path: root/deps/v8/src/arm/ic-arm.cc

// Copyright 2006-2008 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
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "v8.h"

#include "codegen-inl.h"
#include "ic-inl.h"
#include "runtime.h"
#include "stub-cache.h"

namespace v8 {
namespace internal {


// ----------------------------------------------------------------------------
// Static IC stub generators.
//

#define __ ACCESS_MASM(masm)

// Helper function used from LoadIC/CallIC GenerateNormal.
static void GenerateDictionaryLoad(MacroAssembler* masm,
                                   Label* miss,
                                   Register t0,
                                   Register t1) {
  // Register use:
  //
  // t0 - used to hold the property dictionary.
  //
  // t1 - initially the receiver
  //    - used for the index into the property dictionary
  //    - holds the result on exit.
  //
  // r3 - used as temporary and to hold the capacity of the property
  //      dictionary.
  //
  // r2 - holds the name of the property and is unchanged.

  Label done;

  // Check for the absence of an interceptor.
  // Load the map into t0.
  __ ldr(t0, FieldMemOperand(t1, JSObject::kMapOffset));
  // Test the has_named_interceptor bit in the map.
  __ ldr(r3, FieldMemOperand(t0, Map::kInstanceAttributesOffset));
  __ tst(r3, Operand(1 << (Map::kHasNamedInterceptor + (3 * 8))));
  // Jump to miss if the interceptor bit is set.
  __ b(ne, miss);

  // Bail out if we have a JS global proxy object.
  __ ldrb(r3, FieldMemOperand(t0, Map::kInstanceTypeOffset));
  __ cmp(r3, Operand(JS_GLOBAL_PROXY_TYPE));
  __ b(eq, miss);

  // Possible work-around for http://crbug.com/16276.
  // See also: http://codereview.chromium.org/155418.
  __ cmp(r3, Operand(JS_GLOBAL_OBJECT_TYPE));
  __ b(eq, miss);
  __ cmp(r3, Operand(JS_BUILTINS_OBJECT_TYPE));
  __ b(eq, miss);

  // Check that the properties array is a dictionary.
  __ ldr(t0, FieldMemOperand(t1, JSObject::kPropertiesOffset));
  __ ldr(r3, FieldMemOperand(t0, HeapObject::kMapOffset));
  __ LoadRoot(ip, Heap::kHashTableMapRootIndex);
  __ cmp(r3, ip);
  __ b(ne, miss);

  // Compute the capacity mask.
  const int kCapacityOffset = StringDictionary::kHeaderSize +
      StringDictionary::kCapacityIndex * kPointerSize;
  __ ldr(r3, FieldMemOperand(t0, kCapacityOffset));
  __ mov(r3, Operand(r3, ASR, kSmiTagSize));  // convert smi to int
  __ sub(r3, r3, Operand(1));

  const int kElementsStartOffset = StringDictionary::kHeaderSize +
      StringDictionary::kElementsStartIndex * kPointerSize;

  // 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.
  static const int kProbes = 4;
  for (int i = 0; i < kProbes; i++) {
    // Compute the masked index: (hash + i + i * i) & mask.
    __ ldr(t1, FieldMemOperand(r2, 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));
      __ add(t1, t1, Operand(
          StringDictionary::GetProbeOffset(i) << String::kHashShift));
    }
    __ and_(t1, r3, Operand(t1, LSR, String::kHashShift));

    // Scale the index by multiplying by the element size.
    ASSERT(StringDictionary::kEntrySize == 3);
    __ add(t1, t1, Operand(t1, LSL, 1));  // t1 = t1 * 3

    // Check if the key is identical to the name.
    __ add(t1, t0, Operand(t1, LSL, 2));
    __ ldr(ip, FieldMemOperand(t1, kElementsStartOffset));
    __ cmp(r2, Operand(ip));
    if (i != kProbes - 1) {
      __ b(eq, &done);
    } else {
      __ b(ne, miss);
    }
  }

  // Check that the value is a normal property.
  __ bind(&done);  // t1 == t0 + 4*index
  __ ldr(r3, FieldMemOperand(t1, kElementsStartOffset + 2 * kPointerSize));
  __ tst(r3, Operand(PropertyDetails::TypeField::mask() << kSmiTagSize));
  __ b(ne, miss);

  // Get the value at the masked, scaled index and return.
  __ ldr(t1, FieldMemOperand(t1, kElementsStartOffset + 1 * kPointerSize));
}


void LoadIC::GenerateArrayLength(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r2    : name
  //  -- lr    : return address
  //  -- [sp]  : receiver
  // -----------------------------------
  Label miss;

  __ ldr(r0, MemOperand(sp, 0));

  StubCompiler::GenerateLoadArrayLength(masm, r0, r3, &miss);
  __ bind(&miss);
  StubCompiler::GenerateLoadMiss(masm, Code::LOAD_IC);
}


void LoadIC::GenerateStringLength(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r2    : name
  //  -- lr    : return address
  //  -- [sp]  : receiver
  // -----------------------------------
  Label miss;

  __ ldr(r0, MemOperand(sp, 0));

  StubCompiler::GenerateLoadStringLength(masm, r0, r1, r3, &miss);
  // Cache miss: Jump to runtime.
  __ bind(&miss);
  StubCompiler::GenerateLoadMiss(masm, Code::LOAD_IC);
}


void LoadIC::GenerateFunctionPrototype(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r2    : name
  //  -- lr    : return address
  //  -- [sp]  : receiver
  // -----------------------------------
  Label miss;

  // Load receiver.
  __ ldr(r0, MemOperand(sp, 0));

  StubCompiler::GenerateLoadFunctionPrototype(masm, r0, r1, r3, &miss);
  __ bind(&miss);
  StubCompiler::GenerateLoadMiss(masm, Code::LOAD_IC);
}


// Defined in ic.cc.
Object* CallIC_Miss(Arguments args);

void CallIC::GenerateMegamorphic(MacroAssembler* masm, int argc) {
  // ----------- S t a t e -------------
  //  -- r2    : name
  //  -- lr    : return address
  // -----------------------------------
  Label number, non_number, non_string, boolean, probe, miss;

  // Get the receiver of the function from the stack into r1.
  __ ldr(r1, MemOperand(sp, argc * kPointerSize));

  // Probe the stub cache.
  Code::Flags flags =
      Code::ComputeFlags(Code::CALL_IC, NOT_IN_LOOP, MONOMORPHIC, NORMAL, argc);
  StubCache::GenerateProbe(masm, flags, r1, r2, r3, no_reg);

  // If the stub cache probing failed, the receiver might be a value.
  // For value objects, we use the map of the prototype objects for
  // the corresponding JSValue for the cache and that is what we need
  // to probe.
  //
  // Check for number.
  __ tst(r1, Operand(kSmiTagMask));
  __ b(eq, &number);
  __ CompareObjectType(r1, r3, r3, HEAP_NUMBER_TYPE);
  __ b(ne, &non_number);
  __ bind(&number);
  StubCompiler::GenerateLoadGlobalFunctionPrototype(
      masm, Context::NUMBER_FUNCTION_INDEX, r1);
  __ b(&probe);

