A64: Synchronize with r18764.

src/mips/code-stubs-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 183 matching lines @@
 }
 
 
 static void InitializeArrayConstructorDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor,
     int constant_stack_parameter_count) {
   // register state
   // a0 -- number of arguments
   // a1 -- function
-  // a2 -- type info cell with elements kind
+  // a2 -- allocation site with elements kind
   static Register registers_variable_args[] = { a1, a2, a0 };
   static Register registers_no_args[] = { a1, a2 };
 
   if (constant_stack_parameter_count == 0) {
     descriptor->register_param_count_ = 2;
     descriptor->register_params_ = registers_no_args;
   } else {
     // stack param count needs (constructor pointer, and single argument)
     descriptor->handler_arguments_mode_ = PASS_ARGUMENTS;
     descriptor->stack_parameter_count_ = a0;
@@ skipping 129 matching lines @@
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
   static Register registers[] = { a2, a1, a0 };
   descriptor->register_param_count_ = 3;
   descriptor->register_params_ = registers;
   descriptor->deoptimization_handler_ =
       FUNCTION_ADDR(BinaryOpIC_MissWithAllocationSite);
 }
 
 
-void NewStringAddStub::InitializeInterfaceDescriptor(
+void StringAddStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
   static Register registers[] = { a1, a0 };
   descriptor->register_param_count_ = 2;
   descriptor->register_params_ = registers;
   descriptor->deoptimization_handler_ =
       Runtime::FunctionForId(Runtime::kStringAdd)->entry;
 }
 
 
@@ skipping 311 matching lines @@
     // Load double input.
     __ ldc1(double_scratch, MemOperand(input_reg, double_offset));
 
     // Clear cumulative exception flags and save the FCSR.
     __ cfc1(scratch2, FCSR);
     __ ctc1(zero_reg, FCSR);
 
     // Try a conversion to a signed integer.
     __ Trunc_w_d(double_scratch, double_scratch);
     // Move the converted value into the result register.
-    __ mfc1(result_reg, double_scratch);
+    __ mfc1(scratch3, double_scratch);
 
     // Retrieve and restore the FCSR.
     __ cfc1(scratch, FCSR);
     __ ctc1(scratch2, FCSR);
 
     // Check for overflow and NaNs.
     __ And(
         scratch, scratch,
         kFCSROverflowFlagMask | kFCSRUnderflowFlagMask
            | kFCSRInvalidOpFlagMask);
-    // If we had no exceptions we are done.
-    __ Branch(&done, eq, scratch, Operand(zero_reg));
+    // If we had no exceptions then set result_reg and we are done.
+    Label error;
+    __ Branch(&error, ne, scratch, Operand(zero_reg));
+    __ Move(result_reg, scratch3);
+    __ Branch(&done);
+    __ bind(&error);
   }
 
   // Load the double value and perform a manual truncation.
   Register input_high = scratch2;
   Register input_low = scratch3;
 
   __ lw(input_low, MemOperand(input_reg, double_offset));
   __ lw(input_high, MemOperand(input_reg, double_offset + kIntSize));
 
   Label normal_exponent, restore_sign;
@@ skipping 2905 matching lines @@
   __ CallRuntime(Runtime::kCharFromCode, 1);
   __ Move(result_, v0);
 
   call_helper.AfterCall(masm);
   __ Branch(&exit_);
 
   __ Abort(kUnexpectedFallthroughFromCharFromCodeSlowCase);
 }
 
 
-void StringHelper::GenerateCopyCharacters(MacroAssembler* masm,
-                                          Register dest,
-                                          Register src,
-                                          Register count,
-                                          Register scratch,
-                                          bool ascii) {
-  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);
-}
-
-
 enum CopyCharactersFlags {
   COPY_ASCII = 1,
   DEST_ALWAYS_ALIGNED = 2
 };
 
 
 void StringHelper::GenerateCopyCharactersLong(MacroAssembler* masm,
                                               Register dest,
                                               Register src,
                                               Register count,
@@ skipping 98 matching lines @@
   __ lbu(scratch1, MemOperand(src));
   __ addiu(src, src, 1);
   __ sb(scratch1, MemOperand(dest));
   __ addiu(dest, dest, 1);
   __ Branch(&byte_loop);
 
