v8/src/ia32/ic-ia32.cc

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// Copyright 2006-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "v8.h"
#include "codegen-inl.h"
#include "ic-inl.h"
#include "runtime.h"
#include "stub-cache.h"
namespace v8 {
namespace internal {
// ----------------------------------------------------------------------------
// Static IC stub generators.
//
#define __ ACCESS_MASM(masm)
// Helper function used to load a property from a dictionary backing storage.
// This function may return false negatives, so miss_label
// must always call a backup property load that is complete.
// This function is safe to call if the receiver has fast properties,
// or if name is not a symbol, and will jump to the miss_label in that case.
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 unchanged.
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);
// Bail out if we have a JS global proxy object.
__ movzx_b(r0, FieldOperand(r0, Map::kInstanceTypeOffset));
__ cmp(r0, JS_GLOBAL_PROXY_TYPE);
__ j(equal, miss_label, not_taken);
// Possible work-around for http://crbug.com/16276.
__ cmp(r0, JS_GLOBAL_OBJECT_TYPE);
__ j(equal, miss_label, not_taken);
__ cmp(r0, JS_BUILTINS_OBJECT_TYPE);
__ j(equal, 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 =
StringDictionary::kHeaderSize +
StringDictionary::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 =
StringDictionary::kHeaderSize +
StringDictionary::kElementsStartIndex * kPointerSize;
for (int i = 0; i < kProbes; i++) {
// Compute the masked index: (hash + i + i * i) & mask.
__ mov(r1, FieldOperand(name, String::kLengthOffset));
__ shr(r1, String::kHashShift);
if (i > 0) {
__ add(Operand(r1), Immediate(StringDictionary::GetProbeOffset(i)));
}
__ and_(r1, Operand(r2));
// Scale the index by multiplying by the entry size.
ASSERT(StringDictionary::kEntrySize == 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));
}
// Helper function used to check that a value is either not an object
// or is loaded if it is an object.
static void GenerateCheckNonObjectOrLoaded(MacroAssembler* masm, Label* miss,
Register value, Register scratch) {
Label done;
// Check if the value is a Smi.
__ test(value, Immediate(kSmiTagMask));
__ j(zero, &done, not_taken);
// Check if the object has been loaded.
__ mov(scratch, FieldOperand(value, JSFunction::kMapOffset));
__ mov(scratch, FieldOperand(scratch, Map::kBitField2Offset));
__ test(scratch, Immediate(1 << Map::kNeedsLoading));
__ j(not_zero, miss, not_taken);
__ bind(&done);
}
// The offset from the inlined patch site to the start of the
// inlined load instruction. It is 7 bytes (test eax, imm) plus
// 6 bytes (jne slow_label).
const int LoadIC::kOffsetToLoadInstruction = 13;
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::GenerateStringLength(MacroAssembler* masm) {
// ----------- S t a t e -------------
// -- ecx : name
// -- esp[0] : return address
// -- esp[4] : receiver
// -----------------------------------
Label miss;
__ mov(eax, Operand(esp, kPointerSize));
StubCompiler::GenerateLoadStringLength(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);
}
#ifdef DEBUG
// For use in assert below.
static int TenToThe(int exponent) {
ASSERT(exponent <= 9);
ASSERT(exponent >= 1);
int answer = 10;
for (int i = 1; i < exponent; i++) answer *= 10;
return answer;
}
#endif
void KeyedLoadIC::GenerateGeneric(MacroAssembler* masm) {
// ----------- S t a t e -------------
// -- esp[0] : return address
// -- esp[4] : name
// -- esp[8] : receiver
// -----------------------------------
Label slow, check_string, index_int, index_string, check_pixel_array;
// Load name and receiver.
__ 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);
// Get the map of the receiver.
__ mov(edx, FieldOperand(ecx, HeapObject::kMapOffset));
// Check that the receiver does not require access checks. We need
// to check this explicitly since this generic stub does not perform
// map checks.
