __ GetObjectType(candidate, scratch, scratch);
+    __ Branch(&is_string, ne, scratch, Operand(ODDBALL_TYPE));
+
+    __ Branch(not_found, eq, undefined, Operand(candidate));
+    // Must be null (deleted entry).
+    if (FLAG_debug_code) {
+      __ LoadRoot(scratch, Heap::kNullValueRootIndex);
+      __ Assert(eq, "oddball in symbol table is not undefined or null",
+          scratch, Operand(candidate));
+    }
+    __ jmp(&next_probe[i]);
+
+    __ bind(&is_string);
+
+    // Check that the candidate is a non-external ASCII string.  The instance
+    // type is still in the scratch register from the CompareObjectType
+    // operation.
+    __ JumpIfInstanceTypeIsNotSequentialAscii(scratch, scratch, &next_probe[i]);
+
+    // If length is not 2 the string is not a candidate.
+    __ lw(scratch, FieldMemOperand(candidate, String::kLengthOffset));
+    __ Branch(&next_probe[i], ne, scratch, Operand(Smi::FromInt(2)));
+
+    // Check if the two characters match.
+    // Assumes that word load is little endian.
+    __ lhu(scratch, FieldMemOperand(candidate, SeqAsciiString::kHeaderSize));
+    __ Branch(&found_in_symbol_table, eq, chars, Operand(scratch));
+    __ bind(&next_probe[i]);
+  }
+
+  // No matching 2 character string found by probing.
+  __ jmp(not_found);
+
+  // Scratch register contains result when we fall through to here.
+  Register result = candidate;
+  __ bind(&found_in_symbol_table);
+  __ mov(v0, result);
 }
 
 
 void StringHelper::GenerateHashInit(MacroAssembler* masm,
                                       Register hash,
                                       Register character) {
-  UNIMPLEMENTED_MIPS();
+  // hash = character + (character << 10);
+  __ sll(hash, character, 10);
+  __ addu(hash, hash, character);
+  // hash ^= hash >> 6;
+  __ sra(at, hash, 6);
+  __ xor_(hash, hash, at);
 }
 
 
 void StringHelper::GenerateHashAddCharacter(MacroAssembler* masm,
                                               Register hash,
                                               Register character) {
-  UNIMPLEMENTED_MIPS();
+  // hash += character;
+  __ addu(hash, hash, character);
+  // hash += hash << 10;
+  __ sll(at, hash, 10);
+  __ addu(hash, hash, at);
+  // hash ^= hash >> 6;
+  __ sra(at, hash, 6);
+  __ xor_(hash, hash, at);
 }
 
 
 void StringHelper::GenerateHashGetHash(MacroAssembler* masm,
                                          Register hash) {
-  UNIMPLEMENTED_MIPS();
+  // hash += hash << 3;
+  __ sll(at, hash, 3);
+  __ addu(hash, hash, at);
+  // hash ^= hash >> 11;
+  __ sra(at, hash, 11);
+  __ xor_(hash, hash, at);
+  // hash += hash << 15;
+  __ sll(at, hash, 15);
+  __ addu(hash, hash, at);
+
+  // if (hash == 0) hash = 27;
+  __ ori(at, zero_reg, 27);
+  __ movz(hash, at, hash);
 }
 