  // Check for string.
  __ bind(&non_number);
  __ cmp(r3, Operand(FIRST_NONSTRING_TYPE));
  __ b(hs, &non_string);
  StubCompiler::GenerateLoadGlobalFunctionPrototype(
      masm, Context::STRING_FUNCTION_INDEX, r1);
  __ b(&probe);

  // Check for boolean.
  __ bind(&non_string);
  __ LoadRoot(ip, Heap::kTrueValueRootIndex);
  __ cmp(r1, ip);
  __ b(eq, &boolean);
  __ LoadRoot(ip, Heap::kFalseValueRootIndex);
  __ cmp(r1, ip);
  __ b(ne, &miss);
  __ bind(&boolean);
  StubCompiler::GenerateLoadGlobalFunctionPrototype(
      masm, Context::BOOLEAN_FUNCTION_INDEX, r1);

  // Probe the stub cache for the value object.
  __ bind(&probe);
  StubCache::GenerateProbe(masm, flags, r1, r2, r3, no_reg);

  // Cache miss: Jump to runtime.
  __ bind(&miss);
  GenerateMiss(masm, argc);
}


static void GenerateNormalHelper(MacroAssembler* masm,
                                 int argc,
                                 bool is_global_object,
                                 Label* miss) {
  // Search dictionary - put result in register r1.
  GenerateDictionaryLoad(masm, miss, r0, r1);

  // Check that the value isn't a smi.
  __ tst(r1, Operand(kSmiTagMask));
  __ b(eq, miss);

  // Check that the value is a JSFunction.
  __ CompareObjectType(r1, r0, r0, JS_FUNCTION_TYPE);
  __ b(ne, miss);

  // Patch the receiver with the global proxy if necessary.
  if (is_global_object) {
    __ ldr(r0, MemOperand(sp, argc * kPointerSize));
    __ ldr(r0, FieldMemOperand(r0, GlobalObject::kGlobalReceiverOffset));
    __ str(r0, MemOperand(sp, argc * kPointerSize));
  }

  // Invoke the function.
  ParameterCount actual(argc);
  __ InvokeFunction(r1, actual, JUMP_FUNCTION);
}


void CallIC::GenerateNormal(MacroAssembler* masm, int argc) {
  // ----------- S t a t e -------------
  //  -- r2    : name
  //  -- lr    : return address
  // -----------------------------------
  Label miss, global_object, non_global_object;

  // Get the receiver of the function from the stack into r1.
  __ ldr(r1, MemOperand(sp, argc * kPointerSize));

  // Check that the receiver isn't a smi.
  __ tst(r1, Operand(kSmiTagMask));
  __ b(eq, &miss);

  // Check that the receiver is a valid JS object.  Put the map in r3.
  __ CompareObjectType(r1, r3, r0, FIRST_JS_OBJECT_TYPE);
  __ b(lt, &miss);

  // If this assert fails, we have to check upper bound too.
  ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);

  // Check for access to global object.
  __ cmp(r0, Operand(JS_GLOBAL_OBJECT_TYPE));
  __ b(eq, &global_object);
  __ cmp(r0, Operand(JS_BUILTINS_OBJECT_TYPE));
  __ b(ne, &non_global_object);

  // Accessing global object: Load and invoke.
  __ bind(&global_object);
  // Check that the global object does not require access checks.
  __ ldrb(r3, FieldMemOperand(r3, Map::kBitFieldOffset));
  __ tst(r3, Operand(1 << Map::kIsAccessCheckNeeded));
  __ b(ne, &miss);
  GenerateNormalHelper(masm, argc, true, &miss);

  // Accessing non-global object: Check for access to global proxy.
  Label global_proxy, invoke;
  __ bind(&non_global_object);
  __ cmp(r0, Operand(JS_GLOBAL_PROXY_TYPE));
  __ b(eq, &global_proxy);
  // Check that the non-global, non-global-proxy object does not
  // require access checks.
  __ ldrb(r3, FieldMemOperand(r3, Map::kBitFieldOffset));
  __ tst(r3, Operand(1 << Map::kIsAccessCheckNeeded));
  __ b(ne, &miss);
  __ bind(&invoke);
  GenerateNormalHelper(masm, argc, false, &miss);

  // Global object access: Check access rights.
  __ bind(&global_proxy);
  __ CheckAccessGlobalProxy(r1, r0, &miss);
  __ b(&invoke);

  // Cache miss: Jump to runtime.
  __ bind(&miss);
  GenerateMiss(masm, argc);
}


void CallIC::GenerateMiss(MacroAssembler* masm, int argc) {
  // ----------- S t a t e -------------
  //  -- r2    : name
  //  -- lr    : return address
  // -----------------------------------

  // Get the receiver of the function from the stack.
  __ ldr(r3, MemOperand(sp, argc * kPointerSize));

  __ EnterInternalFrame();

  // Push the receiver and the name of the function.
  __ stm(db_w, sp, r2.bit() | r3.bit());

  // Call the entry.
  __ mov(r0, Operand(2));
  __ mov(r1, Operand(ExternalReference(IC_Utility(kCallIC_Miss))));

  CEntryStub stub(1);
  __ CallStub(&stub);

  // Move result to r1 and leave the internal frame.
  __ mov(r1, Operand(r0));
  __ LeaveInternalFrame();

  // Check if the receiver is a global object of some sort.
  Label invoke, global;
  __ ldr(r2, MemOperand(sp, argc * kPointerSize));  // receiver
  __ tst(r2, Operand(kSmiTagMask));
  __ b(eq, &invoke);
  __ CompareObjectType(r2, r3, r3, JS_GLOBAL_OBJECT_TYPE);
  __ b(eq, &global);
  __ cmp(r3, Operand(JS_BUILTINS_OBJECT_TYPE));
  __ b(ne, &invoke);

  // Patch the receiver on the stack.
  __ bind(&global);
  __ ldr(r2, FieldMemOperand(r2, GlobalObject::kGlobalReceiverOffset));
  __ str(r2, MemOperand(sp, argc * kPointerSize));

  // Invoke the function.
  ParameterCount actual(argc);
  __ bind(&invoke);
  __ InvokeFunction(r1, actual, JUMP_FUNCTION);
}


// Defined in ic.cc.
Object* LoadIC_Miss(Arguments args);

void LoadIC::GenerateMegamorphic(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r2    : name
  //  -- lr    : return address
  //  -- [sp]  : receiver
  // -----------------------------------

  __ ldr(r0, MemOperand(sp, 0));
  // Probe the stub cache.
  Code::Flags flags = Code::ComputeFlags(Code::LOAD_IC,
                                         NOT_IN_LOOP,
                                         MONOMORPHIC);
  StubCache::GenerateProbe(masm, flags, r0, r2, r3, no_reg);

  // Cache miss: Jump to runtime.
  GenerateMiss(masm);
}


void LoadIC::GenerateNormal(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r2    : name
  //  -- lr    : return address
  //  -- [sp]  : receiver
  // -----------------------------------
  Label miss, probe, global;

  __ ldr(r0, MemOperand(sp, 0));
  // Check that the receiver isn't a smi.
  __ tst(r0, Operand(kSmiTagMask));
  __ b(eq, &miss);

  // Check that the receiver is a valid JS object.  Put the map in r3.
  __ CompareObjectType(r0, r3, r1, FIRST_JS_OBJECT_TYPE);
  __ b(lt, &miss);
  // If this assert fails, we have to check upper bound too.
  ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);