__ movzx_b(ebx, FieldOperand(edx, Map::kBitFieldOffset));
__ test(ebx, Immediate(1 << Map::kIsAccessCheckNeeded));
__ j(not_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);
__ 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.
__ bind(&index_int);
__ mov(ecx, FieldOperand(ecx, JSObject::kElementsOffset));
// Check that the object is in fast mode (not dictionary).
__ cmp(FieldOperand(ecx, HeapObject::kMapOffset),
Immediate(Factory::fixed_array_map()));
__ j(not_equal, &check_pixel_array);
// Check that the key (index) is within bounds.
__ cmp(eax, FieldOperand(ecx, FixedArray::kLengthOffset));
__ j(above_equal, &slow);
// Fast case: Do the load.
__ mov(eax,
Operand(ecx, eax, times_4, FixedArray::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);
__ IncrementCounter(&Counters::keyed_load_generic_smi, 1);
__ ret(0);
// Check whether the elements is a pixel array.
// eax: untagged index
// ecx: elements array
__ bind(&check_pixel_array);
__ cmp(FieldOperand(ecx, HeapObject::kMapOffset),
Immediate(Factory::pixel_array_map()));
__ j(not_equal, &slow);
__ cmp(eax, FieldOperand(ecx, PixelArray::kLengthOffset));
__ j(above_equal, &slow);
__ mov(ecx, FieldOperand(ecx, PixelArray::kExternalPointerOffset));
__ movzx_b(eax, Operand(ecx, eax, times_1, 0));
__ shl(eax, kSmiTagSize);
__ ret(0);
// 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::kKeyedGetProperty));
__ bind(&check_string);
// The key is not a smi.
// Is it a string?
__ CmpObjectType(eax, FIRST_NONSTRING_TYPE, edx);
__ j(above_equal, &slow);
// Is the string an array index, with cached numeric value?
__ mov(ebx, FieldOperand(eax, String::kLengthOffset));
__ test(ebx, Immediate(String::kIsArrayIndexMask));
__ j(not_zero, &index_string, not_taken);
// If the string is a symbol, do a quick inline probe of the receiver's
// dictionary, if it exists.
__ movzx_b(ebx, FieldOperand(edx, Map::kInstanceTypeOffset));
__ test(ebx, Immediate(kIsSymbolMask));
__ j(zero, &slow, not_taken);
// Probe the dictionary leaving result in ecx.
GenerateDictionaryLoad(masm, &slow, ebx, ecx, edx, eax);
GenerateCheckNonObjectOrLoaded(masm, &slow, ecx, edx);
__ mov(eax, Operand(ecx));
__ IncrementCounter(&Counters::keyed_load_generic_symbol, 1);
__ ret(0);
// Array index string: If short enough use cache in length/hash field (ebx).
// We assert that there are enough bits in an int32_t after the hash shift
// bits have been subtracted to allow space for the length and the cached
// array index.
ASSERT(TenToThe(String::kMaxCachedArrayIndexLength) <
(1 << (String::kShortLengthShift - String::kHashShift)));
__ bind(&index_string);
const int kLengthFieldLimit =
(String::kMaxCachedArrayIndexLength + 1) << String::kShortLengthShift;
__ cmp(ebx, kLengthFieldLimit);
__ j(above_equal, &slow);
__ mov(eax, Operand(ebx));
__ and_(eax, (1 << String::kShortLengthShift) - 1);
__ shr(eax, String::kLongLengthShift);
__ jmp(&index_int);
}
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, check_pixel_array;
// Get the receiver from the stack.
__ mov(edx, Operand(esp, 2 * kPointerSize)); // 2 ~ return address, key
// Check that the object isn't a smi.
__ test(edx, Immediate(kSmiTagMask));
__ j(zero, &slow, not_taken);
// Get the map from the receiver.
__ mov(ecx, FieldOperand(edx, HeapObject::kMapOffset));
// Check that the receiver does not require access checks. We need
// to do this because this generic stub does not perform map checks.
__ movzx_b(ebx, FieldOperand(ecx, Map::kBitFieldOffset));
__ test(ebx, Immediate(1 << Map::kIsAccessCheckNeeded));
__ j(not_zero, &slow, not_taken);
// Get the key from the stack.
__ mov(ebx, Operand(esp, 1 * kPointerSize)); // 1 ~ return address
// Check that the key is a smi.