 
 void SubStringStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label sub_string_runtime;
+  // Stack frame on entry.
+  //  ra: return address
+  //  sp[0]: to
+  //  sp[4]: from
+  //  sp[8]: string
+
+  // This stub is called from the native-call %_SubString(...), so
+  // nothing can be assumed about the arguments. It is tested that:
+  //  "string" is a sequential string,
+  //  both "from" and "to" are smis, and
+  //  0 <= from <= to <= string.length.
+  // If any of these assumptions fail, we call the runtime system.
+
+  static const int kToOffset = 0 * kPointerSize;
+  static const int kFromOffset = 1 * kPointerSize;
+  static const int kStringOffset = 2 * kPointerSize;
+
+  Register to = t2;
+  Register from = t3;
+
+  // Check bounds and smi-ness.
+  __ lw(to, MemOperand(sp, kToOffset));
+  __ lw(from, MemOperand(sp, kFromOffset));
+  STATIC_ASSERT(kFromOffset == kToOffset + 4);
+  STATIC_ASSERT(kSmiTag == 0);
+  STATIC_ASSERT(kSmiTagSize + kSmiShiftSize == 1);
+
+  __ JumpIfNotSmi(from, &sub_string_runtime);
+  __ JumpIfNotSmi(to, &sub_string_runtime);
+
+  __ sra(a3, from, kSmiTagSize);  // Remove smi tag.
+  __ sra(t5, to, kSmiTagSize);  // Remove smi tag.
+
+  // a3: from index (untagged smi)
+  // t5: to index (untagged smi)
+
+  __ Branch(&sub_string_runtime, lt, a3, Operand(zero_reg));  // From < 0.
+
+  __ subu(a2, t5, a3);
+  __ Branch(&sub_string_runtime, gt, a3, Operand(t5));  // Fail if from > to.
+
+  // Special handling of sub-strings of length 1 and 2. One character strings
+  // are handled in the runtime system (looked up in the single character
+  // cache). Two character strings are looked for in the symbol cache.
+  __ Branch(&sub_string_runtime, lt, a2, Operand(2));
+
+  // Both to and from are smis.
+
+  // a2: result string length
+  // a3: from index (untagged smi)
+  // t2: (a.k.a. to): to (smi)
+  // t3: (a.k.a. from): from offset (smi)
+  // t5: to index (untagged smi)
+
+  // Make sure first argument is a sequential (or flat) string.
+  __ lw(t1, MemOperand(sp, kStringOffset));
+  __ Branch(&sub_string_runtime, eq, t1, Operand(kSmiTagMask));
+
+  __ lw(a1, FieldMemOperand(t1, HeapObject::kMapOffset));
+  __ lbu(a1, FieldMemOperand(a1, Map::kInstanceTypeOffset));
+  __ And(t4, a1, Operand(kIsNotStringMask));
+
+  __ Branch(&sub_string_runtime, ne, t4, Operand(zero_reg));
+
+  // a1: instance type
+  // a2: result string length
+  // a3: from index (untagged smi)
+  // t1: string
+  // t2: (a.k.a. to): to (smi)
+  // t3: (a.k.a. from): from offset (smi)
+  // t5: to index (untagged smi)
+
+  Label seq_string;
+  __ And(t0, a1, Operand(kStringRepresentationMask));
+  STATIC_ASSERT(kSeqStringTag < kConsStringTag);
+  STATIC_ASSERT(kConsStringTag < kExternalStringTag);
+
+  // External strings go to runtime.
+  __ Branch(&sub_string_runtime, gt, t0, Operand(kConsStringTag));
+
+  // Sequential strings are handled directly.
+  __ Branch(&seq_string, lt, t0, Operand(kConsStringTag));
+
+  // Cons string. Try to recurse (once) on the first substring.
+  // (This adds a little more generality than necessary to handle flattened
+  // cons strings, but not much).
+  __ lw(t1, FieldMemOperand(t1, ConsString::kFirstOffset));
+  __ lw(t0, FieldMemOperand(t1, HeapObject::kMapOffset));
+  __ lbu(a1, FieldMemOperand(t0, Map::kInstanceTypeOffset));
+  STATIC_ASSERT(kSeqStringTag == 0);
+  // Cons and External strings go to runtime.
+  __ Branch(&sub_string_runtime, ne, a1, Operand(kStringRepresentationMask));
+
+  // Definitly a sequential string.
+  __ bind(&seq_string);
+
+  // a1: instance type
+  // a2: result string length
+  // a3: from index (untagged smi)
+  // t1: string
+  // t2: (a.k.a. to): to (smi)
+  // t3: (a.k.a. from): from offset (smi)
+  // t5: to index (untagged smi)
+
+  __ lw(t0, FieldMemOperand(t1, String::kLengthOffset));
+  __ Branch(&sub_string_runtime, lt, t0, Operand(to));  // Fail if to > length.
+  to = no_reg;
+
+  // a1: instance type
+  // a2: result string length
+  // a3: from index (untagged smi)
+  // t1: string
+  // t3: (a.k.a. from): from offset (smi)
+  // t5: to index (untagged smi)
+
+  // Check for flat ASCII string.
+  Label non_ascii_flat;
+  STATIC_ASSERT(kTwoByteStringTag == 0);
+
+  __ And(t4, a1, Operand(kStringEncodingMask));
+  __ Branch(&non_ascii_flat, eq, t4, Operand(zero_reg));
+
+  Label result_longer_than_two;
+  __ Branch(&result_longer_than_two, gt, a2, Operand(2));
+
+  // Sub string of length 2 requested.
+  // Get the two characters forming the sub string.
+  __ Addu(t1, t1, Operand(a3));
+  __ lbu(a3, FieldMemOperand(t1, SeqAsciiString::kHeaderSize));
+  __ lbu(t0, FieldMemOperand(t1, SeqAsciiString::kHeaderSize + 1));
+
+  // Try to lookup two character string in symbol table.
+  Label make_two_character_string;
+  StringHelper::GenerateTwoCharacterSymbolTableProbe(
+      masm, a3, t0, a1, t1, t2, t3, t4, &make_two_character_string);
+  Counters* counters = masm->isolate()->counters();
+  __ IncrementCounter(counters->sub_string_native(), 1, a3, t0);
+  __ Addu(sp, sp, Operand(3 * kPointerSize));
+  __ Ret();
+
+
+  // a2: result string length.
+  // a3: two characters combined into halfword in little endian byte order.
+  __ bind(&make_two_character_string);
+  __ AllocateAsciiString(v0, a2, t0, t1, t4, &sub_string_runtime);
+  __ sh(a3, FieldMemOperand(v0, SeqAsciiString::kHeaderSize));
+  __ IncrementCounter(counters->sub_string_native(), 1, a3, t0);
+  __ Addu(sp, sp, Operand(3 * kPointerSize));
+  __ Ret();
+
+  __ bind(&result_longer_than_two);
+
+  // Allocate the result.
+  __ AllocateAsciiString(v0, a2, t4, t0, a1, &sub_string_runtime);
+
+  // v0: result string.
+  // a2: result string length.
+  // a3: from index (untagged smi)
+  // t1: string.
+  // t3: (a.k.a. from): from offset (smi)
+  // Locate first character of result.
+  __ Addu(a1, v0, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+  // Locate 'from' character of string.
+  __ Addu(t1, t1, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+  __ Addu(t1, t1, Operand(a3));
+
+  // v0: result string.
+  // a1: first character of result string.
+  // a2: result string length.
+  // t1: first character of sub string to copy.
+  STATIC_ASSERT((SeqAsciiString::kHeaderSize & kObjectAlignmentMask) == 0);
+  StringHelper::GenerateCopyCharactersLong(
+      masm, a1, t1, a2, a3, t0, t2, t3, t4, COPY_ASCII | DEST_ALWAYS_ALIGNED);
+  __ IncrementCounter(counters->sub_string_native(), 1, a3, t0);
+  __ Addu(sp, sp, Operand(3 * kPointerSize));
+  __ Ret();
+
+  __ bind(&non_ascii_flat);
+  // a2: result string length.
+  // t1: string.
+  // t3: (a.k.a. from): from offset (smi)
+  // Check for flat two byte string.
+
+  // Allocate the result.
+  __ AllocateTwoByteString(v0, a2, a1, a3, t0, &sub_string_runtime);
+
+  // v0: result string.
+  // a2: result string length.
+  // t1: string.
+  // Locate first character of result.
+  __ Addu(a1, v0, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
+  // Locate 'from' character of string.
+  __ Addu(t1, t1, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
+  // As "from" is a smi it is 2 times the value which matches the size of a two
+  // byte character.
+  __ Addu(t1, t1, Operand(from));
+  from = no_reg;
+
+  // v0: result string.
+  // a1: first character of result.
+  // a2: result length.
+  // t1: first character of string to copy.
+  STATIC_ASSERT((SeqTwoByteString::kHeaderSize & kObjectAlignmentMask) == 0);
+  StringHelper::GenerateCopyCharactersLong(
+      masm, a1, t1, a2, a3, t0, t2, t3, t4, DEST_ALWAYS_ALIGNED);
+  __ IncrementCounter(counters->sub_string_native(), 1, a3, t0);
+  __ Addu(sp, sp, Operand(3 * kPointerSize));
+  __ Ret();
+
+  // Just jump to runtime to create the sub string.
+  __ bind(&sub_string_runtime);
+  __ TailCallRuntime(Runtime::kSubString, 3, 1);
+}
+
+
+void StringCompareStub::GenerateFlatAsciiStringEquals(MacroAssembler* masm,
+                                                      Register left,
+                                                      Register right,
+                                                      Register scratch1,
+                                                      Register scratch2,
+                                                      Register scratch3) {
+  Register length = scratch1;
+
+  // Compare lengths.
+  Label strings_not_equal, check_zero_length;
+  __ lw(length, FieldMemOperand(left, String::kLengthOffset));
+  __ lw(scratch2, FieldMemOperand(right, String::kLengthOffset));
+  __ Branch(&check_zero_length, eq, length, Operand(scratch2));
+  __ bind(&strings_not_equal);
+  __ li(v0, Operand(Smi::FromInt(NOT_EQUAL)));
+  __ Ret();
+
+  // Check if the length is zero.
+  Label compare_chars;
+  __ bind(&check_zero_length);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ Branch(&compare_chars, ne, length, Operand(zero_reg));
+  __ li(v0, Operand(Smi::FromInt(EQUAL)));
+  __ Ret();
+
+  // Compare characters.
+  __ bind(&compare_chars);
+
+  GenerateAsciiCharsCompareLoop(masm,
+                                left, right, length, scratch2, scratch3, v0,
+                                &strings_not_equal);
+
+  // Characters are equal.
+  __ li(v0, Operand(Smi::FromInt(EQUAL)));
+  __ Ret();
 }
 
