root/src/mips/macro-assembler-mips.cc

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DEFINITIONS

This source file includes following definitions.
  1. has_frame_
  2. LoadRoot
  3. LoadRoot
  4. StoreRoot
  5. StoreRoot
  6. LoadHeapObject
  7. PushSafepointRegisters
  8. PopSafepointRegisters
  9. PushSafepointRegistersAndDoubles
  10. PopSafepointRegistersAndDoubles
  11. StoreToSafepointRegistersAndDoublesSlot
  12. StoreToSafepointRegisterSlot
  13. LoadFromSafepointRegisterSlot
  14. SafepointRegisterStackIndex
  15. SafepointRegisterSlot
  16. SafepointRegistersAndDoublesSlot
  17. InNewSpace
  18. RecordWriteField
  19. RecordWrite
  20. RememberedSetHelper
  21. CheckAccessGlobalProxy
  22. GetNumberHash
  23. LoadFromNumberDictionary
  24. Addu
  25. Subu
  26. Mul
  27. Mult
  28. Multu
  29. Div
  30. Divu
  31. And
  32. Or
  33. Xor
  34. Nor
  35. Neg
  36. Slt
  37. Sltu
  38. Ror
  39. li
  40. MultiPush
  41. MultiPushReversed
  42. MultiPop
  43. MultiPopReversed
  44. MultiPushFPU
  45. MultiPushReversedFPU
  46. MultiPopFPU
  47. MultiPopReversedFPU
  48. FlushICache
  49. Ext
  50. Ins
  51. Cvt_d_uw
  52. Cvt_d_uw
  53. Trunc_uw_d
  54. Trunc_w_d
  55. Round_w_d
  56. Floor_w_d
  57. Ceil_w_d
  58. Trunc_uw_d
  59. BranchF
  60. Move
  61. Movz
  62. Movn
  63. Movt
  64. Movf
  65. Clz
  66. ConvertToInt32
  67. EmitFPUTruncate
  68. EmitOutOfInt32RangeTruncate
  69. EmitECMATruncate
  70. GetLeastBitsFromSmi
  71. GetLeastBitsFromInt32
  72. Branch
  73. Branch
  74. Branch
  75. Branch
  76. BranchShort
  77. BranchShort
  78. BranchShort
  79. BranchShort
  80. BranchAndLink
  81. BranchAndLink
  82. BranchAndLink
  83. BranchAndLink
  84. BranchAndLinkShort
  85. BranchAndLinkShort
  86. BranchAndLinkShort
  87. BranchAndLinkShort
  88. Jump
  89. Jump
  90. Jump
  91. Jump
  92. CallSize
  93. Call
  94. CallSize
  95. Call
  96. CallSize
  97. Call
  98. Ret
  99. J
  100. Jr
  101. Jalr
  102. DropAndRet
  103. DropAndRet
  104. Drop
  105. Swap
  106. Call
  107. Push
  108. DebugBreak
  109. PushTryHandler
  110. PopTryHandler
  111. JumpToHandlerEntry
  112. Throw
  113. ThrowUncatchable
  114. AllocateInNewSpace
  115. AllocateInNewSpace
  116. UndoAllocationInNewSpace
  117. AllocateTwoByteString
  118. AllocateAsciiString
  119. AllocateTwoByteConsString
  120. AllocateAsciiConsString
  121. AllocateTwoByteSlicedString
  122. AllocateAsciiSlicedString
  123. AllocateHeapNumber
  124. AllocateHeapNumberWithValue
  125. CopyFields
  126. CopyBytes
  127. InitializeFieldsWithFiller
  128. CheckFastElements
  129. CheckFastObjectElements
  130. CheckFastSmiElements
  131. StoreNumberToDoubleElements
  132. CompareMapAndBranch
  133. CompareMapAndBranch
  134. CheckMap
  135. DispatchMap
  136. CheckMap
  137. GetCFunctionDoubleResult
  138. SetCallCDoubleArguments
  139. SetCallCDoubleArguments
  140. SetCallCDoubleArguments
  141. SetCallKind
  142. InvokePrologue
  143. InvokeCode
  144. InvokeCode
  145. InvokeFunction
  146. InvokeFunction
  147. IsObjectJSObjectType
  148. IsInstanceJSObjectType
  149. IsObjectJSStringType
  150. TryGetFunctionPrototype
  151. GetObjectType
  152. CallStub
  153. TailCallStub
  154. AddressOffset
  155. CallApiFunctionAndReturn
  156. AllowThisStubCall
  157. IllegalOperation
  158. IndexFromHash
  159. ObjectToDoubleFPURegister
  160. SmiToDoubleFPURegister
  161. AdduAndCheckForOverflow
  162. SubuAndCheckForOverflow
  163. CallRuntime
  164. CallRuntimeSaveDoubles
  165. CallRuntime
  166. CallExternalReference
  167. TailCallExternalReference
  168. TailCallRuntime
  169. JumpToExternalReference
  170. InvokeBuiltin
  171. GetBuiltinFunction
  172. GetBuiltinEntry
  173. SetCounter
  174. IncrementCounter
  175. DecrementCounter
  176. Assert
  177. AssertRegisterIsRoot
  178. AssertFastElements
  179. Check
  180. Abort
  181. LoadContext
  182. LoadTransitionedArrayMapConditional
  183. LoadInitialArrayMap
  184. LoadGlobalFunction
  185. LoadGlobalFunctionInitialMap
  186. EnterFrame
  187. LeaveFrame
  188. EnterExitFrame
  189. LeaveExitFrame
  190. InitializeNewString
  191. ActivationFrameAlignment
  192. AssertStackIsAligned
  193. JumpIfNotPowerOfTwoOrZero
  194. SmiTagCheckOverflow
  195. SmiTagCheckOverflow
  196. UntagAndJumpIfSmi
  197. UntagAndJumpIfNotSmi
  198. JumpIfSmi
  199. JumpIfNotSmi
  200. JumpIfNotBothSmi
  201. JumpIfEitherSmi
  202. AbortIfSmi
  203. AbortIfNotSmi
  204. AbortIfNotString
  205. AbortIfNotRootValue
  206. JumpIfNotHeapNumber
  207. JumpIfNonSmisNotBothSequentialAsciiStrings
  208. JumpIfNotBothSequentialAsciiStrings
  209. JumpIfBothInstanceTypesAreNotSequentialAscii
  210. JumpIfInstanceTypeIsNotSequentialAscii
  211. CalculateStackPassedWords
  212. PrepareCallCFunction
  213. PrepareCallCFunction
  214. CallCFunction
  215. CallCFunction
  216. CallCFunction
  217. CallCFunction
  218. CallCFunctionHelper
  219. PatchRelocatedValue
  220. GetRelocatedValue
  221. CheckPageFlag
  222. JumpIfBlack
  223. HasColor
  224. JumpIfDataObject
  225. GetMarkBits
  226. EnsureNotWhite
  227. LoadInstanceDescriptors
  228. CheckEnumCache
  229. ClampUint8
  230. ClampDoubleToUint8
  231. AreAliased
  232. masm_
  233. Emit
  234. Emit
  235. ChangeBranchCondition

// 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
//       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 <limits.h>  // For LONG_MIN, LONG_MAX.

#include "v8.h"

#if defined(V8_TARGET_ARCH_MIPS)

#include "bootstrapper.h"
#include "codegen.h"
#include "debug.h"
#include "runtime.h"

namespace v8 {
namespace internal {

MacroAssembler::MacroAssembler(Isolate* arg_isolate, void* buffer, int size)
    : Assembler(arg_isolate, buffer, size),
      generating_stub_(false),
      allow_stub_calls_(true),
      has_frame_(false) {
  if (isolate() != NULL) {
    code_object_ = Handle<Object>(isolate()->heap()->undefined_value(),
                                  isolate());
  }
}


void MacroAssembler::LoadRoot(Register destination,
                              Heap::RootListIndex index) {
  lw(destination, MemOperand(s6, index << kPointerSizeLog2));
}


void MacroAssembler::LoadRoot(Register destination,
                              Heap::RootListIndex index,
                              Condition cond,
                              Register src1, const Operand& src2) {
  Branch(2, NegateCondition(cond), src1, src2);
  lw(destination, MemOperand(s6, index << kPointerSizeLog2));
}


void MacroAssembler::StoreRoot(Register source,
                               Heap::RootListIndex index) {
  sw(source, MemOperand(s6, index << kPointerSizeLog2));
}


void MacroAssembler::StoreRoot(Register source,
                               Heap::RootListIndex index,
                               Condition cond,
                               Register src1, const Operand& src2) {
  Branch(2, NegateCondition(cond), src1, src2);
  sw(source, MemOperand(s6, index << kPointerSizeLog2));
}


void MacroAssembler::LoadHeapObject(Register result,
                                    Handle<HeapObject> object) {
  if (isolate()->heap()->InNewSpace(*object)) {
    Handle<JSGlobalPropertyCell> cell =
        isolate()->factory()->NewJSGlobalPropertyCell(object);
    li(result, Operand(cell));
    lw(result, FieldMemOperand(result, JSGlobalPropertyCell::kValueOffset));
  } else {
    li(result, Operand(object));
  }
}


// Push and pop all registers that can hold pointers.
void MacroAssembler::PushSafepointRegisters() {
  // Safepoints expect a block of kNumSafepointRegisters values on the
  // stack, so adjust the stack for unsaved registers.
  const int num_unsaved = kNumSafepointRegisters - kNumSafepointSavedRegisters;
  ASSERT(num_unsaved >= 0);
  if (num_unsaved > 0) {
    Subu(sp, sp, Operand(num_unsaved * kPointerSize));
  }
  MultiPush(kSafepointSavedRegisters);
}


void MacroAssembler::PopSafepointRegisters() {
  const int num_unsaved = kNumSafepointRegisters - kNumSafepointSavedRegisters;
  MultiPop(kSafepointSavedRegisters);
  if (num_unsaved > 0) {
    Addu(sp, sp, Operand(num_unsaved * kPointerSize));
  }
}


void MacroAssembler::PushSafepointRegistersAndDoubles() {
  PushSafepointRegisters();
  Subu(sp, sp, Operand(FPURegister::kNumAllocatableRegisters * kDoubleSize));
  for (int i = 0; i < FPURegister::kNumAllocatableRegisters; i+=2) {
    FPURegister reg = FPURegister::FromAllocationIndex(i);
    sdc1(reg, MemOperand(sp, i * kDoubleSize));
  }
}


void MacroAssembler::PopSafepointRegistersAndDoubles() {
  for (int i = 0; i < FPURegister::kNumAllocatableRegisters; i+=2) {
    FPURegister reg = FPURegister::FromAllocationIndex(i);
    ldc1(reg, MemOperand(sp, i * kDoubleSize));
  }
  Addu(sp, sp, Operand(FPURegister::kNumAllocatableRegisters * kDoubleSize));
  PopSafepointRegisters();
}


void MacroAssembler::StoreToSafepointRegistersAndDoublesSlot(Register src,
                                                             Register dst) {
  sw(src, SafepointRegistersAndDoublesSlot(dst));
}


void MacroAssembler::StoreToSafepointRegisterSlot(Register src, Register dst) {
  sw(src, SafepointRegisterSlot(dst));
}


void MacroAssembler::LoadFromSafepointRegisterSlot(Register dst, Register src) {
  lw(dst, SafepointRegisterSlot(src));
}


int MacroAssembler::SafepointRegisterStackIndex(int reg_code) {
  // The registers are pushed starting with the highest encoding,
  // which means that lowest encodings are closest to the stack pointer.
  return kSafepointRegisterStackIndexMap[reg_code];
}


MemOperand MacroAssembler::SafepointRegisterSlot(Register reg) {
  return MemOperand(sp, SafepointRegisterStackIndex(reg.code()) * kPointerSize);
}


MemOperand MacroAssembler::SafepointRegistersAndDoublesSlot(Register reg) {
  UNIMPLEMENTED_MIPS();
  // General purpose registers are pushed last on the stack.
  int doubles_size = FPURegister::kNumAllocatableRegisters * kDoubleSize;
  int register_offset = SafepointRegisterStackIndex(reg.code()) * kPointerSize;
  return MemOperand(sp, doubles_size + register_offset);
}


void MacroAssembler::InNewSpace(Register object,
                                Register scratch,
                                Condition cc,
                                Label* branch) {
  ASSERT(cc == eq || cc == ne);
  And(scratch, object, Operand(ExternalReference::new_space_mask(isolate())));
  Branch(branch, cc, scratch,
         Operand(ExternalReference::new_space_start(isolate())));
}


void MacroAssembler::RecordWriteField(
    Register object,
    int offset,
    Register value,
    Register dst,
    RAStatus ra_status,
    SaveFPRegsMode save_fp,
    RememberedSetAction remembered_set_action,
    SmiCheck smi_check) {
  ASSERT(!AreAliased(value, dst, t8, object));
  // First, check if a write barrier is even needed. The tests below
  // catch stores of Smis.
  Label done;

  // Skip barrier if writing a smi.
  if (smi_check == INLINE_SMI_CHECK) {
    JumpIfSmi(value, &done);
  }

  // Although the object register is tagged, the offset is relative to the start
  // of the object, so so offset must be a multiple of kPointerSize.
  ASSERT(IsAligned(offset, kPointerSize));

  Addu(dst, object, Operand(offset - kHeapObjectTag));
  if (emit_debug_code()) {
    Label ok;
    And(t8, dst, Operand((1 << kPointerSizeLog2) - 1));
    Branch(&ok, eq, t8, Operand(zero_reg));
    stop("Unaligned cell in write barrier");
    bind(&ok);
  }

  RecordWrite(object,
              dst,
              value,
              ra_status,
              save_fp,
              remembered_set_action,
              OMIT_SMI_CHECK);

  bind(&done);

  // Clobber clobbered input registers when running with the debug-code flag
  // turned on to provoke errors.
  if (emit_debug_code()) {
    li(value, Operand(BitCast<int32_t>(kZapValue + 4)));
    li(dst, Operand(BitCast<int32_t>(kZapValue + 8)));
  }
}


// Will clobber 4 registers: object, address, scratch, ip.  The
// register 'object' contains a heap object pointer.  The heap object
// tag is shifted away.
void MacroAssembler::RecordWrite(Register object,
                                 Register address,
                                 Register value,
                                 RAStatus ra_status,
                                 SaveFPRegsMode fp_mode,
                                 RememberedSetAction remembered_set_action,
                                 SmiCheck smi_check) {
  ASSERT(!AreAliased(object, address, value, t8));
  ASSERT(!AreAliased(object, address, value, t9));
  // The compiled code assumes that record write doesn't change the
  // context register, so we check that none of the clobbered
  // registers are cp.
  ASSERT(!address.is(cp) && !value.is(cp));

  if (emit_debug_code()) {
    lw(at, MemOperand(address));
    Assert(
        eq, "Wrong address or value passed to RecordWrite", at, Operand(value));
  }

  Label done;

  if (smi_check == INLINE_SMI_CHECK) {
    ASSERT_EQ(0, kSmiTag);
    JumpIfSmi(value, &done);
  }

  CheckPageFlag(value,
                value,  // Used as scratch.
                MemoryChunk::kPointersToHereAreInterestingMask,
                eq,
                &done);
  CheckPageFlag(object,
                value,  // Used as scratch.
                MemoryChunk::kPointersFromHereAreInterestingMask,
                eq,
                &done);

  // Record the actual write.
  if (ra_status == kRAHasNotBeenSaved) {
    push(ra);
  }
  RecordWriteStub stub(object, value, address, remembered_set_action, fp_mode);
  CallStub(&stub);
  if (ra_status == kRAHasNotBeenSaved) {
    pop(ra);
  }

  bind(&done);

  // Clobber clobbered registers when running with the debug-code flag
  // turned on to provoke errors.
  if (emit_debug_code()) {
    li(address, Operand(BitCast<int32_t>(kZapValue + 12)));
    li(value, Operand(BitCast<int32_t>(kZapValue + 16)));
  }
}


void MacroAssembler::RememberedSetHelper(Register object,  // For debug tests.
                                         Register address,
                                         Register scratch,
                                         SaveFPRegsMode fp_mode,
                                         RememberedSetFinalAction and_then) {
  Label done;
  if (emit_debug_code()) {
    Label ok;
    JumpIfNotInNewSpace(object, scratch, &ok);
    stop("Remembered set pointer is in new space");
    bind(&ok);
  }
  // Load store buffer top.
  ExternalReference store_buffer =
      ExternalReference::store_buffer_top(isolate());
  li(t8, Operand(store_buffer));
  lw(scratch, MemOperand(t8));
  // Store pointer to buffer and increment buffer top.
  sw(address, MemOperand(scratch));
  Addu(scratch, scratch, kPointerSize);
  // Write back new top of buffer.
  sw(scratch, MemOperand(t8));
  // Call stub on end of buffer.
  // Check for end of buffer.
  And(t8, scratch, Operand(StoreBuffer::kStoreBufferOverflowBit));
  if (and_then == kFallThroughAtEnd) {
    Branch(&done, eq, t8, Operand(zero_reg));
  } else {
    ASSERT(and_then == kReturnAtEnd);
    Ret(eq, t8, Operand(zero_reg));
  }
  push(ra);
  StoreBufferOverflowStub store_buffer_overflow =
      StoreBufferOverflowStub(fp_mode);
  CallStub(&store_buffer_overflow);
  pop(ra);
  bind(&done);
  if (and_then == kReturnAtEnd) {
    Ret();
  }
}


// -----------------------------------------------------------------------------
// Allocation support.


void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
                                            Register scratch,
                                            Label* miss) {
  Label same_contexts;

  ASSERT(!holder_reg.is(scratch));
  ASSERT(!holder_reg.is(at));
  ASSERT(!scratch.is(at));

  // Load current lexical context from the stack frame.
  lw(scratch, MemOperand(fp, StandardFrameConstants::kContextOffset));
  // In debug mode, make sure the lexical context is set.
#ifdef DEBUG
  Check(ne, "we should not have an empty lexical context",
      scratch, Operand(zero_reg));
#endif

  // Load the global context of the current context.
  int offset = Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
  lw(scratch, FieldMemOperand(scratch, offset));
  lw(scratch, FieldMemOperand(scratch, GlobalObject::kGlobalContextOffset));

  // Check the context is a global context.
  if (emit_debug_code()) {
    // TODO(119): Avoid push(holder_reg)/pop(holder_reg).
    push(holder_reg);  // Temporarily save holder on the stack.
    // Read the first word and compare to the global_context_map.
    lw(holder_reg, FieldMemOperand(scratch, HeapObject::kMapOffset));
    LoadRoot(at, Heap::kGlobalContextMapRootIndex);
    Check(eq, "JSGlobalObject::global_context should be a global context.",
          holder_reg, Operand(at));
    pop(holder_reg);  // Restore holder.
  }

  // Check if both contexts are the same.
  lw(at, FieldMemOperand(holder_reg, JSGlobalProxy::kContextOffset));
  Branch(&same_contexts, eq, scratch, Operand(at));

  // Check the context is a global context.
  if (emit_debug_code()) {
    // TODO(119): Avoid push(holder_reg)/pop(holder_reg).
    push(holder_reg);  // Temporarily save holder on the stack.
    mov(holder_reg, at);  // Move at to its holding place.
    LoadRoot(at, Heap::kNullValueRootIndex);
    Check(ne, "JSGlobalProxy::context() should not be null.",
          holder_reg, Operand(at));

    lw(holder_reg, FieldMemOperand(holder_reg, HeapObject::kMapOffset));
    LoadRoot(at, Heap::kGlobalContextMapRootIndex);
    Check(eq, "JSGlobalObject::global_context should be a global context.",
          holder_reg, Operand(at));
    // Restore at is not needed. at is reloaded below.
    pop(holder_reg);  // Restore holder.
    // Restore at to holder's context.
    lw(at, FieldMemOperand(holder_reg, JSGlobalProxy::kContextOffset));
  }

  // Check that the security token in the calling global object is
  // compatible with the security token in the receiving global
  // object.
  int token_offset = Context::kHeaderSize +
                     Context::SECURITY_TOKEN_INDEX * kPointerSize;

  lw(scratch, FieldMemOperand(scratch, token_offset));
  lw(at, FieldMemOperand(at, token_offset));
  Branch(miss, ne, scratch, Operand(at));

  bind(&same_contexts);
}


void MacroAssembler::GetNumberHash(Register reg0, Register scratch) {
  // First of all we assign the hash seed to scratch.
  LoadRoot(scratch, Heap::kHashSeedRootIndex);
  SmiUntag(scratch);

  // Xor original key with a seed.
  xor_(reg0, reg0, scratch);

  // Compute the hash code from the untagged key.  This must be kept in sync
  // with ComputeIntegerHash in utils.h.
  //
  // hash = ~hash + (hash << 15);
  nor(scratch, reg0, zero_reg);
  sll(at, reg0, 15);
  addu(reg0, scratch, at);

  // hash = hash ^ (hash >> 12);
  srl(at, reg0, 12);
  xor_(reg0, reg0, at);

  // hash = hash + (hash << 2);
  sll(at, reg0, 2);
  addu(reg0, reg0, at);

  // hash = hash ^ (hash >> 4);
  srl(at, reg0, 4);
  xor_(reg0, reg0, at);

  // hash = hash * 2057;
  sll(scratch, reg0, 11);
  sll(at, reg0, 3);
  addu(reg0, reg0, at);
  addu(reg0, reg0, scratch);

  // hash = hash ^ (hash >> 16);
  srl(at, reg0, 16);
  xor_(reg0, reg0, at);
}


void MacroAssembler::LoadFromNumberDictionary(Label* miss,
                                              Register elements,
                                              Register key,
                                              Register result,
                                              Register reg0,
                                              Register reg1,
                                              Register reg2) {
  // Register use:
  //
  // elements - holds the slow-case elements of the receiver on entry.
  //            Unchanged unless 'result' is the same register.
  //
  // key      - holds the smi key on entry.
  //            Unchanged unless 'result' is the same register.
  //
  //
  // result   - holds the result on exit if the load succeeded.
  //            Allowed to be the same as 'key' or 'result'.
  //            Unchanged on bailout so 'key' or 'result' can be used
  //            in further computation.
  //
  // Scratch registers:
  //
  // reg0 - holds the untagged key on entry and holds the hash once computed.
  //
  // reg1 - Used to hold the capacity mask of the dictionary.
  //
  // reg2 - Used for the index into the dictionary.
  // at   - Temporary (avoid MacroAssembler instructions also using 'at').
  Label done;

  GetNumberHash(reg0, reg1);

  // Compute the capacity mask.
  lw(reg1, FieldMemOperand(elements, SeededNumberDictionary::kCapacityOffset));
  sra(reg1, reg1, kSmiTagSize);
  Subu(reg1, reg1, Operand(1));

  // Generate an unrolled loop that performs a few probes before giving up.
  static const int kProbes = 4;
  for (int i = 0; i < kProbes; i++) {
    // Use reg2 for index calculations and keep the hash intact in reg0.
    mov(reg2, reg0);
    // Compute the masked index: (hash + i + i * i) & mask.
    if (i > 0) {
      Addu(reg2, reg2, Operand(SeededNumberDictionary::GetProbeOffset(i)));
    }
    and_(reg2, reg2, reg1);

    // Scale the index by multiplying by the element size.
    ASSERT(SeededNumberDictionary::kEntrySize == 3);
    sll(at, reg2, 1);  // 2x.
    addu(reg2, reg2, at);  // reg2 = reg2 * 3.