__ test(ebx, Immediate(kSmiTagMask));
__ j(not_zero, &slow, not_taken);
// Get the instance type from the map of the receiver.
__ 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::fixed_array_map()));
__ j(not_equal, &check_pixel_array, 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, 1);
// Check whether the elements is a pixel array.
// eax: value
// ecx: elements array
// ebx: index (as a smi)
__ bind(&check_pixel_array);
__ cmp(FieldOperand(ecx, HeapObject::kMapOffset),
Immediate(Factory::pixel_array_map()));
__ j(not_equal, &slow);
// Check that the value is a smi. If a conversion is needed call into the
// runtime to convert and clamp.
__ test(eax, Immediate(kSmiTagMask));
__ j(not_zero, &slow);
__ sar(ebx, kSmiTagSize); // Untag the index.
__ cmp(ebx, FieldOperand(ecx, PixelArray::kLengthOffset));
__ j(above_equal, &slow);
__ sar(eax, kSmiTagSize); // Untag the value.
{ // Clamp the value to [0..255].
Label done, check_255;
__ cmp(eax, 0);
__ j(greater_equal, &check_255);
__ mov(eax, Immediate(0));
__ jmp(&done);
__ bind(&check_255);
__ cmp(eax, 255);
__ j(less_equal, &done);
__ mov(eax, Immediate(255));
__ bind(&done);
}
__ mov(ecx, FieldOperand(ecx, PixelArray::kExternalPointerOffset));
__ mov_b(Operand(ecx, ebx, times_1, 0), eax);
__ ret(0);
// 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::fixed_array_map()));
__ j(not_equal, &check_pixel_array);
// 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.
__ bind(&fast);
// eax: value
// ecx: FixedArray
// ebx: index (as a smi)
__ mov(Operand(ecx, ebx, times_2, FixedArray::kHeaderSize - kHeapObjectTag),
eax);
// Update write barrier for the elements array address.
__ mov(edx, Operand(eax));
__ RecordWrite(ecx, 0, edx, ebx);
__ ret(0);
}
// Defined in ic.cc.
Object* CallIC_Miss(Arguments args);
void CallIC::GenerateMegamorphic(MacroAssembler* masm, int argc) {
// ----------- S t a t e -------------
// -----------------------------------
Label number, non_number, non_string, boolean, probe, miss;
// Get the receiver of the function from the stack; 1 ~ return address.
__ mov(edx, Operand(esp, (argc + 1) * kPointerSize));
// Get the name of the function from the stack; 2 ~ return address, receiver
__ mov(ecx, Operand(esp, (argc + 2) * kPointerSize));
// Probe the stub cache.
Code::Flags flags =
Code::ComputeFlags(Code::CALL_IC, NOT_IN_LOOP, MONOMORPHIC, NORMAL, argc);
StubCache::GenerateProbe(masm, flags, edx, ecx, ebx, eax);
// If the stub cache probing failed, the receiver might be a value.
// For value objects, we use the map of the prototype objects for
// the corresponding JSValue for the cache and that is what we need
// to probe.
//
// Check for number.
__ test(edx, Immediate(kSmiTagMask));
__ j(zero, &number, not_taken);
__ CmpObjectType(edx, HEAP_NUMBER_TYPE, ebx);
__ j(not_equal, &non_number, taken);
__ bind(&number);
StubCompiler::GenerateLoadGlobalFunctionPrototype(
masm, Context::NUMBER_FUNCTION_INDEX, edx);
__ jmp(&probe);
// Check for string.
__ bind(&non_number);
__ cmp(ebx, FIRST_NONSTRING_TYPE);
__ j(above_equal, &non_string, taken);
StubCompiler::GenerateLoadGlobalFunctionPrototype(
masm, Context::STRING_FUNCTION_INDEX, edx);
__ jmp(&probe);
// Check for boolean.
__ bind(&non_string);
__ cmp(edx, Factory::true_value());
__ j(equal, &boolean, not_taken);
__ cmp(edx, Factory::false_value());
__ j(not_equal, &miss, taken);
__ bind(&boolean);
StubCompiler::GenerateLoadGlobalFunctionPrototype(
masm, Context::BOOLEAN_FUNCTION_INDEX, edx);
// Probe the stub cache for the value object.