   __ bind(&done);
 }
 
 
-void StringHelper::GenerateTwoCharacterStringTableProbe(MacroAssembler* masm,
-                                                        Register c1,
-                                                        Register c2,
-                                                        Register scratch1,
-                                                        Register scratch2,
-                                                        Register scratch3,
-                                                        Register scratch4,
-                                                        Register scratch5,
-                                                        Label* not_found) {
-  // 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 string 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 string table.
-  // Load address of first element of the string table.
-  Register string_table = c2;
-  __ LoadRoot(string_table, Heap::kStringTableRootIndex);
-
-  Register undefined = scratch4;
-  __ LoadRoot(undefined, Heap::kUndefinedValueRootIndex);
-
-  // Calculate capacity mask from the string table capacity.
-  Register mask = scratch2;
-  __ lw(mask, FieldMemOperand(string_table, StringTable::kCapacityOffset));
-  __ sra(mask, mask, 1);
-  __ Addu(mask, mask, -1);
-
-  // Calculate untagged address of the first element of the string table.
-  Register first_string_table_element = string_table;
-  __ Addu(first_string_table_element, string_table,
-         Operand(StringTable::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_string_table_element: address of the first element of
-  //                             the string table
-  // undefined: the undefined object
-  // scratch: -
-
-  // Perform a number of probes in the string table.
-  const int kProbes = 4;
-  Label found_in_string_table;
-  Label next_probe[kProbes];
-  Register candidate = scratch5;  // Scratch register contains candidate.
-  for (int i = 0; i < kProbes; i++) {
-    // Calculate entry in string table.
-    if (i > 0) {
-      __ Addu(candidate, hash, Operand(StringTable::GetProbeOffset(i)));
-    } else {
-      __ mov(candidate, hash);
-    }
-
-    __ And(candidate, candidate, Operand(mask));
-
-    // Load the entry from the symble table.
-    STATIC_ASSERT(StringTable::kEntrySize == 1);
-    __ sll(scratch, candidate, kPointerSizeLog2);
-    __ Addu(scratch, scratch, first_string_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 the hole (deleted entry).
-    if (FLAG_debug_code) {
-      __ LoadRoot(scratch, Heap::kTheHoleValueRootIndex);
-      __ Assert(eq, kOddballInStringTableIsNotUndefinedOrTheHole,
-          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, SeqOneByteString::kHeaderSize));
-    __ Branch(&found_in_string_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_string_table);
-  __ mov(v0, result);
-}
-
-
 void StringHelper::GenerateHashInit(MacroAssembler* masm,
                                     Register hash,
                                     Register character) {
   // hash = seed + character + ((seed + character) << 10);
   __ LoadRoot(hash, Heap::kHashSeedRootIndex);
   // Untag smi seed and add the character.
   __ SmiUntag(hash);
   __ addu(hash, hash, character);
   __ sll(at, hash, 10);
   __ addu(hash, hash, at);
@@ skipping 407 matching lines @@
   // 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 ArrayPushStub::Generate(MacroAssembler* masm) {
+  Register receiver = a0;
+  Register scratch = a1;
+
+  int argc = arguments_count();
+
+  if (argc == 0) {
+    // Nothing to do, just return the length.
+    __ lw(v0, FieldMemOperand(receiver, JSArray::kLengthOffset));
+    __ DropAndRet(argc + 1);