    // Check if the key is identical to the name.
    sll(at, reg2, kPointerSizeLog2);
    addu(reg2, elements, at);

    lw(at, FieldMemOperand(reg2, SeededNumberDictionary::kElementsStartOffset));
    if (i != kProbes - 1) {
      Branch(&done, eq, key, Operand(at));
    } else {
      Branch(miss, ne, key, Operand(at));
    }
  }

  bind(&done);
  // Check that the value is a normal property.
  // reg2: elements + (index * kPointerSize).
  const int kDetailsOffset =
      SeededNumberDictionary::kElementsStartOffset + 2 * kPointerSize;
  lw(reg1, FieldMemOperand(reg2, kDetailsOffset));
  And(at, reg1, Operand(Smi::FromInt(PropertyDetails::TypeField::kMask)));
  Branch(miss, ne, at, Operand(zero_reg));

  // Get the value at the masked, scaled index and return.
  const int kValueOffset =
      SeededNumberDictionary::kElementsStartOffset + kPointerSize;
  lw(result, FieldMemOperand(reg2, kValueOffset));
}


// ---------------------------------------------------------------------------
// Instruction macros.

void MacroAssembler::Addu(Register rd, Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    addu(rd, rs, rt.rm());
  } else {
    if (is_int16(rt.imm32_) && !MustUseReg(rt.rmode_)) {
      addiu(rd, rs, rt.imm32_);
    } else {
      // li handles the relocation.
      ASSERT(!rs.is(at));
      li(at, rt);
      addu(rd, rs, at);
    }
  }
}


void MacroAssembler::Subu(Register rd, Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    subu(rd, rs, rt.rm());
  } else {
    if (is_int16(rt.imm32_) && !MustUseReg(rt.rmode_)) {
      addiu(rd, rs, -rt.imm32_);  // No subiu instr, use addiu(x, y, -imm).
    } else {
      // li handles the relocation.
      ASSERT(!rs.is(at));
      li(at, rt);
      subu(rd, rs, at);
    }
  }
}


void MacroAssembler::Mul(Register rd, Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    if (kArchVariant == kLoongson) {
      mult(rs, rt.rm());
      mflo(rd);
    } else {
      mul(rd, rs, rt.rm());
    }
  } else {
    // li handles the relocation.
    ASSERT(!rs.is(at));
    li(at, rt);
    if (kArchVariant == kLoongson) {
      mult(rs, at);
      mflo(rd);
    } else {
      mul(rd, rs, at);
    }
  }
}


void MacroAssembler::Mult(Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    mult(rs, rt.rm());
  } else {
    // li handles the relocation.
    ASSERT(!rs.is(at));
    li(at, rt);
    mult(rs, at);
  }
}


void MacroAssembler::Multu(Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    multu(rs, rt.rm());
  } else {
    // li handles the relocation.
    ASSERT(!rs.is(at));
    li(at, rt);
    multu(rs, at);
  }
}


void MacroAssembler::Div(Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    div(rs, rt.rm());
  } else {
    // li handles the relocation.
    ASSERT(!rs.is(at));
    li(at, rt);
    div(rs, at);
  }
}


void MacroAssembler::Divu(Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    divu(rs, rt.rm());
  } else {
    // li handles the relocation.
    ASSERT(!rs.is(at));
    li(at, rt);
    divu(rs, at);
  }
}


void MacroAssembler::And(Register rd, Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    and_(rd, rs, rt.rm());
  } else {
    if (is_uint16(rt.imm32_) && !MustUseReg(rt.rmode_)) {
      andi(rd, rs, rt.imm32_);
    } else {
      // li handles the relocation.
      ASSERT(!rs.is(at));
      li(at, rt);
      and_(rd, rs, at);
    }
  }
}


void MacroAssembler::Or(Register rd, Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    or_(rd, rs, rt.rm());
  } else {
    if (is_uint16(rt.imm32_) && !MustUseReg(rt.rmode_)) {
      ori(rd, rs, rt.imm32_);
    } else {
      // li handles the relocation.
      ASSERT(!rs.is(at));
      li(at, rt);
      or_(rd, rs, at);
    }
  }
}


void MacroAssembler::Xor(Register rd, Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    xor_(rd, rs, rt.rm());
  } else {
    if (is_uint16(rt.imm32_) && !MustUseReg(rt.rmode_)) {
      xori(rd, rs, rt.imm32_);
    } else {
      // li handles the relocation.
      ASSERT(!rs.is(at));
      li(at, rt);
      xor_(rd, rs, at);
    }
  }
}


void MacroAssembler::Nor(Register rd, Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    nor(rd, rs, rt.rm());
  } else {
    // li handles the relocation.
    ASSERT(!rs.is(at));
    li(at, rt);
    nor(rd, rs, at);
  }
}


void MacroAssembler::Neg(Register rs, const Operand& rt) {
  ASSERT(rt.is_reg());
  ASSERT(!at.is(rs));
  ASSERT(!at.is(rt.rm()));
  li(at, -1);
  xor_(rs, rt.rm(), at);
}


void MacroAssembler::Slt(Register rd, Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    slt(rd, rs, rt.rm());
  } else {
    if (is_int16(rt.imm32_) && !MustUseReg(rt.rmode_)) {
      slti(rd, rs, rt.imm32_);
    } else {
      // li handles the relocation.
      ASSERT(!rs.is(at));
      li(at, rt);
      slt(rd, rs, at);
    }
  }
}


void MacroAssembler::Sltu(Register rd, Register rs, const Operand& rt) {
  if (rt.is_reg()) {
    sltu(rd, rs, rt.rm());
  } else {
    if (is_uint16(rt.imm32_) && !MustUseReg(rt.rmode_)) {
      sltiu(rd, rs, rt.imm32_);
    } else {
      // li handles the relocation.
      ASSERT(!rs.is(at));
      li(at, rt);
      sltu(rd, rs, at);
    }
  }
}


void MacroAssembler::Ror(Register rd, Register rs, const Operand& rt) {
  if (kArchVariant == kMips32r2) {
    if (rt.is_reg()) {
      rotrv(rd, rs, rt.rm());
    } else {
      rotr(rd, rs, rt.imm32_);
    }
  } else {
    if (rt.is_reg()) {
      subu(at, zero_reg, rt.rm());
      sllv(at, rs, at);
      srlv(rd, rs, rt.rm());
      or_(rd, rd, at);
    } else {
      if (rt.imm32_ == 0) {
        srl(rd, rs, 0);
      } else {
        srl(at, rs, rt.imm32_);
        sll(rd, rs, (0x20 - rt.imm32_) & 0x1f);
        or_(rd, rd, at);
      }
    }
  }
}

//------------Pseudo-instructions-------------

void MacroAssembler::li(Register rd, Operand j, LiFlags mode) {
  ASSERT(!j.is_reg());
  BlockTrampolinePoolScope block_trampoline_pool(this);
  if (!MustUseReg(j.rmode_) && mode == OPTIMIZE_SIZE) {
    // Normal load of an immediate value which does not need Relocation Info.
    if (is_int16(j.imm32_)) {
      addiu(rd, zero_reg, j.imm32_);
    } else if (!(j.imm32_ & kHiMask)) {
      ori(rd, zero_reg, j.imm32_);
    } else if (!(j.imm32_ & kImm16Mask)) {
      lui(rd, (j.imm32_ >> kLuiShift) & kImm16Mask);
    } else {
      lui(rd, (j.imm32_ >> kLuiShift) & kImm16Mask);
      ori(rd, rd, (j.imm32_ & kImm16Mask));
    }
  } else {
    if (MustUseReg(j.rmode_)) {
      RecordRelocInfo(j.rmode_, j.imm32_);
    }
    // We always need the same number of instructions as we may need to patch
    // this code to load another value which may need 2 instructions to load.
    lui(rd, (j.imm32_ >> kLuiShift) & kImm16Mask);
    ori(rd, rd, (j.imm32_ & kImm16Mask));
  }
}


void MacroAssembler::MultiPush(RegList regs) {
  int16_t num_to_push = NumberOfBitsSet(regs);
  int16_t stack_offset = num_to_push * kPointerSize;

  Subu(sp, sp, Operand(stack_offset));
  for (int16_t i = kNumRegisters - 1; i >= 0; i--) {
    if ((regs & (1 << i)) != 0) {
      stack_offset -= kPointerSize;
      sw(ToRegister(i), MemOperand(sp, stack_offset));
    }
  }
}


void MacroAssembler::MultiPushReversed(RegList regs) {
  int16_t num_to_push = NumberOfBitsSet(regs);
  int16_t stack_offset = num_to_push * kPointerSize;

  Subu(sp, sp, Operand(stack_offset));
  for (int16_t i = 0; i < kNumRegisters; i++) {
    if ((regs & (1 << i)) != 0) {
      stack_offset -= kPointerSize;
      sw(ToRegister(i), MemOperand(sp, stack_offset));
    }
  }
}


void MacroAssembler::MultiPop(RegList regs) {
  int16_t stack_offset = 0;

  for (int16_t i = 0; i < kNumRegisters; i++) {
    if ((regs & (1 << i)) != 0) {
      lw(ToRegister(i), MemOperand(sp, stack_offset));
      stack_offset += kPointerSize;
    }
  }
  addiu(sp, sp, stack_offset);
}


void MacroAssembler::MultiPopReversed(RegList regs) {
  int16_t stack_offset = 0;

  for (int16_t i = kNumRegisters - 1; i >= 0; i--) {
    if ((regs & (1 << i)) != 0) {
      lw(ToRegister(i), MemOperand(sp, stack_offset));
      stack_offset += kPointerSize;
    }
  }
  addiu(sp, sp, stack_offset);
}


void MacroAssembler::MultiPushFPU(RegList regs) {
  CpuFeatures::Scope scope(FPU);
  int16_t num_to_push = NumberOfBitsSet(regs);
  int16_t stack_offset = num_to_push * kDoubleSize;

  Subu(sp, sp, Operand(stack_offset));
  for (int16_t i = kNumRegisters - 1; i >= 0; i--) {
    if ((regs & (1 << i)) != 0) {
      stack_offset -= kDoubleSize;
      sdc1(FPURegister::from_code(i), MemOperand(sp, stack_offset));
    }
  }
}


void MacroAssembler::MultiPushReversedFPU(RegList regs) {
  CpuFeatures::Scope scope(FPU);
  int16_t num_to_push = NumberOfBitsSet(regs);
  int16_t stack_offset = num_to_push * kDoubleSize;

  Subu(sp, sp, Operand(stack_offset));
  for (int16_t i = 0; i < kNumRegisters; i++) {
    if ((regs & (1 << i)) != 0) {
      stack_offset -= kDoubleSize;
      sdc1(FPURegister::from_code(i), MemOperand(sp, stack_offset));
    }
  }
}


void MacroAssembler::MultiPopFPU(RegList regs) {
  CpuFeatures::Scope scope(FPU);
  int16_t stack_offset = 0;

  for (int16_t i = 0; i < kNumRegisters; i++) {
    if ((regs & (1 << i)) != 0) {
      ldc1(FPURegister::from_code(i), MemOperand(sp, stack_offset));
      stack_offset += kDoubleSize;
    }
  }
  addiu(sp, sp, stack_offset);
}


void MacroAssembler::MultiPopReversedFPU(RegList regs) {
  CpuFeatures::Scope scope(FPU);
  int16_t stack_offset = 0;

  for (int16_t i = kNumRegisters - 1; i >= 0; i--) {
    if ((regs & (1 << i)) != 0) {
      ldc1(FPURegister::from_code(i), MemOperand(sp, stack_offset));
      stack_offset += kDoubleSize;
    }
  }
  addiu(sp, sp, stack_offset);
}


void MacroAssembler::FlushICache(Register address, unsigned instructions) {
  RegList saved_regs = kJSCallerSaved | ra.bit();
  MultiPush(saved_regs);
  AllowExternalCallThatCantCauseGC scope(this);

  // Save to a0 in case address == t0.
  Move(a0, address);
  PrepareCallCFunction(2, t0);

  li(a1, instructions * kInstrSize);
  CallCFunction(ExternalReference::flush_icache_function(isolate()), 2);
  MultiPop(saved_regs);
}


void MacroAssembler::Ext(Register rt,
                         Register rs,
                         uint16_t pos,
                         uint16_t size) {
  ASSERT(pos < 32);
  ASSERT(pos + size < 33);

  if (kArchVariant == kMips32r2) {
    ext_(rt, rs, pos, size);
  } else {
    // Move rs to rt and shift it left then right to get the
    // desired bitfield on the right side and zeroes on the left.
    int shift_left = 32 - (pos + size);
    sll(rt, rs, shift_left);  // Acts as a move if shift_left == 0.

    int shift_right = 32 - size;
    if (shift_right > 0) {
      srl(rt, rt, shift_right);
    }
  }
}


void MacroAssembler::Ins(Register rt,
                         Register rs,
                         uint16_t pos,
                         uint16_t size) {
  ASSERT(pos < 32);
  ASSERT(pos + size <= 32);
  ASSERT(size != 0);

  if (kArchVariant == kMips32r2) {
    ins_(rt, rs, pos, size);
  } else {
    ASSERT(!rt.is(t8) && !rs.is(t8));
    Subu(at, zero_reg, Operand(1));
    srl(at, at, 32 - size);
    and_(t8, rs, at);
    sll(t8, t8, pos);
    sll(at, at, pos);
    nor(at, at, zero_reg);
    and_(at, rt, at);
    or_(rt, t8, at);
  }
}


void MacroAssembler::Cvt_d_uw(FPURegister fd,
                              FPURegister fs,
                              FPURegister scratch) {
  // Move the data from fs to t8.
  mfc1(t8, fs);
  Cvt_d_uw(fd, t8, scratch);
}


void MacroAssembler::Cvt_d_uw(FPURegister fd,
                              Register rs,
                              FPURegister scratch) {
  // Convert rs to a FP value in fd (and fd + 1).
  // We do this by converting rs minus the MSB to avoid sign conversion,
  // then adding 2^31 to the result (if needed).

  ASSERT(!fd.is(scratch));
  ASSERT(!rs.is(t9));
  ASSERT(!rs.is(at));

  // Save rs's MSB to t9.
  Ext(t9, rs, 31, 1);
  // Remove rs's MSB.
  Ext(at, rs, 0, 31);
  // Move the result to fd.
  mtc1(at, fd);

  // Convert fd to a real FP value.
  cvt_d_w(fd, fd);

  Label conversion_done;

  // If rs's MSB was 0, it's done.
  // Otherwise we need to add that to the FP register.
  Branch(&conversion_done, eq, t9, Operand(zero_reg));

  // Load 2^31 into f20 as its float representation.
  li(at, 0x41E00000);
  mtc1(at, FPURegister::from_code(scratch.code() + 1));
  mtc1(zero_reg, scratch);
  // Add it to fd.
  add_d(fd, fd, scratch);

  bind(&conversion_done);
}


void MacroAssembler::Trunc_uw_d(FPURegister fd,
                                FPURegister fs,
                                FPURegister scratch) {
  Trunc_uw_d(fs, t8, scratch);
  mtc1(t8, fd);
}

void MacroAssembler::Trunc_w_d(FPURegister fd, FPURegister fs) {
  if (kArchVariant == kLoongson && fd.is(fs)) {
    mfc1(t8, FPURegister::from_code(fs.code() + 1));
    trunc_w_d(fd, fs);
    mtc1(t8, FPURegister::from_code(fs.code() + 1));
  } else {
    trunc_w_d(fd, fs);
  }
}

void MacroAssembler::Round_w_d(FPURegister fd, FPURegister fs) {
  if (kArchVariant == kLoongson && fd.is(fs)) {
    mfc1(t8, FPURegister::from_code(fs.code() + 1));
    round_w_d(fd, fs);
    mtc1(t8, FPURegister::from_code(fs.code() + 1));
  } else {
    round_w_d(fd, fs);
  }
}


void MacroAssembler::Floor_w_d(FPURegister fd, FPURegister fs) {
  if (kArchVariant == kLoongson && fd.is(fs)) {
    mfc1(t8, FPURegister::from_code(fs.code() + 1));
    floor_w_d(fd, fs);
    mtc1(t8, FPURegister::from_code(fs.code() + 1));
  } else {
    floor_w_d(fd, fs);
  }
}


void MacroAssembler::Ceil_w_d(FPURegister fd, FPURegister fs) {
  if (kArchVariant == kLoongson && fd.is(fs)) {
    mfc1(t8, FPURegister::from_code(fs.code() + 1));
    ceil_w_d(fd, fs);
    mtc1(t8, FPURegister::from_code(fs.code() + 1));
  } else {
    ceil_w_d(fd, fs);
  }
}


void MacroAssembler::Trunc_uw_d(FPURegister fd,
                                Register rs,
                                FPURegister scratch) {
  ASSERT(!fd.is(scratch));
  ASSERT(!rs.is(at));

  // Load 2^31 into scratch as its float representation.
  li(at, 0x41E00000);
  mtc1(at, FPURegister::from_code(scratch.code() + 1));
  mtc1(zero_reg, scratch);
  // Test if scratch > fd.
  // If fd < 2^31 we can convert it normally.
  Label simple_convert;
  BranchF(&simple_convert, NULL, lt, fd, scratch);

  // First we subtract 2^31 from fd, then trunc it to rs
  // and add 2^31 to rs.
  sub_d(scratch, fd, scratch);
  trunc_w_d(scratch, scratch);
  mfc1(rs, scratch);
  Or(rs, rs, 1 << 31);

  Label done;
  Branch(&done);
  // Simple conversion.
  bind(&simple_convert);
  trunc_w_d(scratch, fd);
  mfc1(rs, scratch);

  bind(&done);
}


void MacroAssembler::BranchF(Label* target,
                             Label* nan,
                             Condition cc,
                             FPURegister cmp1,
                             FPURegister cmp2,
                             BranchDelaySlot bd) {
  if (cc == al) {
    Branch(bd, target);
    return;
  }

  ASSERT(nan || target);
  // Check for unordered (NaN) cases.
  if (nan) {
    c(UN, D, cmp1, cmp2);
    bc1t(nan);
  }

  if (target) {
    // Here NaN cases were either handled by this function or are assumed to
    // have been handled by the caller.
    // Unsigned conditions are treated as their signed counterpart.
    switch (cc) {
      case Uless:
      case less:
        c(OLT, D, cmp1, cmp2);
        bc1t(target);
        break;
      case Ugreater:
      case greater:
        c(ULE, D, cmp1, cmp2);
        bc1f(target);
        break;
      case Ugreater_equal:
      case greater_equal:
        c(ULT, D, cmp1, cmp2);
        bc1f(target);
        break;
      case Uless_equal:
      case less_equal:
        c(OLE, D, cmp1, cmp2);
        bc1t(target);
        break;
      case eq:
        c(EQ, D, cmp1, cmp2);
        bc1t(target);
        break;
      case ne:
        c(EQ, D, cmp1, cmp2);
        bc1f(target);
        break;
      default:
        CHECK(0);
    };
  }

  if (bd == PROTECT) {
    nop();
  }
}


void MacroAssembler::Move(FPURegister dst, double imm) {
  ASSERT(CpuFeatures::IsEnabled(FPU));
  static const DoubleRepresentation minus_zero(-0.0);
  static const DoubleRepresentation zero(0.0);
  DoubleRepresentation value(imm);
  // Handle special values first.
  bool force_load = dst.is(kDoubleRegZero);
  if (value.bits == zero.bits && !force_load) {
    mov_d(dst, kDoubleRegZero);
  } else if (value.bits == minus_zero.bits && !force_load) {
    neg_d(dst, kDoubleRegZero);
  } else {
    uint32_t lo, hi;
    DoubleAsTwoUInt32(imm, &lo, &hi);
    // Move the low part of the double into the lower of the corresponding FPU
    // register of FPU register pair.
    if (lo != 0) {
      li(at, Operand(lo));
      mtc1(at, dst);
    } else {
      mtc1(zero_reg, dst);
    }
    // Move the high part of the double into the higher of the corresponding FPU
    // register of FPU register pair.
    if (hi != 0) {
      li(at, Operand(hi));
      mtc1(at, dst.high());
    } else {
      mtc1(zero_reg, dst.high());
    }
  }
}


void MacroAssembler::Movz(Register rd, Register rs, Register rt) {
  if (kArchVariant == kLoongson) {
    Label done;
    Branch(&done, ne, rt, Operand(zero_reg));
    mov(rd, rs);
    bind(&done);
  } else {
    movz(rd, rs, rt);
  }
}


void MacroAssembler::Movn(Register rd, Register rs, Register rt) {
  if (kArchVariant == kLoongson) {
    Label done;
    Branch(&done, eq, rt, Operand(zero_reg));
    mov(rd, rs);
    bind(&done);
  } else {
    movn(rd, rs, rt);
  }
}


void MacroAssembler::Movt(Register rd, Register rs, uint16_t cc) {
  if (kArchVariant == kLoongson) {
    // Tests an FP condition code and then conditionally move rs to rd.
    // We do not currently use any FPU cc bit other than bit 0.
    ASSERT(cc == 0);
    ASSERT(!(rs.is(t8) || rd.is(t8)));
    Label done;
    Register scratch = t8;
    // For testing purposes we need to fetch content of the FCSR register and
    // than test its cc (floating point condition code) bit (for cc = 0, it is
    // 24. bit of the FCSR).
    cfc1(scratch, FCSR);
    // For the MIPS I, II and III architectures, the contents of scratch is
    // UNPREDICTABLE for the instruction immediately following CFC1.
    nop();
    srl(scratch, scratch, 16);
    andi(scratch, scratch, 0x0080);
    Branch(&done, eq, scratch, Operand(zero_reg));
    mov(rd, rs);
    bind(&done);
  } else {
    movt(rd, rs, cc);
  }
}


void MacroAssembler::Movf(Register rd, Register rs, uint16_t cc) {
  if (kArchVariant == kLoongson) {
    // Tests an FP condition code and then conditionally move rs to rd.
    // We do not currently use any FPU cc bit other than bit 0.
    ASSERT(cc == 0);
    ASSERT(!(rs.is(t8) || rd.is(t8)));
    Label done;
    Register scratch = t8;
    // For testing purposes we need to fetch content of the FCSR register and
    // than test its cc (floating point condition code) bit (for cc = 0, it is
    // 24. bit of the FCSR).
    cfc1(scratch, FCSR);
    // For the MIPS I, II and III architectures, the contents of scratch is
    // UNPREDICTABLE for the instruction immediately following CFC1.
    nop();
    srl(scratch, scratch, 16);
    andi(scratch, scratch, 0x0080);
    Branch(&done, ne, scratch, Operand(zero_reg));
    mov(rd, rs);
    bind(&done);
  } else {
    movf(rd, rs, cc);
  }
}


void MacroAssembler::Clz(Register rd, Register rs) {
  if (kArchVariant == kLoongson) {
    ASSERT(!(rd.is(t8) || rd.is(t9)) && !(rs.is(t8) || rs.is(t9)));
    Register mask = t8;
    Register scratch = t9;
    Label loop, end;
    mov(at, rs);
    mov(rd, zero_reg);
    lui(mask, 0x8000);
    bind(&loop);
    and_(scratch, at, mask);
    Branch(&end, ne, scratch, Operand(zero_reg));
    addiu(rd, rd, 1);
    Branch(&loop, ne, mask, Operand(zero_reg), USE_DELAY_SLOT);
    srl(mask, mask, 1);
    bind(&end);
  } else {
    clz(rd, rs);
  }
}