__ bind(&probe);
StubCache::GenerateProbe(masm, flags, edx, ecx, ebx, no_reg);
// Cache miss: Jump to runtime.
__ bind(&miss);
Generate(masm, argc, ExternalReference(IC_Utility(kCallIC_Miss)));
}
static void GenerateNormalHelper(MacroAssembler* masm,
int argc,
bool is_global_object,
Label* miss) {
// Search dictionary - put result in register edx.
GenerateDictionaryLoad(masm, miss, eax, edx, ebx, ecx);
// Move the result to register edi and check that it isn't a smi.
__ mov(edi, Operand(edx));
__ test(edx, Immediate(kSmiTagMask));
__ j(zero, miss, not_taken);
// Check that the value is a JavaScript function.
__ CmpObjectType(edx, JS_FUNCTION_TYPE, edx);
__ j(not_equal, miss, not_taken);
// Check that the function has been loaded.
__ mov(edx, FieldOperand(edi, JSFunction::kMapOffset));
__ mov(edx, FieldOperand(edx, Map::kBitField2Offset));
__ test(edx, Immediate(1 << Map::kNeedsLoading));
__ j(not_zero, miss, not_taken);
// Patch the receiver with the global proxy if necessary.
if (is_global_object) {
__ mov(edx, Operand(esp, (argc + 1) * kPointerSize));
__ mov(edx, FieldOperand(edx, GlobalObject::kGlobalReceiverOffset));
__ mov(Operand(esp, (argc + 1) * kPointerSize), edx);
}
// Invoke the function.
ParameterCount actual(argc);
__ InvokeFunction(edi, actual, JUMP_FUNCTION);
}
void CallIC::GenerateNormal(MacroAssembler* masm, int argc) {
// ----------- S t a t e -------------
// -----------------------------------
Label miss, global_object, non_global_object;
// Get the receiver of the function from the stack; 1 ~ return address.
__ mov(edx, Operand(esp, (argc + 1) * kPointerSize));
// Get the name of the function from the stack; 2 ~ return address, receiver.
__ mov(ecx, Operand(esp, (argc + 2) * kPointerSize));
// Check that the receiver isn't a smi.
__ test(edx, Immediate(kSmiTagMask));
__ j(zero, &miss, not_taken);
// Check that the receiver is a valid JS object.
__ mov(ebx, FieldOperand(edx, HeapObject::kMapOffset));
__ movzx_b(eax, FieldOperand(ebx, Map::kInstanceTypeOffset));
__ cmp(eax, FIRST_JS_OBJECT_TYPE);
__ j(below, &miss, not_taken);
// If this assert fails, we have to check upper bound too.
ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);
// Check for access to global object.
__ cmp(eax, JS_GLOBAL_OBJECT_TYPE);
__ j(equal, &global_object);
__ cmp(eax, JS_BUILTINS_OBJECT_TYPE);
__ j(not_equal, &non_global_object);
// Accessing global object: Load and invoke.
__ bind(&global_object);
// Check that the global object does not require access checks.
__ movzx_b(ebx, FieldOperand(ebx, Map::kBitFieldOffset));
__ test(ebx, Immediate(1 << Map::kIsAccessCheckNeeded));
__ j(not_equal, &miss, not_taken);
GenerateNormalHelper(masm, argc, true, &miss);
// Accessing non-global object: Check for access to global proxy.
Label global_proxy, invoke;
__ bind(&non_global_object);
__ cmp(eax, JS_GLOBAL_PROXY_TYPE);
__ j(equal, &global_proxy, not_taken);
// Check that the non-global, non-global-proxy object does not
// require access checks.
__ movzx_b(ebx, FieldOperand(ebx, Map::kBitFieldOffset));
__ test(ebx, Immediate(1 << Map::kIsAccessCheckNeeded));
__ j(not_equal, &miss, not_taken);
__ bind(&invoke);
GenerateNormalHelper(masm, argc, false, &miss);
// Global object proxy access: Check access rights.