+    return;
+  }
+
+  Isolate* isolate = masm->isolate();
+
+  if (argc != 1) {
+    __ TailCallExternalReference(
+        ExternalReference(Builtins::c_ArrayPush, isolate), argc + 1, 1);
+    return;
+  }
+
+  Label call_builtin, attempt_to_grow_elements, with_write_barrier;
+
+  Register elements = t2;
+  Register end_elements = t1;
+  // Get the elements array of the object.
+  __ lw(elements, FieldMemOperand(receiver, JSArray::kElementsOffset));
+
+  if (IsFastSmiOrObjectElementsKind(elements_kind())) {
+    // Check that the elements are in fast mode and writable.
+    __ CheckMap(elements,
+                scratch,
+                Heap::kFixedArrayMapRootIndex,
+                &call_builtin,
+                DONT_DO_SMI_CHECK);
+  }
+
+  // Get the array's length into scratch and calculate new length.
+  __ lw(scratch, FieldMemOperand(receiver, JSArray::kLengthOffset));
+  __ Addu(scratch, scratch, Operand(Smi::FromInt(argc)));
+
+  // Get the elements' length.
+  __ lw(t0, FieldMemOperand(elements, FixedArray::kLengthOffset));
+
+  const int kEndElementsOffset =
+      FixedArray::kHeaderSize - kHeapObjectTag - argc * kPointerSize;
+
+  if (IsFastSmiOrObjectElementsKind(elements_kind())) {
+    // Check if we could survive without allocation.
+    __ Branch(&attempt_to_grow_elements, gt, scratch, Operand(t0));
+
+    // Check if value is a smi.
+    __ lw(t0, MemOperand(sp, (argc - 1) * kPointerSize));
+    __ JumpIfNotSmi(t0, &with_write_barrier);
+
+    // Store the value.
+    // We may need a register containing the address end_elements below,
+    // so write back the value in end_elements.
+    __ sll(end_elements, scratch, kPointerSizeLog2 - kSmiTagSize);
+    __ Addu(end_elements, elements, end_elements);
+    __ Addu(end_elements, end_elements, kEndElementsOffset);
+    __ sw(t0, MemOperand(end_elements));
+  } else {
+    // Check if we could survive without allocation.
+    __ Branch(&call_builtin, gt, scratch, Operand(t0));
+
+    __ lw(t0, MemOperand(sp, (argc - 1) * kPointerSize));
+    __ StoreNumberToDoubleElements(t0, scratch, elements, a3, t1, a2,
+                                   &call_builtin, argc * kDoubleSize);
+  }
+
+  // Save new length.
+  __ sw(scratch, FieldMemOperand(receiver, JSArray::kLengthOffset));
+  __ mov(v0, scratch);
+  __ DropAndRet(argc + 1);
+
+  if (IsFastDoubleElementsKind(elements_kind())) {
+    __ bind(&call_builtin);
+    __ TailCallExternalReference(
+        ExternalReference(Builtins::c_ArrayPush, isolate), argc + 1, 1);
+    return;
+  }
+
+  __ bind(&with_write_barrier);
+
+  if (IsFastSmiElementsKind(elements_kind())) {
+    if (FLAG_trace_elements_transitions) __ jmp(&call_builtin);
+
+    __ lw(t3, FieldMemOperand(t0, HeapObject::kMapOffset));
+    __ LoadRoot(at, Heap::kHeapNumberMapRootIndex);
+    __ Branch(&call_builtin, eq, t3, Operand(at));
+
+    ElementsKind target_kind = IsHoleyElementsKind(elements_kind())
+        ? FAST_HOLEY_ELEMENTS : FAST_ELEMENTS;
+    __ lw(a3, ContextOperand(cp, Context::GLOBAL_OBJECT_INDEX));
+    __ lw(a3, FieldMemOperand(a3, GlobalObject::kNativeContextOffset));
+    __ lw(a3, ContextOperand(a3, Context::JS_ARRAY_MAPS_INDEX));
+    const int header_size = FixedArrayBase::kHeaderSize;
+    // Verify that the object can be transitioned in place.
+    const int origin_offset = header_size + elements_kind() * kPointerSize;
+    __ lw(a2, FieldMemOperand(receiver, origin_offset));
+    __ lw(at, FieldMemOperand(a3, HeapObject::kMapOffset));
+    __ Branch(&call_builtin, ne, a2, Operand(at));
+
+
+    const int target_offset = header_size + target_kind * kPointerSize;
+    __ lw(a3, FieldMemOperand(a3, target_offset));