  // Check for access to global object (unlikely).
  __ cmp(r1, Operand(JS_GLOBAL_PROXY_TYPE));
  __ b(eq, &global);

  // Check for non-global object that requires access check.
  __ ldrb(r3, FieldMemOperand(r3, Map::kBitFieldOffset));
  __ tst(r3, Operand(1 << Map::kIsAccessCheckNeeded));
  __ b(ne, &miss);

  __ bind(&probe);
  GenerateDictionaryLoad(masm, &miss, r1, r0);
  __ Ret();

  // Global object access: Check access rights.
  __ bind(&global);
  __ CheckAccessGlobalProxy(r0, r1, &miss);
  __ b(&probe);

  // Cache miss: Restore receiver from stack and jump to runtime.
  __ bind(&miss);
  GenerateMiss(masm);
}


void LoadIC::GenerateMiss(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r2    : name
  //  -- lr    : return address
  //  -- [sp]  : receiver
  // -----------------------------------

  __ ldr(r3, MemOperand(sp, 0));
  __ stm(db_w, sp, r2.bit() | r3.bit());

  // Perform tail call to the entry.
  ExternalReference ref = ExternalReference(IC_Utility(kLoadIC_Miss));
  __ TailCallExternalReference(ref, 2, 1);
}


// TODO(181): Implement map patching once loop nesting is tracked on the
// ARM platform so we can generate inlined fast-case code loads in
// loops.
void LoadIC::ClearInlinedVersion(Address address) {}
bool LoadIC::PatchInlinedLoad(Address address, Object* map, int offset) {
  return false;
}

void KeyedLoadIC::ClearInlinedVersion(Address address) {}
bool KeyedLoadIC::PatchInlinedLoad(Address address, Object* map) {
  return false;
}

void KeyedStoreIC::ClearInlinedVersion(Address address) {}
void KeyedStoreIC::RestoreInlinedVersion(Address address) {}
bool KeyedStoreIC::PatchInlinedStore(Address address, Object* map) {
  return false;
}


Object* KeyedLoadIC_Miss(Arguments args);


void KeyedLoadIC::GenerateMiss(MacroAssembler* masm) {
  // ---------- S t a t e --------------
  //  -- lr     : return address
  //  -- sp[0]  : key
  //  -- sp[4]  : receiver
  // -----------------------------------

  __ ldm(ia, sp, r2.bit() | r3.bit());
  __ stm(db_w, sp, r2.bit() | r3.bit());

  ExternalReference ref = ExternalReference(IC_Utility(kKeyedLoadIC_Miss));
  __ TailCallExternalReference(ref, 2, 1);
}


void KeyedLoadIC::GenerateRuntimeGetProperty(MacroAssembler* masm) {
  // ---------- S t a t e --------------
  //  -- lr     : return address
  //  -- sp[0]  : key
  //  -- sp[4]  : receiver
  // -----------------------------------

  __ ldm(ia, sp, r2.bit() | r3.bit());
  __ stm(db_w, sp, r2.bit() | r3.bit());

  __ TailCallRuntime(Runtime::kGetProperty, 2, 1);
}


void KeyedLoadIC::GenerateGeneric(MacroAssembler* masm) {
  // ---------- S t a t e --------------
  //  -- lr     : return address
  //  -- sp[0]  : key
  //  -- sp[4]  : receiver
  // -----------------------------------
  Label slow, fast, check_pixel_array;

  // Get the key and receiver object from the stack.
  __ ldm(ia, sp, r0.bit() | r1.bit());

  // Check that the object isn't a smi.
  __ BranchOnSmi(r1, &slow);
  // Get the map of the receiver.
  __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
  // Check bit field.
  __ ldrb(r3, FieldMemOperand(r2, Map::kBitFieldOffset));
  __ tst(r3, Operand(kSlowCaseBitFieldMask));
  __ b(ne, &slow);
  // Check that the object is some kind of JS object EXCEPT JS Value type.
  // In the case that the object is a value-wrapper object,
  // we enter the runtime system to make sure that indexing into string
  // objects work as intended.
  ASSERT(JS_OBJECT_TYPE > JS_VALUE_TYPE);
  __ ldrb(r2, FieldMemOperand(r2, Map::kInstanceTypeOffset));
  __ cmp(r2, Operand(JS_OBJECT_TYPE));
  __ b(lt, &slow);

  // Check that the key is a smi.
  __ BranchOnNotSmi(r0, &slow);
  __ mov(r0, Operand(r0, ASR, kSmiTagSize));

  // Get the elements array of the object.
  __ ldr(r1, FieldMemOperand(r1, JSObject::kElementsOffset));
  // Check that the object is in fast mode (not dictionary).
  __ ldr(r3, FieldMemOperand(r1, HeapObject::kMapOffset));
  __ LoadRoot(ip, Heap::kFixedArrayMapRootIndex);
  __ cmp(r3, ip);
  __ b(ne, &slow);
  // Check that the key (index) is within bounds.
  __ ldr(r3, FieldMemOperand(r1, Array::kLengthOffset));
  __ cmp(r0, Operand(r3));
  __ b(lo, &fast);

  // Check whether the elements is a pixel array.
  __ bind(&check_pixel_array);
  __ LoadRoot(ip, Heap::kPixelArrayMapRootIndex);
  __ cmp(r3, ip);
  __ b(ne, &slow);
  __ ldr(ip, FieldMemOperand(r1, PixelArray::kLengthOffset));
  __ cmp(r0, ip);
  __ b(hs, &slow);
  __ ldr(ip, FieldMemOperand(r1, PixelArray::kExternalPointerOffset));
  __ ldrb(r0, MemOperand(ip, r0));
  __ mov(r0, Operand(r0, LSL, kSmiTagSize));  // Tag result as smi.
  __ Ret();

  // Slow case: Push extra copies of the arguments (2).
  __ bind(&slow);
  __ IncrementCounter(&Counters::keyed_load_generic_slow, 1, r0, r1);
  GenerateRuntimeGetProperty(masm);

  // Fast case: Do the load.
  __ bind(&fast);
  __ add(r3, r1, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
  __ ldr(r0, MemOperand(r3, r0, LSL, kPointerSizeLog2));
  __ LoadRoot(ip, Heap::kTheHoleValueRootIndex);
  __ cmp(r0, ip);
  // In case the loaded value is the_hole we have to consult GetProperty
  // to ensure the prototype chain is searched.
  __ b(eq, &slow);

  __ Ret();
}


void KeyedLoadIC::GenerateString(MacroAssembler* masm) {
  // ---------- S t a t e --------------
  //  -- lr     : return address
  //  -- sp[0]  : key
  //  -- sp[4]  : receiver
  // -----------------------------------

  GenerateGeneric(masm);
}


// Convert unsigned integer with specified number of leading zeroes in binary
// representation to IEEE 754 double.
// Integer to convert is passed in register hiword.
// Resulting double is returned in registers hiword:loword.
// This functions does not work correctly for 0.
static void GenerateUInt2Double(MacroAssembler* masm,
                                Register hiword,
                                Register loword,
                                Register scratch,
                                int leading_zeroes) {
  const int meaningful_bits = kBitsPerInt - leading_zeroes - 1;
  const int biased_exponent = HeapNumber::kExponentBias + meaningful_bits;

  const int mantissa_shift_for_hi_word =
      meaningful_bits - HeapNumber::kMantissaBitsInTopWord;

  const int mantissa_shift_for_lo_word =
      kBitsPerInt - mantissa_shift_for_hi_word;