__ bind(&global_proxy);
Split window support from V8. Here is a description of the background and design of split window in Chrome and V8: https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables. V8 support of split window: There are a small number of changes on V8 api to support split window: Security context is removed from V8, so does related API functions; A global object can be detached from its context and reused by a new context; Access checks on an object template can be turned on/off by default; An object can turn on its access checks later; V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc. Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object. When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks. It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding. I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8. Review URL: http://codereview.chromium.org/7366 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-10-21 19:07:58 +00:00
__ CheckAccessGlobalProxy(edx, eax, &miss);
__ jmp(&invoke);
// Cache miss: Jump to runtime.
__ bind(&miss);
Generate(masm, argc, ExternalReference(IC_Utility(kCallIC_Miss)));
}
void CallIC::Generate(MacroAssembler* masm,
int argc,
const ExternalReference& f) {
// ----------- S t a t e -------------
// -----------------------------------
// Get the receiver of the function from the stack; 1 ~ return address.
__ mov(edx, Operand(esp, (argc + 1) * kPointerSize));
// Get the name of the function to call from the stack.
// 2 ~ receiver, return address.
__ mov(ebx, Operand(esp, (argc + 2) * kPointerSize));
// Enter an internal frame.
__ EnterInternalFrame();
// Push the receiver and the name of the function.
__ push(edx);
__ push(ebx);
// Call the entry.
CEntryStub stub(1);
__ mov(eax, Immediate(2));
__ mov(ebx, Immediate(f));
__ CallStub(&stub);
// Move result to edi and exit the internal frame.
__ mov(edi, eax);
__ LeaveInternalFrame();
// Check if the receiver is a global object of some sort.
Label invoke, global;
__ mov(edx, Operand(esp, (argc + 1) * kPointerSize)); // receiver
__ test(edx, Immediate(kSmiTagMask));
__ j(zero, &invoke, not_taken);
__ mov(ecx, FieldOperand(edx, HeapObject::kMapOffset));
__ movzx_b(ecx, FieldOperand(ecx, Map::kInstanceTypeOffset));
__ cmp(ecx, JS_GLOBAL_OBJECT_TYPE);
__ j(equal, &global);
__ cmp(ecx, JS_BUILTINS_OBJECT_TYPE);
__ j(not_equal, &invoke);
// Patch the receiver on the stack.
__ bind(&global);
__ mov(edx, FieldOperand(edx, GlobalObject::kGlobalReceiverOffset));
__ mov(Operand(esp, (argc + 1) * kPointerSize), edx);
// Invoke the function.
ParameterCount actual(argc);
__ bind(&invoke);
__ InvokeFunction(edi, actual, JUMP_FUNCTION);
}
// Defined in ic.cc.
Object* LoadIC_Miss(Arguments args);
void LoadIC::GenerateMegamorphic(MacroAssembler* masm) {
// ----------- S t a t e -------------
// -- ecx : name
// -- esp[0] : return address
// -- esp[4] : receiver
// -----------------------------------
__ mov(eax, Operand(esp, kPointerSize));
// Probe the stub cache.
Code::Flags flags = Code::ComputeFlags(Code::LOAD_IC,
NOT_IN_LOOP,
MONOMORPHIC);
StubCache::GenerateProbe(masm, flags, eax, ecx, ebx, edx);
// Cache miss: Jump to runtime.
Generate(masm, ExternalReference(IC_Utility(kLoadIC_Miss)));
}
void LoadIC::GenerateNormal(MacroAssembler* masm) {
// ----------- S t a t e -------------
// -- ecx : name
// -- esp[0] : return address
// -- esp[4] : receiver
// -----------------------------------
Label miss, probe, global;
__ mov(eax, Operand(esp, kPointerSize));
// Check that the receiver isn't a smi.
__ test(eax, Immediate(kSmiTagMask));
__ j(zero, &miss, not_taken);
// Check that the receiver is a valid JS object.
__ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
__ movzx_b(edx, FieldOperand(ebx, Map::kInstanceTypeOffset));
__ cmp(edx, FIRST_JS_OBJECT_TYPE);
__ j(less, &miss, not_taken);
// If this assert fails, we have to check upper bound too.
ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);
// Check for access to global object (unlikely).
Split window support from V8. Here is a description of the background and design of split window in Chrome and V8: https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables. V8 support of split window: There are a small number of changes on V8 api to support split window: Security context is removed from V8, so does related API functions; A global object can be detached from its context and reused by a new context; Access checks on an object template can be turned on/off by default; An object can turn on its access checks later; V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc. Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object. When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks. It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding. I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8. Review URL: http://codereview.chromium.org/7366 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-10-21 19:07:58 +00:00
__ cmp(edx, JS_GLOBAL_PROXY_TYPE);
__ j(equal, &global, not_taken);
// Check for non-global object that requires access check.
__ movzx_b(ebx, FieldOperand(ebx, Map::kBitFieldOffset));
__ test(ebx, Immediate(1 << Map::kIsAccessCheckNeeded));
__ j(not_zero, &miss, not_taken);
// Search the dictionary placing the result in eax.
__ bind(&probe);
GenerateDictionaryLoad(masm, &miss, edx, eax, ebx, ecx);
GenerateCheckNonObjectOrLoaded(masm, &miss, eax, edx);
__ ret(0);
// Global object access: Check access rights.
__ bind(&global);
Split window support from V8. Here is a description of the background and design of split window in Chrome and V8: https://docs.google.com/a/google.com/Doc?id=chhjkpg_47fwddxbfr This change list splits the window object into two parts: 1) an inner window object used as the global object of contexts; 2) an outer window object exposed to JavaScript and accessible by the name 'window'. Firefox did it awhile ago, here are some discussions: https://wiki.mozilla.org/Gecko:SplitWindow. One additional benefit of splitting window in Chrome is that accessing global variables don't need security checks anymore, it can improve applications that use many global variables. V8 support of split window: There are a small number of changes on V8 api to support split window: Security context is removed from V8, so does related API functions; A global object can be detached from its context and reused by a new context; Access checks on an object template can be turned on/off by default; An object can turn on its access checks later; V8 has a new object type, ApiGlobalObject, which is the outer window object type. The existing JSGlobalObject becomes the inner window object type. Security checks are moved from JSGlobalObject to ApiGlobalObject. ApiGlobalObject is the one exposed to JavaScript, it is accessible through Context::Global(). ApiGlobalObject's prototype is set to JSGlobalObject so that property lookups are forwarded to JSGlobalObject. ApiGlobalObject forwards all other property access requests to JSGlobalObject, such as SetProperty, DeleteProperty, etc. Security token is moved to a global context, and ApiGlobalObject has a reference to its global context. JSGlobalObject has a reference to its global context as well. When accessing properties on a global object in JavaScript, the domain security check is performed by comparing the security token of the lexical context (Top::global_context()) to the token of global object's context. The check is only needed when the receiver is a window object, such as 'window.document'. Accessing global variables, such as 'var foo = 3; foo' does not need checks because the receiver is the inner window object. When an outer window is detached from its global context (when a frame navigates away from a page), it is completely detached from the inner window. A new context is created for the new page, and the outer global object is reused. At this point, the access check on the DOMWindow wrapper of the old context is turned on. The code in old context is still able to access DOMWindow properties, but it has to go through domain security checks. It is debatable on how to implement the outer window object. Currently each property access function has to check if the receiver is ApiGlobalObject type. This approach might be error-prone that one may forget to check the receiver when adding new functions. It is unlikely a performance issue because accessing global variables are more common than 'window.foo' style coding. I am still working on the ARM port, and I'd like to hear comments and suggestions on the best way to support it in V8. Review URL: http://codereview.chromium.org/7366 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@540 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2008-10-21 19:07:58 +00:00
__ CheckAccessGlobalProxy(eax, edx, &miss);
__ jmp(&probe);
// Cache miss: Restore receiver from stack and jump to runtime.