+    __ mov(a2, receiver);
+    ElementsTransitionGenerator::GenerateMapChangeElementsTransition(
+        masm, DONT_TRACK_ALLOCATION_SITE, NULL);
+  }
+
+  // Save new length.
+  __ sw(scratch, FieldMemOperand(receiver, JSArray::kLengthOffset));
+
+  // Store the value.
+  // We may need a register containing the address end_elements below, so write
+  // back the value in end_elements.
+  __ sll(end_elements, scratch, kPointerSizeLog2 - kSmiTagSize);
+  __ Addu(end_elements, elements, end_elements);
+  __ Addu(end_elements, end_elements, kEndElementsOffset);
+  __ sw(t0, MemOperand(end_elements));
+
+  __ RecordWrite(elements,
+                 end_elements,
+                 t0,
+                 kRAHasNotBeenSaved,
+                 kDontSaveFPRegs,
+                 EMIT_REMEMBERED_SET,
+                 OMIT_SMI_CHECK);
+  __ mov(v0, scratch);
+  __ DropAndRet(argc + 1);
+
+  __ bind(&attempt_to_grow_elements);
+  // scratch: array's length + 1.
+
+  if (!FLAG_inline_new) {
+    __ bind(&call_builtin);
+    __ TailCallExternalReference(
+        ExternalReference(Builtins::c_ArrayPush, isolate), argc + 1, 1);
+    return;
+  }
+
+  __ lw(a2, MemOperand(sp, (argc - 1) * kPointerSize));
+  // Growing elements that are SMI-only requires special handling in case the
+  // new element is non-Smi. For now, delegate to the builtin.
+  if (IsFastSmiElementsKind(elements_kind())) {
+    __ JumpIfNotSmi(a2, &call_builtin);
+  }
+
+  // We could be lucky and the elements array could be at the top of new-space.
+  // In this case we can just grow it in place by moving the allocation pointer
+  // up.
+  ExternalReference new_space_allocation_top =
+      ExternalReference::new_space_allocation_top_address(isolate);
+  ExternalReference new_space_allocation_limit =
+      ExternalReference::new_space_allocation_limit_address(isolate);
+
+  const int kAllocationDelta = 4;
+  ASSERT(kAllocationDelta >= argc);
+  // Load top and check if it is the end of elements.
+  __ sll(end_elements, scratch, kPointerSizeLog2 - kSmiTagSize);
+  __ Addu(end_elements, elements, end_elements);
+  __ Addu(end_elements, end_elements, Operand(kEndElementsOffset));
+  __ li(t0, Operand(new_space_allocation_top));
+  __ lw(a3, MemOperand(t0));
+  __ Branch(&call_builtin, ne, a3, Operand(end_elements));
+
+  __ li(t3, Operand(new_space_allocation_limit));
+  __ lw(t3, MemOperand(t3));
+  __ Addu(a3, a3, Operand(kAllocationDelta * kPointerSize));
+  __ Branch(&call_builtin, hi, a3, Operand(t3));
+
+  // We fit and could grow elements.
+  // Update new_space_allocation_top.
+  __ sw(a3, MemOperand(t0));
+  // Push the argument.
+  __ sw(a2, MemOperand(end_elements));
+  // Fill the rest with holes.
+  __ LoadRoot(a3, Heap::kTheHoleValueRootIndex);
+  for (int i = 1; i < kAllocationDelta; i++) {
+    __ sw(a3, MemOperand(end_elements, i * kPointerSize));
+  }
+
+  // Update elements' and array's sizes.
+  __ sw(scratch, FieldMemOperand(receiver, JSArray::kLengthOffset));
+  __ lw(t0, FieldMemOperand(elements, FixedArray::kLengthOffset));
+  __ Addu(t0, t0, Operand(Smi::FromInt(kAllocationDelta)));
+  __ sw(t0, FieldMemOperand(elements, FixedArray::kLengthOffset));
+
+  // Elements are in new space, so write barrier is not required.
+  __ mov(v0, scratch);
+  __ DropAndRet(argc + 1);
+
+  __ bind(&call_builtin);
+  __ TailCallExternalReference(
+      ExternalReference(Builtins::c_ArrayPush, isolate), argc + 1, 1);
+}
+
+
 void BinaryOpICWithAllocationSiteStub::Generate(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- a1    : left
   //  -- a0    : right
   //  -- ra    : return address
   // -----------------------------------
   Isolate* isolate = masm->isolate();
 