  __ mov(scratch, Operand(biased_exponent << HeapNumber::kExponentShift));
  if (mantissa_shift_for_hi_word > 0) {
    __ mov(loword, Operand(hiword, LSL, mantissa_shift_for_lo_word));
    __ orr(hiword, scratch, Operand(hiword, LSR, mantissa_shift_for_hi_word));
  } else {
    __ mov(loword, Operand(0));
    __ orr(hiword, scratch, Operand(hiword, LSL, mantissa_shift_for_hi_word));
  }

  // If least significant bit of biased exponent was not 1 it was corrupted
  // by most significant bit of mantissa so we should fix that.
  if (!(biased_exponent & 1)) {
    __ bic(hiword, hiword, Operand(1 << HeapNumber::kExponentShift));
  }
}


void KeyedLoadIC::GenerateExternalArray(MacroAssembler* masm,
                                        ExternalArrayType array_type) {
  // ---------- S t a t e --------------
  //  -- lr     : return address
  //  -- sp[0]  : key
  //  -- sp[4]  : receiver
  // -----------------------------------
  Label slow, failed_allocation;

  // Get the key and receiver object from the stack.
  __ ldm(ia, sp, r0.bit() | r1.bit());

  // r0: key
  // r1: receiver object

  // Check that the object isn't a smi
  __ BranchOnSmi(r1, &slow);

  // Check that the key is a smi.
  __ BranchOnNotSmi(r0, &slow);

  // Check that the object is a JS object. Load map into r2.
  __ CompareObjectType(r1, r2, r3, FIRST_JS_OBJECT_TYPE);
  __ b(lt, &slow);

  // Check that the receiver does not require access checks.  We need
  // to check this explicitly since this generic stub does not perform
  // map checks.
  __ ldrb(r3, FieldMemOperand(r2, Map::kBitFieldOffset));
  __ tst(r3, Operand(1 << Map::kIsAccessCheckNeeded));
  __ b(ne, &slow);

  // Check that the elements array is the appropriate type of
  // ExternalArray.
  // r0: index (as a smi)
  // r1: JSObject
  __ ldr(r1, FieldMemOperand(r1, JSObject::kElementsOffset));
  __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
  __ LoadRoot(ip, Heap::RootIndexForExternalArrayType(array_type));
  __ cmp(r2, ip);
  __ b(ne, &slow);

  // Check that the index is in range.
  __ ldr(ip, FieldMemOperand(r1, ExternalArray::kLengthOffset));
  __ cmp(r1, Operand(r0, ASR, kSmiTagSize));
  // Unsigned comparison catches both negative and too-large values.
  __ b(lo, &slow);

  // r0: index (smi)
  // r1: elements array
  __ ldr(r1, FieldMemOperand(r1, ExternalArray::kExternalPointerOffset));
  // r1: base pointer of external storage

  // We are not untagging smi key and instead work with it
  // as if it was premultiplied by 2.
  ASSERT((kSmiTag == 0) && (kSmiTagSize == 1));

  switch (array_type) {
    case kExternalByteArray:
      __ ldrsb(r0, MemOperand(r1, r0, LSR, 1));
      break;
    case kExternalUnsignedByteArray:
      __ ldrb(r0, MemOperand(r1, r0, LSR, 1));
      break;
    case kExternalShortArray:
      __ ldrsh(r0, MemOperand(r1, r0, LSL, 0));
      break;
    case kExternalUnsignedShortArray:
      __ ldrh(r0, MemOperand(r1, r0, LSL, 0));
      break;
    case kExternalIntArray:
    case kExternalUnsignedIntArray:
      __ ldr(r0, MemOperand(r1, r0, LSL, 1));
      break;
    case kExternalFloatArray:
      if (CpuFeatures::IsSupported(VFP3)) {
        CpuFeatures::Scope scope(VFP3);
        __ add(r0, r1, Operand(r0, LSL, 1));
        __ vldr(s0, r0, 0);
      } else {
        __ ldr(r0, MemOperand(r1, r0, LSL, 1));
      }
      break;
    default:
      UNREACHABLE();
      break;
  }

  // For integer array types:
  // r0: value
  // For floating-point array type
  // s0: value (if VFP3 is supported)
  // r0: value (if VFP3 is not supported)

  if (array_type == kExternalIntArray) {
    // For the Int and UnsignedInt array types, we need to see whether
    // the value can be represented in a Smi. If not, we need to convert
    // it to a HeapNumber.
    Label box_int;
    __ cmp(r0, Operand(0xC0000000));
    __ b(mi, &box_int);
    __ mov(r0, Operand(r0, LSL, kSmiTagSize));
    __ Ret();

    __ bind(&box_int);

    __ mov(r1, r0);
    // Allocate a HeapNumber for the int and perform int-to-double
    // conversion.
    __ AllocateHeapNumber(r0, r3, r4, &slow);

    if (CpuFeatures::IsSupported(VFP3)) {
      CpuFeatures::Scope scope(VFP3);
      __ vmov(s0, r1);
      __ vcvt_f64_s32(d0, s0);
      __ sub(r1, r0, Operand(kHeapObjectTag));
      __ vstr(d0, r1, HeapNumber::kValueOffset);
      __ Ret();
    } else {
      WriteInt32ToHeapNumberStub stub(r1, r0, r3);
      __ TailCallStub(&stub);
    }
  } else if (array_type == kExternalUnsignedIntArray) {
    // The test is different for unsigned int values. Since we need
    // the value to be in the range of a positive smi, we can't
    // handle either of the top two bits being set in the value.
    if (CpuFeatures::IsSupported(VFP3)) {
      CpuFeatures::Scope scope(VFP3);
      Label box_int, done;
      __ tst(r0, Operand(0xC0000000));
      __ b(ne, &box_int);

      __ mov(r0, Operand(r0, LSL, kSmiTagSize));
      __ Ret();

      __ bind(&box_int);
      __ vmov(s0, r0);
      __ AllocateHeapNumber(r0, r1, r2, &slow);

      __ vcvt_f64_u32(d0, s0);
      __ sub(r1, r0, Operand(kHeapObjectTag));
      __ vstr(d0, r1, HeapNumber::kValueOffset);
      __ Ret();
    } else {
      // Check whether unsigned integer fits into smi.
      Label box_int_0, box_int_1, done;
      __ tst(r0, Operand(0x80000000));
      __ b(ne, &box_int_0);
      __ tst(r0, Operand(0x40000000));
      __ b(ne, &box_int_1);

      // Tag integer as smi and return it.
      __ mov(r0, Operand(r0, LSL, kSmiTagSize));
      __ Ret();

      __ bind(&box_int_0);
      // Integer does not have leading zeros.
      GenerateUInt2Double(masm, r0, r1, r2, 0);
      __ b(&done);

      __ bind(&box_int_1);
      // Integer has one leading zero.
      GenerateUInt2Double(masm, r0, r1, r2, 1);

      __ bind(&done);
      // Integer was converted to double in registers r0:r1.
      // Wrap it into a HeapNumber.
      __ AllocateHeapNumber(r2, r3, r5, &slow);

      __ str(r0, FieldMemOperand(r2, HeapNumber::kExponentOffset));
      __ str(r1, FieldMemOperand(r2, HeapNumber::kMantissaOffset));

      __ mov(r0, r2);

      __ Ret();
    }
  } else if (array_type == kExternalFloatArray) {
    // For the floating-point array type, we need to always allocate a
    // HeapNumber.
    if (CpuFeatures::IsSupported(VFP3)) {
      CpuFeatures::Scope scope(VFP3);
      __ AllocateHeapNumber(r0, r1, r2, &slow);
      __ vcvt_f64_f32(d0, s0);
      __ sub(r1, r0, Operand(kHeapObjectTag));
      __ vstr(d0, r1, HeapNumber::kValueOffset);
      __ Ret();
    } else {
      __ AllocateHeapNumber(r3, r1, r2, &slow);
      // VFP is not available, do manual single to double conversion.