__ bind(&miss);
__ mov(eax, Operand(esp, 1 * kPointerSize));
Generate(masm, ExternalReference(IC_Utility(kLoadIC_Miss)));
}
void LoadIC::GenerateMiss(MacroAssembler* masm) {
// ----------- S t a t e -------------
// -- ecx : name
// -- esp[0] : return address
// -- esp[4] : receiver
// -----------------------------------
Generate(masm, ExternalReference(IC_Utility(kLoadIC_Miss)));
}
void LoadIC::Generate(MacroAssembler* masm, const ExternalReference& f) {
// ----------- S t a t e -------------
// -- ecx : name
// -- esp[0] : return address
// -- esp[4] : receiver
// -----------------------------------
__ mov(eax, Operand(esp, kPointerSize));
__ pop(ebx);
__ push(eax); // receiver
__ push(ecx); // name
__ push(ebx); // return address
// Perform tail call to the entry.
__ TailCallRuntime(f, 2, 1);
}
// One byte opcode for test eax,0xXXXXXXXX.
static const byte kTestEaxByte = 0xA9;
void LoadIC::ClearInlinedVersion(Address address) {
// Reset the map check of the inlined inobject property load (if
// present) to guarantee failure by holding an invalid map (the null
// value). The offset can be patched to anything.
PatchInlinedLoad(address, Heap::null_value(), kMaxInt);
}
void KeyedLoadIC::ClearInlinedVersion(Address address) {
// Insert null as the map to check for to make sure the map check fails
// sending control flow to the IC instead of the inlined version.
PatchInlinedLoad(address, Heap::null_value());
}
void KeyedStoreIC::ClearInlinedVersion(Address address) {
// Insert null as the elements map to check for. This will make
// sure that the elements fast-case map check fails so that control
// flows to the IC instead of the inlined version.
PatchInlinedStore(address, Heap::null_value());
}
void KeyedStoreIC::RestoreInlinedVersion(Address address) {
// Restore the fast-case elements map check so that the inlined
// version can be used again.
PatchInlinedStore(address, Heap::fixed_array_map());
}
bool LoadIC::PatchInlinedLoad(Address address, Object* map, int offset) {
// The address of the instruction following the call.
Address test_instruction_address =
address + Assembler::kPatchReturnSequenceLength;
// If the instruction following the call is not a test eax, nothing
// was inlined.
if (*test_instruction_address != kTestEaxByte) return false;
Address delta_address = test_instruction_address + 1;
// The delta to the start of the map check instruction.
int delta = *reinterpret_cast<int*>(delta_address);
// The map address is the last 4 bytes of the 7-byte
// operand-immediate compare instruction, so we add 3 to get the
// offset to the last 4 bytes.
Address map_address = test_instruction_address + delta + 3;
*(reinterpret_cast<Object**>(map_address)) = map;
// The offset is in the last 4 bytes of a six byte
// memory-to-register move instruction, so we add 2 to get the
// offset to the last 4 bytes.
Address offset_address =
test_instruction_address + delta + kOffsetToLoadInstruction + 2;
*reinterpret_cast<int*>(offset_address) = offset - kHeapObjectTag;
return true;
}
static bool PatchInlinedMapCheck(Address address, Object* map) {
Address test_instruction_address =
address + Assembler::kPatchReturnSequenceLength;
// The keyed load has a fast inlined case if the IC call instruction
// is immediately followed by a test instruction.
if (*test_instruction_address != kTestEaxByte) return false;
// Fetch the offset from the test instruction to the map cmp
// instruction. This offset is stored in the last 4 bytes of the 5
// byte test instruction.
Address delta_address = test_instruction_address + 1;
int delta = *reinterpret_cast<int*>(delta_address);
// Compute the map address. The map address is in the last 4 bytes
// of the 7-byte operand-immediate compare instruction, so we add 3
// to the offset to get the map address.
Address map_address = test_instruction_address + delta + 3;
// Patch the map check.
*(reinterpret_cast<Object**>(map_address)) = map;
return true;
}
bool KeyedLoadIC::PatchInlinedLoad(Address address, Object* map) {
return PatchInlinedMapCheck(address, map);
}
bool KeyedStoreIC::PatchInlinedStore(Address address, Object* map) {
return PatchInlinedMapCheck(address, map);
}
// Defined in ic.cc.