   // Load a2 with the allocation site. We stick an undefined dummy value here
   // and replace it with the real allocation site later when we instantiate this
   // stub in BinaryOpICWithAllocationSiteStub::GetCodeCopyFromTemplate().
   __ li(a2, handle(isolate->heap()->undefined_value()));
 
   // Make sure that we actually patched the allocation site.
   if (FLAG_debug_code) {
     __ And(at, a2, Operand(kSmiTagMask));
     __ Assert(ne, kExpectedAllocationSite, at, Operand(zero_reg));
     __ lw(t0, FieldMemOperand(a2, HeapObject::kMapOffset));
     __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);
     __ Assert(eq, kExpectedAllocationSite, t0, Operand(at));
   }
 
   // Tail call into the stub that handles binary operations with allocation
   // sites.
   BinaryOpWithAllocationSiteStub stub(state_);
   __ TailCallStub(&stub);
 }
 
 
-void StringAddStub::Generate(MacroAssembler* masm) {
-  Label call_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.
-  // Otherwise, at least one of the arguments is definitely a string,
-  // and we convert the one that is not known to be a string.
-  if ((flags_ & STRING_ADD_CHECK_BOTH) == STRING_ADD_CHECK_BOTH) {
-    ASSERT((flags_ & STRING_ADD_CHECK_LEFT) == STRING_ADD_CHECK_LEFT);
-    ASSERT((flags_ & STRING_ADD_CHECK_RIGHT) == STRING_ADD_CHECK_RIGHT);
-    __ JumpIfEitherSmi(a0, a1, &call_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(&call_runtime, ne, t4, Operand(zero_reg));
-  } else if ((flags_ & STRING_ADD_CHECK_LEFT) == STRING_ADD_CHECK_LEFT) {
-    ASSERT((flags_ & STRING_ADD_CHECK_RIGHT) == 0);
-    GenerateConvertArgument(
-        masm, 1 * kPointerSize, a0, a2, a3, t0, t1, &call_builtin);
-    builtin_id = Builtins::STRING_ADD_RIGHT;
-  } else if ((flags_ & STRING_ADD_CHECK_RIGHT) == STRING_ADD_CHECK_RIGHT) {
-    ASSERT((flags_ & STRING_ADD_CHECK_LEFT) == 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);
-    __ DropAndRet(2);
-
-    __ 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 string table when adding two one character strings, as it
-  // helps later optimizations to return a string here.
-  __ Branch(&longer_than_two, ne, t2, Operand(2));
-
-  // Check that both strings are non-external ASCII strings.
-  if ((flags_ & STRING_ADD_CHECK_BOTH) != STRING_ADD_CHECK_BOTH) {
-    __ 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,
-                                                 &call_runtime);
-
-  // Get the two characters forming the sub string.
-  __ lbu(a2, FieldMemOperand(a0, SeqOneByteString::kHeaderSize));
-  __ lbu(a3, FieldMemOperand(a1, SeqOneByteString::kHeaderSize));
-
-  // Try to lookup two character string in string table. If it is not found
-  // just allocate a new one.
-  Label make_two_character_string;
-  StringHelper::GenerateTwoCharacterStringTableProbe(
-      masm, a2, a3, t2, t3, t0, t1, t5, &make_two_character_string);
-  __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
-  __ DropAndRet(2);
-
-  __ 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, t5, &call_runtime);
-  __ sh(a2, FieldMemOperand(v0, SeqOneByteString::kHeaderSize));
-  __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
-  __ DropAndRet(2);
-
-  __ bind(&longer_than_two);
-  // Check if resulting string will be flat.
-  __ Branch(&string_add_flat_result, lt, t2, Operand(ConsString::kMinLength));
-  // 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(&call_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_ & STRING_ADD_CHECK_BOTH) != STRING_ADD_CHECK_BOTH) {