 
@@ -756,50 +5610,844 @@ void StringCompareStub::GenerateCompareFlatAsciiStrings(MacroAssembler* masm,
                                                         Register scratch2,
                                                         Register scratch3,
                                                         Register scratch4) {
-  UNIMPLEMENTED_MIPS();
+  Label result_not_equal, compare_lengths;
+  // Find minimum length and length difference.
+  __ lw(scratch1, FieldMemOperand(left, String::kLengthOffset));
+  __ lw(scratch2, FieldMemOperand(right, String::kLengthOffset));
+  __ Subu(scratch3, scratch1, Operand(scratch2));
+  Register length_delta = scratch3;
+  __ slt(scratch4, scratch2, scratch1);
+  __ movn(scratch1, scratch2, scratch4);
+  Register min_length = scratch1;
+  STATIC_ASSERT(kSmiTag == 0);
+  __ Branch(&compare_lengths, eq, min_length, Operand(zero_reg));
+
+  // Compare loop.
+  GenerateAsciiCharsCompareLoop(masm,
+                                left, right, min_length, scratch2, scratch4, v0,
+                                &result_not_equal);
+
+  // Compare lengths - strings up to min-length are equal.
+  __ bind(&compare_lengths);
+  ASSERT(Smi::FromInt(EQUAL) == static_cast<Smi*>(0));
+  // Use length_delta as result if it's zero.
+  __ mov(scratch2, length_delta);
+  __ mov(scratch4, zero_reg);
+  __ mov(v0, zero_reg);
+
+  __ bind(&result_not_equal);
+  // Conditionally update the result based either on length_delta or
+  // the last comparion performed in the loop above.
+  Label ret;
+  __ Branch(&ret, eq, scratch2, Operand(scratch4));
+  __ li(v0, Operand(Smi::FromInt(GREATER)));
+  __ Branch(&ret, gt, scratch2, Operand(scratch4));
+  __ li(v0, Operand(Smi::FromInt(LESS)));
+  __ bind(&ret);
+  __ Ret();
+}
+
+
+void StringCompareStub::GenerateAsciiCharsCompareLoop(
+    MacroAssembler* masm,
+    Register left,
+    Register right,
+    Register length,
+    Register scratch1,
+    Register scratch2,
+    Register scratch3,
+    Label* chars_not_equal) {
+  // Change index to run from -length to -1 by adding length to string
+  // start. This means that loop ends when index reaches zero, which
+  // doesn't need an additional compare.
+  __ SmiUntag(length);
+  __ Addu(scratch1, length,
+          Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+  __ Addu(left, left, Operand(scratch1));
+  __ Addu(right, right, Operand(scratch1));
+  __ Subu(length, zero_reg, length);
+  Register index = length;  // index = -length;
+
+
+  // Compare loop.
+  Label loop;
+  __ bind(&loop);
+  __ Addu(scratch3, left, index);
+  __ lbu(scratch1, MemOperand(scratch3));
+  __ Addu(scratch3, right, index);
+  __ lbu(scratch2, MemOperand(scratch3));
+  __ Branch(chars_not_equal, ne, scratch1, Operand(scratch2));
+  __ Addu(index, index, 1);
+  __ Branch(&loop, ne, index, Operand(zero_reg));
 }
 
 
 void StringCompareStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label runtime;
+
+  Counters* counters = masm->isolate()->counters();
+
+  // Stack frame on entry.
+  //  sp[0]: right string
+  //  sp[4]: left string
+  __ lw(a1, MemOperand(sp, 1 * kPointerSize));  // Left.
+  __ lw(a0, MemOperand(sp, 0 * kPointerSize));  // Right.
+
+  Label not_same;
+  __ Branch(&not_same, ne, a0, Operand(a1));
+  STATIC_ASSERT(EQUAL == 0);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ li(v0, Operand(Smi::FromInt(EQUAL)));
+  __ IncrementCounter(counters->string_compare_native(), 1, a1, a2);
+  __ Addu(sp, sp, Operand(2 * kPointerSize));
+  __ Ret();
+
+  __ bind(&not_same);
+
+  // Check that both objects are sequential ASCII strings.
+  __ JumpIfNotBothSequentialAsciiStrings(a1, a0, a2, a3, &runtime);
+
+  // Compare flat ASCII strings natively. Remove arguments from stack first.
+  __ IncrementCounter(counters->string_compare_native(), 1, a2, a3);
+  __ Addu(sp, sp, Operand(2 * kPointerSize));
+  GenerateCompareFlatAsciiStrings(masm, a1, a0, a2, a3, t0, t1);
+
+  __ bind(&runtime);
+  __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
 }
 