      // r0: floating point value (binary32)

      // Extract mantissa to r1.
      __ and_(r1, r0, Operand(kBinary32MantissaMask));

      // Extract exponent to r2.
      __ mov(r2, Operand(r0, LSR, kBinary32MantissaBits));
      __ and_(r2, r2, Operand(kBinary32ExponentMask >> kBinary32MantissaBits));

      Label exponent_rebiased;
      __ teq(r2, Operand(0x00));
      __ b(eq, &exponent_rebiased);

      __ teq(r2, Operand(0xff));
      __ mov(r2, Operand(0x7ff), LeaveCC, eq);
      __ b(eq, &exponent_rebiased);

      // Rebias exponent.
      __ add(r2,
             r2,
             Operand(-kBinary32ExponentBias + HeapNumber::kExponentBias));

      __ bind(&exponent_rebiased);
      __ and_(r0, r0, Operand(kBinary32SignMask));
      __ orr(r0, r0, Operand(r2, LSL, HeapNumber::kMantissaBitsInTopWord));

      // Shift mantissa.
      static const int kMantissaShiftForHiWord =
          kBinary32MantissaBits - HeapNumber::kMantissaBitsInTopWord;

      static const int kMantissaShiftForLoWord =
          kBitsPerInt - kMantissaShiftForHiWord;

      __ orr(r0, r0, Operand(r1, LSR, kMantissaShiftForHiWord));
      __ mov(r1, Operand(r1, LSL, kMantissaShiftForLoWord));

      __ str(r0, FieldMemOperand(r3, HeapNumber::kExponentOffset));
      __ str(r1, FieldMemOperand(r3, HeapNumber::kMantissaOffset));
      __ mov(r0, r3);
      __ Ret();
    }

  } else {
    __ mov(r0, Operand(r0, LSL, kSmiTagSize));
    __ Ret();
  }

  // Slow case: Load name and receiver from stack and jump to runtime.
  __ bind(&slow);
  __ IncrementCounter(&Counters::keyed_load_external_array_slow, 1, r0, r1);
  GenerateRuntimeGetProperty(masm);
}


void KeyedLoadIC::GenerateIndexedInterceptor(MacroAssembler* masm) {
  // ---------- S t a t e --------------
  //  -- lr     : return address
  //  -- sp[0]  : key
  //  -- sp[4]  : receiver
  // -----------------------------------
  Label slow;

  // Get the key and receiver object from the stack.
  __ ldm(ia, sp, r0.bit() | r1.bit());

  // Check that the receiver isn't a smi.
  __ BranchOnSmi(r1, &slow);

  // Check that the key is a smi.
  __ BranchOnNotSmi(r0, &slow);

  // Get the map of the receiver.
  __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));

  // Check that it has indexed interceptor and access checks
  // are not enabled for this object.
  __ ldrb(r3, FieldMemOperand(r2, Map::kBitFieldOffset));
  __ and_(r3, r3, Operand(kSlowCaseBitFieldMask));
  __ cmp(r3, Operand(1 << Map::kHasIndexedInterceptor));
  __ b(ne, &slow);

  // Everything is fine, call runtime.
  __ push(r1);  // receiver
  __ push(r0);  // key

  // Perform tail call to the entry.
  __ TailCallExternalReference(ExternalReference(
        IC_Utility(kKeyedLoadPropertyWithInterceptor)), 2, 1);

  __ bind(&slow);
  GenerateMiss(masm);
}


void KeyedStoreIC::GenerateMiss(MacroAssembler* masm) {
  // ---------- S t a t e --------------
  //  -- r0     : value
  //  -- lr     : return address
  //  -- sp[0]  : key
  //  -- sp[1]  : receiver
  // -----------------------------------

  __ ldm(ia, sp, r2.bit() | r3.bit());
  __ stm(db_w, sp, r0.bit() | r2.bit() | r3.bit());

  ExternalReference ref = ExternalReference(IC_Utility(kKeyedStoreIC_Miss));
  __ TailCallExternalReference(ref, 3, 1);
}


void KeyedStoreIC::GenerateRuntimeSetProperty(MacroAssembler* masm) {
  // ---------- S t a t e --------------
  //  -- r0     : value
  //  -- lr     : return address
  //  -- sp[0]  : key
  //  -- sp[1]  : receiver
  // -----------------------------------
  __ ldm(ia, sp, r1.bit() | r3.bit());  // r0 == value, r1 == key, r3 == object
  __ stm(db_w, sp, r0.bit() | r1.bit() | r3.bit());

  __ TailCallRuntime(Runtime::kSetProperty, 3, 1);
}


void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm) {
  // ---------- S t a t e --------------
  //  -- r0     : value
  //  -- lr     : return address
  //  -- sp[0]  : key
  //  -- sp[1]  : receiver
  // -----------------------------------
  Label slow, fast, array, extra, exit, check_pixel_array;

  // Get the key and the object from the stack.
  __ ldm(ia, sp, r1.bit() | r3.bit());  // r1 = key, r3 = receiver
  // Check that the key is a smi.
  __ tst(r1, Operand(kSmiTagMask));
  __ b(ne, &slow);
  // Check that the object isn't a smi.
  __ tst(r3, Operand(kSmiTagMask));
  __ b(eq, &slow);
  // Get the map of the object.
  __ ldr(r2, FieldMemOperand(r3, HeapObject::kMapOffset));
  // Check that the receiver does not require access checks.  We need
  // to do this because this generic stub does not perform map checks.
  __ ldrb(ip, FieldMemOperand(r2, Map::kBitFieldOffset));
  __ tst(ip, Operand(1 << Map::kIsAccessCheckNeeded));
  __ b(ne, &slow);
  // Check if the object is a JS array or not.
  __ ldrb(r2, FieldMemOperand(r2, Map::kInstanceTypeOffset));
  __ cmp(r2, Operand(JS_ARRAY_TYPE));
  // r1 == key.
  __ b(eq, &array);
  // Check that the object is some kind of JS object.
  __ cmp(r2, Operand(FIRST_JS_OBJECT_TYPE));
  __ b(lt, &slow);