-    __ 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(v0, t2, t0, t1, &call_runtime);
-  __ bind(&allocated);
-  // Fill the fields of the cons string.
-  Label skip_write_barrier, after_writing;
-  ExternalReference high_promotion_mode = ExternalReference::
-      new_space_high_promotion_mode_active_address(masm->isolate());
-  __ li(t0, Operand(high_promotion_mode));
-  __ lw(t0, MemOperand(t0, 0));
-  __ Branch(&skip_write_barrier, eq, t0, Operand(zero_reg));
-
-  __ mov(t3, v0);
-  __ sw(a0, FieldMemOperand(t3, ConsString::kFirstOffset));
-  __ RecordWriteField(t3,
-                      ConsString::kFirstOffset,
-                      a0,
-                      t0,
-                      kRAHasNotBeenSaved,
-                      kDontSaveFPRegs);
-  __ sw(a1, FieldMemOperand(t3, ConsString::kSecondOffset));
-  __ RecordWriteField(t3,
-                      ConsString::kSecondOffset,
-                      a1,
-                      t0,
-                      kRAHasNotBeenSaved,
-                      kDontSaveFPRegs);
-  __ jmp(&after_writing);
-
-  __ bind(&skip_write_barrier);
-  __ sw(a0, FieldMemOperand(v0, ConsString::kFirstOffset));
-  __ sw(a1, FieldMemOperand(v0, ConsString::kSecondOffset));
-
-  __ bind(&after_writing);
-
-  __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
-  __ DropAndRet(2);
-
-  __ bind(&non_ascii);
-  // At least one of the strings is two-byte. Check whether it happens
-  // to contain only one byte characters.
-  // t0: first instance type.
-  // t1: second instance type.
-  // Branch to if _both_ instances have kOneByteDataHintMask set.
-  __ And(at, t0, Operand(kOneByteDataHintMask));
-  __ and_(at, at, t1);
-  __ Branch(&ascii_data, ne, at, Operand(zero_reg));
-  __ Xor(t0, t0, Operand(t1));
-  STATIC_ASSERT(kOneByteStringTag != 0 && kOneByteDataHintTag != 0);
-  __ And(t0, t0, Operand(kOneByteStringTag | kOneByteDataHintTag));
-  __ Branch(&ascii_data, eq, t0,
-      Operand(kOneByteStringTag | kOneByteDataHintTag));
-
-  // Allocate a two byte cons string.
-  __ AllocateTwoByteConsString(v0, t2, t0, t1, &call_runtime);
-  __ Branch(&allocated);
-
-  // We cannot encounter sliced strings or cons strings here since:
-  STATIC_ASSERT(SlicedString::kMinLength >= ConsString::kMinLength);
-  // Handle creating a flat result from either external or sequential strings.
-  // Locate the first characters' locations.
-  // 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.
-  Label first_prepared, second_prepared;
-  __ bind(&string_add_flat_result);
-  if ((flags_ & STRING_ADD_CHECK_BOTH) != STRING_ADD_CHECK_BOTH) {
-    __ 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 whether both strings have same encoding
-  __ Xor(t3, t0, Operand(t1));
-  __ And(t3, t3, Operand(kStringEncodingMask));
-  __ Branch(&call_runtime, ne, t3, Operand(zero_reg));
-
-  STATIC_ASSERT(kSeqStringTag == 0);
-  __ And(t4, t0, Operand(kStringRepresentationMask));
-
-  STATIC_ASSERT(SeqOneByteString::kHeaderSize == SeqTwoByteString::kHeaderSize);
-  Label skip_first_add;
-  __ Branch(&skip_first_add, ne, t4, Operand(zero_reg));
-  __ Branch(USE_DELAY_SLOT, &first_prepared);
-  __ addiu(t3, a0, SeqOneByteString::kHeaderSize - kHeapObjectTag);
-  __ bind(&skip_first_add);
-  // External string: rule out short external string and load string resource.
-  STATIC_ASSERT(kShortExternalStringTag != 0);
-  __ And(t4, t0, Operand(kShortExternalStringMask));
-  __ Branch(&call_runtime, ne, t4, Operand(zero_reg));