 
 void StringAddStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  Label string_add_runtime, call_builtin;
+  Builtins::JavaScript builtin_id = Builtins::ADD;
+
+  Counters* counters = masm->isolate()->counters();
+
+  // Stack on entry:
+  // sp[0]: second argument (right).
+  // sp[4]: first argument (left).
+
+  // Load the two arguments.
+  __ lw(a0, MemOperand(sp, 1 * kPointerSize));  // First argument.
+  __ lw(a1, MemOperand(sp, 0 * kPointerSize));  // Second argument.
+
+  // Make sure that both arguments are strings if not known in advance.
+  if (flags_ == NO_STRING_ADD_FLAGS) {
+    __ JumpIfEitherSmi(a0, a1, &string_add_runtime);
+    // Load instance types.
+    __ lw(t0, FieldMemOperand(a0, HeapObject::kMapOffset));
+    __ lw(t1, FieldMemOperand(a1, HeapObject::kMapOffset));
+    __ lbu(t0, FieldMemOperand(t0, Map::kInstanceTypeOffset));
+    __ lbu(t1, FieldMemOperand(t1, Map::kInstanceTypeOffset));
+    STATIC_ASSERT(kStringTag == 0);
+    // If either is not a string, go to runtime.
+    __ Or(t4, t0, Operand(t1));
+    __ And(t4, t4, Operand(kIsNotStringMask));
+    __ Branch(&string_add_runtime, ne, t4, Operand(zero_reg));
+  } else {
+    // Here at least one of the arguments is definitely a string.
+    // We convert the one that is not known to be a string.
+    if ((flags_ & NO_STRING_CHECK_LEFT_IN_STUB) == 0) {
+      ASSERT((flags_ & NO_STRING_CHECK_RIGHT_IN_STUB) != 0);
+      GenerateConvertArgument(
+          masm, 1 * kPointerSize, a0, a2, a3, t0, t1, &call_builtin);
+      builtin_id = Builtins::STRING_ADD_RIGHT;
+    } else if ((flags_ & NO_STRING_CHECK_RIGHT_IN_STUB) == 0) {
+      ASSERT((flags_ & NO_STRING_CHECK_LEFT_IN_STUB) != 0);
+      GenerateConvertArgument(
+          masm, 0 * kPointerSize, a1, a2, a3, t0, t1, &call_builtin);
+      builtin_id = Builtins::STRING_ADD_LEFT;
+    }
+  }
+
+  // Both arguments are strings.
+  // a0: first string
+  // a1: second string
+  // t0: first string instance type (if flags_ == NO_STRING_ADD_FLAGS)
+  // t1: second string instance type (if flags_ == NO_STRING_ADD_FLAGS)
+  {
+    Label strings_not_empty;
+    // Check if either of the strings are empty. In that case return the other.
+    // These tests use zero-length check on string-length whch is an Smi.
+    // Assert that Smi::FromInt(0) is really 0.
+    STATIC_ASSERT(kSmiTag == 0);
+    ASSERT(Smi::FromInt(0) == 0);
+    __ lw(a2, FieldMemOperand(a0, String::kLengthOffset));
+    __ lw(a3, FieldMemOperand(a1, String::kLengthOffset));
+    __ mov(v0, a0);       // Assume we'll return first string (from a0).
+    __ movz(v0, a1, a2);  // If first is empty, return second (from a1).
+    __ slt(t4, zero_reg, a2);   // if (a2 > 0) t4 = 1.
+    __ slt(t5, zero_reg, a3);   // if (a3 > 0) t5 = 1.
+    __ and_(t4, t4, t5);        // Branch if both strings were non-empty.
+    __ Branch(&strings_not_empty, ne, t4, Operand(zero_reg));
+
+    __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
+    __ Addu(sp, sp, Operand(2 * kPointerSize));
+    __ Ret();
+
+    __ bind(&strings_not_empty);
+  }
+
+  // Untag both string-lengths.
+  __ sra(a2, a2, kSmiTagSize);
+  __ sra(a3, a3, kSmiTagSize);
+
+  // Both strings are non-empty.
+  // a0: first string
+  // a1: second string
+  // a2: length of first string
+  // a3: length of second string
+  // t0: first string instance type (if flags_ == NO_STRING_ADD_FLAGS)
+  // t1: second string instance type (if flags_ == NO_STRING_ADD_FLAGS)
+  // Look at the length of the result of adding the two strings.
+  Label string_add_flat_result, longer_than_two;
+  // Adding two lengths can't overflow.
+  STATIC_ASSERT(String::kMaxLength < String::kMaxLength * 2);
+  __ Addu(t2, a2, Operand(a3));
+  // Use the symbol table when adding two one character strings, as it
+  // helps later optimizations to return a symbol here.
+  __ Branch(&longer_than_two, ne, t2, Operand(2));
+
+  // Check that both strings are non-external ASCII strings.
+  if (flags_ != NO_STRING_ADD_FLAGS) {
+    __ lw(t0, FieldMemOperand(a0, HeapObject::kMapOffset));
+    __ lw(t1, FieldMemOperand(a1, HeapObject::kMapOffset));
+    __ lbu(t0, FieldMemOperand(t0, Map::kInstanceTypeOffset));
+    __ lbu(t1, FieldMemOperand(t1, Map::kInstanceTypeOffset));
+  }
+  __ JumpIfBothInstanceTypesAreNotSequentialAscii(t0, t1, t2, t3,
+                                                 &string_add_runtime);
+
+  // Get the two characters forming the sub string.
+  __ lbu(a2, FieldMemOperand(a0, SeqAsciiString::kHeaderSize));
+  __ lbu(a3, FieldMemOperand(a1, SeqAsciiString::kHeaderSize));
+
+  // Try to lookup two character string in symbol table. If it is not found
+  // just allocate a new one.
+  Label make_two_character_string;
+  StringHelper::GenerateTwoCharacterSymbolTableProbe(
+      masm, a2, a3, t2, t3, t0, t1, t4, &make_two_character_string);
+  __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
+  __ Addu(sp, sp, Operand(2 * kPointerSize));
+  __ Ret();
+
+  __ bind(&make_two_character_string);
+  // Resulting string has length 2 and first chars of two strings
+  // are combined into single halfword in a2 register.
+  // So we can fill resulting string without two loops by a single
+  // halfword store instruction (which assumes that processor is
+  // in a little endian mode).
+  __ li(t2, Operand(2));
+  __ AllocateAsciiString(v0, t2, t0, t1, t4, &string_add_runtime);
+  __ sh(a2, FieldMemOperand(v0, SeqAsciiString::kHeaderSize));
+  __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
+  __ Addu(sp, sp, Operand(2 * kPointerSize));
+  __ Ret();
+
+  __ bind(&longer_than_two);
+  // Check if resulting string will be flat.
+  __ Branch(&string_add_flat_result, lt, t2,
+           Operand(String::kMinNonFlatLength));
+  // Handle exceptionally long strings in the runtime system.
+  STATIC_ASSERT((String::kMaxLength & 0x80000000) == 0);
+  ASSERT(IsPowerOf2(String::kMaxLength + 1));
+  // kMaxLength + 1 is representable as shifted literal, kMaxLength is not.
+  __ Branch(&string_add_runtime, hs, t2, Operand(String::kMaxLength + 1));
+
+  // If result is not supposed to be flat, allocate a cons string object.
+  // If both strings are ASCII the result is an ASCII cons string.
+  if (flags_ != NO_STRING_ADD_FLAGS) {
+    __ lw(t0, FieldMemOperand(a0, HeapObject::kMapOffset));
+    __ lw(t1, FieldMemOperand(a1, HeapObject::kMapOffset));
+    __ lbu(t0, FieldMemOperand(t0, Map::kInstanceTypeOffset));
+    __ lbu(t1, FieldMemOperand(t1, Map::kInstanceTypeOffset));
+  }
+  Label non_ascii, allocated, ascii_data;
+  STATIC_ASSERT(kTwoByteStringTag == 0);
+  // Branch to non_ascii if either string-encoding field is zero (non-ascii).
+  __ And(t4, t0, Operand(t1));
+  __ And(t4, t4, Operand(kStringEncodingMask));
+  __ Branch(&non_ascii, eq, t4, Operand(zero_reg));
+
+  // Allocate an ASCII cons string.
+  __ bind(&ascii_data);
+  __ AllocateAsciiConsString(t3, t2, t0, t1, &string_add_runtime);
+  __ bind(&allocated);
+  // Fill the fields of the cons string.
+  __ sw(a0, FieldMemOperand(t3, ConsString::kFirstOffset));
+  __ sw(a1, FieldMemOperand(t3, ConsString::kSecondOffset));
+  __ mov(v0, t3);
+  __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
+  __ Addu(sp, sp, Operand(2 * kPointerSize));
+  __ Ret();
+
+  __ bind(&non_ascii);
+  // At least one of the strings is two-byte. Check whether it happens
+  // to contain only ASCII characters.