  // Object case: Check key against length in the elements array.
  __ ldr(r3, FieldMemOperand(r3, JSObject::kElementsOffset));
  // Check that the object is in fast mode (not dictionary).
  __ ldr(r2, FieldMemOperand(r3, HeapObject::kMapOffset));
  __ LoadRoot(ip, Heap::kFixedArrayMapRootIndex);
  __ cmp(r2, ip);
  __ b(ne, &check_pixel_array);
  // Untag the key (for checking against untagged length in the fixed array).
  __ mov(r1, Operand(r1, ASR, kSmiTagSize));
  // Compute address to store into and check array bounds.
  __ add(r2, r3, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
  __ add(r2, r2, Operand(r1, LSL, kPointerSizeLog2));
  __ ldr(ip, FieldMemOperand(r3, FixedArray::kLengthOffset));
  __ cmp(r1, Operand(ip));
  __ b(lo, &fast);


  // Slow case:
  __ bind(&slow);
  GenerateRuntimeSetProperty(masm);

  // Check whether the elements is a pixel array.
  // r0: value
  // r1: index (as a smi), zero-extended.
  // r3: elements array
  __ bind(&check_pixel_array);
  __ LoadRoot(ip, Heap::kPixelArrayMapRootIndex);
  __ cmp(r2, ip);
  __ b(ne, &slow);
  // Check that the value is a smi. If a conversion is needed call into the
  // runtime to convert and clamp.
  __ BranchOnNotSmi(r0, &slow);
  __ mov(r1, Operand(r1, ASR, kSmiTagSize));  // Untag the key.
  __ ldr(ip, FieldMemOperand(r3, PixelArray::kLengthOffset));
  __ cmp(r1, Operand(ip));
  __ b(hs, &slow);
  __ mov(r4, r0);  // Save the value.
  __ mov(r0, Operand(r0, ASR, kSmiTagSize));  // Untag the value.
  {  // Clamp the value to [0..255].
    Label done;
    __ tst(r0, Operand(0xFFFFFF00));
    __ b(eq, &done);
    __ mov(r0, Operand(0), LeaveCC, mi);  // 0 if negative.
    __ mov(r0, Operand(255), LeaveCC, pl);  // 255 if positive.
    __ bind(&done);
  }
  __ ldr(r2, FieldMemOperand(r3, PixelArray::kExternalPointerOffset));
  __ strb(r0, MemOperand(r2, r1));
  __ mov(r0, Operand(r4));  // Return the original value.
  __ Ret();


  // Extra capacity case: Check if there is extra capacity to
  // perform the store and update the length. Used for adding one
  // element to the array by writing to array[array.length].
  // r0 == value, r1 == key, r2 == elements, r3 == object
  __ bind(&extra);
  __ b(ne, &slow);  // do not leave holes in the array
  __ mov(r1, Operand(r1, ASR, kSmiTagSize));  // untag
  __ ldr(ip, FieldMemOperand(r2, Array::kLengthOffset));
  __ cmp(r1, Operand(ip));
  __ b(hs, &slow);
  __ mov(r1, Operand(r1, LSL, kSmiTagSize));  // restore tag
  __ add(r1, r1, Operand(1 << kSmiTagSize));  // and increment
  __ str(r1, FieldMemOperand(r3, JSArray::kLengthOffset));
  __ mov(r3, Operand(r2));
  // NOTE: Computing the address to store into must take the fact
  // that the key has been incremented into account.
  int displacement = FixedArray::kHeaderSize - kHeapObjectTag -
      ((1 << kSmiTagSize) * 2);
  __ add(r2, r2, Operand(displacement));
  __ add(r2, r2, Operand(r1, LSL, kPointerSizeLog2 - kSmiTagSize));
  __ b(&fast);


  // Array case: Get the length and the elements array from the JS
  // array. Check that the array is in fast mode; if it is the
  // length is always a smi.
  // r0 == value, r3 == object
  __ bind(&array);
  __ ldr(r2, FieldMemOperand(r3, JSObject::kElementsOffset));
  __ ldr(r1, FieldMemOperand(r2, HeapObject::kMapOffset));
  __ LoadRoot(ip, Heap::kFixedArrayMapRootIndex);
  __ cmp(r1, ip);
  __ b(ne, &slow);

  // Check the key against the length in the array, compute the
  // address to store into and fall through to fast case.
  __ ldr(r1, MemOperand(sp));  // restore key
  // r0 == value, r1 == key, r2 == elements, r3 == object.
  __ ldr(ip, FieldMemOperand(r3, JSArray::kLengthOffset));
  __ cmp(r1, Operand(ip));
  __ b(hs, &extra);
  __ mov(r3, Operand(r2));
  __ add(r2, r2, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
  __ add(r2, r2, Operand(r1, LSL, kPointerSizeLog2 - kSmiTagSize));


  // Fast case: Do the store.
  // r0 == value, r2 == address to store into, r3 == elements
  __ bind(&fast);
  __ str(r0, MemOperand(r2));
  // Skip write barrier if the written value is a smi.
  __ tst(r0, Operand(kSmiTagMask));
  __ b(eq, &exit);
  // Update write barrier for the elements array address.
  __ sub(r1, r2, Operand(r3));
  __ RecordWrite(r3, r1, r2);

  __ bind(&exit);
  __ Ret();
}


// Convert int passed in register ival to IEE 754 single precision
// floating point value and store it into register fval.
// If VFP3 is available use it for conversion.
static void ConvertIntToFloat(MacroAssembler* masm,
                              Register ival,
                              Register fval,
                              Register scratch1,
                              Register scratch2) {
  if (CpuFeatures::IsSupported(VFP3)) {
    CpuFeatures::Scope scope(VFP3);
    __ vmov(s0, ival);
    __ vcvt_f32_s32(s0, s0);
    __ vmov(fval, s0);
  } else {
    Label not_special, done;
    // 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.
    ASSERT(kBinary32SignMask == 0x80000000u);

    __ and_(fval, ival, Operand(kBinary32SignMask), SetCC);
    // Negate value if it is negative.
    __ rsb(ival, ival, Operand(0), LeaveCC, ne);

    // We have -1, 0 or 1, which we treat specially. Register ival 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).
    __ cmp(ival, Operand(1));
    __ b(gt, &not_special);

    // For 1 or -1 we need to or in the 0 exponent (biased).
    static const uint32_t exponent_word_for_1 =
        kBinary32ExponentBias << kBinary32ExponentShift;

    __ orr(fval, fval, Operand(exponent_word_for_1), LeaveCC, eq);
    __ b(&done);

    __ bind(&not_special);
    // Count leading zeros.
    // Gets the wrong answer for 0, but we already checked for that case above.
    Register zeros = scratch2;
    __ CountLeadingZeros(ival, scratch1, zeros);

    // Compute exponent and or it into the exponent register.
    __ rsb(scratch1,
           zeros,
           Operand((kBitsPerInt - 1) + kBinary32ExponentBias));

    __ orr(fval,
           fval,
           Operand(scratch1, LSL, kBinary32ExponentShift));

    // Shift up the source chopping the top bit off.
    __ add(zeros, zeros, Operand(1));
    // This wouldn't work for 1 and -1 as the shift would be 32 which means 0.
    __ mov(ival, Operand(ival, LSL, zeros));
    // And the top (top 20 bits).
    __ orr(fval,
           fval,
           Operand(ival, LSR, kBitsPerInt - kBinary32MantissaBits));