// Tries to get a signed int32 out of a double precision floating point heap
// number. Rounds towards 0. Branch to 'not_int32' if the double is out of the
// 32bits signed integer range.
// This method implementation differs from the ARM version for performance
// reasons.
void MacroAssembler::ConvertToInt32(Register source,
                                    Register dest,
                                    Register scratch,
                                    Register scratch2,
                                    FPURegister double_scratch,
                                    Label *not_int32) {
  Label right_exponent, done;
  // Get exponent word (ENDIAN issues).
  lw(scratch, FieldMemOperand(source, HeapNumber::kExponentOffset));
  // Get exponent alone in scratch2.
  And(scratch2, scratch, Operand(HeapNumber::kExponentMask));
  // Load dest with zero.  We use this either for the final shift or
  // for the answer.
  mov(dest, zero_reg);
  // Check whether the exponent matches a 32 bit signed int that is not a Smi.
  // A non-Smi integer is 1.xxx * 2^30 so the exponent is 30 (biased).  This is
  // the exponent that we are fastest at and also the highest exponent we can
  // handle here.
  const uint32_t non_smi_exponent =
      (HeapNumber::kExponentBias + 30) << HeapNumber::kExponentShift;
  // If we have a match of the int32-but-not-Smi exponent then skip some logic.
  Branch(&right_exponent, eq, scratch2, Operand(non_smi_exponent));
  // If the exponent is higher than that then go to not_int32 case.  This
  // catches numbers that don't fit in a signed int32, infinities and NaNs.
  Branch(not_int32, gt, scratch2, Operand(non_smi_exponent));

  // We know the exponent is smaller than 30 (biased).  If it is less than
  // 0 (biased) then the number is smaller in magnitude than 1.0 * 2^0, i.e.
  // it rounds to zero.
  const uint32_t zero_exponent =
      (HeapNumber::kExponentBias + 0) << HeapNumber::kExponentShift;
  Subu(scratch2, scratch2, Operand(zero_exponent));
  // Dest already has a Smi zero.
  Branch(&done, lt, scratch2, Operand(zero_reg));
  if (!CpuFeatures::IsSupported(FPU)) {
    // We have a shifted exponent between 0 and 30 in scratch2.
    srl(dest, scratch2, HeapNumber::kExponentShift);
    // We now have the exponent in dest.  Subtract from 30 to get
    // how much to shift down.
    li(at, Operand(30));
    subu(dest, at, dest);
  }
  bind(&right_exponent);
  if (CpuFeatures::IsSupported(FPU)) {
    CpuFeatures::Scope scope(FPU);
    // MIPS FPU instructions implementing double precision to integer
    // conversion using round to zero. Since the FP value was qualified
    // above, the resulting integer should be a legal int32.
    // The original 'Exponent' word is still in scratch.
    lwc1(double_scratch, FieldMemOperand(source, HeapNumber::kMantissaOffset));
    mtc1(scratch, FPURegister::from_code(double_scratch.code() + 1));
    trunc_w_d(double_scratch, double_scratch);
    mfc1(dest, double_scratch);
  } else {
    // On entry, dest has final downshift, scratch has original sign/exp/mant.
    // Save sign bit in top bit of dest.
    And(scratch2, scratch, Operand(0x80000000));
    Or(dest, dest, Operand(scratch2));
    // Put back the implicit 1, just above mantissa field.
    Or(scratch, scratch, Operand(1 << HeapNumber::kExponentShift));

    // Shift up the mantissa bits to take up the space the exponent used to
    // take. We just orred in the implicit bit so that took care of one and
    // we want to leave the sign bit 0 so we subtract 2 bits from the shift
    // distance. But we want to clear the sign-bit so shift one more bit
    // left, then shift right one bit.
    const int shift_distance = HeapNumber::kNonMantissaBitsInTopWord - 2;
    sll(scratch, scratch, shift_distance + 1);
    srl(scratch, scratch, 1);

    // Get the second half of the double. For some exponents we don't
    // actually need this because the bits get shifted out again, but
    // it's probably slower to test than just to do it.
    lw(scratch2, FieldMemOperand(source, HeapNumber::kMantissaOffset));
    // Extract the top 10 bits, and insert those bottom 10 bits of scratch.
    // The width of the field here is the same as the shift amount above.
    const int field_width = shift_distance;
    Ext(scratch2, scratch2, 32-shift_distance, field_width);
    Ins(scratch, scratch2, 0, field_width);
    // Move down according to the exponent.
    srlv(scratch, scratch, dest);
    // Prepare the negative version of our integer.
    subu(scratch2, zero_reg, scratch);
    // Trick to check sign bit (msb) held in dest, count leading zero.
    // 0 indicates negative, save negative version with conditional move.
    Clz(dest, dest);
    Movz(scratch, scratch2, dest);
    mov(dest, scratch);
  }
  bind(&done);
}


void MacroAssembler::EmitFPUTruncate(FPURoundingMode rounding_mode,
                                     FPURegister result,
                                     DoubleRegister double_input,
                                     Register scratch1,
                                     Register except_flag,
                                     CheckForInexactConversion check_inexact) {
  ASSERT(CpuFeatures::IsSupported(FPU));
  CpuFeatures::Scope scope(FPU);

  int32_t except_mask = kFCSRFlagMask;  // Assume interested in all exceptions.

  if (check_inexact == kDontCheckForInexactConversion) {
    // Ingore inexact exceptions.
    except_mask &= ~kFCSRInexactFlagMask;
  }

  // Save FCSR.
  cfc1(scratch1, FCSR);
  // Disable FPU exceptions.
  ctc1(zero_reg, FCSR);

  // Do operation based on rounding mode.
  switch (rounding_mode) {
    case kRoundToNearest:
      Round_w_d(result, double_input);
      break;
    case kRoundToZero:
      Trunc_w_d(result, double_input);
      break;
    case kRoundToPlusInf:
      Ceil_w_d(result, double_input);
      break;
    case kRoundToMinusInf:
      Floor_w_d(result, double_input);
      break;
  }  // End of switch-statement.

  // Retrieve FCSR.
  cfc1(except_flag, FCSR);
  // Restore FCSR.
  ctc1(scratch1, FCSR);

  // Check for fpu exceptions.
  And(except_flag, except_flag, Operand(except_mask));
}


void MacroAssembler::EmitOutOfInt32RangeTruncate(Register result,
                                                 Register input_high,
                                                 Register input_low,
                                                 Register scratch) {
  Label done, normal_exponent, restore_sign;
  // Extract the biased exponent in result.
  Ext(result,
      input_high,
      HeapNumber::kExponentShift,
      HeapNumber::kExponentBits);

  // Check for Infinity and NaNs, which should return 0.
  Subu(scratch, result, HeapNumber::kExponentMask);
  Movz(result, zero_reg, scratch);
  Branch(&done, eq, scratch, Operand(zero_reg));

  // Express exponent as delta to (number of mantissa bits + 31).
  Subu(result,
       result,
       Operand(HeapNumber::kExponentBias + HeapNumber::kMantissaBits + 31));

  // If the delta is strictly positive, all bits would be shifted away,
  // which means that we can return 0.
  Branch(&normal_exponent, le, result, Operand(zero_reg));
  mov(result, zero_reg);
  Branch(&done);

  bind(&normal_exponent);
  const int kShiftBase = HeapNumber::kNonMantissaBitsInTopWord - 1;
  // Calculate shift.
  Addu(scratch, result, Operand(kShiftBase + HeapNumber::kMantissaBits));

  // Save the sign.
  Register sign = result;
  result = no_reg;
  And(sign, input_high, Operand(HeapNumber::kSignMask));

  // On ARM shifts > 31 bits are valid and will result in zero. On MIPS we need
  // to check for this specific case.
  Label high_shift_needed, high_shift_done;
  Branch(&high_shift_needed, lt, scratch, Operand(32));
  mov(input_high, zero_reg);
  Branch(&high_shift_done);
  bind(&high_shift_needed);

  // Set the implicit 1 before the mantissa part in input_high.
  Or(input_high,
     input_high,
     Operand(1 << HeapNumber::kMantissaBitsInTopWord));
  // Shift the mantissa bits to the correct position.
  // We don't need to clear non-mantissa bits as they will be shifted away.
  // If they weren't, it would mean that the answer is in the 32bit range.
  sllv(input_high, input_high, scratch);

  bind(&high_shift_done);

  // Replace the shifted bits with bits from the lower mantissa word.
  Label pos_shift, shift_done;
  li(at, 32);
  subu(scratch, at, scratch);
  Branch(&pos_shift, ge, scratch, Operand(zero_reg));

  // Negate scratch.
  Subu(scratch, zero_reg, scratch);
  sllv(input_low, input_low, scratch);
  Branch(&shift_done);

  bind(&pos_shift);
  srlv(input_low, input_low, scratch);

  bind(&shift_done);
  Or(input_high, input_high, Operand(input_low));
  // Restore sign if necessary.
  mov(scratch, sign);
  result = sign;
  sign = no_reg;
  Subu(result, zero_reg, input_high);
  Movz(result, input_high, scratch);
  bind(&done);
}


void MacroAssembler::EmitECMATruncate(Register result,
                                      FPURegister double_input,
                                      FPURegister single_scratch,
                                      Register scratch,
                                      Register scratch2,
                                      Register scratch3) {
  CpuFeatures::Scope scope(FPU);
  ASSERT(!scratch2.is(result));
  ASSERT(!scratch3.is(result));
  ASSERT(!scratch3.is(scratch2));
  ASSERT(!scratch.is(result) &&
         !scratch.is(scratch2) &&
         !scratch.is(scratch3));
  ASSERT(!single_scratch.is(double_input));

  Label done;
  Label manual;

  // 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(single_scratch, double_input);
  mfc1(result, single_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));

  // Load the double value and perform a manual truncation.
  Register input_high = scratch2;
  Register input_low = scratch3;
  Move(input_low, input_high, double_input);
  EmitOutOfInt32RangeTruncate(result,
                              input_high,
                              input_low,
                              scratch);
  bind(&done);
}


void MacroAssembler::GetLeastBitsFromSmi(Register dst,
                                         Register src,
                                         int num_least_bits) {
  Ext(dst, src, kSmiTagSize, num_least_bits);
}


void MacroAssembler::GetLeastBitsFromInt32(Register dst,
                                           Register src,
                                           int num_least_bits) {
  And(dst, src, Operand((1 << num_least_bits) - 1));
}


// Emulated condtional branches do not emit a nop in the branch delay slot.
//
// BRANCH_ARGS_CHECK checks that conditional jump arguments are correct.
#define BRANCH_ARGS_CHECK(cond, rs, rt) ASSERT(                                \
    (cond == cc_always && rs.is(zero_reg) && rt.rm().is(zero_reg)) ||          \
    (cond != cc_always && (!rs.is(zero_reg) || !rt.rm().is(zero_reg))))


void MacroAssembler::Branch(int16_t offset, BranchDelaySlot bdslot) {
  BranchShort(offset, bdslot);
}


void MacroAssembler::Branch(int16_t offset, Condition cond, Register rs,
                            const Operand& rt,
                            BranchDelaySlot bdslot) {
  BranchShort(offset, cond, rs, rt, bdslot);
}


void MacroAssembler::Branch(Label* L, BranchDelaySlot bdslot) {
  if (L->is_bound()) {
    if (is_near(L)) {
      BranchShort(L, bdslot);
    } else {
      Jr(L, bdslot);
    }
  } else {
    if (is_trampoline_emitted()) {
      Jr(L, bdslot);
    } else {
      BranchShort(L, bdslot);
    }
  }
}


void MacroAssembler::Branch(Label* L, Condition cond, Register rs,
                            const Operand& rt,
                            BranchDelaySlot bdslot) {
  if (L->is_bound()) {
    if (is_near(L)) {
      BranchShort(L, cond, rs, rt, bdslot);
    } else {
      Label skip;
      Condition neg_cond = NegateCondition(cond);
      BranchShort(&skip, neg_cond, rs, rt);
      Jr(L, bdslot);
      bind(&skip);
    }
  } else {
    if (is_trampoline_emitted()) {
      Label skip;
      Condition neg_cond = NegateCondition(cond);
      BranchShort(&skip, neg_cond, rs, rt);
      Jr(L, bdslot);
      bind(&skip);
    } else {
      BranchShort(L, cond, rs, rt, bdslot);
    }
  }
}


void MacroAssembler::Branch(Label* L,
                            Condition cond,
                            Register rs,
                            Heap::RootListIndex index,
                            BranchDelaySlot bdslot) {
  LoadRoot(at, index);
  Branch(L, cond, rs, Operand(at), bdslot);
}


void MacroAssembler::BranchShort(int16_t offset, BranchDelaySlot bdslot) {
  b(offset);

  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}


void MacroAssembler::BranchShort(int16_t offset, Condition cond, Register rs,
                                 const Operand& rt,
                                 BranchDelaySlot bdslot) {
  BRANCH_ARGS_CHECK(cond, rs, rt);
  ASSERT(!rs.is(zero_reg));
  Register r2 = no_reg;
  Register scratch = at;

  if (rt.is_reg()) {
    // NOTE: 'at' can be clobbered by Branch but it is legal to use it as rs or
    // rt.
    r2 = rt.rm_;
    switch (cond) {
      case cc_always:
        b(offset);
        break;
      case eq:
        beq(rs, r2, offset);
        break;
      case ne:
        bne(rs, r2, offset);
        break;
      // Signed comparison.
      case greater:
        if (r2.is(zero_reg)) {
          bgtz(rs, offset);
        } else {
          slt(scratch, r2, rs);
          bne(scratch, zero_reg, offset);
        }
        break;
      case greater_equal:
        if (r2.is(zero_reg)) {
          bgez(rs, offset);
        } else {
          slt(scratch, rs, r2);
          beq(scratch, zero_reg, offset);
        }
        break;
      case less:
        if (r2.is(zero_reg)) {
          bltz(rs, offset);
        } else {
          slt(scratch, rs, r2);
          bne(scratch, zero_reg, offset);
        }
        break;
      case less_equal:
        if (r2.is(zero_reg)) {
          blez(rs, offset);
        } else {
          slt(scratch, r2, rs);
          beq(scratch, zero_reg, offset);
        }
        break;
      // Unsigned comparison.
      case Ugreater:
        if (r2.is(zero_reg)) {
          bgtz(rs, offset);
        } else {
          sltu(scratch, r2, rs);
          bne(scratch, zero_reg, offset);
        }
        break;
      case Ugreater_equal:
        if (r2.is(zero_reg)) {
          bgez(rs, offset);
        } else {
          sltu(scratch, rs, r2);
          beq(scratch, zero_reg, offset);
        }
        break;
      case Uless:
        if (r2.is(zero_reg)) {
          // No code needs to be emitted.
          return;
        } else {
          sltu(scratch, rs, r2);
          bne(scratch, zero_reg, offset);
        }
        break;
      case Uless_equal:
        if (r2.is(zero_reg)) {
          b(offset);
        } else {
          sltu(scratch, r2, rs);
          beq(scratch, zero_reg, offset);
        }
        break;
      default:
        UNREACHABLE();
    }
  } else {
    // Be careful to always use shifted_branch_offset only just before the
    // branch instruction, as the location will be remember for patching the
    // target.
    switch (cond) {
      case cc_always:
        b(offset);
        break;
      case eq:
        // We don't want any other register but scratch clobbered.
        ASSERT(!scratch.is(rs));
        r2 = scratch;
        li(r2, rt);
        beq(rs, r2, offset);
        break;
      case ne:
        // We don't want any other register but scratch clobbered.
        ASSERT(!scratch.is(rs));
        r2 = scratch;
        li(r2, rt);
        bne(rs, r2, offset);
        break;
      // Signed comparison.
      case greater:
        if (rt.imm32_ == 0) {
          bgtz(rs, offset);
        } else {
          r2 = scratch;
          li(r2, rt);
          slt(scratch, r2, rs);
          bne(scratch, zero_reg, offset);
        }
        break;
      case greater_equal:
        if (rt.imm32_ == 0) {
          bgez(rs, offset);
        } else if (is_int16(rt.imm32_)) {
          slti(scratch, rs, rt.imm32_);
          beq(scratch, zero_reg, offset);
        } else {
          r2 = scratch;
          li(r2, rt);
          slt(scratch, rs, r2);
          beq(scratch, zero_reg, offset);
        }
        break;
      case less:
        if (rt.imm32_ == 0) {
          bltz(rs, offset);
        } else if (is_int16(rt.imm32_)) {
          slti(scratch, rs, rt.imm32_);
          bne(scratch, zero_reg, offset);
        } else {
          r2 = scratch;
          li(r2, rt);
          slt(scratch, rs, r2);
          bne(scratch, zero_reg, offset);
        }
        break;
      case less_equal:
        if (rt.imm32_ == 0) {
          blez(rs, offset);
        } else {
          r2 = scratch;
          li(r2, rt);
          slt(scratch, r2, rs);
          beq(scratch, zero_reg, offset);
       }
       break;
      // Unsigned comparison.
      case Ugreater:
        if (rt.imm32_ == 0) {
          bgtz(rs, offset);
        } else {
          r2 = scratch;
          li(r2, rt);
          sltu(scratch, r2, rs);
          bne(scratch, zero_reg, offset);
        }
        break;
      case Ugreater_equal:
        if (rt.imm32_ == 0) {
          bgez(rs, offset);
        } else if (is_int16(rt.imm32_)) {
          sltiu(scratch, rs, rt.imm32_);
          beq(scratch, zero_reg, offset);
        } else {
          r2 = scratch;
          li(r2, rt);
          sltu(scratch, rs, r2);
          beq(scratch, zero_reg, offset);
        }
        break;
      case Uless:
        if (rt.imm32_ == 0) {
          // No code needs to be emitted.
          return;
        } else if (is_int16(rt.imm32_)) {
          sltiu(scratch, rs, rt.imm32_);
          bne(scratch, zero_reg, offset);
        } else {
          r2 = scratch;
          li(r2, rt);
          sltu(scratch, rs, r2);
          bne(scratch, zero_reg, offset);
        }
        break;
      case Uless_equal:
        if (rt.imm32_ == 0) {
          b(offset);
        } else {
          r2 = scratch;
          li(r2, rt);
          sltu(scratch, r2, rs);
          beq(scratch, zero_reg, offset);
        }
        break;
      default:
        UNREACHABLE();
    }
  }
  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}


void MacroAssembler::BranchShort(Label* L, BranchDelaySlot bdslot) {
  // We use branch_offset as an argument for the branch instructions to be sure
  // it is called just before generating the branch instruction, as needed.

  b(shifted_branch_offset(L, false));

  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}


void MacroAssembler::BranchShort(Label* L, Condition cond, Register rs,
                                 const Operand& rt,
                                 BranchDelaySlot bdslot) {
  BRANCH_ARGS_CHECK(cond, rs, rt);

  int32_t offset;
  Register r2 = no_reg;
  Register scratch = at;
  if (rt.is_reg()) {
    r2 = rt.rm_;
    // Be careful to always use shifted_branch_offset only just before the
    // branch instruction, as the location will be remember for patching the
    // target.
    switch (cond) {
      case cc_always:
        offset = shifted_branch_offset(L, false);
        b(offset);
        break;
      case eq:
        offset = shifted_branch_offset(L, false);
        beq(rs, r2, offset);
        break;
      case ne:
        offset = shifted_branch_offset(L, false);
        bne(rs, r2, offset);
        break;
      // Signed comparison.
      case greater:
        if (r2.is(zero_reg)) {
          offset = shifted_branch_offset(L, false);
          bgtz(rs, offset);
        } else {
          slt(scratch, r2, rs);
          offset = shifted_branch_offset(L, false);
          bne(scratch, zero_reg, offset);
        }
        break;
      case greater_equal:
        if (r2.is(zero_reg)) {
          offset = shifted_branch_offset(L, false);
          bgez(rs, offset);
        } else {
          slt(scratch, rs, r2);
          offset = shifted_branch_offset(L, false);
          beq(scratch, zero_reg, offset);
        }
        break;
      case less:
        if (r2.is(zero_reg)) {
          offset = shifted_branch_offset(L, false);
          bltz(rs, offset);
        } else {
          slt(scratch, rs, r2);
          offset = shifted_branch_offset(L, false);
          bne(scratch, zero_reg, offset);
        }
        break;
      case less_equal:
        if (r2.is(zero_reg)) {
          offset = shifted_branch_offset(L, false);
          blez(rs, offset);
        } else {
          slt(scratch, r2, rs);
          offset = shifted_branch_offset(L, false);
          beq(scratch, zero_reg, offset);
        }
        break;
      // Unsigned comparison.
      case Ugreater:
        if (r2.is(zero_reg)) {
          offset = shifted_branch_offset(L, false);
           bgtz(rs, offset);
        } else {
          sltu(scratch, r2, rs);
          offset = shifted_branch_offset(L, false);
          bne(scratch, zero_reg, offset);
        }
        break;
      case Ugreater_equal:
        if (r2.is(zero_reg)) {
          offset = shifted_branch_offset(L, false);
          bgez(rs, offset);
        } else {
          sltu(scratch, rs, r2);
          offset = shifted_branch_offset(L, false);
          beq(scratch, zero_reg, offset);
        }
        break;
      case Uless:
        if (r2.is(zero_reg)) {
          // No code needs to be emitted.
          return;
        } else {
          sltu(scratch, rs, r2);
          offset = shifted_branch_offset(L, false);
          bne(scratch, zero_reg, offset);
        }
        break;
      case Uless_equal:
        if (r2.is(zero_reg)) {
          offset = shifted_branch_offset(L, false);
          b(offset);
        } else {
          sltu(scratch, r2, rs);
          offset = shifted_branch_offset(L, false);
          beq(scratch, zero_reg, offset);
        }
        break;
      default:
        UNREACHABLE();
    }
  } else {
    // Be careful to always use shifted_branch_offset only just before the
    // branch instruction, as the location will be remember for patching the
    // target.
    switch (cond) {
      case cc_always:
        offset = shifted_branch_offset(L, false);
        b(offset);
        break;
      case eq:
        ASSERT(!scratch.is(rs));
        r2 = scratch;
        li(r2, rt);
        offset = shifted_branch_offset(L, false);
        beq(rs, r2, offset);
        break;
      case ne:
        ASSERT(!scratch.is(rs));
        r2 = scratch;
        li(r2, rt);
        offset = shifted_branch_offset(L, false);
        bne(rs, r2, offset);
        break;
      // Signed comparison.
      case greater:
        if (rt.imm32_ == 0) {
          offset = shifted_branch_offset(L, false);
          bgtz(rs, offset);
        } else {
          ASSERT(!scratch.is(rs));
          r2 = scratch;
          li(r2, rt);
          slt(scratch, r2, rs);
          offset = shifted_branch_offset(L, false);
          bne(scratch, zero_reg, offset);
        }
        break;
      case greater_equal:
        if (rt.imm32_ == 0) {
          offset = shifted_branch_offset(L, false);
          bgez(rs, offset);
        } else if (is_int16(rt.imm32_)) {
          slti(scratch, rs, rt.imm32_);
          offset = shifted_branch_offset(L, false);
          beq(scratch, zero_reg, offset);
        } else {
          ASSERT(!scratch.is(rs));
          r2 = scratch;
          li(r2, rt);
          slt(scratch, rs, r2);
          offset = shifted_branch_offset(L, false);
          beq(scratch, zero_reg, offset);
        }
        break;
      case less:
        if (rt.imm32_ == 0) {
          offset = shifted_branch_offset(L, false);
          bltz(rs, offset);
        } else if (is_int16(rt.imm32_)) {
          slti(scratch, rs, rt.imm32_);
          offset = shifted_branch_offset(L, false);
          bne(scratch, zero_reg, offset);
        } else {
          ASSERT(!scratch.is(rs));
          r2 = scratch;
          li(r2, rt);
          slt(scratch, rs, r2);
          offset = shifted_branch_offset(L, false);
          bne(scratch, zero_reg, offset);
        }
        break;
      case less_equal:
        if (rt.imm32_ == 0) {
          offset = shifted_branch_offset(L, false);
          blez(rs, offset);
        } else {
          ASSERT(!scratch.is(rs));
          r2 = scratch;
          li(r2, rt);
          slt(scratch, r2, rs);
          offset = shifted_branch_offset(L, false);
          beq(scratch, zero_reg, offset);
        }
        break;
      // Unsigned comparison.
      case Ugreater:
        if (rt.imm32_ == 0) {
          offset = shifted_branch_offset(L, false);
          bgtz(rs, offset);
        } else {
          ASSERT(!scratch.is(rs));
          r2 = scratch;
          li(r2, rt);
          sltu(scratch, r2, rs);
          offset = shifted_branch_offset(L, false);
          bne(scratch, zero_reg, offset);
        }
        break;
      case Ugreater_equal:
        if (rt.imm32_ == 0) {
          offset = shifted_branch_offset(L, false);
          bgez(rs, offset);
        } else if (is_int16(rt.imm32_)) {
          sltiu(scratch, rs, rt.imm32_);
          offset = shifted_branch_offset(L, false);
          beq(scratch, zero_reg, offset);
        } else {
          ASSERT(!scratch.is(rs));
          r2 = scratch;
          li(r2, rt);
          sltu(scratch, rs, r2);
          offset = shifted_branch_offset(L, false);
          beq(scratch, zero_reg, offset);
        }
        break;
     case Uless:
        if (rt.imm32_ == 0) {
          // No code needs to be emitted.
          return;
        } else if (is_int16(rt.imm32_)) {
          sltiu(scratch, rs, rt.imm32_);
          offset = shifted_branch_offset(L, false);
          bne(scratch, zero_reg, offset);
        } else {
          ASSERT(!scratch.is(rs));
          r2 = scratch;
          li(r2, rt);
          sltu(scratch, rs, r2);
          offset = shifted_branch_offset(L, false);
          bne(scratch, zero_reg, offset);
        }
        break;
      case Uless_equal:
        if (rt.imm32_ == 0) {
          offset = shifted_branch_offset(L, false);
          b(offset);
        } else {
          ASSERT(!scratch.is(rs));
          r2 = scratch;
          li(r2, rt);
          sltu(scratch, r2, rs);
          offset = shifted_branch_offset(L, false);
          beq(scratch, zero_reg, offset);
        }
        break;
      default:
        UNREACHABLE();
    }
  }
  // Check that offset could actually hold on an int16_t.
  ASSERT(is_int16(offset));
  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}


void MacroAssembler::BranchAndLink(int16_t offset, BranchDelaySlot bdslot) {
  BranchAndLinkShort(offset, bdslot);
}


void MacroAssembler::BranchAndLink(int16_t offset, Condition cond, Register rs,
                                   const Operand& rt,
                                   BranchDelaySlot bdslot) {
  BranchAndLinkShort(offset, cond, rs, rt, bdslot);
}


void MacroAssembler::BranchAndLink(Label* L, BranchDelaySlot bdslot) {
  if (L->is_bound()) {
    if (is_near(L)) {
      BranchAndLinkShort(L, bdslot);
    } else {
      Jalr(L, bdslot);
    }
  } else {
    if (is_trampoline_emitted()) {
      Jalr(L, bdslot);
    } else {
      BranchAndLinkShort(L, bdslot);
    }
  }
}


void MacroAssembler::BranchAndLink(Label* L, Condition cond, Register rs,
                                   const Operand& rt,
                                   BranchDelaySlot bdslot) {
  if (L->is_bound()) {
    if (is_near(L)) {
      BranchAndLinkShort(L, cond, rs, rt, bdslot);
    } else {
      Label skip;
      Condition neg_cond = NegateCondition(cond);
      BranchShort(&skip, neg_cond, rs, rt);
      Jalr(L, bdslot);
      bind(&skip);
    }
  } else {
    if (is_trampoline_emitted()) {
      Label skip;
      Condition neg_cond = NegateCondition(cond);
      BranchShort(&skip, neg_cond, rs, rt);
      Jalr(L, bdslot);
      bind(&skip);
    } else {
      BranchAndLinkShort(L, cond, rs, rt, bdslot);
    }
  }
}


// We need to use a bgezal or bltzal, but they can't be used directly with the
// slt instructions. We could use sub or add instead but we would miss overflow
// cases, so we keep slt and add an intermediate third instruction.
void MacroAssembler::BranchAndLinkShort(int16_t offset,
                                        BranchDelaySlot bdslot) {
  bal(offset);

  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}


void MacroAssembler::BranchAndLinkShort(int16_t offset, Condition cond,
                                        Register rs, const Operand& rt,
                                        BranchDelaySlot bdslot) {
  BRANCH_ARGS_CHECK(cond, rs, rt);
  Register r2 = no_reg;
  Register scratch = at;

  if (rt.is_reg()) {
    r2 = rt.rm_;
  } else if (cond != cc_always) {
    r2 = scratch;
    li(r2, rt);
  }

  switch (cond) {
    case cc_always:
      bal(offset);
      break;
    case eq:
      bne(rs, r2, 2);
      nop();
      bal(offset);
      break;
    case ne:
      beq(rs, r2, 2);
      nop();
      bal(offset);
      break;

    // Signed comparison.
    case greater:
      slt(scratch, r2, rs);
      addiu(scratch, scratch, -1);
      bgezal(scratch, offset);
      break;
    case greater_equal:
      slt(scratch, rs, r2);
      addiu(scratch, scratch, -1);
      bltzal(scratch, offset);
      break;
    case less:
      slt(scratch, rs, r2);
      addiu(scratch, scratch, -1);
      bgezal(scratch, offset);
      break;
    case less_equal:
      slt(scratch, r2, rs);
      addiu(scratch, scratch, -1);
      bltzal(scratch, offset);
      break;

    // Unsigned comparison.
    case Ugreater:
      sltu(scratch, r2, rs);
      addiu(scratch, scratch, -1);
      bgezal(scratch, offset);
      break;
    case Ugreater_equal:
      sltu(scratch, rs, r2);
      addiu(scratch, scratch, -1);
      bltzal(scratch, offset);
      break;
    case Uless:
      sltu(scratch, rs, r2);
      addiu(scratch, scratch, -1);
      bgezal(scratch, offset);
      break;
    case Uless_equal:
      sltu(scratch, r2, rs);
      addiu(scratch, scratch, -1);
      bltzal(scratch, offset);
      break;

    default:
      UNREACHABLE();
  }
  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}


void MacroAssembler::BranchAndLinkShort(Label* L, BranchDelaySlot bdslot) {
  bal(shifted_branch_offset(L, false));

  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}


void MacroAssembler::BranchAndLinkShort(Label* L, Condition cond, Register rs,
                                        const Operand& rt,
                                        BranchDelaySlot bdslot) {
  BRANCH_ARGS_CHECK(cond, rs, rt);

  int32_t offset;
  Register r2 = no_reg;
  Register scratch = at;
  if (rt.is_reg()) {
    r2 = rt.rm_;
  } else if (cond != cc_always) {
    r2 = scratch;
    li(r2, rt);
  }

  switch (cond) {
    case cc_always:
      offset = shifted_branch_offset(L, false);
      bal(offset);
      break;
    case eq:
      bne(rs, r2, 2);
      nop();
      offset = shifted_branch_offset(L, false);
      bal(offset);
      break;
    case ne:
      beq(rs, r2, 2);
      nop();
      offset = shifted_branch_offset(L, false);
      bal(offset);
      break;

    // Signed comparison.
    case greater:
      slt(scratch, r2, rs);
      addiu(scratch, scratch, -1);
      offset = shifted_branch_offset(L, false);
      bgezal(scratch, offset);
      break;
    case greater_equal:
      slt(scratch, rs, r2);
      addiu(scratch, scratch, -1);
      offset = shifted_branch_offset(L, false);
      bltzal(scratch, offset);
      break;
    case less:
      slt(scratch, rs, r2);
      addiu(scratch, scratch, -1);
      offset = shifted_branch_offset(L, false);
      bgezal(scratch, offset);
      break;
    case less_equal:
      slt(scratch, r2, rs);
      addiu(scratch, scratch, -1);
      offset = shifted_branch_offset(L, false);
      bltzal(scratch, offset);
      break;

    // Unsigned comparison.
    case Ugreater:
      sltu(scratch, r2, rs);
      addiu(scratch, scratch, -1);
      offset = shifted_branch_offset(L, false);
      bgezal(scratch, offset);
      break;
    case Ugreater_equal:
      sltu(scratch, rs, r2);
      addiu(scratch, scratch, -1);
      offset = shifted_branch_offset(L, false);
      bltzal(scratch, offset);
      break;
    case Uless:
      sltu(scratch, rs, r2);
      addiu(scratch, scratch, -1);
      offset = shifted_branch_offset(L, false);
      bgezal(scratch, offset);
      break;
    case Uless_equal:
      sltu(scratch, r2, rs);
      addiu(scratch, scratch, -1);
      offset = shifted_branch_offset(L, false);
      bltzal(scratch, offset);
      break;

    default:
      UNREACHABLE();
  }

  // Check that offset could actually hold on an int16_t.
  ASSERT(is_int16(offset));

  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}


void MacroAssembler::Jump(Register target,
                          Condition cond,
                          Register rs,
                          const Operand& rt,
                          BranchDelaySlot bd) {
  BlockTrampolinePoolScope block_trampoline_pool(this);
  if (cond == cc_always) {
    jr(target);
  } else {
    BRANCH_ARGS_CHECK(cond, rs, rt);
    Branch(2, NegateCondition(cond), rs, rt);
    jr(target);
  }
  // Emit a nop in the branch delay slot if required.
  if (bd == PROTECT)
    nop();
}


void MacroAssembler::Jump(intptr_t target,
                          RelocInfo::Mode rmode,
                          Condition cond,
                          Register rs,
                          const Operand& rt,
                          BranchDelaySlot bd) {
  Label skip;
  if (cond != cc_always) {
    Branch(USE_DELAY_SLOT, &skip, NegateCondition(cond), rs, rt);
  }
  // The first instruction of 'li' may be placed in the delay slot.
  // This is not an issue, t9 is expected to be clobbered anyway.
  li(t9, Operand(target, rmode));
  Jump(t9, al, zero_reg, Operand(zero_reg), bd);
  bind(&skip);
}


void MacroAssembler::Jump(Address target,
                          RelocInfo::Mode rmode,
                          Condition cond,
                          Register rs,
                          const Operand& rt,
                          BranchDelaySlot bd) {
  ASSERT(!RelocInfo::IsCodeTarget(rmode));
  Jump(reinterpret_cast<intptr_t>(target), rmode, cond, rs, rt, bd);
}


void MacroAssembler::Jump(Handle<Code> code,
                          RelocInfo::Mode rmode,
                          Condition cond,
                          Register rs,
                          const Operand& rt,
                          BranchDelaySlot bd) {
  ASSERT(RelocInfo::IsCodeTarget(rmode));
  Jump(reinterpret_cast<intptr_t>(code.location()), rmode, cond, rs, rt, bd);
}


int MacroAssembler::CallSize(Register target,
                             Condition cond,
                             Register rs,
                             const Operand& rt,
                             BranchDelaySlot bd) {
  int size = 0;

  if (cond == cc_always) {
    size += 1;
  } else {
    size += 3;
  }

  if (bd == PROTECT)
    size += 1;

  return size * kInstrSize;
}


// Note: To call gcc-compiled C code on mips, you must call thru t9.
void MacroAssembler::Call(Register target,
                          Condition cond,
                          Register rs,
                          const Operand& rt,
                          BranchDelaySlot bd) {
  BlockTrampolinePoolScope block_trampoline_pool(this);
  Label start;
  bind(&start);
  if (cond == cc_always) {
    jalr(target);
  } else {
    BRANCH_ARGS_CHECK(cond, rs, rt);
    Branch(2, NegateCondition(cond), rs, rt);
    jalr(target);
  }
  // Emit a nop in the branch delay slot if required.
  if (bd == PROTECT)
    nop();

  ASSERT_EQ(CallSize(target, cond, rs, rt, bd),
            SizeOfCodeGeneratedSince(&start));
}


int MacroAssembler::CallSize(Address target,
                             RelocInfo::Mode rmode,
                             Condition cond,
                             Register rs,
                             const Operand& rt,
                             BranchDelaySlot bd) {
  int size = CallSize(t9, cond, rs, rt, bd);
  return size + 2 * kInstrSize;
}


void MacroAssembler::Call(Address target,
                          RelocInfo::Mode rmode,
                          Condition cond,
                          Register rs,
                          const Operand& rt,
                          BranchDelaySlot bd) {
  BlockTrampolinePoolScope block_trampoline_pool(this);
  Label start;
  bind(&start);
  int32_t target_int = reinterpret_cast<int32_t>(target);
  // Must record previous source positions before the
  // li() generates a new code target.
  positions_recorder()->WriteRecordedPositions();
  li(t9, Operand(target_int, rmode), CONSTANT_SIZE);
  Call(t9, cond, rs, rt, bd);
  ASSERT_EQ(CallSize(target, rmode, cond, rs, rt, bd),
            SizeOfCodeGeneratedSince(&start));
}


int MacroAssembler::CallSize(Handle<Code> code,
                             RelocInfo::Mode rmode,
                             unsigned ast_id,
                             Condition cond,
                             Register rs,
                             const Operand& rt,
                             BranchDelaySlot bd) {
  return CallSize(reinterpret_cast<Address>(code.location()),
      rmode, cond, rs, rt, bd);
}


void MacroAssembler::Call(Handle<Code> code,
                          RelocInfo::Mode rmode,
                          unsigned ast_id,
                          Condition cond,
                          Register rs,
                          const Operand& rt,
                          BranchDelaySlot bd) {
  BlockTrampolinePoolScope block_trampoline_pool(this);
  Label start;
  bind(&start);
  ASSERT(RelocInfo::IsCodeTarget(rmode));
  if (rmode == RelocInfo::CODE_TARGET && ast_id != kNoASTId) {
    SetRecordedAstId(ast_id);
    rmode = RelocInfo::CODE_TARGET_WITH_ID;
  }
  Call(reinterpret_cast<Address>(code.location()), rmode, cond, rs, rt, bd);
  ASSERT_EQ(CallSize(code, rmode, ast_id, cond, rs, rt, bd),
            SizeOfCodeGeneratedSince(&start));
}


void MacroAssembler::Ret(Condition cond,
                         Register rs,
                         const Operand& rt,
                         BranchDelaySlot bd) {
  Jump(ra, cond, rs, rt, bd);
}


void MacroAssembler::J(Label* L, BranchDelaySlot bdslot) {
  BlockTrampolinePoolScope block_trampoline_pool(this);

  uint32_t imm28;
  imm28 = jump_address(L);
  imm28 &= kImm28Mask;
  { BlockGrowBufferScope block_buf_growth(this);
    // Buffer growth (and relocation) must be blocked for internal references
    // until associated instructions are emitted and available to be patched.
    RecordRelocInfo(RelocInfo::INTERNAL_REFERENCE);
    j(imm28);
  }
  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}


void MacroAssembler::Jr(Label* L, BranchDelaySlot bdslot) {
  BlockTrampolinePoolScope block_trampoline_pool(this);

  uint32_t imm32;
  imm32 = jump_address(L);
  { BlockGrowBufferScope block_buf_growth(this);
    // Buffer growth (and relocation) must be blocked for internal references
    // until associated instructions are emitted and available to be patched.
    RecordRelocInfo(RelocInfo::INTERNAL_REFERENCE);
    lui(at, (imm32 & kHiMask) >> kLuiShift);
    ori(at, at, (imm32 & kImm16Mask));
  }
  jr(at);

  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}


void MacroAssembler::Jalr(Label* L, BranchDelaySlot bdslot) {
  BlockTrampolinePoolScope block_trampoline_pool(this);

  uint32_t imm32;
  imm32 = jump_address(L);
  { BlockGrowBufferScope block_buf_growth(this);
    // Buffer growth (and relocation) must be blocked for internal references
    // until associated instructions are emitted and available to be patched.
    RecordRelocInfo(RelocInfo::INTERNAL_REFERENCE);
    lui(at, (imm32 & kHiMask) >> kLuiShift);
    ori(at, at, (imm32 & kImm16Mask));
  }
  jalr(at);

  // Emit a nop in the branch delay slot if required.
  if (bdslot == PROTECT)
    nop();
}

void MacroAssembler::DropAndRet(int drop) {
  Ret(USE_DELAY_SLOT);
  addiu(sp, sp, drop * kPointerSize);
}

void MacroAssembler::DropAndRet(int drop,
                                Condition cond,
                                Register r1,
                                const Operand& r2) {
  // Both Drop and Ret need to be conditional.
  Label skip;
  if (cond != cc_always) {
    Branch(&skip, NegateCondition(cond), r1, r2);
  }

  Drop(drop);
  Ret();

  if (cond != cc_always) {
    bind(&skip);
  }
}


void MacroAssembler::Drop(int count,
                          Condition cond,
                          Register reg,
                          const Operand& op) {
  if (count <= 0) {
    return;
  }

  Label skip;

  if (cond != al) {
     Branch(&skip, NegateCondition(cond), reg, op);
  }

  addiu(sp, sp, count * kPointerSize);

  if (cond != al) {
    bind(&skip);
  }
}



void MacroAssembler::Swap(Register reg1,
                          Register reg2,
                          Register scratch) {
  if (scratch.is(no_reg)) {
    Xor(reg1, reg1, Operand(reg2));
    Xor(reg2, reg2, Operand(reg1));
    Xor(reg1, reg1, Operand(reg2));
  } else {
    mov(scratch, reg1);
    mov(reg1, reg2);
    mov(reg2, scratch);
  }
}


void MacroAssembler::Call(Label* target) {
  BranchAndLink(target);
}


void MacroAssembler::Push(Handle<Object> handle) {
  li(at, Operand(handle));
  push(at);
}


#ifdef ENABLE_DEBUGGER_SUPPORT

void MacroAssembler::DebugBreak() {
  PrepareCEntryArgs(0);
  PrepareCEntryFunction(ExternalReference(Runtime::kDebugBreak, isolate()));
  CEntryStub ces(1);
  ASSERT(AllowThisStubCall(&ces));
  Call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
}

#endif  // ENABLE_DEBUGGER_SUPPORT


// ---------------------------------------------------------------------------
// Exception handling.

void MacroAssembler::PushTryHandler(StackHandler::Kind kind,
                                    int handler_index) {
  // Adjust this code if not the case.
  STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);

  // For the JSEntry handler, we must preserve a0-a3 and s0.
  // t1-t3 are available. We will build up the handler from the bottom by
  // pushing on the stack.
  // Set up the code object (t1) and the state (t2) for pushing.
  unsigned state =
      StackHandler::IndexField::encode(handler_index) |
      StackHandler::KindField::encode(kind);
  li(t1, Operand(CodeObject()), CONSTANT_SIZE);
  li(t2, Operand(state));

  // Push the frame pointer, context, state, and code object.
  if (kind == StackHandler::JS_ENTRY) {
    ASSERT_EQ(Smi::FromInt(0), 0);
    // The second zero_reg indicates no context.
    // The first zero_reg is the NULL frame pointer.
    // The operands are reversed to match the order of MultiPush/Pop.
    Push(zero_reg, zero_reg, t2, t1);
  } else {
    MultiPush(t1.bit() | t2.bit() | cp.bit() | fp.bit());
  }

  // Link the current handler as the next handler.
  li(t2, Operand(ExternalReference(Isolate::kHandlerAddress, isolate())));
  lw(t1, MemOperand(t2));
  push(t1);
  // Set this new handler as the current one.
  sw(sp, MemOperand(t2));
}


void MacroAssembler::PopTryHandler() {
  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
  pop(a1);
  Addu(sp, sp, Operand(StackHandlerConstants::kSize - kPointerSize));
  li(at, Operand(ExternalReference(Isolate::kHandlerAddress, isolate())));
  sw(a1, MemOperand(at));
}


void MacroAssembler::JumpToHandlerEntry() {
  // Compute the handler entry address and jump to it.  The handler table is
  // a fixed array of (smi-tagged) code offsets.
  // v0 = exception, a1 = code object, a2 = state.
  lw(a3, FieldMemOperand(a1, Code::kHandlerTableOffset));  // Handler table.
  Addu(a3, a3, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
  srl(a2, a2, StackHandler::kKindWidth);  // Handler index.
  sll(a2, a2, kPointerSizeLog2);
  Addu(a2, a3, a2);
  lw(a2, MemOperand(a2));  // Smi-tagged offset.
  Addu(a1, a1, Operand(Code::kHeaderSize - kHeapObjectTag));  // Code start.
  sra(t9, a2, kSmiTagSize);
  Addu(t9, t9, a1);
  Jump(t9);  // Jump.
}


void MacroAssembler::Throw(Register value) {
  // Adjust this code if not the case.
  STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
  STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);

  // The exception is expected in v0.
  Move(v0, value);

  // Drop the stack pointer to the top of the top handler.
  li(a3, Operand(ExternalReference(Isolate::kHandlerAddress,
                                   isolate())));
  lw(sp, MemOperand(a3));

  // Restore the next handler.
  pop(a2);
  sw(a2, MemOperand(a3));

  // Get the code object (a1) and state (a2).  Restore the context and frame
  // pointer.
  MultiPop(a1.bit() | a2.bit() | cp.bit() | fp.bit());

  // If the handler is a JS frame, restore the context to the frame.
  // (kind == ENTRY) == (fp == 0) == (cp == 0), so we could test either fp
  // or cp.
  Label done;
  Branch(&done, eq, cp, Operand(zero_reg));
  sw(cp, MemOperand(fp, StandardFrameConstants::kContextOffset));
  bind(&done);

  JumpToHandlerEntry();
}


void MacroAssembler::ThrowUncatchable(Register value) {
  // Adjust this code if not the case.
  STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);

  // The exception is expected in v0.
  if (!value.is(v0)) {
    mov(v0, value);
  }
  // Drop the stack pointer to the top of the top stack handler.
  li(a3, Operand(ExternalReference(Isolate::kHandlerAddress, isolate())));
  lw(sp, MemOperand(a3));

  // Unwind the handlers until the ENTRY handler is found.
  Label fetch_next, check_kind;
  jmp(&check_kind);
  bind(&fetch_next);
  lw(sp, MemOperand(sp, StackHandlerConstants::kNextOffset));

  bind(&check_kind);
  STATIC_ASSERT(StackHandler::JS_ENTRY == 0);
  lw(a2, MemOperand(sp, StackHandlerConstants::kStateOffset));
  And(a2, a2, Operand(StackHandler::KindField::kMask));
  Branch(&fetch_next, ne, a2, Operand(zero_reg));

  // Set the top handler address to next handler past the top ENTRY handler.
  pop(a2);
  sw(a2, MemOperand(a3));

  // Get the code object (a1) and state (a2).  Clear the context and frame
  // pointer (0 was saved in the handler).
  MultiPop(a1.bit() | a2.bit() | cp.bit() | fp.bit());

  JumpToHandlerEntry();
}


void MacroAssembler::AllocateInNewSpace(int object_size,
                                        Register result,
                                        Register scratch1,
                                        Register scratch2,
                                        Label* gc_required,
                                        AllocationFlags flags) {
  if (!FLAG_inline_new) {
    if (emit_debug_code()) {
      // Trash the registers to simulate an allocation failure.
      li(result, 0x7091);
      li(scratch1, 0x7191);
      li(scratch2, 0x7291);
    }
    jmp(gc_required);
    return;
  }

  ASSERT(!result.is(scratch1));
  ASSERT(!result.is(scratch2));
  ASSERT(!scratch1.is(scratch2));
  ASSERT(!scratch1.is(t9));
  ASSERT(!scratch2.is(t9));
  ASSERT(!result.is(t9));

  // Make object size into bytes.
  if ((flags & SIZE_IN_WORDS) != 0) {
    object_size *= kPointerSize;
  }
  ASSERT_EQ(0, object_size & kObjectAlignmentMask);

  // Check relative positions of allocation top and limit addresses.
  // ARM adds additional checks to make sure the ldm instruction can be
  // used. On MIPS we don't have ldm so we don't need additional checks either.
  ExternalReference new_space_allocation_top =
      ExternalReference::new_space_allocation_top_address(isolate());
  ExternalReference new_space_allocation_limit =
      ExternalReference::new_space_allocation_limit_address(isolate());
  intptr_t top   =
      reinterpret_cast<intptr_t>(new_space_allocation_top.address());
  intptr_t limit =
      reinterpret_cast<intptr_t>(new_space_allocation_limit.address());
  ASSERT((limit - top) == kPointerSize);

  // Set up allocation top address and object size registers.
  Register topaddr = scratch1;
  Register obj_size_reg = scratch2;
  li(topaddr, Operand(new_space_allocation_top));
  li(obj_size_reg, Operand(object_size));

  // This code stores a temporary value in t9.
  if ((flags & RESULT_CONTAINS_TOP) == 0) {
    // Load allocation top into result and allocation limit into t9.
    lw(result, MemOperand(topaddr));
    lw(t9, MemOperand(topaddr, kPointerSize));
  } else {
    if (emit_debug_code()) {
      // Assert that result actually contains top on entry. t9 is used
      // immediately below so this use of t9 does not cause difference with
      // respect to register content between debug and release mode.
      lw(t9, MemOperand(topaddr));
      Check(eq, "Unexpected allocation top", result, Operand(t9));
    }
    // Load allocation limit into t9. Result already contains allocation top.
    lw(t9, MemOperand(topaddr, limit - top));
  }

  // Calculate new top and bail out if new space is exhausted. Use result
  // to calculate the new top.
  Addu(scratch2, result, Operand(obj_size_reg));
  Branch(gc_required, Ugreater, scratch2, Operand(t9));
  sw(scratch2, MemOperand(topaddr));

  // Tag object if requested.
  if ((flags & TAG_OBJECT) != 0) {
    Addu(result, result, Operand(kHeapObjectTag));
  }
}


void MacroAssembler::AllocateInNewSpace(Register object_size,
                                        Register result,
                                        Register scratch1,
                                        Register scratch2,
                                        Label* gc_required,
                                        AllocationFlags flags) {
  if (!FLAG_inline_new) {
    if (emit_debug_code()) {
      // Trash the registers to simulate an allocation failure.
      li(result, 0x7091);
      li(scratch1, 0x7191);
      li(scratch2, 0x7291);
    }
    jmp(gc_required);
    return;
  }

  ASSERT(!result.is(scratch1));
  ASSERT(!result.is(scratch2));
  ASSERT(!scratch1.is(scratch2));
  ASSERT(!object_size.is(t9));
  ASSERT(!scratch1.is(t9) && !scratch2.is(t9) && !result.is(t9));

  // Check relative positions of allocation top and limit addresses.
  // ARM adds additional checks to make sure the ldm instruction can be
  // used. On MIPS we don't have ldm so we don't need additional checks either.
  ExternalReference new_space_allocation_top =
      ExternalReference::new_space_allocation_top_address(isolate());
  ExternalReference new_space_allocation_limit =
      ExternalReference::new_space_allocation_limit_address(isolate());
  intptr_t top   =
      reinterpret_cast<intptr_t>(new_space_allocation_top.address());
  intptr_t limit =
      reinterpret_cast<intptr_t>(new_space_allocation_limit.address());
  ASSERT((limit - top) == kPointerSize);

  // Set up allocation top address and object size registers.
  Register topaddr = scratch1;
  li(topaddr, Operand(new_space_allocation_top));

  // This code stores a temporary value in t9.
  if ((flags & RESULT_CONTAINS_TOP) == 0) {
    // Load allocation top into result and allocation limit into t9.
    lw(result, MemOperand(topaddr));
    lw(t9, MemOperand(topaddr, kPointerSize));
  } else {
    if (emit_debug_code()) {
      // Assert that result actually contains top on entry. t9 is used
      // immediately below so this use of t9 does not cause difference with
      // respect to register content between debug and release mode.
      lw(t9, MemOperand(topaddr));
      Check(eq, "Unexpected allocation top", result, Operand(t9));
    }
    // Load allocation limit into t9. Result already contains allocation top.
    lw(t9, MemOperand(topaddr, limit - top));
  }

  // Calculate new top and bail out if new space is exhausted. Use result
  // to calculate the new top. Object size may be in words so a shift is
  // required to get the number of bytes.
  if ((flags & SIZE_IN_WORDS) != 0) {
    sll(scratch2, object_size, kPointerSizeLog2);
    Addu(scratch2, result, scratch2);
  } else {
    Addu(scratch2, result, Operand(object_size));
  }
  Branch(gc_required, Ugreater, scratch2, Operand(t9));

  // Update allocation top. result temporarily holds the new top.
  if (emit_debug_code()) {
    And(t9, scratch2, Operand(kObjectAlignmentMask));
    Check(eq, "Unaligned allocation in new space", t9, Operand(zero_reg));
  }
  sw(scratch2, MemOperand(topaddr));

  // Tag object if requested.
  if ((flags & TAG_OBJECT) != 0) {
    Addu(result, result, Operand(kHeapObjectTag));
  }
}


void MacroAssembler::UndoAllocationInNewSpace(Register object,
                                              Register scratch) {
  ExternalReference new_space_allocation_top =
      ExternalReference::new_space_allocation_top_address(isolate());

  // Make sure the object has no tag before resetting top.
  And(object, object, Operand(~kHeapObjectTagMask));
#ifdef DEBUG
  // Check that the object un-allocated is below the current top.
  li(scratch, Operand(new_space_allocation_top));
  lw(scratch, MemOperand(scratch));
  Check(less, "Undo allocation of non allocated memory",
      object, Operand(scratch));
#endif
  // Write the address of the object to un-allocate as the current top.
  li(scratch, Operand(new_space_allocation_top));
  sw(object, MemOperand(scratch));
}


void MacroAssembler::AllocateTwoByteString(Register result,
                                           Register length,
                                           Register scratch1,
                                           Register scratch2,
                                           Register scratch3,
                                           Label* gc_required) {
  // Calculate the number of bytes needed for the characters in the string while
  // observing object alignment.
  ASSERT((SeqTwoByteString::kHeaderSize & kObjectAlignmentMask) == 0);
  sll(scratch1, length, 1);  // Length in bytes, not chars.
  addiu(scratch1, scratch1,
       kObjectAlignmentMask + SeqTwoByteString::kHeaderSize);
  And(scratch1, scratch1, Operand(~kObjectAlignmentMask));

  // Allocate two-byte string in new space.
  AllocateInNewSpace(scratch1,
                     result,
                     scratch2,
                     scratch3,
                     gc_required,
                     TAG_OBJECT);

  // Set the map, length and hash field.
  InitializeNewString(result,
                      length,
                      Heap::kStringMapRootIndex,
                      scratch1,
                      scratch2);
}


void MacroAssembler::AllocateAsciiString(Register result,
                                         Register length,
                                         Register scratch1,
                                         Register scratch2,
                                         Register scratch3,
                                         Label* gc_required) {
  // Calculate the number of bytes needed for the characters in the string
  // while observing object alignment.
  ASSERT((SeqAsciiString::kHeaderSize & kObjectAlignmentMask) == 0);
  ASSERT(kCharSize == 1);
  addiu(scratch1, length, kObjectAlignmentMask + SeqAsciiString::kHeaderSize);
  And(scratch1, scratch1, Operand(~kObjectAlignmentMask));

  // Allocate ASCII string in new space.
  AllocateInNewSpace(scratch1,
                     result,
                     scratch2,
                     scratch3,
                     gc_required,
                     TAG_OBJECT);

  // Set the map, length and hash field.
  InitializeNewString(result,
                      length,
                      Heap::kAsciiStringMapRootIndex,
                      scratch1,
                      scratch2);
}


void MacroAssembler::AllocateTwoByteConsString(Register result,
                                               Register length,
                                               Register scratch1,
                                               Register scratch2,
                                               Label* gc_required) {
  AllocateInNewSpace(ConsString::kSize,
                     result,
                     scratch1,
                     scratch2,
                     gc_required,
                     TAG_OBJECT);
  InitializeNewString(result,
                      length,
                      Heap::kConsStringMapRootIndex,
                      scratch1,
                      scratch2);
}


void MacroAssembler::AllocateAsciiConsString(Register result,
                                             Register length,
                                             Register scratch1,
                                             Register scratch2,
                                             Label* gc_required) {
  AllocateInNewSpace(ConsString::kSize,
                     result,
                     scratch1,
                     scratch2,
                     gc_required,
                     TAG_OBJECT);
  InitializeNewString(result,
                      length,
                      Heap::kConsAsciiStringMapRootIndex,
                      scratch1,
                      scratch2);
}


void MacroAssembler::AllocateTwoByteSlicedString(Register result,
                                                 Register length,
                                                 Register scratch1,
                                                 Register scratch2,
                                                 Label* gc_required) {
  AllocateInNewSpace(SlicedString::kSize,
                     result,
                     scratch1,
                     scratch2,
                     gc_required,
                     TAG_OBJECT);

  InitializeNewString(result,
                      length,
                      Heap::kSlicedStringMapRootIndex,
                      scratch1,
                      scratch2);
}


void MacroAssembler::AllocateAsciiSlicedString(Register result,
                                               Register length,
                                               Register scratch1,
                                               Register scratch2,
                                               Label* gc_required) {
  AllocateInNewSpace(SlicedString::kSize,
                     result,
                     scratch1,
                     scratch2,
                     gc_required,
                     TAG_OBJECT);

  InitializeNewString(result,
                      length,
                      Heap::kSlicedAsciiStringMapRootIndex,
                      scratch1,
                      scratch2);
}


// Allocates a heap number or jumps to the label if the young space is full and
// a scavenge is needed.
void MacroAssembler::AllocateHeapNumber(Register result,
                                        Register scratch1,
                                        Register scratch2,
                                        Register heap_number_map,
                                        Label* need_gc) {
  // Allocate an object in the heap for the heap number and tag it as a heap
  // object.
  AllocateInNewSpace(HeapNumber::kSize,
                     result,
                     scratch1,
                     scratch2,
                     need_gc,
                     TAG_OBJECT);

  // Store heap number map in the allocated object.
  AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
  sw(heap_number_map, FieldMemOperand(result, HeapObject::kMapOffset));
}


void MacroAssembler::AllocateHeapNumberWithValue(Register result,
                                                 FPURegister value,
                                                 Register scratch1,
                                                 Register scratch2,
                                                 Label* gc_required) {
  LoadRoot(t8, Heap::kHeapNumberMapRootIndex);
  AllocateHeapNumber(result, scratch1, scratch2, t8, gc_required);
  sdc1(value, FieldMemOperand(result, HeapNumber::kValueOffset));
}


// Copies a fixed number of fields of heap objects from src to dst.
void MacroAssembler::CopyFields(Register dst,
                                Register src,
                                RegList temps,
                                int field_count) {
  ASSERT((temps & dst.bit()) == 0);
  ASSERT((temps & src.bit()) == 0);
  // Primitive implementation using only one temporary register.

  Register tmp = no_reg;
  // Find a temp register in temps list.
  for (int i = 0; i < kNumRegisters; i++) {
    if ((temps & (1 << i)) != 0) {
      tmp.code_ = i;
      break;
    }
  }
  ASSERT(!tmp.is(no_reg));

  for (int i = 0; i < field_count; i++) {
    lw(tmp, FieldMemOperand(src, i * kPointerSize));
    sw(tmp, FieldMemOperand(dst, i * kPointerSize));
  }
}


void MacroAssembler::CopyBytes(Register src,
                               Register dst,
                               Register length,
                               Register scratch) {
  Label align_loop, align_loop_1, word_loop, byte_loop, byte_loop_1, done;

  // Align src before copying in word size chunks.
  bind(&align_loop);
  Branch(&done, eq, length, Operand(zero_reg));
  bind(&align_loop_1);
  And(scratch, src, kPointerSize - 1);
  Branch(&word_loop, eq, scratch, Operand(zero_reg));
  lbu(scratch, MemOperand(src));
  Addu(src, src, 1);
  sb(scratch, MemOperand(dst));
  Addu(dst, dst, 1);
  Subu(length, length, Operand(1));
  Branch(&byte_loop_1, ne, length, Operand(zero_reg));

  // Copy bytes in word size chunks.
  bind(&word_loop);
  if (emit_debug_code()) {
    And(scratch, src, kPointerSize - 1);
    Assert(eq, "Expecting alignment for CopyBytes",
        scratch, Operand(zero_reg));
  }
  Branch(&byte_loop, lt, length, Operand(kPointerSize));
  lw(scratch, MemOperand(src));
  Addu(src, src, kPointerSize);

  // TODO(kalmard) check if this can be optimized to use sw in most cases.
  // Can't use unaligned access - copy byte by byte.
  sb(scratch, MemOperand(dst, 0));
  srl(scratch, scratch, 8);
  sb(scratch, MemOperand(dst, 1));
  srl(scratch, scratch, 8);
  sb(scratch, MemOperand(dst, 2));
  srl(scratch, scratch, 8);
  sb(scratch, MemOperand(dst, 3));
  Addu(dst, dst, 4);

  Subu(length, length, Operand(kPointerSize));
  Branch(&word_loop);

  // Copy the last bytes if any left.
  bind(&byte_loop);
  Branch(&done, eq, length, Operand(zero_reg));
  bind(&byte_loop_1);
  lbu(scratch, MemOperand(src));
  Addu(src, src, 1);
  sb(scratch, MemOperand(dst));
  Addu(dst, dst, 1);
  Subu(length, length, Operand(1));
  Branch(&byte_loop_1, ne, length, Operand(zero_reg));
  bind(&done);
}


void MacroAssembler::InitializeFieldsWithFiller(Register start_offset,
                                                Register end_offset,
                                                Register filler) {
  Label loop, entry;
  Branch(&entry);
  bind(&loop);
  sw(filler, MemOperand(start_offset));
  Addu(start_offset, start_offset, kPointerSize);
  bind(&entry);
  Branch(&loop, lt, start_offset, Operand(end_offset));
}


void MacroAssembler::CheckFastElements(Register map,
                                       Register scratch,
                                       Label* fail) {
  STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
  STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
  STATIC_ASSERT(FAST_ELEMENTS == 2);
  STATIC_ASSERT(FAST_HOLEY_ELEMENTS == 3);
  lbu(scratch, FieldMemOperand(map, Map::kBitField2Offset));
  Branch(fail, hi, scratch,
         Operand(Map::kMaximumBitField2FastHoleyElementValue));
}


void MacroAssembler::CheckFastObjectElements(Register map,
                                             Register scratch,
                                             Label* fail) {
  STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
  STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
  STATIC_ASSERT(FAST_ELEMENTS == 2);
  STATIC_ASSERT(FAST_HOLEY_ELEMENTS == 3);
  lbu(scratch, FieldMemOperand(map, Map::kBitField2Offset));
  Branch(fail, ls, scratch,
         Operand(Map::kMaximumBitField2FastHoleySmiElementValue));
  Branch(fail, hi, scratch,
         Operand(Map::kMaximumBitField2FastHoleyElementValue));
}


void MacroAssembler::CheckFastSmiElements(Register map,
                                          Register scratch,
                                          Label* fail) {
  STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
  STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
  lbu(scratch, FieldMemOperand(map, Map::kBitField2Offset));
  Branch(fail, hi, scratch,
         Operand(Map::kMaximumBitField2FastHoleySmiElementValue));
}


void MacroAssembler::StoreNumberToDoubleElements(Register value_reg,
                                                 Register key_reg,
                                                 Register receiver_reg,
                                                 Register elements_reg,
                                                 Register scratch1,
                                                 Register scratch2,
                                                 Register scratch3,
                                                 Register scratch4,
                                                 Label* fail) {
  Label smi_value, maybe_nan, have_double_value, is_nan, done;
  Register mantissa_reg = scratch2;
  Register exponent_reg = scratch3;

  // Handle smi values specially.
  JumpIfSmi(value_reg, &smi_value);

  // Ensure that the object is a heap number
  CheckMap(value_reg,
           scratch1,
           Heap::kHeapNumberMapRootIndex,
           fail,
           DONT_DO_SMI_CHECK);

  // Check for nan: all NaN values have a value greater (signed) than 0x7ff00000
  // in the exponent.
  li(scratch1, Operand(kNaNOrInfinityLowerBoundUpper32));
  lw(exponent_reg, FieldMemOperand(value_reg, HeapNumber::kExponentOffset));
  Branch(&maybe_nan, ge, exponent_reg, Operand(scratch1));

  lw(mantissa_reg, FieldMemOperand(value_reg, HeapNumber::kMantissaOffset));

  bind(&have_double_value);
  sll(scratch1, key_reg, kDoubleSizeLog2 - kSmiTagSize);
  Addu(scratch1, scratch1, elements_reg);
  sw(mantissa_reg, FieldMemOperand(scratch1, FixedDoubleArray::kHeaderSize));
  uint32_t offset = FixedDoubleArray::kHeaderSize + sizeof(kHoleNanLower32);
  sw(exponent_reg, FieldMemOperand(scratch1, offset));
  jmp(&done);

  bind(&maybe_nan);
  // Could be NaN or Infinity. If fraction is not zero, it's NaN, otherwise
  // it's an Infinity, and the non-NaN code path applies.
  Branch(&is_nan, gt, exponent_reg, Operand(scratch1));
  lw(mantissa_reg, FieldMemOperand(value_reg, HeapNumber::kMantissaOffset));
  Branch(&have_double_value, eq, mantissa_reg, Operand(zero_reg));
  bind(&is_nan);
  // Load canonical NaN for storing into the double array.
  uint64_t nan_int64 = BitCast<uint64_t>(
      FixedDoubleArray::canonical_not_the_hole_nan_as_double());
  li(mantissa_reg, Operand(static_cast<uint32_t>(nan_int64)));
  li(exponent_reg, Operand(static_cast<uint32_t>(nan_int64 >> 32)));
  jmp(&have_double_value);

  bind(&smi_value);
  Addu(scratch1, elements_reg,
      Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag));
  sll(scratch2, key_reg, kDoubleSizeLog2 - kSmiTagSize);
  Addu(scratch1, scratch1, scratch2);
  // scratch1 is now effective address of the double element

  FloatingPointHelper::Destination destination;
  if (CpuFeatures::IsSupported(FPU)) {
    destination = FloatingPointHelper::kFPURegisters;
  } else {
    destination = FloatingPointHelper::kCoreRegisters;
  }

  Register untagged_value = receiver_reg;
  SmiUntag(untagged_value, value_reg);
  FloatingPointHelper::ConvertIntToDouble(this,
                                          untagged_value,
                                          destination,
                                          f0,
                                          mantissa_reg,
                                          exponent_reg,
                                          scratch4,
                                          f2);
  if (destination == FloatingPointHelper::kFPURegisters) {
    CpuFeatures::Scope scope(FPU);
    sdc1(f0, MemOperand(scratch1, 0));
  } else {
    sw(mantissa_reg, MemOperand(scratch1, 0));
    sw(exponent_reg, MemOperand(scratch1, Register::kSizeInBytes));
  }
  bind(&done);
}


void MacroAssembler::CompareMapAndBranch(Register obj,
                                         Register scratch,
                                         Handle<Map> map,
                                         Label* early_success,
                                         Condition cond,
                                         Label* branch_to,
                                         CompareMapMode mode) {
  lw(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
  CompareMapAndBranch(scratch, map, early_success, cond, branch_to, mode);
}


void MacroAssembler::CompareMapAndBranch(Register obj_map,
                                         Handle<Map> map,
                                         Label* early_success,
                                         Condition cond,
                                         Label* branch_to,
                                         CompareMapMode mode) {
  Operand right = Operand(map);
  if (mode == ALLOW_ELEMENT_TRANSITION_MAPS) {
    ElementsKind kind = map->elements_kind();
    if (IsFastElementsKind(kind)) {
      bool packed = IsFastPackedElementsKind(kind);
      Map* current_map = *map;
      while (CanTransitionToMoreGeneralFastElementsKind(kind, packed)) {
        kind = GetNextMoreGeneralFastElementsKind(kind, packed);
        current_map = current_map->LookupElementsTransitionMap(kind);
        if (!current_map) break;
        Branch(early_success, eq, obj_map, right);
        right = Operand(Handle<Map>(current_map));
      }
    }
  }

  Branch(branch_to, cond, obj_map, right);
}


void MacroAssembler::CheckMap(Register obj,
                              Register scratch,
                              Handle<Map> map,
                              Label* fail,
                              SmiCheckType smi_check_type,
                              CompareMapMode mode) {
  if (smi_check_type == DO_SMI_CHECK) {
    JumpIfSmi(obj, fail);
  }
  Label success;
  CompareMapAndBranch(obj, scratch, map, &success, ne, fail, mode);
  bind(&success);
}


void MacroAssembler::DispatchMap(Register obj,
                                 Register scratch,
                                 Handle<Map> map,
                                 Handle<Code> success,
                                 SmiCheckType smi_check_type) {
  Label fail;
  if (smi_check_type == DO_SMI_CHECK) {
    JumpIfSmi(obj, &fail);
  }
  lw(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
  Jump(success, RelocInfo::CODE_TARGET, eq, scratch, Operand(map));
  bind(&fail);
}


void MacroAssembler::CheckMap(Register obj,
                              Register scratch,
                              Heap::RootListIndex index,
                              Label* fail,
                              SmiCheckType smi_check_type) {
  if (smi_check_type == DO_SMI_CHECK) {
    JumpIfSmi(obj, fail);
  }
  lw(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
  LoadRoot(at, index);
  Branch(fail, ne, scratch, Operand(at));
}


void MacroAssembler::GetCFunctionDoubleResult(const DoubleRegister dst) {
  CpuFeatures::Scope scope(FPU);
  if (IsMipsSoftFloatABI) {
    Move(dst, v0, v1);
  } else {
    Move(dst, f0);  // Reg f0 is o32 ABI FP return value.
  }
}


void MacroAssembler::SetCallCDoubleArguments(DoubleRegister dreg) {
  CpuFeatures::Scope scope(FPU);
  if (!IsMipsSoftFloatABI) {
    Move(f12, dreg);
  } else {
    Move(a0, a1, dreg);
  }
}


void MacroAssembler::SetCallCDoubleArguments(DoubleRegister dreg1,
                                             DoubleRegister dreg2) {
  CpuFeatures::Scope scope(FPU);
  if (!IsMipsSoftFloatABI) {
    if (dreg2.is(f12)) {
      ASSERT(!dreg1.is(f14));
      Move(f14, dreg2);
      Move(f12, dreg1);
    } else {
      Move(f12, dreg1);
      Move(f14, dreg2);
    }
  } else {
    Move(a0, a1, dreg1);
    Move(a2, a3, dreg2);
  }
}


void MacroAssembler::SetCallCDoubleArguments(DoubleRegister dreg,
                                             Register reg) {
  CpuFeatures::Scope scope(FPU);
  if (!IsMipsSoftFloatABI) {
    Move(f12, dreg);
    Move(a2, reg);
  } else {
    Move(a2, reg);
    Move(a0, a1, dreg);
  }
}


void MacroAssembler::SetCallKind(Register dst, CallKind call_kind) {
  // This macro takes the dst register to make the code more readable
  // at the call sites. However, the dst register has to be t1 to
  // follow the calling convention which requires the call type to be
  // in t1.
  ASSERT(dst.is(t1));
  if (call_kind == CALL_AS_FUNCTION) {
    li(dst, Operand(Smi::FromInt(1)));
  } else {
    li(dst, Operand(Smi::FromInt(0)));
  }
}


// -----------------------------------------------------------------------------
// JavaScript invokes.

void MacroAssembler::InvokePrologue(const ParameterCount& expected,
                                    const ParameterCount& actual,
                                    Handle<Code> code_constant,
                                    Register code_reg,
                                    Label* done,
                                    bool* definitely_mismatches,
                                    InvokeFlag flag,
                                    const CallWrapper& call_wrapper,
                                    CallKind call_kind) {
  bool definitely_matches = false;
  *definitely_mismatches = false;
  Label regular_invoke;

  // Check whether the expected and actual arguments count match. If not,
  // setup registers according to contract with ArgumentsAdaptorTrampoline:
  //  a0: actual arguments count
  //  a1: function (passed through to callee)
  //  a2: expected arguments count
  //  a3: callee code entry

  // The code below is made a lot easier because the calling code already sets
  // up actual and expected registers according to the contract if values are
  // passed in registers.
  ASSERT(actual.is_immediate() || actual.reg().is(a0));
  ASSERT(expected.is_immediate() || expected.reg().is(a2));
  ASSERT((!code_constant.is_null() && code_reg.is(no_reg)) || code_reg.is(a3));

  if (expected.is_immediate()) {
    ASSERT(actual.is_immediate());
    if (expected.immediate() == actual.immediate()) {
      definitely_matches = true;
    } else {
      li(a0, Operand(actual.immediate()));
      const int sentinel = SharedFunctionInfo::kDontAdaptArgumentsSentinel;
      if (expected.immediate() == sentinel) {
        // Don't worry about adapting arguments for builtins that
        // don't want that done. Skip adaption code by making it look
        // like we have a match between expected and actual number of
        // arguments.
        definitely_matches = true;
      } else {
        *definitely_mismatches = true;
        li(a2, Operand(expected.immediate()));
      }
    }
  } else if (actual.is_immediate()) {
    Branch(&regular_invoke, eq, expected.reg(), Operand(actual.immediate()));
    li(a0, Operand(actual.immediate()));
  } else {
    Branch(&regular_invoke, eq, expected.reg(), Operand(actual.reg()));
  }

  if (!definitely_matches) {
    if (!code_constant.is_null()) {
      li(a3, Operand(code_constant));
      addiu(a3, a3, Code::kHeaderSize - kHeapObjectTag);
    }

    Handle<Code> adaptor =
        isolate()->builtins()->ArgumentsAdaptorTrampoline();
    if (flag == CALL_FUNCTION) {
      call_wrapper.BeforeCall(CallSize(adaptor));
      SetCallKind(t1, call_kind);
      Call(adaptor);
      call_wrapper.AfterCall();
      if (!*definitely_mismatches) {
        Branch(done);
      }
    } else {
      SetCallKind(t1, call_kind);
      Jump(adaptor, RelocInfo::CODE_TARGET);
    }
    bind(&regular_invoke);
  }
}


void MacroAssembler::InvokeCode(Register code,
                                const ParameterCount& expected,
                                const ParameterCount& actual,
                                InvokeFlag flag,
                                const CallWrapper& call_wrapper,
                                CallKind call_kind) {
  // You can't call a function without a valid frame.
  ASSERT(flag == JUMP_FUNCTION || has_frame());

  Label done;

  bool definitely_mismatches = false;
  InvokePrologue(expected, actual, Handle<Code>::null(), code,
                 &done, &definitely_mismatches, flag,
                 call_wrapper, call_kind);
  if (!definitely_mismatches) {
    if (flag == CALL_FUNCTION) {
      call_wrapper.BeforeCall(CallSize(code));
      SetCallKind(t1, call_kind);
      Call(code);
      call_wrapper.AfterCall();
    } else {
      ASSERT(flag == JUMP_FUNCTION);
      SetCallKind(t1, call_kind);
      Jump(code);
    }
    // Continue here if InvokePrologue does handle the invocation due to
    // mismatched parameter counts.
    bind(&done);
  }
}


void MacroAssembler::InvokeCode(Handle<Code> code,
                                const ParameterCount& expected,
                                const ParameterCount& actual,
                                RelocInfo::Mode rmode,
                                InvokeFlag flag,
                                CallKind call_kind) {
  // You can't call a function without a valid frame.
  ASSERT(flag == JUMP_FUNCTION || has_frame());

  Label done;

  bool definitely_mismatches = false;
  InvokePrologue(expected, actual, code, no_reg,
                 &done, &definitely_mismatches, flag,
                 NullCallWrapper(), call_kind);
  if (!definitely_mismatches) {
    if (flag == CALL_FUNCTION) {
      SetCallKind(t1, call_kind);
      Call(code, rmode);
    } else {
      SetCallKind(t1, call_kind);
      Jump(code, rmode);
    }
    // Continue here if InvokePrologue does handle the invocation due to
    // mismatched parameter counts.
    bind(&done);
  }
}


void MacroAssembler::InvokeFunction(Register function,
                                    const ParameterCount& actual,
                                    InvokeFlag flag,
                                    const CallWrapper& call_wrapper,
                                    CallKind call_kind) {
  // You can't call a function without a valid frame.
  ASSERT(flag == JUMP_FUNCTION || has_frame());

  // Contract with called JS functions requires that function is passed in a1.
  ASSERT(function.is(a1));
  Register expected_reg = a2;
  Register code_reg = a3;

  lw(code_reg, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
  lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));
  lw(expected_reg,
      FieldMemOperand(code_reg,
                      SharedFunctionInfo::kFormalParameterCountOffset));
  sra(expected_reg, expected_reg, kSmiTagSize);
  lw(code_reg, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));

  ParameterCount expected(expected_reg);
  InvokeCode(code_reg, expected, actual, flag, call_wrapper, call_kind);
}


void MacroAssembler::InvokeFunction(Handle<JSFunction> function,
                                    const ParameterCount& actual,
                                    InvokeFlag flag,
                                    const CallWrapper& call_wrapper,
                                    CallKind call_kind) {
  // You can't call a function without a valid frame.
  ASSERT(flag == JUMP_FUNCTION || has_frame());

  // Get the function and setup the context.
  LoadHeapObject(a1, function);
  lw(cp, FieldMemOperand(a1, JSFunction::kContextOffset));

  ParameterCount expected(function->shared()->formal_parameter_count());
  // We call indirectly through the code field in the function to
  // allow recompilation to take effect without changing any of the
  // call sites.
  lw(a3, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
  InvokeCode(a3, expected, actual, flag, call_wrapper, call_kind);
}


void MacroAssembler::IsObjectJSObjectType(Register heap_object,
                                          Register map,
                                          Register scratch,
                                          Label* fail) {
  lw(map, FieldMemOperand(heap_object, HeapObject::kMapOffset));
  IsInstanceJSObjectType(map, scratch, fail);
}


void MacroAssembler::IsInstanceJSObjectType(Register map,
                                            Register scratch,
                                            Label* fail) {
  lbu(scratch, FieldMemOperand(map, Map::kInstanceTypeOffset));
  Branch(fail, lt, scratch, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
  Branch(fail, gt, scratch, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE));
}


void MacroAssembler::IsObjectJSStringType(Register object,
                                          Register scratch,
                                          Label* fail) {
  ASSERT(kNotStringTag != 0);

  lw(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
  lbu(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
  And(scratch, scratch, Operand(kIsNotStringMask));
  Branch(fail, ne, scratch, Operand(zero_reg));
}


// ---------------------------------------------------------------------------
// Support functions.


void MacroAssembler::TryGetFunctionPrototype(Register function,
                                             Register result,
                                             Register scratch,
                                             Label* miss,
                                             bool miss_on_bound_function) {
  // Check that the receiver isn't a smi.
  JumpIfSmi(function, miss);

  // Check that the function really is a function.  Load map into result reg.
  GetObjectType(function, result, scratch);
  Branch(miss, ne, scratch, Operand(JS_FUNCTION_TYPE));

  if (miss_on_bound_function) {
    lw(scratch,
       FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
    lw(scratch,
       FieldMemOperand(scratch, SharedFunctionInfo::kCompilerHintsOffset));
    And(scratch, scratch,
        Operand(Smi::FromInt(1 << SharedFunctionInfo::kBoundFunction)));
    Branch(miss, ne, scratch, Operand(zero_reg));
  }

  // Make sure that the function has an instance prototype.
  Label non_instance;
  lbu(scratch, FieldMemOperand(result, Map::kBitFieldOffset));
  And(scratch, scratch, Operand(1 << Map::kHasNonInstancePrototype));
  Branch(&non_instance, ne, scratch, Operand(zero_reg));

  // Get the prototype or initial map from the function.
  lw(result,
     FieldMemOperand(function, JSFunction::kPrototypeOrInitialMapOffset));

  // If the prototype or initial map is the hole, don't return it and
  // simply miss the cache instead. This will allow us to allocate a
  // prototype object on-demand in the runtime system.
  LoadRoot(t8, Heap::kTheHoleValueRootIndex);
  Branch(miss, eq, result, Operand(t8));

  // If the function does not have an initial map, we're done.
  Label done;
  GetObjectType(result, scratch, scratch);
  Branch(&done, ne, scratch, Operand(MAP_TYPE));

  // Get the prototype from the initial map.
  lw(result, FieldMemOperand(result, Map::kPrototypeOffset));
  jmp(&done);

  // Non-instance prototype: Fetch prototype from constructor field
  // in initial map.
  bind(&non_instance);
  lw(result, FieldMemOperand(result, Map::kConstructorOffset));

  // All done.
  bind(&done);
}


void MacroAssembler::GetObjectType(Register object,
                                   Register map,
                                   Register type_reg) {
  lw(map, FieldMemOperand(object, HeapObject::kMapOffset));
  lbu(type_reg, FieldMemOperand(map, Map::kInstanceTypeOffset));
}


// -----------------------------------------------------------------------------
// Runtime calls.

void MacroAssembler::CallStub(CodeStub* stub,
                              Condition cond,
                              Register r1,
                              const Operand& r2,
                              BranchDelaySlot bd) {
  ASSERT(AllowThisStubCall(stub));  // Stub calls are not allowed in some stubs.
  Call(stub->GetCode(), RelocInfo::CODE_TARGET, kNoASTId, cond, r1, r2, bd);
}


void MacroAssembler::TailCallStub(CodeStub* stub) {
  ASSERT(allow_stub_calls_ || stub->CompilingCallsToThisStubIsGCSafe());
  Jump(stub->GetCode(), RelocInfo::CODE_TARGET);
}


static int AddressOffset(ExternalReference ref0, ExternalReference ref1) {
  return ref0.address() - ref1.address();
}


void MacroAssembler::CallApiFunctionAndReturn(ExternalReference function,
                                              int stack_space) {
  ExternalReference next_address =
      ExternalReference::handle_scope_next_address();
  const int kNextOffset = 0;
  const int kLimitOffset = AddressOffset(
      ExternalReference::handle_scope_limit_address(),
      next_address);
  const int kLevelOffset = AddressOffset(
      ExternalReference::handle_scope_level_address(),
      next_address);

  // Allocate HandleScope in callee-save registers.
  li(s3, Operand(next_address));
  lw(s0, MemOperand(s3, kNextOffset));
  lw(s1, MemOperand(s3, kLimitOffset));
  lw(s2, MemOperand(s3, kLevelOffset));
  Addu(s2, s2, Operand(1));
  sw(s2, MemOperand(s3, kLevelOffset));

  // The O32 ABI requires us to pass a pointer in a0 where the returned struct
  // (4 bytes) will be placed. This is also built into the Simulator.
  // Set up the pointer to the returned value (a0). It was allocated in
  // EnterExitFrame.
  addiu(a0, fp, ExitFrameConstants::kStackSpaceOffset);

  // Native call returns to the DirectCEntry stub which redirects to the
  // return address pushed on stack (could have moved after GC).
  // DirectCEntry stub itself is generated early and never moves.
  DirectCEntryStub stub;
  stub.GenerateCall(this, function);

  // As mentioned above, on MIPS a pointer is returned - we need to dereference
  // it to get the actual return value (which is also a pointer).
  lw(v0, MemOperand(v0));

  Label promote_scheduled_exception;
  Label delete_allocated_handles;
  Label leave_exit_frame;

  // If result is non-zero, dereference to get the result value
  // otherwise set it to undefined.
  Label skip;
  LoadRoot(a0, Heap::kUndefinedValueRootIndex);
  Branch(&skip, eq, v0, Operand(zero_reg));
  lw(a0, MemOperand(v0));
  bind(&skip);
  mov(v0, a0);

  // No more valid handles (the result handle was the last one). Restore
  // previous handle scope.
  sw(s0, MemOperand(s3, kNextOffset));
  if (emit_debug_code()) {
    lw(a1, MemOperand(s3, kLevelOffset));
    Check(eq, "Unexpected level after return from api call", a1, Operand(s2));
  }
  Subu(s2, s2, Operand(1));
  sw(s2, MemOperand(s3, kLevelOffset));
  lw(at, MemOperand(s3, kLimitOffset));
  Branch(&delete_allocated_handles, ne, s1, Operand(at));

  // Check if the function scheduled an exception.
  bind(&leave_exit_frame);
  LoadRoot(t0, Heap::kTheHoleValueRootIndex);
  li(at, Operand(ExternalReference::scheduled_exception_address(isolate())));
  lw(t1, MemOperand(at));
  Branch(&promote_scheduled_exception, ne, t0, Operand(t1));
  li(s0, Operand(stack_space));
  LeaveExitFrame(false, s0, true);

  bind(&promote_scheduled_exception);
  TailCallExternalReference(
      ExternalReference(Runtime::kPromoteScheduledException, isolate()),
      0,
      1);

  // HandleScope limit has changed. Delete allocated extensions.
  bind(&delete_allocated_handles);
  sw(s1, MemOperand(s3, kLimitOffset));
  mov(s0, v0);
  mov(a0, v0);
  PrepareCallCFunction(1, s1);
  li(a0, Operand(ExternalReference::isolate_address()));
  CallCFunction(ExternalReference::delete_handle_scope_extensions(isolate()),
      1);
  mov(v0, s0);
  jmp(&leave_exit_frame);
}


bool MacroAssembler::AllowThisStubCall(CodeStub* stub) {
  if (!has_frame_ && stub->SometimesSetsUpAFrame()) return false;
  return allow_stub_calls_ || stub->CompilingCallsToThisStubIsGCSafe();
}


void MacroAssembler::IllegalOperation(int num_arguments) {
  if (num_arguments > 0) {
    addiu(sp, sp, num_arguments * kPointerSize);
  }
  LoadRoot(v0, Heap::kUndefinedValueRootIndex);
}


void MacroAssembler::IndexFromHash(Register hash,
                                   Register index) {
  // If the hash field contains an array index pick it out. The assert checks
  // that the constants for the maximum number of digits for an array index
  // cached in the hash field and the number of bits reserved for it does not
  // conflict.
  ASSERT(TenToThe(String::kMaxCachedArrayIndexLength) <
         (1 << String::kArrayIndexValueBits));
  // We want the smi-tagged index in key.  kArrayIndexValueMask has zeros in
  // the low kHashShift bits.
  STATIC_ASSERT(kSmiTag == 0);
  Ext(hash, hash, String::kHashShift, String::kArrayIndexValueBits);
  sll(index, hash, kSmiTagSize);
}


void MacroAssembler::ObjectToDoubleFPURegister(Register object,
                                               FPURegister result,
                                               Register scratch1,
                                               Register scratch2,
                                               Register heap_number_map,
                                               Label* not_number,
                                               ObjectToDoubleFlags flags) {
  Label done;
  if ((flags & OBJECT_NOT_SMI) == 0) {
    Label not_smi;
    JumpIfNotSmi(object, &not_smi);
    // Remove smi tag and convert to double.
    sra(scratch1, object, kSmiTagSize);
    mtc1(scratch1, result);
    cvt_d_w(result, result);
    Branch(&done);
    bind(&not_smi);
  }
  // Check for heap number and load double value from it.
  lw(scratch1, FieldMemOperand(object, HeapObject::kMapOffset));
  Branch(not_number, ne, scratch1, Operand(heap_number_map));

  if ((flags & AVOID_NANS_AND_INFINITIES) != 0) {
    // If exponent is all ones the number is either a NaN or +/-Infinity.
    Register exponent = scratch1;
    Register mask_reg = scratch2;
    lw(exponent, FieldMemOperand(object, HeapNumber::kExponentOffset));
    li(mask_reg, HeapNumber::kExponentMask);

    And(exponent, exponent, mask_reg);
    Branch(not_number, eq, exponent, Operand(mask_reg));
  }
  ldc1(result, FieldMemOperand(object, HeapNumber::kValueOffset));
  bind(&done);
}


void MacroAssembler::SmiToDoubleFPURegister(Register smi,
                                            FPURegister value,
                                            Register scratch1) {
  sra(scratch1, smi, kSmiTagSize);
  mtc1(scratch1, value);
  cvt_d_w(value, value);
}


void MacroAssembler::AdduAndCheckForOverflow(Register dst,
                                             Register left,
                                             Register right,
                                             Register overflow_dst,
                                             Register scratch) {
  ASSERT(!dst.is(overflow_dst));
  ASSERT(!dst.is(scratch));
  ASSERT(!overflow_dst.is(scratch));
  ASSERT(!overflow_dst.is(left));
  ASSERT(!overflow_dst.is(right));

  if (left.is(right) && dst.is(left)) {
    ASSERT(!dst.is(t9));
    ASSERT(!scratch.is(t9));
    ASSERT(!left.is(t9));
    ASSERT(!right.is(t9));
    ASSERT(!overflow_dst.is(t9));
    mov(t9, right);
    right = t9;
  }

  if (dst.is(left)) {
    mov(scratch, left);  // Preserve left.
    addu(dst, left, right);  // Left is overwritten.
    xor_(scratch, dst, scratch);  // Original left.
    xor_(overflow_dst, dst, right);
    and_(overflow_dst, overflow_dst, scratch);
  } else if (dst.is(right)) {
    mov(scratch, right);  // Preserve right.
    addu(dst, left, right);  // Right is overwritten.
    xor_(scratch, dst, scratch);  // Original right.
    xor_(overflow_dst, dst, left);
    and_(overflow_dst, overflow_dst, scratch);
  } else {
    addu(dst, left, right);
    xor_(overflow_dst, dst, left);
    xor_(scratch, dst, right);
    and_(overflow_dst, scratch, overflow_dst);
  }
}


void MacroAssembler::SubuAndCheckForOverflow(Register dst,
                                             Register left,
                                             Register right,
                                             Register overflow_dst,
                                             Register scratch) {
  ASSERT(!dst.is(overflow_dst));
  ASSERT(!dst.is(scratch));
  ASSERT(!overflow_dst.is(scratch));
  ASSERT(!overflow_dst.is(left));
  ASSERT(!overflow_dst.is(right));
  ASSERT(!scratch.is(left));
  ASSERT(!scratch.is(right));

  // This happens with some crankshaft code. Since Subu works fine if
  // left == right, let's not make that restriction here.
  if (left.is(right)) {
    mov(dst, zero_reg);
    mov(overflow_dst, zero_reg);
    return;
  }

  if (dst.is(left)) {
    mov(scratch, left);  // Preserve left.
    subu(dst, left, right);  // Left is overwritten.
    xor_(overflow_dst, dst, scratch);  // scratch is original left.
    xor_(scratch, scratch, right);  // scratch is original left.
    and_(overflow_dst, scratch, overflow_dst);
  } else if (dst.is(right)) {
    mov(scratch, right);  // Preserve right.
    subu(dst, left, right);  // Right is overwritten.
    xor_(overflow_dst, dst, left);
    xor_(scratch, left, scratch);  // Original right.
    and_(overflow_dst, scratch, overflow_dst);
  } else {
    subu(dst, left, right);
    xor_(overflow_dst, dst, left);
    xor_(scratch, left, right);
    and_(overflow_dst, scratch, overflow_dst);
  }
}


void MacroAssembler::CallRuntime(const Runtime::Function* f,
                                 int num_arguments) {
  // All parameters are on the stack. v0 has the return value after call.

  // If the expected number of arguments of the runtime function is
  // constant, we check that the actual number of arguments match the
  // expectation.
  if (f->nargs >= 0 && f->nargs != num_arguments) {
    IllegalOperation(num_arguments);
    return;
  }

  // TODO(1236192): Most runtime routines don't need the number of
  // arguments passed in because it is constant. At some point we
  // should remove this need and make the runtime routine entry code
  // smarter.
  PrepareCEntryArgs(num_arguments);
  PrepareCEntryFunction(ExternalReference(f, isolate()));
  CEntryStub stub(1);
  CallStub(&stub);
}


void MacroAssembler::CallRuntimeSaveDoubles(Runtime::FunctionId id) {
  const Runtime::Function* function = Runtime::FunctionForId(id);
  PrepareCEntryArgs(function->nargs);
  PrepareCEntryFunction(ExternalReference(function, isolate()));
  CEntryStub stub(1, kSaveFPRegs);
  CallStub(&stub);
}


void MacroAssembler::CallRuntime(Runtime::FunctionId fid, int num_arguments) {
  CallRuntime(Runtime::FunctionForId(fid), num_arguments);
}


void MacroAssembler::CallExternalReference(const ExternalReference& ext,
                                           int num_arguments,
                                           BranchDelaySlot bd) {
  PrepareCEntryArgs(num_arguments);
  PrepareCEntryFunction(ext);

  CEntryStub stub(1);
  CallStub(&stub, al, zero_reg, Operand(zero_reg), bd);
}


void MacroAssembler::TailCallExternalReference(const ExternalReference& ext,
                                               int num_arguments,
                                               int result_size) {
  // TODO(1236192): Most runtime routines don't need the number of
  // arguments passed in because it is constant. At some point we
  // should remove this need and make the runtime routine entry code
  // smarter.
  PrepareCEntryArgs(num_arguments);
  JumpToExternalReference(ext);
}


void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid,
                                     int num_arguments,
                                     int result_size) {
  TailCallExternalReference(ExternalReference(fid, isolate()),
                            num_arguments,
                            result_size);
}


void MacroAssembler::JumpToExternalReference(const ExternalReference& builtin,
                                             BranchDelaySlot bd) {
  PrepareCEntryFunction(builtin);
  CEntryStub stub(1);
  Jump(stub.GetCode(),
       RelocInfo::CODE_TARGET,
       al,
       zero_reg,
       Operand(zero_reg),
       bd);
}


void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
                                   InvokeFlag flag,
                                   const CallWrapper& call_wrapper) {
  // You can't call a builtin without a valid frame.
  ASSERT(flag == JUMP_FUNCTION || has_frame());

  GetBuiltinEntry(t9, id);
  if (flag == CALL_FUNCTION) {
    call_wrapper.BeforeCall(CallSize(t9));
    SetCallKind(t1, CALL_AS_METHOD);
    Call(t9);
    call_wrapper.AfterCall();
  } else {
    ASSERT(flag == JUMP_FUNCTION);
    SetCallKind(t1, CALL_AS_METHOD);
    Jump(t9);
  }
}


void MacroAssembler::GetBuiltinFunction(Register target,
                                        Builtins::JavaScript id) {
  // Load the builtins object into target register.
  lw(target, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
  lw(target, FieldMemOperand(target, GlobalObject::kBuiltinsOffset));
  // Load the JavaScript builtin function from the builtins object.
  lw(target, FieldMemOperand(target,
                          JSBuiltinsObject::OffsetOfFunctionWithId(id)));
}


void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) {
  ASSERT(!target.is(a1));
  GetBuiltinFunction(a1, id);
  // Load the code entry point from the builtins object.
  lw(target, FieldMemOperand(a1, JSFunction::kCodeEntryOffset));
}


void MacroAssembler::SetCounter(StatsCounter* counter, int value,
                                Register scratch1, Register scratch2) {
  if (FLAG_native_code_counters && counter->Enabled()) {
    li(scratch1, Operand(value));
    li(scratch2, Operand(ExternalReference(counter)));
    sw(scratch1, MemOperand(scratch2));
  }
}


void MacroAssembler::IncrementCounter(StatsCounter* counter, int value,
                                      Register scratch1, Register scratch2) {
  ASSERT(value > 0);
  if (FLAG_native_code_counters && counter->Enabled()) {
    li(scratch2, Operand(ExternalReference(counter)));
    lw(scratch1, MemOperand(scratch2));
    Addu(scratch1, scratch1, Operand(value));
    sw(scratch1, MemOperand(scratch2));
  }
}


void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
                                      Register scratch1, Register scratch2) {
  ASSERT(value > 0);
  if (FLAG_native_code_counters && counter->Enabled()) {
    li(scratch2, Operand(ExternalReference(counter)));
    lw(scratch1, MemOperand(scratch2));
    Subu(scratch1, scratch1, Operand(value));
    sw(scratch1, MemOperand(scratch2));
  }
}


// -----------------------------------------------------------------------------
// Debugging.

void MacroAssembler::Assert(Condition cc, const char* msg,
                            Register rs, Operand rt) {
  if (emit_debug_code())
    Check(cc, msg, rs, rt);
}


void MacroAssembler::AssertRegisterIsRoot(Register reg,
                                          Heap::RootListIndex index) {
  if (emit_debug_code()) {
    LoadRoot(at, index);
    Check(eq, "Register did not match expected root", reg, Operand(at));
  }
}


void MacroAssembler::AssertFastElements(Register elements) {
  if (emit_debug_code()) {
    ASSERT(!elements.is(at));
    Label ok;
    push(elements);
    lw(elements, FieldMemOperand(elements, HeapObject::kMapOffset));
    LoadRoot(at, Heap::kFixedArrayMapRootIndex);
    Branch(&ok, eq, elements, Operand(at));
    LoadRoot(at, Heap::kFixedDoubleArrayMapRootIndex);
    Branch(&ok, eq, elements, Operand(at));
    LoadRoot(at, Heap::kFixedCOWArrayMapRootIndex);
    Branch(&ok, eq, elements, Operand(at));
    Abort("JSObject with fast elements map has slow elements");
    bind(&ok);
    pop(elements);
  }
}


void MacroAssembler::Check(Condition cc, const char* msg,
                           Register rs, Operand rt) {
  Label L;
  Branch(&L, cc, rs, rt);
  Abort(msg);
  // Will not return here.
  bind(&L);
}


void MacroAssembler::Abort(const char* msg) {
  Label abort_start;
  bind(&abort_start);
  // We want to pass the msg string like a smi to avoid GC
  // problems, however msg is not guaranteed to be aligned
  // properly. Instead, we pass an aligned pointer that is
  // a proper v8 smi, but also pass the alignment difference
  // from the real pointer as a smi.
  intptr_t p1 = reinterpret_cast<intptr_t>(msg);
  intptr_t p0 = (p1 & ~kSmiTagMask) + kSmiTag;
  ASSERT(reinterpret_cast<Object*>(p0)->IsSmi());
#ifdef DEBUG
  if (msg != NULL) {
    RecordComment("Abort message: ");
    RecordComment(msg);
  }
#endif

  li(a0, Operand(p0));
  push(a0);
  li(a0, Operand(Smi::FromInt(p1 - p0)));
  push(a0);
  // Disable stub call restrictions to always allow calls to abort.
  if (!has_frame_) {
    // We don't actually want to generate a pile of code for this, so just
    // claim there is a stack frame, without generating one.
    FrameScope scope(this, StackFrame::NONE);
    CallRuntime(Runtime::kAbort, 2);
  } else {
    CallRuntime(Runtime::kAbort, 2);
  }
  // Will not return here.
  if (is_trampoline_pool_blocked()) {
    // If the calling code cares about the exact number of
    // instructions generated, we insert padding here to keep the size
    // of the Abort macro constant.
    // Currently in debug mode with debug_code enabled the number of
    // generated instructions is 14, so we use this as a maximum value.
    static const int kExpectedAbortInstructions = 14;
    int abort_instructions = InstructionsGeneratedSince(&abort_start);
    ASSERT(abort_instructions <= kExpectedAbortInstructions);
    while (abort_instructions++ < kExpectedAbortInstructions) {
      nop();
    }
  }
}


void MacroAssembler::LoadContext(Register dst, int context_chain_length) {
  if (context_chain_length > 0) {
    // Move up the chain of contexts to the context containing the slot.
    lw(dst, MemOperand(cp, Context::SlotOffset(Context::PREVIOUS_INDEX)));
    for (int i = 1; i < context_chain_length; i++) {
      lw(dst, MemOperand(dst, Context::SlotOffset(Context::PREVIOUS_INDEX)));
    }
  } else {
    // Slot is in the current function context.  Move it into the
    // destination register in case we store into it (the write barrier
    // cannot be allowed to destroy the context in esi).
    Move(dst, cp);
  }
}


void MacroAssembler::LoadTransitionedArrayMapConditional(
    ElementsKind expected_kind,
    ElementsKind transitioned_kind,
    Register map_in_out,
    Register scratch,
    Label* no_map_match) {
  // Load the global or builtins object from the current context.
  lw(scratch, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
  lw(scratch, FieldMemOperand(scratch, GlobalObject::kGlobalContextOffset));

  // Check that the function's map is the same as the expected cached map.
  lw(scratch,
     MemOperand(scratch,
                Context::SlotOffset(Context::JS_ARRAY_MAPS_INDEX)));
  size_t offset = expected_kind * kPointerSize +
      FixedArrayBase::kHeaderSize;
  lw(at, FieldMemOperand(scratch, offset));
  Branch(no_map_match, ne, map_in_out, Operand(at));

  // Use the transitioned cached map.
  offset = transitioned_kind * kPointerSize +
      FixedArrayBase::kHeaderSize;
  lw(map_in_out, FieldMemOperand(scratch, offset));
}


void MacroAssembler::LoadInitialArrayMap(
    Register function_in, Register scratch,
    Register map_out, bool can_have_holes) {
  ASSERT(!function_in.is(map_out));
  Label done;
  lw(map_out, FieldMemOperand(function_in,
                              JSFunction::kPrototypeOrInitialMapOffset));
  if (!FLAG_smi_only_arrays) {
    ElementsKind kind = can_have_holes ? FAST_HOLEY_ELEMENTS : FAST_ELEMENTS;
    LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
                                        kind,
                                        map_out,
                                        scratch,
                                        &done);
  } else if (can_have_holes) {
    LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
                                        FAST_HOLEY_SMI_ELEMENTS,
                                        map_out,
                                        scratch,
                                        &done);
  }
  bind(&done);
}


void MacroAssembler::LoadGlobalFunction(int index, Register function) {
  // Load the global or builtins object from the current context.
  lw(function, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
  // Load the global context from the global or builtins object.
  lw(function, FieldMemOperand(function,
                               GlobalObject::kGlobalContextOffset));
  // Load the function from the global context.
  lw(function, MemOperand(function, Context::SlotOffset(index)));
}


void MacroAssembler::LoadGlobalFunctionInitialMap(Register function,
                                                  Register map,
                                                  Register scratch) {
  // Load the initial map. The global functions all have initial maps.
  lw(map, FieldMemOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
  if (emit_debug_code()) {
    Label ok, fail;
    CheckMap(map, scratch, Heap::kMetaMapRootIndex, &fail, DO_SMI_CHECK);
    Branch(&ok);
    bind(&fail);
    Abort("Global functions must have initial map");
    bind(&ok);
  }
}


void MacroAssembler::EnterFrame(StackFrame::Type type) {
  addiu(sp, sp, -5 * kPointerSize);
  li(t8, Operand(Smi::FromInt(type)));
  li(t9, Operand(CodeObject()), CONSTANT_SIZE);
  sw(ra, MemOperand(sp, 4 * kPointerSize));
  sw(fp, MemOperand(sp, 3 * kPointerSize));
  sw(cp, MemOperand(sp, 2 * kPointerSize));
  sw(t8, MemOperand(sp, 1 * kPointerSize));
  sw(t9, MemOperand(sp, 0 * kPointerSize));
  addiu(fp, sp, 3 * kPointerSize);
}


void MacroAssembler::LeaveFrame(StackFrame::Type type) {
  mov(sp, fp);
  lw(fp, MemOperand(sp, 0 * kPointerSize));
  lw(ra, MemOperand(sp, 1 * kPointerSize));
  addiu(sp, sp, 2 * kPointerSize);
}


void MacroAssembler::EnterExitFrame(bool save_doubles,
                                    int stack_space) {
  // Set up the frame structure on the stack.
  STATIC_ASSERT(2 * kPointerSize == ExitFrameConstants::kCallerSPDisplacement);
  STATIC_ASSERT(1 * kPointerSize == ExitFrameConstants::kCallerPCOffset);
  STATIC_ASSERT(0 * kPointerSize == ExitFrameConstants::kCallerFPOffset);

  // This is how the stack will look:
  // fp + 2 (==kCallerSPDisplacement) - old stack's end
  // [fp + 1 (==kCallerPCOffset)] - saved old ra
  // [fp + 0 (==kCallerFPOffset)] - saved old fp
  // [fp - 1 (==kSPOffset)] - sp of the called function
  // [fp - 2 (==kCodeOffset)] - CodeObject
  // fp - (2 + stack_space + alignment) == sp == [fp - kSPOffset] - top of the
  //   new stack (will contain saved ra)

  // Save registers.
  addiu(sp, sp, -4 * kPointerSize);
  sw(ra, MemOperand(sp, 3 * kPointerSize));
  sw(fp, MemOperand(sp, 2 * kPointerSize));
  addiu(fp, sp, 2 * kPointerSize);  // Set up new frame pointer.

  if (emit_debug_code()) {
    sw(zero_reg, MemOperand(fp, ExitFrameConstants::kSPOffset));
  }

  // Accessed from ExitFrame::code_slot.
  li(t8, Operand(CodeObject()), CONSTANT_SIZE);
  sw(t8, MemOperand(fp, ExitFrameConstants::kCodeOffset));

  // Save the frame pointer and the context in top.
  li(t8, Operand(ExternalReference(Isolate::kCEntryFPAddress, isolate())));
  sw(fp, MemOperand(t8));
  li(t8, Operand(ExternalReference(Isolate::kContextAddress, isolate())));
  sw(cp, MemOperand(t8));

  const int frame_alignment = MacroAssembler::ActivationFrameAlignment();
  if (save_doubles) {
    // The stack  must be allign to 0 modulo 8 for stores with sdc1.
    ASSERT(kDoubleSize == frame_alignment);
    if (frame_alignment > 0) {
      ASSERT(IsPowerOf2(frame_alignment));
      And(sp, sp, Operand(-frame_alignment));  // Align stack.
    }
    int space = FPURegister::kNumRegisters * kDoubleSize;
    Subu(sp, sp, Operand(space));
    // Remember: we only need to save every 2nd double FPU value.
    for (int i = 0; i < FPURegister::kNumRegisters; i+=2) {
      FPURegister reg = FPURegister::from_code(i);
      sdc1(reg, MemOperand(sp, i * kDoubleSize));
    }
  }

  // Reserve place for the return address, stack space and an optional slot
  // (used by the DirectCEntryStub to hold the return value if a struct is
  // returned) and align the frame preparing for calling the runtime function.
  ASSERT(stack_space >= 0);
  Subu(sp, sp, Operand((stack_space + 2) * kPointerSize));
  if (frame_alignment > 0) {
    ASSERT(IsPowerOf2(frame_alignment));
    And(sp, sp, Operand(-frame_alignment));  // Align stack.
  }

  // Set the exit frame sp value to point just before the return address
  // location.
  addiu(at, sp, kPointerSize);
  sw(at, MemOperand(fp, ExitFrameConstants::kSPOffset));
}


void MacroAssembler::LeaveExitFrame(bool save_doubles,
                                    Register argument_count,
                                    bool do_return) {
  // Optionally restore all double registers.
  if (save_doubles) {
    // Remember: we only need to restore every 2nd double FPU value.
    lw(t8, MemOperand(fp, ExitFrameConstants::kSPOffset));
    for (int i = 0; i < FPURegister::kNumRegisters; i+=2) {
      FPURegister reg = FPURegister::from_code(i);
      ldc1(reg, MemOperand(t8, i  * kDoubleSize + kPointerSize));
    }
  }

  // Clear top frame.
  li(t8, Operand(ExternalReference(Isolate::kCEntryFPAddress, isolate())));
  sw(zero_reg, MemOperand(t8));

  // Restore current context from top and clear it in debug mode.
  li(t8, Operand(ExternalReference(Isolate::kContextAddress, isolate())));
  lw(cp, MemOperand(t8));
#ifdef DEBUG
  sw(a3, MemOperand(t8));
#endif

  // Pop the arguments, restore registers, and return.
  mov(sp, fp);  // Respect ABI stack constraint.
  lw(fp, MemOperand(sp, ExitFrameConstants::kCallerFPOffset));
  lw(ra, MemOperand(sp, ExitFrameConstants::kCallerPCOffset));

  if (argument_count.is_valid()) {
    sll(t8, argument_count, kPointerSizeLog2);
    addu(sp, sp, t8);
  }

  if (do_return) {
    Ret(USE_DELAY_SLOT);
    // If returning, the instruction in the delay slot will be the addiu below.
  }
  addiu(sp, sp, 8);
}


void MacroAssembler::InitializeNewString(Register string,
                                         Register length,
                                         Heap::RootListIndex map_index,
                                         Register scratch1,
                                         Register scratch2) {
  sll(scratch1, length, kSmiTagSize);
  LoadRoot(scratch2, map_index);
  sw(scratch1, FieldMemOperand(string, String::kLengthOffset));
  li(scratch1, Operand(String::kEmptyHashField));
  sw(scratch2, FieldMemOperand(string, HeapObject::kMapOffset));
  sw(scratch1, FieldMemOperand(string, String::kHashFieldOffset));
}


int MacroAssembler::ActivationFrameAlignment() {
#if defined(V8_HOST_ARCH_MIPS)
  // Running on the real platform. Use the alignment as mandated by the local
  // environment.
  // Note: This will break if we ever start generating snapshots on one Mips
  // platform for another Mips platform with a different alignment.
  return OS::ActivationFrameAlignment();
#else  // defined(V8_HOST_ARCH_MIPS)
  // If we are using the simulator then we should always align to the expected
  // alignment. As the simulator is used to generate snapshots we do not know
  // if the target platform will need alignment, so this is controlled from a
  // flag.
  return FLAG_sim_stack_alignment;
#endif  // defined(V8_HOST_ARCH_MIPS)
}


void MacroAssembler::AssertStackIsAligned() {
  if (emit_debug_code()) {
      const int frame_alignment = ActivationFrameAlignment();
      const int frame_alignment_mask = frame_alignment - 1;

      if (frame_alignment > kPointerSize) {
        Label alignment_as_expected;
        ASSERT(IsPowerOf2(frame_alignment));
        andi(at, sp, frame_alignment_mask);
        Branch(&alignment_as_expected, eq, at, Operand(zero_reg));
        // Don't use Check here, as it will call Runtime_Abort re-entering here.
        stop("Unexpected stack alignment");
        bind(&alignment_as_expected);
      }
    }
}


void MacroAssembler::JumpIfNotPowerOfTwoOrZero(
    Register reg,
    Register scratch,
    Label* not_power_of_two_or_zero) {
  Subu(scratch, reg, Operand(1));
  Branch(USE_DELAY_SLOT, not_power_of_two_or_zero, lt,
         scratch, Operand(zero_reg));
  and_(at, scratch, reg);  // In the delay slot.
  Branch(not_power_of_two_or_zero, ne, at, Operand(zero_reg));
}


void MacroAssembler::SmiTagCheckOverflow(Register reg, Register overflow) {
  ASSERT(!reg.is(overflow));
  mov(overflow, reg);  // Save original value.
  SmiTag(reg);
  xor_(overflow, overflow, reg);  // Overflow if (value ^ 2 * value) < 0.
}


void MacroAssembler::SmiTagCheckOverflow(Register dst,
                                         Register src,
                                         Register overflow) {
  if (dst.is(src)) {
    // Fall back to slower case.
    SmiTagCheckOverflow(dst, overflow);
  } else {
    ASSERT(!dst.is(src));
    ASSERT(!dst.is(overflow));
    ASSERT(!src.is(overflow));
    SmiTag(dst, src);
    xor_(overflow, dst, src);  // Overflow if (value ^ 2 * value) < 0.
  }
}


void MacroAssembler::UntagAndJumpIfSmi(Register dst,
                                       Register src,
                                       Label* smi_case) {
  JumpIfSmi(src, smi_case, at, USE_DELAY_SLOT);
  SmiUntag(dst, src);
}


void MacroAssembler::UntagAndJumpIfNotSmi(Register dst,
                                          Register src,
                                          Label* non_smi_case) {
  JumpIfNotSmi(src, non_smi_case, at, USE_DELAY_SLOT);
  SmiUntag(dst, src);
}

void MacroAssembler::JumpIfSmi(Register value,
                               Label* smi_label,
                               Register scratch,
                               BranchDelaySlot bd) {
  ASSERT_EQ(0, kSmiTag);
  andi(scratch, value, kSmiTagMask);
  Branch(bd, smi_label, eq, scratch, Operand(zero_reg));
}

void MacroAssembler::JumpIfNotSmi(Register value,
                                  Label* not_smi_label,
                                  Register scratch,
                                  BranchDelaySlot bd) {
  ASSERT_EQ(0, kSmiTag);
  andi(scratch, value, kSmiTagMask);
  Branch(bd, not_smi_label, ne, scratch, Operand(zero_reg));
}


void MacroAssembler::JumpIfNotBothSmi(Register reg1,
                                      Register reg2,
                                      Label* on_not_both_smi) {
  STATIC_ASSERT(kSmiTag == 0);
  ASSERT_EQ(1, kSmiTagMask);
  or_(at, reg1, reg2);
  JumpIfNotSmi(at, on_not_both_smi);
}


void MacroAssembler::JumpIfEitherSmi(Register reg1,
                                     Register reg2,
                                     Label* on_either_smi) {
  STATIC_ASSERT(kSmiTag == 0);
  ASSERT_EQ(1, kSmiTagMask);
  // Both Smi tags must be 1 (not Smi).
  and_(at, reg1, reg2);
  JumpIfSmi(at, on_either_smi);
}


void MacroAssembler::AbortIfSmi(Register object) {
  STATIC_ASSERT(kSmiTag == 0);
  andi(at, object, kSmiTagMask);
  Assert(ne, "Operand is a smi", at, Operand(zero_reg));
}


void MacroAssembler::AbortIfNotSmi(Register object) {
  STATIC_ASSERT(kSmiTag == 0);
  andi(at, object, kSmiTagMask);
  Assert(eq, "Operand is a smi", at, Operand(zero_reg));
}


void MacroAssembler::AbortIfNotString(Register object) {
  STATIC_ASSERT(kSmiTag == 0);
  And(t0, object, Operand(kSmiTagMask));
  Assert(ne, "Operand is not a string", t0, Operand(zero_reg));
  push(object);
  lw(object, FieldMemOperand(object, HeapObject::kMapOffset));
  lbu(object, FieldMemOperand(object, Map::kInstanceTypeOffset));
  Assert(lo, "Operand is not a string", object, Operand(FIRST_NONSTRING_TYPE));
  pop(object);
}


void MacroAssembler::AbortIfNotRootValue(Register src,
                                         Heap::RootListIndex root_value_index,
                                         const char* message) {
  ASSERT(!src.is(at));
  LoadRoot(at, root_value_index);
  Assert(eq, message, src, Operand(at));
}


void MacroAssembler::JumpIfNotHeapNumber(Register object,
                                         Register heap_number_map,
                                         Register scratch,
                                         Label* on_not_heap_number) {
  lw(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
  AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
  Branch(on_not_heap_number, ne, scratch, Operand(heap_number_map));
}


void MacroAssembler::JumpIfNonSmisNotBothSequentialAsciiStrings(
    Register first,
    Register second,
    Register scratch1,
    Register scratch2,
    Label* failure) {
  // Test that both first and second are sequential ASCII strings.
  // Assume that they are non-smis.
  lw(scratch1, FieldMemOperand(first, HeapObject::kMapOffset));
  lw(scratch2, FieldMemOperand(second, HeapObject::kMapOffset));
  lbu(scratch1, FieldMemOperand(scratch1, Map::kInstanceTypeOffset));
  lbu(scratch2, FieldMemOperand(scratch2, Map::kInstanceTypeOffset));

  JumpIfBothInstanceTypesAreNotSequentialAscii(scratch1,
                                               scratch2,
                                               scratch1,
                                               scratch2,
                                               failure);
}


void MacroAssembler::JumpIfNotBothSequentialAsciiStrings(Register first,
                                                         Register second,
                                                         Register scratch1,
                                                         Register scratch2,
                                                         Label* failure) {
  // Check that neither is a smi.
  STATIC_ASSERT(kSmiTag == 0);
  And(scratch1, first, Operand(second));
  JumpIfSmi(scratch1, failure);
  JumpIfNonSmisNotBothSequentialAsciiStrings(first,
                                             second,
                                             scratch1,
                                             scratch2,
                                             failure);
}


void MacroAssembler::JumpIfBothInstanceTypesAreNotSequentialAscii(
    Register first,
    Register second,
    Register scratch1,
    Register scratch2,
    Label* failure) {
  int kFlatAsciiStringMask =
      kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask;
  int kFlatAsciiStringTag = ASCII_STRING_TYPE;
  ASSERT(kFlatAsciiStringTag <= 0xffff);  // Ensure this fits 16-bit immed.
  andi(scratch1, first, kFlatAsciiStringMask);
  Branch(failure, ne, scratch1, Operand(kFlatAsciiStringTag));
  andi(scratch2, second, kFlatAsciiStringMask);
  Branch(failure, ne, scratch2, Operand(kFlatAsciiStringTag));
}


void MacroAssembler::JumpIfInstanceTypeIsNotSequentialAscii(Register type,
                                                            Register scratch,
                                                            Label* failure) {
  int kFlatAsciiStringMask =
      kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask;
  int kFlatAsciiStringTag = ASCII_STRING_TYPE;
  And(scratch, type, Operand(kFlatAsciiStringMask));
  Branch(failure, ne, scratch, Operand(kFlatAsciiStringTag));
}


static const int kRegisterPassedArguments = 4;

int MacroAssembler::CalculateStackPassedWords(int num_reg_arguments,
                                              int num_double_arguments) {
  int stack_passed_words = 0;
  num_reg_arguments += 2 * num_double_arguments;

  // Up to four simple arguments are passed in registers a0..a3.
  if (num_reg_arguments > kRegisterPassedArguments) {
    stack_passed_words += num_reg_arguments - kRegisterPassedArguments;
  }
  stack_passed_words += kCArgSlotCount;
  return stack_passed_words;
}


void MacroAssembler::PrepareCallCFunction(int num_reg_arguments,
                                          int num_double_arguments,
                                          Register scratch) {
  int frame_alignment = ActivationFrameAlignment();

  // Up to four simple arguments are passed in registers a0..a3.
  // Those four arguments must have reserved argument slots on the stack for
  // mips, even though those argument slots are not normally used.
  // Remaining arguments are pushed on the stack, above (higher address than)
  // the argument slots.
  int stack_passed_arguments = CalculateStackPassedWords(
      num_reg_arguments, num_double_arguments);
  if (frame_alignment > kPointerSize) {
    // Make stack end at alignment and make room for num_arguments - 4 words
    // and the original value of sp.
    mov(scratch, sp);
    Subu(sp, sp, Operand((stack_passed_arguments + 1) * kPointerSize));
    ASSERT(IsPowerOf2(frame_alignment));
    And(sp, sp, Operand(-frame_alignment));
    sw(scratch, MemOperand(sp, stack_passed_arguments * kPointerSize));
  } else {
    Subu(sp, sp, Operand(stack_passed_arguments * kPointerSize));
  }
}


void MacroAssembler::PrepareCallCFunction(int num_reg_arguments,
                                          Register scratch) {
  PrepareCallCFunction(num_reg_arguments, 0, scratch);
}


void MacroAssembler::CallCFunction(ExternalReference function,
                                   int num_reg_arguments,
                                   int num_double_arguments) {
  li(t8, Operand(function));
  CallCFunctionHelper(t8, num_reg_arguments, num_double_arguments);
}


void MacroAssembler::CallCFunction(Register function,
                                   int num_reg_arguments,
                                   int num_double_arguments) {
  CallCFunctionHelper(function, num_reg_arguments, num_double_arguments);
}


void MacroAssembler::CallCFunction(ExternalReference function,
                                   int num_arguments) {
  CallCFunction(function, num_arguments, 0);
}


void MacroAssembler::CallCFunction(Register function,
                                   int num_arguments) {
  CallCFunction(function, num_arguments, 0);
}


void MacroAssembler::CallCFunctionHelper(Register function,
                                         int num_reg_arguments,
                                         int num_double_arguments) {
  ASSERT(has_frame());
  // Make sure that the stack is aligned before calling a C function unless
  // running in the simulator. The simulator has its own alignment check which
  // provides more information.
  // The argument stots are presumed to have been set up by
  // PrepareCallCFunction. The C function must be called via t9, for mips ABI.

#if defined(V8_HOST_ARCH_MIPS)
  if (emit_debug_code()) {
    int frame_alignment = OS::ActivationFrameAlignment();
    int frame_alignment_mask = frame_alignment - 1;
    if (frame_alignment > kPointerSize) {
      ASSERT(IsPowerOf2(frame_alignment));
      Label alignment_as_expected;
      And(at, sp, Operand(frame_alignment_mask));
      Branch(&alignment_as_expected, eq, at, Operand(zero_reg));
      // Don't use Check here, as it will call Runtime_Abort possibly
      // re-entering here.
      stop("Unexpected alignment in CallCFunction");
      bind(&alignment_as_expected);
    }
  }
#endif  // V8_HOST_ARCH_MIPS

  // Just call directly. The function called cannot cause a GC, or
  // allow preemption, so the return address in the link register
  // stays correct.

  if (!function.is(t9)) {
    mov(t9, function);
    function = t9;
  }

  Call(function);

  int stack_passed_arguments = CalculateStackPassedWords(
      num_reg_arguments, num_double_arguments);

  if (OS::ActivationFrameAlignment() > kPointerSize) {
    lw(sp, MemOperand(sp, stack_passed_arguments * kPointerSize));
  } else {
    Addu(sp, sp, Operand(stack_passed_arguments * sizeof(kPointerSize)));
  }
}


#undef BRANCH_ARGS_CHECK


void MacroAssembler::PatchRelocatedValue(Register li_location,
                                         Register scratch,
                                         Register new_value) {
  lw(scratch, MemOperand(li_location));
  // At this point scratch is a lui(at, ...) instruction.
  if (emit_debug_code()) {
    And(scratch, scratch, kOpcodeMask);
    Check(eq, "The instruction to patch should be a lui.",
        scratch, Operand(LUI));
    lw(scratch, MemOperand(li_location));
  }
  srl(t9, new_value, kImm16Bits);
  Ins(scratch, t9, 0, kImm16Bits);
  sw(scratch, MemOperand(li_location));

  lw(scratch, MemOperand(li_location, kInstrSize));
  // scratch is now ori(at, ...).
  if (emit_debug_code()) {
    And(scratch, scratch, kOpcodeMask);
    Check(eq, "The instruction to patch should be an ori.",
        scratch, Operand(ORI));
    lw(scratch, MemOperand(li_location, kInstrSize));
  }
  Ins(scratch, new_value, 0, kImm16Bits);
  sw(scratch, MemOperand(li_location, kInstrSize));

  // Update the I-cache so the new lui and ori can be executed.
  FlushICache(li_location, 2);
}

void MacroAssembler::GetRelocatedValue(Register li_location,
                                       Register value,
                                       Register scratch) {
  lw(value, MemOperand(li_location));
  if (emit_debug_code()) {
    And(value, value, kOpcodeMask);
    Check(eq, "The instruction should be a lui.",
        value, Operand(LUI));
    lw(value, MemOperand(li_location));
  }

  // value now holds a lui instruction. Extract the immediate.
  sll(value, value, kImm16Bits);

  lw(scratch, MemOperand(li_location, kInstrSize));
  if (emit_debug_code()) {
    And(scratch, scratch, kOpcodeMask);
    Check(eq, "The instruction should be an ori.",
        scratch, Operand(ORI));
    lw(scratch, MemOperand(li_location, kInstrSize));
  }
  // "scratch" now holds an ori instruction. Extract the immediate.
  andi(scratch, scratch, kImm16Mask);

  // Merge the results.
  or_(value, value, scratch);
}


void MacroAssembler::CheckPageFlag(
    Register object,
    Register scratch,
    int mask,
    Condition cc,
    Label* condition_met) {
  And(scratch, object, Operand(~Page::kPageAlignmentMask));
  lw(scratch, MemOperand(scratch, MemoryChunk::kFlagsOffset));
  And(scratch, scratch, Operand(mask));
  Branch(condition_met, cc, scratch, Operand(zero_reg));
}


void MacroAssembler::JumpIfBlack(Register object,
                                 Register scratch0,
                                 Register scratch1,
                                 Label* on_black) {
  HasColor(object, scratch0, scratch1, on_black, 1, 0);  // kBlackBitPattern.
  ASSERT(strcmp(Marking::kBlackBitPattern, "10") == 0);
}


void MacroAssembler::HasColor(Register object,
                              Register bitmap_scratch,
                              Register mask_scratch,
                              Label* has_color,
                              int first_bit,
                              int second_bit) {
  ASSERT(!AreAliased(object, bitmap_scratch, mask_scratch, t8));
  ASSERT(!AreAliased(object, bitmap_scratch, mask_scratch, t9));

  GetMarkBits(object, bitmap_scratch, mask_scratch);

  Label other_color, word_boundary;
  lw(t9, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
  And(t8, t9, Operand(mask_scratch));
  Branch(&other_color, first_bit == 1 ? eq : ne, t8, Operand(zero_reg));
  // Shift left 1 by adding.
  Addu(mask_scratch, mask_scratch, Operand(mask_scratch));
  Branch(&word_boundary, eq, mask_scratch, Operand(zero_reg));
  And(t8, t9, Operand(mask_scratch));
  Branch(has_color, second_bit == 1 ? ne : eq, t8, Operand(zero_reg));
  jmp(&other_color);

  bind(&word_boundary);
  lw(t9, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize + kPointerSize));
  And(t9, t9, Operand(1));
  Branch(has_color, second_bit == 1 ? ne : eq, t9, Operand(zero_reg));
  bind(&other_color);
}


// Detect some, but not all, common pointer-free objects.  This is used by the
// incremental write barrier which doesn't care about oddballs (they are always
// marked black immediately so this code is not hit).
void MacroAssembler::JumpIfDataObject(Register value,
                                      Register scratch,
                                      Label* not_data_object) {
  ASSERT(!AreAliased(value, scratch, t8, no_reg));
  Label is_data_object;
  lw(scratch, FieldMemOperand(value, HeapObject::kMapOffset));
  LoadRoot(t8, Heap::kHeapNumberMapRootIndex);
  Branch(&is_data_object, eq, t8, Operand(scratch));
  ASSERT(kIsIndirectStringTag == 1 && kIsIndirectStringMask == 1);
  ASSERT(kNotStringTag == 0x80 && kIsNotStringMask == 0x80);
  // If it's a string and it's not a cons string then it's an object containing
  // no GC pointers.
  lbu(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
  And(t8, scratch, Operand(kIsIndirectStringMask | kIsNotStringMask));
  Branch(not_data_object, ne, t8, Operand(zero_reg));
  bind(&is_data_object);
}


void MacroAssembler::GetMarkBits(Register addr_reg,
                                 Register bitmap_reg,
                                 Register mask_reg) {
  ASSERT(!AreAliased(addr_reg, bitmap_reg, mask_reg, no_reg));
  And(bitmap_reg, addr_reg, Operand(~Page::kPageAlignmentMask));
  Ext(mask_reg, addr_reg, kPointerSizeLog2, Bitmap::kBitsPerCellLog2);
  const int kLowBits = kPointerSizeLog2 + Bitmap::kBitsPerCellLog2;
  Ext(t8, addr_reg, kLowBits, kPageSizeBits - kLowBits);
  sll(t8, t8, kPointerSizeLog2);
  Addu(bitmap_reg, bitmap_reg, t8);
  li(t8, Operand(1));
  sllv(mask_reg, t8, mask_reg);
}


void MacroAssembler::EnsureNotWhite(
    Register value,
    Register bitmap_scratch,
    Register mask_scratch,
    Register load_scratch,
    Label* value_is_white_and_not_data) {
  ASSERT(!AreAliased(value, bitmap_scratch, mask_scratch, t8));
  GetMarkBits(value, bitmap_scratch, mask_scratch);

  // If the value is black or grey we don't need to do anything.
  ASSERT(strcmp(Marking::kWhiteBitPattern, "00") == 0);
  ASSERT(strcmp(Marking::kBlackBitPattern, "10") == 0);
  ASSERT(strcmp(Marking::kGreyBitPattern, "11") == 0);
  ASSERT(strcmp(Marking::kImpossibleBitPattern, "01") == 0);

  Label done;

  // Since both black and grey have a 1 in the first position and white does
  // not have a 1 there we only need to check one bit.
  lw(load_scratch, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
  And(t8, mask_scratch, load_scratch);
  Branch(&done, ne, t8, Operand(zero_reg));

  if (emit_debug_code()) {
    // Check for impossible bit pattern.
    Label ok;
    // sll may overflow, making the check conservative.
    sll(t8, mask_scratch, 1);
    And(t8, load_scratch, t8);
    Branch(&ok, eq, t8, Operand(zero_reg));
    stop("Impossible marking bit pattern");
    bind(&ok);
  }

  // Value is white.  We check whether it is data that doesn't need scanning.
  // Currently only checks for HeapNumber and non-cons strings.
  Register map = load_scratch;  // Holds map while checking type.
  Register length = load_scratch;  // Holds length of object after testing type.
  Label is_data_object;

  // Check for heap-number
  lw(map, FieldMemOperand(value, HeapObject::kMapOffset));
  LoadRoot(t8, Heap::kHeapNumberMapRootIndex);
  {
    Label skip;
    Branch(&skip, ne, t8, Operand(map));
    li(length, HeapNumber::kSize);
    Branch(&is_data_object);
    bind(&skip);
  }

  // Check for strings.
  ASSERT(kIsIndirectStringTag == 1 && kIsIndirectStringMask == 1);
  ASSERT(kNotStringTag == 0x80 && kIsNotStringMask == 0x80);
  // If it's a string and it's not a cons string then it's an object containing
  // no GC pointers.
  Register instance_type = load_scratch;
  lbu(instance_type, FieldMemOperand(map, Map::kInstanceTypeOffset));
  And(t8, instance_type, Operand(kIsIndirectStringMask | kIsNotStringMask));
  Branch(value_is_white_and_not_data, ne, t8, Operand(zero_reg));
  // It's a non-indirect (non-cons and non-slice) string.
  // If it's external, the length is just ExternalString::kSize.
  // Otherwise it's String::kHeaderSize + string->length() * (1 or 2).
  // External strings are the only ones with the kExternalStringTag bit
  // set.
  ASSERT_EQ(0, kSeqStringTag & kExternalStringTag);
  ASSERT_EQ(0, kConsStringTag & kExternalStringTag);
  And(t8, instance_type, Operand(kExternalStringTag));
  {
    Label skip;
    Branch(&skip, eq, t8, Operand(zero_reg));
    li(length, ExternalString::kSize);
    Branch(&is_data_object);
    bind(&skip);
  }

  // Sequential string, either ASCII or UC16.
  // For ASCII (char-size of 1) we shift the smi tag away to get the length.
  // For UC16 (char-size of 2) we just leave the smi tag in place, thereby
  // getting the length multiplied by 2.
  ASSERT(kAsciiStringTag == 4 && kStringEncodingMask == 4);
  ASSERT(kSmiTag == 0 && kSmiTagSize == 1);
  lw(t9, FieldMemOperand(value, String::kLengthOffset));
  And(t8, instance_type, Operand(kStringEncodingMask));
  {
    Label skip;
    Branch(&skip, eq, t8, Operand(zero_reg));
    srl(t9, t9, 1);
    bind(&skip);
  }
  Addu(length, t9, Operand(SeqString::kHeaderSize + kObjectAlignmentMask));
  And(length, length, Operand(~kObjectAlignmentMask));

  bind(&is_data_object);
  // Value is a data object, and it is white.  Mark it black.  Since we know
  // that the object is white we can make it black by flipping one bit.
  lw(t8, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));
  Or(t8, t8, Operand(mask_scratch));
  sw(t8, MemOperand(bitmap_scratch, MemoryChunk::kHeaderSize));

  And(bitmap_scratch, bitmap_scratch, Operand(~Page::kPageAlignmentMask));
  lw(t8, MemOperand(bitmap_scratch, MemoryChunk::kLiveBytesOffset));
  Addu(t8, t8, Operand(length));
  sw(t8, MemOperand(bitmap_scratch, MemoryChunk::kLiveBytesOffset));

  bind(&done);
}


void MacroAssembler::LoadInstanceDescriptors(Register map,
                                             Register descriptors,
                                             Register scratch) {
  lw(descriptors,
     FieldMemOperand(map, Map::kInstanceDescriptorsOrBackPointerOffset));

  Label ok, fail;
  CheckMap(descriptors,
           scratch,
           isolate()->factory()->fixed_array_map(),
           &fail,
           DONT_DO_SMI_CHECK);
  jmp(&ok);
  bind(&fail);
  LoadRoot(descriptors, Heap::kEmptyDescriptorArrayRootIndex);
  bind(&ok);
}


void MacroAssembler::CheckEnumCache(Register null_value, Label* call_runtime) {
  Label next;
  // Preload a couple of values used in the loop.
  Register  empty_fixed_array_value = t2;
  LoadRoot(empty_fixed_array_value, Heap::kEmptyFixedArrayRootIndex);
  Register empty_descriptor_array_value = t3;
  LoadRoot(empty_descriptor_array_value,
           Heap::kEmptyDescriptorArrayRootIndex);
  mov(a1, a0);
  bind(&next);

  // Check that there are no elements.  Register a1 contains the
  // current JS object we've reached through the prototype chain.
  lw(a2, FieldMemOperand(a1, JSObject::kElementsOffset));
  Branch(call_runtime, ne, a2, Operand(empty_fixed_array_value));

  // Check that instance descriptors are not empty so that we can
  // check for an enum cache.  Leave the map in a2 for the subsequent
  // prototype load.
  lw(a2, FieldMemOperand(a1, HeapObject::kMapOffset));
  lw(a3, FieldMemOperand(a2, Map::kInstanceDescriptorsOrBackPointerOffset));

  CheckMap(a3,
           t3,
           isolate()->factory()->fixed_array_map(),
           call_runtime,
           DONT_DO_SMI_CHECK);

  // Check that there is an enum cache in the non-empty instance
  // descriptors (a3).  This is the case if the next enumeration
  // index field does not contain a smi.
  lw(a3, FieldMemOperand(a3, DescriptorArray::kLastAddedOffset));
  JumpIfSmi(a3, call_runtime);

  // For all objects but the receiver, check that the cache is empty.
  Label check_prototype;
  Branch(&check_prototype, eq, a1, Operand(a0));
  lw(a3, FieldMemOperand(a3, DescriptorArray::kEnumCacheBridgeCacheOffset));
  Branch(call_runtime, ne, a3, Operand(empty_fixed_array_value));

  // Load the prototype from the map and loop if non-null.
  bind(&check_prototype);
  lw(a1, FieldMemOperand(a2, Map::kPrototypeOffset));
  Branch(&next, ne, a1, Operand(null_value));
}


void MacroAssembler::ClampUint8(Register output_reg, Register input_reg) {
  ASSERT(!output_reg.is(input_reg));
  Label done;
  li(output_reg, Operand(255));
  // Normal branch: nop in delay slot.
  Branch(&done, gt, input_reg, Operand(output_reg));
  // Use delay slot in this branch.
  Branch(USE_DELAY_SLOT, &done, lt, input_reg, Operand(zero_reg));
  mov(output_reg, zero_reg);  // In delay slot.
  mov(output_reg, input_reg);  // Value is in range 0..255.
  bind(&done);
}


void MacroAssembler::ClampDoubleToUint8(Register result_reg,
                                        DoubleRegister input_reg,
                                        DoubleRegister temp_double_reg) {
  Label above_zero;
  Label done;
  Label in_bounds;

  Move(temp_double_reg, 0.0);
  BranchF(&above_zero, NULL, gt, input_reg, temp_double_reg);

  // Double value is less than zero, NaN or Inf, return 0.
  mov(result_reg, zero_reg);
  Branch(&done);

  // Double value is >= 255, return 255.
  bind(&above_zero);
  Move(temp_double_reg, 255.0);
  BranchF(&in_bounds, NULL, le, input_reg, temp_double_reg);
  li(result_reg, Operand(255));
  Branch(&done);

  // In 0-255 range, round and truncate.
  bind(&in_bounds);
  round_w_d(temp_double_reg, input_reg);
  mfc1(result_reg, temp_double_reg);
  bind(&done);
}


bool AreAliased(Register r1, Register r2, Register r3, Register r4) {
  if (r1.is(r2)) return true;
  if (r1.is(r3)) return true;
  if (r1.is(r4)) return true;
  if (r2.is(r3)) return true;
  if (r2.is(r4)) return true;
  if (r3.is(r4)) return true;
  return false;
}


CodePatcher::CodePatcher(byte* address, int instructions)
    : address_(address),
      instructions_(instructions),
      size_(instructions * Assembler::kInstrSize),
      masm_(NULL, address, size_ + Assembler::kGap) {
  // Create a new macro assembler pointing to the address of the code to patch.
  // The size is adjusted with kGap on order for the assembler to generate size
  // bytes of instructions without failing with buffer size constraints.
  ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
}


CodePatcher::~CodePatcher() {
  // Indicate that code has changed.
  CPU::FlushICache(address_, size_);

  // Check that the code was patched as expected.
  ASSERT(masm_.pc_ == address_ + size_);
  ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
}


void CodePatcher::Emit(Instr instr) {
  masm()->emit(instr);
}


void CodePatcher::Emit(Address addr) {
  masm()->emit(reinterpret_cast<Instr>(addr));
}


void CodePatcher::ChangeBranchCondition(Condition cond) {
  Instr instr = Assembler::instr_at(masm_.pc_);
  ASSERT(Assembler::IsBranch(instr));
  uint32_t opcode = Assembler::GetOpcodeField(instr);
  // Currently only the 'eq' and 'ne' cond values are supported and the simple
  // branch instructions (with opcode being the branch type).
  // There are some special cases (see Assembler::IsBranch()) so extending this
  // would be tricky.
  ASSERT(opcode == BEQ ||
         opcode == BNE ||
        opcode == BLEZ ||
        opcode == BGTZ ||
        opcode == BEQL ||
        opcode == BNEL ||
       opcode == BLEZL ||
       opcode == BGTZL);
  opcode = (cond == eq) ? BEQ : BNE;
  instr = (instr & ~kOpcodeMask) | opcode;
  masm_.emit(instr);
}


} }  // namespace v8::internal

#endif  // V8_TARGET_ARCH_MIPS

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