+  // t0: first instance type.
+  // t1: second instance type.
+  // Branch to if _both_ instances have kAsciiDataHintMask set.
+  __ And(at, t0, Operand(kAsciiDataHintMask));
+  __ and_(at, at, t1);
+  __ Branch(&ascii_data, ne, at, Operand(zero_reg));
+
+  __ xor_(t0, t0, t1);
+  STATIC_ASSERT(kAsciiStringTag != 0 && kAsciiDataHintTag != 0);
+  __ And(t0, t0, Operand(kAsciiStringTag | kAsciiDataHintTag));
+  __ Branch(&ascii_data, eq, t0, Operand(kAsciiStringTag | kAsciiDataHintTag));
+
+  // Allocate a two byte cons string.
+  __ AllocateTwoByteConsString(t3, t2, t0, t1, &string_add_runtime);
+  __ Branch(&allocated);
+
+  // Handle creating a flat result. First check that both strings are
+  // sequential and that they have the same encoding.
+  // a0: first string
+  // a1: second string
+  // a2: length of first string
+  // a3: length of second string
+  // t0: first string instance type (if flags_ == NO_STRING_ADD_FLAGS)
+  // t1: second string instance type (if flags_ == NO_STRING_ADD_FLAGS)
+  // t2: sum of lengths.
+  __ bind(&string_add_flat_result);
+  if (flags_ != NO_STRING_ADD_FLAGS) {
+    __ lw(t0, FieldMemOperand(a0, HeapObject::kMapOffset));
+    __ lw(t1, FieldMemOperand(a1, HeapObject::kMapOffset));
+    __ lbu(t0, FieldMemOperand(t0, Map::kInstanceTypeOffset));
+    __ lbu(t1, FieldMemOperand(t1, Map::kInstanceTypeOffset));
+  }
+  // Check that both strings are sequential, meaning that we
+  // branch to runtime if either string tag is non-zero.
+  STATIC_ASSERT(kSeqStringTag == 0);
+  __ Or(t4, t0, Operand(t1));
+  __ And(t4, t4, Operand(kStringRepresentationMask));
+  __ Branch(&string_add_runtime, ne, t4, Operand(zero_reg));
+
+  // Now check if both strings have the same encoding (ASCII/Two-byte).
+  // a0: first string
+  // a1: second string
+  // a2: length of first string
+  // a3: length of second string
+  // t0: first string instance type
+  // t1: second string instance type
+  // t2: sum of lengths.
+  Label non_ascii_string_add_flat_result;
+  ASSERT(IsPowerOf2(kStringEncodingMask));  // Just one bit to test.
+  __ xor_(t3, t1, t0);
+  __ And(t3, t3, Operand(kStringEncodingMask));
+  __ Branch(&string_add_runtime, ne, t3, Operand(zero_reg));
+  // And see if it's ASCII (0) or two-byte (1).
+  __ And(t3, t0, Operand(kStringEncodingMask));
+  __ Branch(&non_ascii_string_add_flat_result, eq, t3, Operand(zero_reg));
+
+  // Both strings are sequential ASCII strings. We also know that they are
+  // short (since the sum of the lengths is less than kMinNonFlatLength).
+  // t2: length of resulting flat string
+  __ AllocateAsciiString(t3, t2, t0, t1, t4, &string_add_runtime);
+  // Locate first character of result.
+  __ Addu(t2, t3, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+  // Locate first character of first argument.
+  __ Addu(a0, a0, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+  // a0: first character of first string.
+  // a1: second string.
+  // a2: length of first string.
+  // a3: length of second string.
+  // t2: first character of result.
+  // t3: result string.
+  StringHelper::GenerateCopyCharacters(masm, t2, a0, a2, t0, true);
+
+  // Load second argument and locate first character.
+  __ Addu(a1, a1, Operand(SeqAsciiString::kHeaderSize - kHeapObjectTag));
+  // a1: first character of second string.
+  // a3: length of second string.
+  // t2: next character of result.
+  // t3: result string.
+  StringHelper::GenerateCopyCharacters(masm, t2, a1, a3, t0, true);
+  __ mov(v0, t3);
+  __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
+  __ Addu(sp, sp, Operand(2 * kPointerSize));
+  __ Ret();
+
+  __ bind(&non_ascii_string_add_flat_result);
+  // Both strings are sequential two byte strings.
+  // a0: first string.
+  // a1: second string.
+  // a2: length of first string.
+  // a3: length of second string.
+  // t2: sum of length of strings.
+  __ AllocateTwoByteString(t3, t2, t0, t1, t4, &string_add_runtime);
+  // a0: first string.
+  // a1: second string.
+  // a2: length of first string.
+  // a3: length of second string.
+  // t3: result string.
+
+  // Locate first character of result.
+  __ Addu(t2, t3, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
+  // Locate first character of first argument.
+  __ Addu(a0, a0, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
+
+  // a0: first character of first string.
+  // a1: second string.
+  // a2: length of first string.
+  // a3: length of second string.
+  // t2: first character of result.
+  // t3: result string.
+  StringHelper::GenerateCopyCharacters(masm, t2, a0, a2, t0, false);
+
+  // Locate first character of second argument.
+  __ Addu(a1, a1, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
+
+  // a1: first character of second string.
+  // a3: length of second string.
+  // t2: next character of result (after copy of first string).
+  // t3: result string.
+  StringHelper::GenerateCopyCharacters(masm, t2, a1, a3, t0, false);
+
+  __ mov(v0, t3);
+  __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
+  __ Addu(sp, sp, Operand(2 * kPointerSize));
+  __ Ret();
+
+  // Just jump to runtime to add the two strings.
+  __ bind(&string_add_runtime);
+  __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
+
+  if (call_builtin.is_linked()) {
+    __ bind(&call_builtin);
+    __ InvokeBuiltin(builtin_id, JUMP_FUNCTION);
+  }
+}
+
+
+void StringAddStub::GenerateConvertArgument(MacroAssembler* masm,
+                                            int stack_offset,
+                                            Register arg,
+                                            Register scratch1,
+                                            Register scratch2,
+                                            Register scratch3,
+                                            Register scratch4,
+                                            Label* slow) {
+  // First check if the argument is already a string.
+  Label not_string, done;
+  __ JumpIfSmi(arg, &not_string);
+  __ GetObjectType(arg, scratch1, scratch1);
+  __ Branch(&done, lt, scratch1, Operand(FIRST_NONSTRING_TYPE));
+
+  // Check the number to string cache.
+  Label not_cached;
+  __ bind(&not_string);
+  // Puts the cached result into scratch1.
+  NumberToStringStub::GenerateLookupNumberStringCache(masm,
+                                                      arg,
+                                                      scratch1,
+                                                      scratch2,
+                                                      scratch3,
+                                                      scratch4,
+                                                      false,
+                                                      &not_cached);
+  __ mov(arg, scratch1);
+  __ sw(arg, MemOperand(sp, stack_offset));
+  __ jmp(&done);
+
+  // Check if the argument is a safe string wrapper.
+  __ bind(&not_cached);
+  __ JumpIfSmi(arg, slow);
+  __ GetObjectType(arg, scratch1, scratch2);  // map -> scratch1.
+  __ Branch(slow, ne, scratch2, Operand(JS_VALUE_TYPE));
+  __ lbu(scratch2, FieldMemOperand(scratch1, Map::kBitField2Offset));
+  __ li(scratch4, 1 << Map::kStringWrapperSafeForDefaultValueOf);
+  __ And(scratch2, scratch2, scratch4);
+  __ Branch(slow, ne, scratch2, Operand(scratch4));
+  __ lw(arg, FieldMemOperand(arg, JSValue::kValueOffset));
+  __ sw(arg, MemOperand(sp, stack_offset));
+
+  __ bind(&done);
 }
 
 
 void ICCompareStub::GenerateSmis(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  ASSERT(state_ == CompareIC::SMIS);
+  Label miss;
+  __ Or(a2, a1, a0);
+  __ JumpIfNotSmi(a2, &miss);
+
+  if (GetCondition() == eq) {
+    // For equality we do not care about the sign of the result.
+    __ Subu(v0, a0, a1);
+  } else {
+    // Untag before subtracting to avoid handling overflow.
+    __ SmiUntag(a1);
+    __ SmiUntag(a0);
+    __ Subu(v0, a1, a0);
+  }
+  __ Ret();
+
+  __ bind(&miss);
+  GenerateMiss(masm);
 }
 
 
 void ICCompareStub::GenerateHeapNumbers(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  ASSERT(state_ == CompareIC::HEAP_NUMBERS);
+
+  Label generic_stub;
+  Label unordered;
+  Label miss;
+  __ And(a2, a1, Operand(a0));
+  __ JumpIfSmi(a2, &generic_stub);
+
+  __ GetObjectType(a0, a2, a2);
+  __ Branch(&miss, ne, a2, Operand(HEAP_NUMBER_TYPE));
+  __ GetObjectType(a1, a2, a2);
+  __ Branch(&miss, ne, a2, Operand(HEAP_NUMBER_TYPE));
+
+  // Inlining the double comparison and falling back to the general compare
+  // stub if NaN is involved or FPU is unsupported.
+  if (CpuFeatures::IsSupported(FPU)) {
+    CpuFeatures::Scope scope(FPU);
+
+    // Load left and right operand.
+    __ Subu(a2, a1, Operand(kHeapObjectTag));
+    __ ldc1(f0, MemOperand(a2, HeapNumber::kValueOffset));
+    __ Subu(a2, a0, Operand(kHeapObjectTag));
+    __ ldc1(f2, MemOperand(a2, HeapNumber::kValueOffset));
+
+    Label fpu_eq, fpu_lt, fpu_gt;
+    // Compare operands (test if unordered).
+    __ c(UN, D, f0, f2);
+    // Don't base result on status bits when a NaN is involved.
+    __ bc1t(&unordered);
+    __ nop();
+
+    // Test if equal.
+    __ c(EQ, D, f0, f2);
+    __ bc1t(&fpu_eq);
+    __ nop();
+
+    // Test if unordered or less (unordered case is already handled).
+    __ c(ULT, D, f0, f2);
+    __ bc1t(&fpu_lt);
+    __ nop();
+
+    // Otherwise it's greater.
+    __ bc1f(&fpu_gt);
+    __ nop();
+
+    // Return a result of -1, 0, or 1.
+    __ bind(&fpu_eq);
+    __ li(v0, Operand(EQUAL));
+    __ Ret();
+
+    __ bind(&fpu_lt);
+    __ li(v0, Operand(LESS));
+    __ Ret();
+
+    __ bind(&fpu_gt);
+    __ li(v0, Operand(GREATER));
+    __ Ret();
+
+    __ bind(&unordered);
+  }
+
+  CompareStub stub(GetCondition(), strict(), NO_COMPARE_FLAGS, a1, a0);
+  __ bind(&generic_stub);
+  __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
+
+  __ bind(&miss);
+  GenerateMiss(masm);
 }
 
 
 void ICCompareStub::GenerateSymbols(MacroAssembler* masm) {
-    UNIMPLEMENTED_MIPS();
-  }
+  ASSERT(state_ == CompareIC::SYMBOLS);
+  Label miss;
+
+  // Registers containing left and right operands respectively.
+  Register left = a1;
+  Register right = a0;
+  Register tmp1 = a2;
+  Register tmp2 = a3;
+
+  // Check that both operands are heap objects.
+  __ JumpIfEitherSmi(left, right, &miss);
+
+  // Check that both operands are symbols.
+  __ lw(tmp1, FieldMemOperand(left, HeapObject::kMapOffset));
+  __ lw(tmp2, FieldMemOperand(right, HeapObject::kMapOffset));
+  __ lbu(tmp1, FieldMemOperand(tmp1, Map::kInstanceTypeOffset));
+  __ lbu(tmp2, FieldMemOperand(tmp2, Map::kInstanceTypeOffset));
+  STATIC_ASSERT(kSymbolTag != 0);
+  __ And(tmp1, tmp1, Operand(tmp2));
+  __ And(tmp1, tmp1, kIsSymbolMask);
+  __ Branch(&miss, eq, tmp1, Operand(zero_reg));
+  // Make sure a0 is non-zero. At this point input operands are
+  // guaranteed to be non-zero.
+  ASSERT(right.is(a0));
+  STATIC_ASSERT(EQUAL == 0);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ mov(v0, right);
+  // Symbols are compared by identity.
+  __ Ret(ne, left, Operand(right));
+  __ li(v0, Operand(Smi::FromInt(EQUAL)));
+  __ Ret();
+
+  __ bind(&miss);
+  GenerateMiss(masm);
+}
 
 
 void ICCompareStub::GenerateStrings(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  ASSERT(state_ == CompareIC::STRINGS);
+  Label miss;
+
+  // Registers containing left and right operands respectively.
+  Register left = a1;
+  Register right = a0;
+  Register tmp1 = a2;
+  Register tmp2 = a3;
+  Register tmp3 = t0;
+  Register tmp4 = t1;
+  Register tmp5 = t2;
+
+  // Check that both operands are heap objects.
+  __ JumpIfEitherSmi(left, right, &miss);
+
+  // Check that both operands are strings. This leaves the instance
+  // types loaded in tmp1 and tmp2.
+  __ lw(tmp1, FieldMemOperand(left, HeapObject::kMapOffset));
+  __ lw(tmp2, FieldMemOperand(right, HeapObject::kMapOffset));
+  __ lbu(tmp1, FieldMemOperand(tmp1, Map::kInstanceTypeOffset));
+  __ lbu(tmp2, FieldMemOperand(tmp2, Map::kInstanceTypeOffset));
+  STATIC_ASSERT(kNotStringTag != 0);
+  __ Or(tmp3, tmp1, tmp2);
+  __ And(tmp5, tmp3, Operand(kIsNotStringMask));
+  __ Branch(&miss, ne, tmp5, Operand(zero_reg));
+
+  // Fast check for identical strings.
+  Label left_ne_right;
+  STATIC_ASSERT(EQUAL == 0);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ Branch(&left_ne_right, ne, left, Operand(right), USE_DELAY_SLOT);
+  __ mov(v0, zero_reg);  // In the delay slot.
+  __ Ret();
+  __ bind(&left_ne_right);
+
+  // Handle not identical strings.
+
+  // Check that both strings are symbols. If they are, we're done
+  // because we already know they are not identical.
+  ASSERT(GetCondition() == eq);
+  STATIC_ASSERT(kSymbolTag != 0);
+  __ And(tmp3, tmp1, Operand(tmp2));
+  __ And(tmp5, tmp3, Operand(kIsSymbolMask));
+  Label is_symbol;
+  __ Branch(&is_symbol, eq, tmp5, Operand(zero_reg), USE_DELAY_SLOT);
+  __ mov(v0, a0);  // In the delay slot.
+  // Make sure a0 is non-zero. At this point input operands are
+  // guaranteed to be non-zero.
+  ASSERT(right.is(a0));
+  __ Ret();
+  __ bind(&is_symbol);
+
+  // Check that both strings are sequential ASCII.
+  Label runtime;
+  __ JumpIfBothInstanceTypesAreNotSequentialAscii(tmp1, tmp2, tmp3, tmp4,
+                                                  &runtime);
+
+  // Compare flat ASCII strings. Returns when done.
+  StringCompareStub::GenerateFlatAsciiStringEquals(
+      masm, left, right, tmp1, tmp2, tmp3);
+
+  // Handle more complex cases in runtime.
+  __ bind(&runtime);
+  __ Push(left, right);
+  __ TailCallRuntime(Runtime::kStringEquals, 2, 1);
+
+  __ bind(&miss);
+  GenerateMiss(masm);
 }
 
 
 void ICCompareStub::GenerateObjects(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  ASSERT(state_ == CompareIC::OBJECTS);
+  Label miss;
+  __ And(a2, a1, Operand(a0));
+  __ JumpIfSmi(a2, &miss);
+
+  __ GetObjectType(a0, a2, a2);
+  __ Branch(&miss, ne, a2, Operand(JS_OBJECT_TYPE));
+  __ GetObjectType(a1, a2, a2);
+  __ Branch(&miss, ne, a2, Operand(JS_OBJECT_TYPE));
+
+  ASSERT(GetCondition() == eq);
+  __ Subu(v0, a0, Operand(a1));
+  __ Ret();
+
+  __ bind(&miss);
+  GenerateMiss(masm);
 }
 
 
 void ICCompareStub::GenerateMiss(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  __ Push(a1, a0);
+  __ push(ra);
+
+  // Call the runtime system in a fresh internal frame.
+  ExternalReference miss = ExternalReference(IC_Utility(IC::kCompareIC_Miss),
+                                             masm->isolate());
+  __ EnterInternalFrame();
+  __ Push(a1, a0);
+  __ li(t0, Operand(Smi::FromInt(op_)));
+  __ push(t0);
+  __ CallExternalReference(miss, 3);
+  __ LeaveInternalFrame();
+  // Compute the entry point of the rewritten stub.
+  __ Addu(a2, v0, Operand(Code::kHeaderSize - kHeapObjectTag));
+  // Restore registers.
+  __ pop(ra);
+  __ pop(a0);
+  __ pop(a1);
+  __ Jump(a2);
+}
+
+void DirectCEntryStub::Generate(MacroAssembler* masm) {
+  // No need to pop or drop anything, LeaveExitFrame will restore the old
+  // stack, thus dropping the allocated space for the return value.
+  // The saved ra is after the reserved stack space for the 4 args.
+  __ lw(t9, MemOperand(sp, kCArgsSlotsSize));
+
+  if (FLAG_debug_code && EnableSlowAsserts()) {
+    // In case of an error the return address may point to a memory area
+    // filled with kZapValue by the GC.
+    // Dereference the address and check for this.
+    __ lw(t0, MemOperand(t9));
+    __ Assert(ne, "Received invalid return address.", t0,
+        Operand(reinterpret_cast<uint32_t>(kZapValue)));
+  }
+  __ Jump(t9);
 }
 
 
+void DirectCEntryStub::GenerateCall(MacroAssembler* masm,
+                                    ExternalReference function) {
+  __ li(t9, Operand(function));
+  this->GenerateCall(masm, t9);
+}
+
+void DirectCEntryStub::GenerateCall(MacroAssembler* masm,
+                                    Register target) {
+  __ Move(t9, target);
+  __ AssertStackIsAligned();
+  // Allocate space for arg slots.
+  __ Subu(sp, sp, kCArgsSlotsSize);
+
+  // Block the trampoline pool through the whole function to make sure the
+  // number of generated instructions is constant.
+  Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm);
+
+  // We need to get the current 'pc' value, which is not available on MIPS.
+  Label find_ra;
+  masm->bal(&find_ra);  // ra = pc + 8.
+  masm->nop();  // Branch delay slot nop.
+  masm->bind(&find_ra);
+
+  const int kNumInstructionsToJump = 6;
+  masm->addiu(ra, ra, kNumInstructionsToJump * kPointerSize);
+  // Push return address (accessible to GC through exit frame pc).
+  // This spot for ra was reserved in EnterExitFrame.
+  masm->sw(ra, MemOperand(sp, kCArgsSlotsSize));
+  masm->li(ra, Operand(reinterpret_cast<intptr_t>(GetCode().location()),
+                    RelocInfo::CODE_TARGET), true);
+  // Call the function.
+  masm->Jump(t9);
+  // Make sure the stored 'ra' points to this position.
+  ASSERT_EQ(kNumInstructionsToJump, masm->InstructionsGeneratedSince(&find_ra));
+}
+
+
+MaybeObject* StringDictionaryLookupStub::GenerateNegativeLookup(
+    MacroAssembler* masm,
+    Label* miss,
+    Label* done,
+    Register receiver,
+    Register properties,
+    String* name,
+    Register scratch0) {
+// If names of slots in range from 1 to kProbes - 1 for the hash value are
+  // not equal to the name and kProbes-th slot is not used (its name is the
+  // undefined value), it guarantees the hash table doesn't contain the
+  // property. It's true even if some slots represent deleted properties
+  // (their names are the null value).
+  for (int i = 0; i < kInlinedProbes; i++) {
+    // scratch0 points to properties hash.
+    // Compute the masked index: (hash + i + i * i) & mask.
+    Register index = scratch0;
+    // Capacity is smi 2^n.
+    __ lw(index, FieldMemOperand(properties, kCapacityOffset));
+    __ Subu(index, index, Operand(1));
+    __ And(index, index, Operand(
+         Smi::FromInt(name->Hash() + StringDictionary::GetProbeOffset(i))));
+
+    // Scale the index by multiplying by the entry size.
+    ASSERT(StringDictionary::kEntrySize == 3);
+    // index *= 3.
+    __ mov(at, index);
+    __ sll(index, index, 1);
+    __ Addu(index, index, at);
+
+    Register entity_name = scratch0;
+    // Having undefined at this place means the name is not contained.
+    ASSERT_EQ(kSmiTagSize, 1);
+    Register tmp = properties;
+
+    __ sll(scratch0, index, 1);
+    __ Addu(tmp, properties, scratch0);
+    __ lw(entity_name, FieldMemOperand(tmp, kElementsStartOffset));
+
+    ASSERT(!tmp.is(entity_name));
+    __ LoadRoot(tmp, Heap::kUndefinedValueRootIndex);
+    __ Branch(done, eq, entity_name, Operand(tmp));
+
+    if (i != kInlinedProbes - 1) {
+      // Stop if found the property.
+      __ Branch(miss, eq, entity_name, Operand(Handle<String>(name)));
+
+      // Check if the entry name is not a symbol.
+      __ lw(entity_name, FieldMemOperand(entity_name, HeapObject::kMapOffset));
+      __ lbu(entity_name,
+             FieldMemOperand(entity_name, Map::kInstanceTypeOffset));
+      __ And(scratch0, entity_name, Operand(kIsSymbolMask));
+      __ Branch(miss, eq, scratch0, Operand(zero_reg));
+
+      // Restore the properties.
+      __ lw(properties,
+            FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+    }
+  }
+
+  const int spill_mask =
+      (ra.bit() | t2.bit() | t1.bit() | t0.bit() | a3.bit() |
+       a2.bit() | a1.bit() | a0.bit());
+
+  __ MultiPush(spill_mask);
+  __ lw(a0, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+  __ li(a1, Operand(Handle<String>(name)));
+  StringDictionaryLookupStub stub(NEGATIVE_LOOKUP);
+  MaybeObject* result = masm->TryCallStub(&stub);
+  if (result->IsFailure()) return result;
+  __ MultiPop(spill_mask);
+
+  __ Branch(done, eq, v0, Operand(zero_reg));
+  __ Branch(miss, ne, v0, Operand(zero_reg));
+  return result;
+}
+
+
+// Probe the string dictionary in the |elements| register. Jump to the
+// |done| label if a property with the given name is found. Jump to
+// the |miss| label otherwise.
+// If lookup was successful |scratch2| will be equal to elements + 4 * index.
 void StringDictionaryLookupStub::GeneratePositiveLookup(MacroAssembler* masm,
                                                         Label* miss,
                                                         Label* done,
@@ -807,12 +6455,156 @@ void StringDictionaryLookupStub::GeneratePositiveLookup(MacroAssembler* masm,
                                                         Register name,
                                                         Register scratch1,
                                                         Register scratch2) {
-  UNIMPLEMENTED_MIPS();
+  // Assert that name contains a string.
+  if (FLAG_debug_code) __ AbortIfNotString(name);
+
+  // Compute the capacity mask.
+  __ lw(scratch1, FieldMemOperand(elements, kCapacityOffset));
+  __ sra(scratch1, scratch1, kSmiTagSize);  // convert smi to int
+  __ Subu(scratch1, scratch1, Operand(1));
+
+  // Generate an unrolled loop that performs a few probes before
+  // giving up. Measurements done on Gmail indicate that 2 probes
+  // cover ~93% of loads from dictionaries.
+  for (int i = 0; i < kInlinedProbes; i++) {
+    // Compute the masked index: (hash + i + i * i) & mask.
+    __ lw(scratch2, FieldMemOperand(name, String::kHashFieldOffset));
+    if (i > 0) {
+      // Add the probe offset (i + i * i) left shifted to avoid right shifting
+      // the hash in a separate instruction. The value hash + i + i * i is right
+      // shifted in the following and instruction.
+      ASSERT(StringDictionary::GetProbeOffset(i) <
+             1 << (32 - String::kHashFieldOffset));
+      __ Addu(scratch2, scratch2, Operand(
+           StringDictionary::GetProbeOffset(i) << String::kHashShift));
+    }
+    __ srl(scratch2, scratch2, String::kHashShift);
+    __ And(scratch2, scratch1, scratch2);
+
+    // Scale the index by multiplying by the element size.
+    ASSERT(StringDictionary::kEntrySize == 3);
+    // scratch2 = scratch2 * 3.
+
+    __ mov(at, scratch2);
+    __ sll(scratch2, scratch2, 1);
+    __ Addu(scratch2, scratch2, at);
+
+    // Check if the key is identical to the name.
+    __ sll(at, scratch2, 2);
+    __ Addu(scratch2, elements, at);
+    __ lw(at, FieldMemOperand(scratch2, kElementsStartOffset));
+    __ Branch(done, eq, name, Operand(at));
+  }
+
+  const int spill_mask =
+      (ra.bit() | t2.bit() | t1.bit() | t0.bit() |
+       a3.bit() | a2.bit() | a1.bit() | a0.bit()) &
+      ~(scratch1.bit() | scratch2.bit());
+
+  __ MultiPush(spill_mask);
+  __ Move(a0, elements);
+  __ Move(a1, name);
+  StringDictionaryLookupStub stub(POSITIVE_LOOKUP);
+  __ CallStub(&stub);
+  __ mov(scratch2, a2);
+  __ MultiPop(spill_mask);
+
+  __ Branch(done, ne, v0, Operand(zero_reg));
+  __ Branch(miss, eq, v0, Operand(zero_reg));
 }
 