    __ bind(&done);
  }
}


static bool IsElementTypeSigned(ExternalArrayType array_type) {
  switch (array_type) {
    case kExternalByteArray:
    case kExternalShortArray:
    case kExternalIntArray:
      return true;

    case kExternalUnsignedByteArray:
    case kExternalUnsignedShortArray:
    case kExternalUnsignedIntArray:
      return false;

    default:
      UNREACHABLE();
      return false;
  }
}


void KeyedStoreIC::GenerateExternalArray(MacroAssembler* masm,
                                         ExternalArrayType array_type) {
  // ---------- S t a t e --------------
  //  -- r0     : value
  //  -- lr     : return address
  //  -- sp[0]  : key
  //  -- sp[1]  : receiver
  // -----------------------------------
  Label slow, check_heap_number;

  // Get the key and the object from the stack.
  __ ldm(ia, sp, r1.bit() | r2.bit());  // r1 = key, r2 = receiver

  // Check that the object isn't a smi.
  __ BranchOnSmi(r2, &slow);

  // Check that the object is a JS object. Load map into r3
  __ CompareObjectType(r2, r3, r4, FIRST_JS_OBJECT_TYPE);
  __ b(le, &slow);

  // Check that the receiver does not require access checks.  We need
  // to do this because this generic stub does not perform map checks.
  __ ldrb(ip, FieldMemOperand(r3, Map::kBitFieldOffset));
  __ tst(ip, Operand(1 << Map::kIsAccessCheckNeeded));
  __ b(ne, &slow);

  // Check that the key is a smi.
  __ BranchOnNotSmi(r1, &slow);

  // Check that the elements array is the appropriate type of
  // ExternalArray.
  // r0: value
  // r1: index (smi)
  // r2: object
  __ ldr(r2, FieldMemOperand(r2, JSObject::kElementsOffset));
  __ ldr(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
  __ LoadRoot(ip, Heap::RootIndexForExternalArrayType(array_type));
  __ cmp(r3, ip);
  __ b(ne, &slow);

  // Check that the index is in range.
  __ mov(r1, Operand(r1, ASR, kSmiTagSize));  // Untag the index.
  __ ldr(ip, FieldMemOperand(r2, ExternalArray::kLengthOffset));
  __ cmp(r1, ip);
  // Unsigned comparison catches both negative and too-large values.
  __ b(hs, &slow);

  // Handle both smis and HeapNumbers in the fast path. Go to the
  // runtime for all other kinds of values.
  // r0: value
  // r1: index (integer)
  // r2: array
  __ BranchOnNotSmi(r0, &check_heap_number);
  __ mov(r3, Operand(r0, ASR, kSmiTagSize));  // Untag the value.
  __ ldr(r2, FieldMemOperand(r2, ExternalArray::kExternalPointerOffset));

  // r1: index (integer)
  // r2: base pointer of external storage
  // r3: value (integer)
  switch (array_type) {
    case kExternalByteArray:
    case kExternalUnsignedByteArray:
      __ strb(r3, MemOperand(r2, r1, LSL, 0));
      break;
    case kExternalShortArray:
    case kExternalUnsignedShortArray:
      __ strh(r3, MemOperand(r2, r1, LSL, 1));
      break;
    case kExternalIntArray:
    case kExternalUnsignedIntArray:
      __ str(r3, MemOperand(r2, r1, LSL, 2));
      break;
    case kExternalFloatArray:
      // Need to perform int-to-float conversion.
      ConvertIntToFloat(masm, r3, r4, r5, r6);
      __ str(r4, MemOperand(r2, r1, LSL, 2));
      break;
    default:
      UNREACHABLE();
      break;
  }

  // r0: value
  __ Ret();


  // r0: value
  // r1: index (integer)
  // r2: external array object
  __ bind(&check_heap_number);
  __ CompareObjectType(r0, r3, r4, HEAP_NUMBER_TYPE);
  __ b(ne, &slow);

  __ ldr(r2, FieldMemOperand(r2, ExternalArray::kExternalPointerOffset));

  // The WebGL specification leaves the behavior of storing NaN and
  // +/-Infinity into integer arrays basically undefined. For more
  // reproducible behavior, convert these to zero.
  if (CpuFeatures::IsSupported(VFP3)) {
    CpuFeatures::Scope scope(VFP3);

    // vldr requires offset to be a multiple of 4 so we can not
    // include -kHeapObjectTag into it.
    __ sub(r3, r0, Operand(kHeapObjectTag));
    __ vldr(d0, r3, HeapNumber::kValueOffset);

    if (array_type == kExternalFloatArray) {
      __ vcvt_f32_f64(s0, d0);
      __ vmov(r3, s0);
      __ str(r3, MemOperand(r2, r1, LSL, 2));
    } else {
      Label done;

      // Need to perform float-to-int conversion.
      // Test for NaN.
      __ vcmp(d0, d0);
      // Move vector status bits to normal status bits.
      __ vmrs(v8::internal::pc);
      __ mov(r3, Operand(0), LeaveCC, vs);  // NaN converts to 0
      __ b(vs, &done);

      // Test whether exponent equal to 0x7FF (infinity or NaN)
      __ vmov(r4, r3, d0);
      __ mov(r5, Operand(0x7FF00000));
      __ and_(r3, r3, Operand(r5));
      __ teq(r3, Operand(r5));
      __ mov(r3, Operand(0), LeaveCC, eq);

      // Not infinity or NaN simply convert to int
      if (IsElementTypeSigned(array_type)) {
        __ vcvt_s32_f64(s0, d0, ne);
      } else {
        __ vcvt_u32_f64(s0, d0, ne);
      }

      __ vmov(r3, s0, ne);

      __ bind(&done);
      switch (array_type) {
        case kExternalByteArray:
        case kExternalUnsignedByteArray:
          __ strb(r3, MemOperand(r2, r1, LSL, 0));
          break;
        case kExternalShortArray:
        case kExternalUnsignedShortArray:
          __ strh(r3, MemOperand(r2, r1, LSL, 1));
          break;
        case kExternalIntArray:
        case kExternalUnsignedIntArray:
          __ str(r3, MemOperand(r2, r1, LSL, 2));
          break;
        default:
          UNREACHABLE();
          break;
      }
    }

    // r0: original value
    __ Ret();
  } else {
    // VFP3 is not available do manual conversions
    __ ldr(r3, FieldMemOperand(r0, HeapNumber::kExponentOffset));
    __ ldr(r4, FieldMemOperand(r0, HeapNumber::kMantissaOffset));

    if (array_type == kExternalFloatArray) {
      Label done, nan_or_infinity_or_zero;
      static const int kMantissaInHiWordShift =
          kBinary32MantissaBits - HeapNumber::kMantissaBitsInTopWord;

      static const int kMantissaInLoWordShift =
          kBitsPerInt - kMantissaInHiWordShift;

      // Test for all special exponent values: zeros, subnormal numbers, NaNs
      // and infinities. All these should be converted to 0.
      __ mov(r5, Operand(HeapNumber::kExponentMask));
      __ and_(r6, r3, Operand(r5), SetCC);
      __ b(eq, &nan_or_infinity_or_zero);

      __ teq(r6, Operand(r5));
      __ mov(r6, Operand(kBinary32ExponentMask), LeaveCC, eq);
      __ b(eq, &nan_or_infinity_or_zero);

      // Rebias exponent.
      __ mov(r6, Operand(r6, LSR, HeapNumber::kExponentShift));
      __ add(r6,
             r6,
             Operand(kBinary32ExponentBias - HeapNumber::kExponentBias));

      __ cmp(r6, Operand(kBinary32MaxExponent));
      __ and_(r3, r3, Operand(HeapNumber::kSignMask), LeaveCC, gt);
      __ orr(r3, r3, Operand(kBinary32ExponentMask), LeaveCC, gt);
      __ b(gt, &done);

      __ cmp(r6, Operand(kBinary32MinExponent));
      __ and_(r3, r3, Operand(HeapNumber::kSignMask), LeaveCC, lt);
      __ b(lt, &done);

      __ and_(r7, r3, Operand(HeapNumber::kSignMask));
      __ and_(r3, r3, Operand(HeapNumber::kMantissaMask));
      __ orr(r7, r7, Operand(r3, LSL, kMantissaInHiWordShift));
      __ orr(r7, r7, Operand(r4, LSR, kMantissaInLoWordShift));
      __ orr(r3, r7, Operand(r6, LSL, kBinary32ExponentShift));

      __ bind(&done);
      __ str(r3, MemOperand(r2, r1, LSL, 2));
      __ Ret();

      __ bind(&nan_or_infinity_or_zero);
      __ and_(r7, r3, Operand(HeapNumber::kSignMask));
      __ and_(r3, r3, Operand(HeapNumber::kMantissaMask));
      __ orr(r6, r6, r7);
      __ orr(r6, r6, Operand(r3, LSL, kMantissaInHiWordShift));
      __ orr(r3, r6, Operand(r4, LSR, kMantissaInLoWordShift));
      __ b(&done);
    } else {
      bool is_signed_type  = IsElementTypeSigned(array_type);
      int meaningfull_bits = is_signed_type ? (kBitsPerInt - 1) : kBitsPerInt;
      int32_t min_value    = is_signed_type ? 0x80000000 : 0x00000000;

      Label done, sign;

      // Test for all special exponent values: zeros, subnormal numbers, NaNs
      // and infinities. All these should be converted to 0.
      __ mov(r5, Operand(HeapNumber::kExponentMask));
      __ and_(r6, r3, Operand(r5), SetCC);
      __ mov(r3, Operand(0), LeaveCC, eq);
      __ b(eq, &done);

      __ teq(r6, Operand(r5));
      __ mov(r3, Operand(0), LeaveCC, eq);
      __ b(eq, &done);

      // Unbias exponent.
      __ mov(r6, Operand(r6, LSR, HeapNumber::kExponentShift));
      __ sub(r6, r6, Operand(HeapNumber::kExponentBias), SetCC);
      // If exponent is negative than result is 0.
      __ mov(r3, Operand(0), LeaveCC, mi);
      __ b(mi, &done);

      // If exponent is too big than result is minimal value
      __ cmp(r6, Operand(meaningfull_bits - 1));
      __ mov(r3, Operand(min_value), LeaveCC, ge);
      __ b(ge, &done);

      __ and_(r5, r3, Operand(HeapNumber::kSignMask), SetCC);
      __ and_(r3, r3, Operand(HeapNumber::kMantissaMask));
      __ orr(r3, r3, Operand(1u << HeapNumber::kMantissaBitsInTopWord));

      __ rsb(r6, r6, Operand(HeapNumber::kMantissaBitsInTopWord), SetCC);
      __ mov(r3, Operand(r3, LSR, r6), LeaveCC, pl);
      __ b(pl, &sign);

      __ rsb(r6, r6, Operand(0));
      __ mov(r3, Operand(r3, LSL, r6));
      __ rsb(r6, r6, Operand(meaningfull_bits));
      __ orr(r3, r3, Operand(r4, LSR, r6));

      __ bind(&sign);
      __ teq(r5, Operand(0));
      __ rsb(r3, r3, Operand(0), LeaveCC, ne);

      __ bind(&done);
      switch (array_type) {
        case kExternalByteArray:
        case kExternalUnsignedByteArray:
          __ strb(r3, MemOperand(r2, r1, LSL, 0));
          break;
        case kExternalShortArray:
        case kExternalUnsignedShortArray:
          __ strh(r3, MemOperand(r2, r1, LSL, 1));
          break;
        case kExternalIntArray:
        case kExternalUnsignedIntArray:
          __ str(r3, MemOperand(r2, r1, LSL, 2));
          break;
        default:
          UNREACHABLE();
          break;
      }
    }
  }

  // Slow case: call runtime.
  __ bind(&slow);
  GenerateRuntimeSetProperty(masm);
}


void StoreIC::GenerateMegamorphic(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r0    : value
  //  -- r1    : receiver
  //  -- r2    : name
  //  -- lr    : return address
  // -----------------------------------

  // Get the receiver from the stack and probe the stub cache.
  Code::Flags flags = Code::ComputeFlags(Code::STORE_IC,
                                         NOT_IN_LOOP,
                                         MONOMORPHIC);
  StubCache::GenerateProbe(masm, flags, r1, r2, r3, no_reg);

  // Cache miss: Jump to runtime.
  GenerateMiss(masm);
}


void StoreIC::GenerateMiss(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r0    : value
  //  -- r1    : receiver
  //  -- r2    : name
  //  -- lr    : return address
  // -----------------------------------

  __ push(r1);
  __ stm(db_w, sp, r2.bit() | r0.bit());

  // Perform tail call to the entry.
  ExternalReference ref = ExternalReference(IC_Utility(kStoreIC_Miss));
  __ TailCallExternalReference(ref, 3, 1);
}


void StoreIC::GenerateArrayLength(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- r0    : value
  //  -- r1    : receiver
  //  -- r2    : name
  //  -- lr    : return address
  // -----------------------------------
  //
  // This accepts as a receiver anything JSObject::SetElementsLength accepts
  // (currently anything except for external and pixel arrays which means
  // anything with elements of FixedArray type.), but currently is restricted
  // to JSArray.
  // Value must be a number, but only smis are accepted as the most common case.

  Label miss;

  Register receiver = r1;
  Register value = r0;
  Register scratch = r3;

  // Check that the receiver isn't a smi.
  __ BranchOnSmi(receiver, &miss);

  // Check that the object is a JS array.
  __ CompareObjectType(receiver, scratch, scratch, JS_ARRAY_TYPE);
  __ b(ne, &miss);

  // Check that elements are FixedArray.
  __ ldr(scratch, FieldMemOperand(receiver, JSArray::kElementsOffset));
  __ CompareObjectType(scratch, scratch, scratch, FIXED_ARRAY_TYPE);
  __ b(ne, &miss);

  // Check that value is a smi.
  __ BranchOnNotSmi(value, &miss);

  // Prepare tail call to StoreIC_ArrayLength.
  __ push(receiver);
  __ push(value);

  ExternalReference ref = ExternalReference(IC_Utility(kStoreIC_ArrayLength));
  __ TailCallExternalReference(ref, 2, 1);

  __ bind(&miss);

  GenerateMiss(masm);
}


#undef __


} }  // namespace v8::internal