Object* KeyedLoadIC_Miss(Arguments args);
void KeyedLoadIC::GenerateMiss(MacroAssembler* masm) {
// ----------- S t a t e -------------
// -- esp[0] : return address
// -- esp[4] : name
// -- esp[8] : receiver
// -----------------------------------
Generate(masm, ExternalReference(IC_Utility(kKeyedLoadIC_Miss)));
}
void KeyedLoadIC::Generate(MacroAssembler* masm, const ExternalReference& f) {
// ----------- S t a t e -------------
// -- esp[0] : return address
// -- esp[4] : name
// -- esp[8] : receiver
// -----------------------------------
__ mov(eax, Operand(esp, kPointerSize));
__ mov(ecx, Operand(esp, 2 * kPointerSize));
__ pop(ebx);
__ push(ecx); // receiver
__ push(eax); // name
__ push(ebx); // return address
// Perform tail call to the entry.
__ TailCallRuntime(f, 2, 1);
}
void StoreIC::GenerateMegamorphic(MacroAssembler* masm) {
// ----------- S t a t e -------------
// -- eax : value
// -- ecx : name
// -- esp[0] : return address
// -- esp[4] : receiver
// -----------------------------------
// Get the receiver from the stack and probe the stub cache.
__ mov(edx, Operand(esp, 4));
Code::Flags flags = Code::ComputeFlags(Code::STORE_IC,
NOT_IN_LOOP,
MONOMORPHIC);
StubCache::GenerateProbe(masm, flags, edx, ecx, ebx, no_reg);
// Cache miss: Jump to runtime.
Generate(masm, ExternalReference(IC_Utility(kStoreIC_Miss)));
}
void StoreIC::GenerateExtendStorage(MacroAssembler* masm) {
// ----------- S t a t e -------------
// -- eax : value
// -- ecx : transition map
// -- esp[0] : return address
// -- esp[4] : receiver
// -----------------------------------
__ pop(ebx);
__ push(Operand(esp, 0)); // receiver
__ push(ecx); // transition map
__ push(eax); // value
__ push(ebx); // return address
// Perform tail call to the entry.
__ TailCallRuntime(
ExternalReference(IC_Utility(kSharedStoreIC_ExtendStorage)), 3, 1);
}
void StoreIC::Generate(MacroAssembler* masm, const ExternalReference& f) {
// ----------- S t a t e -------------
// -- eax : value
// -- ecx : name
// -- esp[0] : return address
// -- esp[4] : receiver
// -----------------------------------
// Move the return address below the arguments.
__ pop(ebx);
__ push(Operand(esp, 0));
__ push(ecx);
__ push(eax);
__ push(ebx);
// Perform tail call to the entry.
__ TailCallRuntime(f, 3, 1);
}
// Defined in ic.cc.
Object* KeyedStoreIC_Miss(Arguments args);
void KeyedStoreIC::Generate(MacroAssembler* masm, const ExternalReference& f) {
// ----------- S t a t e -------------
// -- eax : value
// -- esp[0] : return address
// -- esp[4] : key
// -- esp[8] : receiver
// -----------------------------------
// Move the return address below the arguments.
__ pop(ecx);
__ push(Operand(esp, 1 * kPointerSize));
__ push(Operand(esp, 1 * kPointerSize));
__ push(eax);
__ push(ecx);
// Do tail-call to runtime routine.
__ TailCallRuntime(f, 3, 1);
}
void KeyedStoreIC::GenerateExtendStorage(MacroAssembler* masm) {
// ----------- S t a t e -------------
// -- eax : value
// -- ecx : transition map
// -- esp[0] : return address
// -- esp[4] : key
// -- esp[8] : receiver
// -----------------------------------
// Move the return address below the arguments.
__ pop(ebx);
__ push(Operand(esp, 1 * kPointerSize));
__ push(ecx);
__ push(eax);
__ push(ebx);
// Do tail-call to runtime routine.
__ TailCallRuntime(
ExternalReference(IC_Utility(kSharedStoreIC_ExtendStorage)), 3, 1);
}
#undef __
} } // namespace v8::internal