 
 void StringDictionaryLookupStub::Generate(MacroAssembler* masm) {
-  UNIMPLEMENTED_MIPS();
+  // Registers:
+  //  result: StringDictionary to probe
+  //  a1: key
+  //  : StringDictionary to probe.
+  //  index_: will hold an index of entry if lookup is successful.
+  //          might alias with result_.
+  // Returns:
+  //  result_ is zero if lookup failed, non zero otherwise.
+
+  Register result = v0;
+  Register dictionary = a0;
+  Register key = a1;
+  Register index = a2;
+  Register mask = a3;
+  Register hash = t0;
+  Register undefined = t1;
+  Register entry_key = t2;
+
+  Label in_dictionary, maybe_in_dictionary, not_in_dictionary;
+
+  __ lw(mask, FieldMemOperand(dictionary, kCapacityOffset));
+  __ sra(mask, mask, kSmiTagSize);
+  __ Subu(mask, mask, Operand(1));
+
+  __ lw(hash, FieldMemOperand(key, String::kHashFieldOffset));
+
+  __ LoadRoot(undefined, Heap::kUndefinedValueRootIndex);
+
+  for (int i = kInlinedProbes; i < kTotalProbes; i++) {
+    // Compute the masked index: (hash + i + i * i) & mask.
+    // Capacity is smi 2^n.
+    if (i > 0) {
+      // Add the probe offset (i + i * i) left shifted to avoid right shifting
+      // the hash in a separate instruction. The value hash + i + i * i is right
+      // shifted in the following and instruction.
+      ASSERT(StringDictionary::GetProbeOffset(i) <
+             1 << (32 - String::kHashFieldOffset));
+      __ Addu(index, hash, Operand(
+           StringDictionary::GetProbeOffset(i) << String::kHashShift));
+    } else {
+      __ mov(index, hash);
+    }
+    __ srl(index, index, String::kHashShift);
+    __ And(index, mask, index);
+
+    // Scale the index by multiplying by the entry size.
+    ASSERT(StringDictionary::kEntrySize == 3);
+    // index *= 3.
+    __ mov(at, index);
+    __ sll(index, index, 1);
+    __ Addu(index, index, at);
+
+
+    ASSERT_EQ(kSmiTagSize, 1);
+    __ sll(index, index, 2);
+    __ Addu(index, index, dictionary);
+    __ lw(entry_key, FieldMemOperand(index, kElementsStartOffset));
+
+    // Having undefined at this place means the name is not contained.
+    __ Branch(&not_in_dictionary, eq, entry_key, Operand(undefined));
+
+    // Stop if found the property.
+    __ Branch(&in_dictionary, eq, entry_key, Operand(key));
+
+    if (i != kTotalProbes - 1 && mode_ == NEGATIVE_LOOKUP) {
+      // Check if the entry name is not a symbol.
+      __ lw(entry_key, FieldMemOperand(entry_key, HeapObject::kMapOffset));
+      __ lbu(entry_key,
+             FieldMemOperand(entry_key, Map::kInstanceTypeOffset));
+      __ And(result, entry_key, Operand(kIsSymbolMask));
+      __ Branch(&maybe_in_dictionary, eq, result, Operand(zero_reg));
+    }
+  }
+
+  __ bind(&maybe_in_dictionary);
+  // If we are doing negative lookup then probing failure should be
+  // treated as a lookup success. For positive lookup probing failure
+  // should be treated as lookup failure.
+  if (mode_ == POSITIVE_LOOKUP) {
+    __ mov(result, zero_reg);
+    __ Ret();
+  }
+
+  __ bind(&in_dictionary);
+  __ li(result, 1);
+  __ Ret();
+
+  __ bind(&not_in_dictionary);
+  __ mov(result, zero_reg);
+  __ Ret();
 }