-  __ lw(t3, FieldMemOperand(a0, ExternalString::kResourceDataOffset));
-  __ bind(&first_prepared);
-
-  STATIC_ASSERT(kSeqStringTag == 0);
-  __ And(t4, t1, Operand(kStringRepresentationMask));
-  STATIC_ASSERT(SeqOneByteString::kHeaderSize == SeqTwoByteString::kHeaderSize);
-  Label skip_second_add;
-  __ Branch(&skip_second_add, ne, t4, Operand(zero_reg));
-  __ Branch(USE_DELAY_SLOT, &second_prepared);
-  __ addiu(a1, a1, SeqOneByteString::kHeaderSize - kHeapObjectTag);
-  __ bind(&skip_second_add);
-  // External string: rule out short external string and load string resource.
-  STATIC_ASSERT(kShortExternalStringTag != 0);
-  __ And(t4, t1, Operand(kShortExternalStringMask));
-  __ Branch(&call_runtime, ne, t4, Operand(zero_reg));
-  __ lw(a1, FieldMemOperand(a1, ExternalString::kResourceDataOffset));
-  __ bind(&second_prepared);
-
-  Label non_ascii_string_add_flat_result;
-  // t3: first character of first string
-  // a1: first character of second string
-  // a2: length of first string
-  // a3: length of second string
-  // t2: sum of lengths.
-  // Both strings have the same encoding.
-  STATIC_ASSERT(kTwoByteStringTag == 0);
-  __ And(t4, t1, Operand(kStringEncodingMask));
-  __ Branch(&non_ascii_string_add_flat_result, eq, t4, Operand(zero_reg));
-
-  __ AllocateAsciiString(v0, t2, t0, t1, t5, &call_runtime);
-  __ Addu(t2, v0, Operand(SeqOneByteString::kHeaderSize - kHeapObjectTag));
-  // v0: result string.
-  // t3: first character of first string.
-  // a1: first character of second string
-  // a2: length of first string.
-  // a3: length of second string.
-  // t2: first character of result.
-
-  StringHelper::GenerateCopyCharacters(masm, t2, t3, a2, t0, true);
-  // t2: next character of result.
-  StringHelper::GenerateCopyCharacters(masm, t2, a1, a3, t0, true);
-  __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
-  __ DropAndRet(2);
-
-  __ bind(&non_ascii_string_add_flat_result);
-  __ AllocateTwoByteString(v0, t2, t0, t1, t5, &call_runtime);
-  __ Addu(t2, v0, Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
-  // v0: result string.
-  // t3: first character of first string.
-  // a1: first character of second string.
-  // a2: length of first string.
-  // a3: length of second string.
-  // t2: first character of result.
-  StringHelper::GenerateCopyCharacters(masm, t2, t3, a2, t0, false);
-  // t2: next character of result.
-  StringHelper::GenerateCopyCharacters(masm, t2, a1, a3, t0, false);
-
-  __ IncrementCounter(counters->string_add_native(), 1, a2, a3);
-  __ DropAndRet(2);
-
-  // Just jump to runtime to add the two strings.
-  __ bind(&call_runtime);
-  __ TailCallRuntime(Runtime::kStringAdd, 2, 1);
-
-  if (call_builtin.is_linked()) {
-    __ bind(&call_builtin);
-    __ InvokeBuiltin(builtin_id, JUMP_FUNCTION);
-  }
-}
-
-
-void StringAddStub::GenerateRegisterArgsPush(MacroAssembler* masm) {
-  __ push(a0);
-  __ push(a1);
-}
-
-
-void StringAddStub::GenerateRegisterArgsPop(MacroAssembler* masm) {
-  __ pop(a1);
-  __ pop(a0);
-}
-
-
-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.
-  __ bind(&not_string);
-  // Puts the cached result into scratch1.
-  __ LookupNumberStringCache(arg, scratch1, scratch2, scratch3, scratch4, slow);
-  __ mov(arg, scratch1);
-  __ sw(arg, MemOperand(sp, stack_offset));
-  __ bind(&done);
-}
-
-
 void ICCompareStub::GenerateSmis(MacroAssembler* masm) {
   ASSERT(state_ == CompareIC::SMI);
   Label miss;
   __ Or(a2, a1, a0);
   __ JumpIfNotSmi(a2, &miss);
 
