ic-ia32.cc.svn-base

Google浏览器V8内核代码

// Copyright 2006-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// 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
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#include "v8.h"

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

namespace v8 { namespace internal {

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

#define __ masm->


// Helper function used from LoadIC/CallIC GenerateNormal.
static void GenerateDictionaryLoad(MacroAssembler* masm, Label* miss_label,
                                   Register r0, Register r1, Register r2,
                                   Register name) {
  // Register use:
  //
  // r0   - used to hold the property dictionary.
  //
  // r1   - initially the receiver
  //      - used for the index into the property dictionary
  //      - holds the result on exit.
  //
  // r2   - used to hold the capacity of the property dictionary.
  //
  // name - holds the name of the property and is unchanges.

  Label done;

  // Check for the absence of an interceptor.
  // Load the map into r0.
  __ mov(r0, FieldOperand(r1, JSObject::kMapOffset));
  // Test the has_named_interceptor bit in the map.
  __ test(FieldOperand(r0, Map::kInstanceAttributesOffset),
          Immediate(1 << (Map::kHasNamedInterceptor + (3 * 8))));
  // Jump to miss if the interceptor bit is set.
  __ j(not_zero, miss_label, not_taken);

  // Check that the properties array is a dictionary.
  __ mov(r0, FieldOperand(r1, JSObject::kPropertiesOffset));
  __ cmp(FieldOperand(r0, HeapObject::kMapOffset),
         Immediate(Factory::hash_table_map()));
  __ j(not_equal, miss_label);

  // Compute the capacity mask.
  const int kCapacityOffset =
      Array::kHeaderSize + Dictionary::kCapacityIndex * kPointerSize;
  __ mov(r2, FieldOperand(r0, kCapacityOffset));
  __ shr(r2, kSmiTagSize);  // convert smi to int
  __ dec(r2);

  // Generate an unrolled loop that performs a few probes before
  // giving up. Measurements done on Gmail indicate that 2 probes
  // cover ~93% of loads from dictionaries.
  static const int kProbes = 4;
  const int kElementsStartOffset =
      Array::kHeaderSize + Dictionary::kElementsStartIndex * kPointerSize;
  for (int i = 0; i < kProbes; i++) {
    // Compute the masked index: (hash + i + i * i) & mask.
    __ mov(r1, FieldOperand(name, String::kLengthOffset));
    if (i > 0) __ add(Operand(r1), Immediate(Dictionary::GetProbeOffset(i)));
    __ and_(r1, Operand(r2));

    // Scale the index by multiplying by the element size.
    ASSERT(Dictionary::kElementSize == 3);
    __ lea(r1, Operand(r1, r1, times_2, 0));  // r1 = r1 * 3

    // Check if the key is identical to the name.
    __ cmp(name,
           Operand(r0, r1, times_4, kElementsStartOffset - kHeapObjectTag));
    if (i != kProbes - 1) {
      __ j(equal, &done, taken);
    } else {
      __ j(not_equal, miss_label, not_taken);
    }
  }

  // Check that the value is a normal property.
  __ bind(&done);
  const int kDetailsOffset = kElementsStartOffset + 2 * kPointerSize;
  __ test(Operand(r0, r1, times_4, kDetailsOffset - kHeapObjectTag),
          Immediate(PropertyDetails::TypeField::mask() << kSmiTagSize));
  __ j(not_zero, miss_label, not_taken);

  // Get the value at the masked, scaled index.
  const int kValueOffset = kElementsStartOffset + kPointerSize;
  __ mov(r1, Operand(r0, r1, times_4, kValueOffset - kHeapObjectTag));
}


void LoadIC::GenerateArrayLength(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- ecx    : name
  //  -- esp[0] : return address
  //  -- esp[4] : receiver
  // -----------------------------------

  Label miss;

  __ mov(eax, Operand(esp, kPointerSize));

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


void LoadIC::GenerateShortStringLength(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- ecx    : name
  //  -- esp[0] : return address
  //  -- esp[4] : receiver
  // -----------------------------------

  Label miss;

  __ mov(eax, Operand(esp, kPointerSize));

  StubCompiler::GenerateLoadShortStringLength(masm, eax, edx, &miss);
  __ bind(&miss);
  StubCompiler::GenerateLoadMiss(masm, Code::LOAD_IC);
}


void LoadIC::GenerateMediumStringLength(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- ecx    : name
  //  -- esp[0] : return address
  //  -- esp[4] : receiver
  // -----------------------------------

  Label miss;

  __ mov(eax, Operand(esp, kPointerSize));

  StubCompiler::GenerateLoadMediumStringLength(masm, eax, edx, &miss);
  __ bind(&miss);
  StubCompiler::GenerateLoadMiss(masm, Code::LOAD_IC);
}


void LoadIC::GenerateLongStringLength(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- ecx    : name
  //  -- esp[0] : return address
  //  -- esp[4] : receiver
  // -----------------------------------

  Label miss;

  __ mov(eax, Operand(esp, kPointerSize));

  StubCompiler::GenerateLoadLongStringLength(masm, eax, edx, &miss);
  __ bind(&miss);
  StubCompiler::GenerateLoadMiss(masm, Code::LOAD_IC);
}


void LoadIC::GenerateFunctionPrototype(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- ecx    : name
  //  -- esp[0] : return address
  //  -- esp[4] : receiver
  // -----------------------------------

  Label miss;

  __ mov(eax, Operand(esp, kPointerSize));

  StubCompiler::GenerateLoadFunctionPrototype(masm, eax, edx, ebx, &miss);
  __ bind(&miss);
  StubCompiler::GenerateLoadMiss(masm, Code::LOAD_IC);
}


void KeyedLoadIC::GenerateGeneric(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- esp[0] : return address
  //  -- esp[4] : name
  //  -- esp[8] : receiver
  // -----------------------------------
  Label slow, fast, check_string;

  __ mov(eax, (Operand(esp, kPointerSize)));
  __ mov(ecx, (Operand(esp, 2 * kPointerSize)));

  // Check that the object isn't a smi.
  __ test(ecx, Immediate(kSmiTagMask));
  __ j(zero, &slow, not_taken);
  // Check that the object is some kind of JS object EXCEPT JS Value type.
  // In the case that the object is a value-wrapper object,
  // we enter the runtime system to make sure that indexing
  // into string objects work as intended.
  ASSERT(JS_OBJECT_TYPE > JS_VALUE_TYPE);
  __ mov(edx, FieldOperand(ecx, HeapObject::kMapOffset));
  __ movzx_b(edx, FieldOperand(edx, Map::kInstanceTypeOffset));
  __ cmp(edx, JS_OBJECT_TYPE);
  __ j(less, &slow, not_taken);
  // Check that the key is a smi.
  __ test(eax, Immediate(kSmiTagMask));
  __ j(not_zero, &check_string, not_taken);
  __ sar(eax, kSmiTagSize);
  // Get the elements array of the object.
  __ mov(ecx, FieldOperand(ecx, JSObject::kElementsOffset));
  // Check that the object is in fast mode (not dictionary).
  __ cmp(FieldOperand(ecx, HeapObject::kMapOffset),
         Immediate(Factory::hash_table_map()));
  __ j(equal, &slow, not_taken);
  // Check that the key (index) is within bounds.
  __ cmp(eax, FieldOperand(ecx, Array::kLengthOffset));
  __ j(below, &fast, taken);
  // Slow case: Load name and receiver from stack and jump to runtime.
  __ bind(&slow);
  __ IncrementCounter(&Counters::keyed_load_generic_slow, 1);
  KeyedLoadIC::Generate(masm, ExternalReference(Runtime::kGetProperty));
  // Check if the key is a symbol that is not an array index.
  __ bind(&check_string);
  __ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
  __ movzx_b(ebx, FieldOperand(ebx, Map::kInstanceTypeOffset));
  __ test(ebx, Immediate(kIsSymbolMask));
  __ j(zero, &slow, not_taken);
  __ mov(ebx, FieldOperand(eax, String::kLengthOffset));
  __ test(ebx, Immediate(String::kIsArrayIndexMask));
  __ j(not_zero, &slow, not_taken);
  // Probe the dictionary leaving result in ecx.
  GenerateDictionaryLoad(masm, &slow, ebx, ecx, edx, eax);
  __ mov(eax, Operand(ecx));
  __ IncrementCounter(&Counters::keyed_load_generic_symbol, 1);
  __ ret(0);
  // Fast case: Do the load.
  __ bind(&fast);
  __ mov(eax, Operand(ecx, eax, times_4, Array::kHeaderSize - kHeapObjectTag));
  __ cmp(Operand(eax), Immediate(Factory::the_hole_value()));
  // In case the loaded value is the_hole we have to consult GetProperty
  // to ensure the prototype chain is searched.
  __ j(equal, &slow, not_taken);
  __ IncrementCounter(&Counters::keyed_load_generic_smi, 1);
  __ ret(0);
}


void KeyedStoreIC::GenerateGeneric(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- eax    : value
  //  -- esp[0] : return address
  //  -- esp[4] : key
  //  -- esp[8] : receiver
  // -----------------------------------
  Label slow, fast, array, extra;
  // Get the key and the object from the stack.
  __ mov(ebx, Operand(esp, 1 * kPointerSize));  // 1 ~ return address
  __ mov(edx, Operand(esp, 2 * kPointerSize));  // 2 ~ return address, key
  // Check that the key is a smi.
  __ test(ebx, Immediate(kSmiTagMask));
  __ j(not_zero, &slow, not_taken);
  // Check that the object isn't a smi.
  __ test(edx, Immediate(kSmiTagMask));
  __ j(zero, &slow, not_taken);
  // Get the type of the object from its map.
  __ mov(ecx, FieldOperand(edx, HeapObject::kMapOffset));
  __ movzx_b(ecx, FieldOperand(ecx, Map::kInstanceTypeOffset));
  // Check if the object is a JS array or not.
  __ cmp(ecx, JS_ARRAY_TYPE);
  __ j(equal, &array);
  // Check that the object is some kind of JS object.
  __ cmp(ecx, FIRST_JS_OBJECT_TYPE);
  __ j(less, &slow, not_taken);


  // Object case: Check key against length in the elements array.
  // eax: value
  // edx: JSObject
  // ebx: index (as a smi)
  __ mov(ecx, FieldOperand(edx, JSObject::kElementsOffset));
  // Check that the object is in fast mode (not dictionary).
  __ cmp(FieldOperand(ecx, HeapObject::kMapOffset),
         Immediate(Factory::hash_table_map()));
  __ j(equal, &slow, not_taken);
  // Untag the key (for checking against untagged length in the fixed array).
  __ mov(edx, Operand(ebx));
  __ sar(edx, kSmiTagSize);  // untag the index and use it for the comparison
  __ cmp(edx, FieldOperand(ecx, Array::kLengthOffset));
  // eax: value
  // ecx: FixedArray
  // ebx: index (as a smi)
  __ j(below, &fast, taken);


  // Slow case: Push extra copies of the arguments (3).
  __ bind(&slow);
  __ pop(ecx);
  __ push(Operand(esp, 1 * kPointerSize));
  __ push(Operand(esp, 1 * kPointerSize));
  __ push(eax);
  __ push(ecx);
  // Do tail-call to runtime routine.
  __ TailCallRuntime(ExternalReference(Runtime::kSetProperty), 3);


  // Extra capacity case: Check if there is extra capacity to
  // perform the store and update the length. Used for adding one
  // element to the array by writing to array[array.length].
  __ bind(&extra);
  // eax: value
  // edx: JSArray
  // ecx: FixedArray
  // ebx: index (as a smi)
  // flags: compare (ebx, edx.length())
  __ j(not_equal, &slow, not_taken);  // do not leave holes in the array
  __ sar(ebx, kSmiTagSize);  // untag
  __ cmp(ebx, FieldOperand(ecx, Array::kLengthOffset));
  __ j(above_equal, &slow, not_taken);
  // Restore tag and increment.
  __ lea(ebx, Operand(ebx, times_2, 1 << kSmiTagSize));
  __ mov(FieldOperand(edx, JSArray::kLengthOffset), ebx);
  __ sub(Operand(ebx), Immediate(1 << kSmiTagSize));  // decrement ebx again
  __ jmp(&fast);


  // Array case: Get the length and the elements array from the JS
  // array. Check that the array is in fast mode; if it is the
  // length is always a smi.
  __ bind(&array);
  // eax: value
  // edx: JSArray
  // ebx: index (as a smi)
  __ mov(ecx, FieldOperand(edx, JSObject::kElementsOffset));
  __ cmp(FieldOperand(ecx, HeapObject::kMapOffset),
         Immediate(Factory::hash_table_map()));
  __ j(equal, &slow, not_taken);

  // Check the key against the length in the array, compute the
  // address to store into and fall through to fast case.
  __ cmp(ebx, FieldOperand(edx, JSArray::kLengthOffset));
  __ j(above_equal, &extra, not_taken);


  // Fast case: Do the store.