   if (GetCondition() == eq) {
     // For equality we do not care about the sign of the result.
     __ Ret(USE_DELAY_SLOT);
     __ Subu(v0, a0, a1);
@@ skipping 1020 matching lines @@
     // If we reached this point there is a problem.
     __ Abort(kUnexpectedElementsKindInArrayConstructor);
   } else {
     UNREACHABLE();
   }
 }
 
 
 static void CreateArrayDispatchOneArgument(MacroAssembler* masm,
                                            AllocationSiteOverrideMode mode) {
-  // a2 - type info cell (if mode != DISABLE_ALLOCATION_SITES)
+  // a2 - allocation site (if mode != DISABLE_ALLOCATION_SITES)
   // a3 - kind (if mode != DISABLE_ALLOCATION_SITES)
   // a0 - number of arguments
   // a1 - constructor?
   // sp[0] - last argument
   Label normal_sequence;
   if (mode == DONT_OVERRIDE) {
     ASSERT(FAST_SMI_ELEMENTS == 0);
     ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
     ASSERT(FAST_ELEMENTS == 2);
     ASSERT(FAST_HOLEY_ELEMENTS == 3);
@@ skipping 18 matching lines @@
     __ TailCallStub(&stub_holey);
 
     __ bind(&normal_sequence);
     ArraySingleArgumentConstructorStub stub(initial,
                                             DISABLE_ALLOCATION_SITES);
     __ TailCallStub(&stub);
   } else if (mode == DONT_OVERRIDE) {
     // We are going to create a holey array, but our kind is non-holey.
     // Fix kind and retry (only if we have an allocation site in the cell).
     __ Addu(a3, a3, Operand(1));
-    __ lw(t1, FieldMemOperand(a2, Cell::kValueOffset));
 
     if (FLAG_debug_code) {
-      __ lw(t1, FieldMemOperand(t1, 0));
+      __ lw(t1, FieldMemOperand(a2, 0));
       __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);
-      __ Assert(eq, kExpectedAllocationSiteInCell, t1, Operand(at));
-      __ lw(t1, FieldMemOperand(a2, Cell::kValueOffset));
+      __ Assert(eq, kExpectedAllocationSite, t1, Operand(at));
     }
 
     // Save the resulting elements kind in type info. We can't just store a3
     // in the AllocationSite::transition_info field because elements kind is
     // restricted to a portion of the field...upper bits need to be left alone.
     STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
-    __ lw(t0, FieldMemOperand(t1, AllocationSite::kTransitionInfoOffset));
+    __ lw(t0, FieldMemOperand(a2, AllocationSite::kTransitionInfoOffset));
     __ Addu(t0, t0, Operand(Smi::FromInt(kFastElementsKindPackedToHoley)));
-    __ sw(t0, FieldMemOperand(t1, AllocationSite::kTransitionInfoOffset));
+    __ sw(t0, FieldMemOperand(a2, AllocationSite::kTransitionInfoOffset));
 
 
     __ bind(&normal_sequence);
     int last_index = GetSequenceIndexFromFastElementsKind(
         TERMINAL_FAST_ELEMENTS_KIND);
     for (int i = 0; i <= last_index; ++i) {
       ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
       ArraySingleArgumentConstructorStub stub(kind);
       __ TailCallStub(&stub, eq, a3, Operand(kind));
     }
@@ skipping 104 matching lines @@
     __ lw(a3, FieldMemOperand(a2, 0));
     __ Assert(eq, kExpectedPropertyCellInRegisterA2,
         a3, Operand(cell_map));
     __ bind(&okay_here);
   }
 
   Label no_info;
   // Get the elements kind and case on that.
   __ LoadRoot(at, Heap::kUndefinedValueRootIndex);
   __ Branch(&no_info, eq, a2, Operand(at));
-  __ lw(a3, FieldMemOperand(a2, Cell::kValueOffset));
+  __ lw(a2, FieldMemOperand(a2, Cell::kValueOffset));
 
   // If the type cell is undefined, or contains anything other than an
   // AllocationSite, call an array constructor that doesn't use AllocationSites.
-  __ lw(t0, FieldMemOperand(a3, 0));
+  __ lw(t0, FieldMemOperand(a2, 0));
   __ LoadRoot(at, Heap::kAllocationSiteMapRootIndex);
   __ Branch(&no_info, ne, t0, Operand(at));
 
-  __ lw(a3, FieldMemOperand(a3, AllocationSite::kTransitionInfoOffset));
+  __ lw(a3, FieldMemOperand(a2, AllocationSite::kTransitionInfoOffset));
   __ SmiUntag(a3);
   STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
   __ And(a3, a3, Operand(AllocationSite::ElementsKindBits::kMask));
   GenerateDispatchToArrayStub(masm, DONT_OVERRIDE);
 
   __ bind(&no_info);
   GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);
 }
 
 
@@ skipping 69 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS