// 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 "v8.h"
#if defined(V8_TARGET_ARCH_IA32)
#include "bootstrapper.h"
#include "codegen.h"
#include "debug.h"
#include "runtime.h"
#include "serialize.h"
namespace v8 {
namespace internal {
// -------------------------------------------------------------------------
// MacroAssembler implementation.
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::InNewSpace(
Register object,
Register scratch,
Condition cc,
Label* condition_met,
Label::Distance condition_met_distance) {
ASSERT(cc == equal || cc == not_equal);
if (scratch.is(object)) {
and_(scratch, Immediate(~Page::kPageAlignmentMask));
} else {
mov(scratch, Immediate(~Page::kPageAlignmentMask));
and_(scratch, object);
}
// Check that we can use a test_b.
ASSERT(MemoryChunk::IN_FROM_SPACE < 8);
ASSERT(MemoryChunk::IN_TO_SPACE < 8);
int mask = (1 << MemoryChunk::IN_FROM_SPACE)
| (1 << MemoryChunk::IN_TO_SPACE);
// If non-zero, the page belongs to new-space.
test_b(Operand(scratch, MemoryChunk::kFlagsOffset),
static_cast<uint8_t>(mask));
j(cc, condition_met, condition_met_distance);
}
void MacroAssembler::RememberedSetHelper(
Register object, // Only used for debug checks.
Register addr,
Register scratch,
SaveFPRegsMode save_fp,
MacroAssembler::RememberedSetFinalAction and_then) {
Label done;
if (FLAG_debug_code) {
Label ok;
JumpIfNotInNewSpace(object, scratch, &ok, Label::kNear);
int3();
bind(&ok);
}
// Load store buffer top.
ExternalReference store_buffer =
ExternalReference::store_buffer_top(isolate());
mov(scratch, Operand::StaticVariable(store_buffer));
// Store pointer to buffer.
mov(Operand(scratch, 0), addr);
// Increment buffer top.
add(scratch, Immediate(kPointerSize));
// Write back new top of buffer.
mov(Operand::StaticVariable(store_buffer), scratch);
// Call stub on end of buffer.
// Check for end of buffer.
test(scratch, Immediate(StoreBuffer::kStoreBufferOverflowBit));
if (and_then == kReturnAtEnd) {
Label buffer_overflowed;
j(not_equal, &buffer_overflowed, Label::kNear);
ret(0);
bind(&buffer_overflowed);
} else {
ASSERT(and_then == kFallThroughAtEnd);
j(equal, &done, Label::kNear);
}
StoreBufferOverflowStub store_buffer_overflow =
StoreBufferOverflowStub(save_fp);
CallStub(&store_buffer_overflow);
if (and_then == kReturnAtEnd) {
ret(0);
} else {
ASSERT(and_then == kFallThroughAtEnd);
bind(&done);
}
}
void MacroAssembler::ClampDoubleToUint8(XMMRegister input_reg,
XMMRegister scratch_reg,
Register result_reg) {
Label done;
ExternalReference zero_ref = ExternalReference::address_of_zero();
movdbl(scratch_reg, Operand::StaticVariable(zero_ref));
Set(result_reg, Immediate(0));
ucomisd(input_reg, scratch_reg);
j(below, &done, Label::kNear);
ExternalReference half_ref = ExternalReference::address_of_one_half();
movdbl(scratch_reg, Operand::StaticVariable(half_ref));
addsd(scratch_reg, input_reg);
cvttsd2si(result_reg, Operand(scratch_reg));
test(result_reg, Immediate(0xFFFFFF00));
j(zero, &done, Label::kNear);
Set(result_reg, Immediate(255));
bind(&done);
}
void MacroAssembler::ClampUint8(Register reg) {
Label done;
test(reg, Immediate(0xFFFFFF00));
j(zero, &done, Label::kNear);
setcc(negative, reg); // 1 if negative, 0 if positive.
dec_b(reg); // 0 if negative, 255 if positive.
bind(&done);
}
void MacroAssembler::RecordWriteArray(Register object,
Register value,
Register index,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action,
SmiCheck smi_check) {
// 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) {
ASSERT_EQ(0, kSmiTag);
test(value, Immediate(kSmiTagMask));
j(zero, &done);
}
// Array access: calculate the destination address in the same manner as
// KeyedStoreIC::GenerateGeneric. Multiply a smi by 2 to get an offset
// into an array of words.
Register dst = index;
lea(dst, Operand(object, index, times_half_pointer_size,
FixedArray::kHeaderSize - kHeapObjectTag));
RecordWrite(
object, dst, value, 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()) {
mov(value, Immediate(BitCast<int32_t>(kZapValue)));
mov(index, Immediate(BitCast<int32_t>(kZapValue)));
}
}
void MacroAssembler::RecordWriteField(
Register object,
int offset,
Register value,
Register dst,
SaveFPRegsMode save_fp,
RememberedSetAction remembered_set_action,
SmiCheck smi_check) {
// 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, Label::kNear);
}
// 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));
lea(dst, FieldOperand(object, offset));
if (emit_debug_code()) {
Label ok;
test_b(dst, (1 << kPointerSizeLog2) - 1);
j(zero, &ok, Label::kNear);
int3();
bind(&ok);
}
RecordWrite(
object, dst, value, 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()) {
mov(value, Immediate(BitCast<int32_t>(kZapValue)));
mov(dst, Immediate(BitCast<int32_t>(kZapValue)));
}
}
void MacroAssembler::RecordWrite(Register object,
Register address,
Register value,
SaveFPRegsMode fp_mode,
RememberedSetAction remembered_set_action,
SmiCheck smi_check) {
ASSERT(!object.is(value));
ASSERT(!object.is(address));
ASSERT(!value.is(address));
if (emit_debug_code()) {
AbortIfSmi(object);
}
if (remembered_set_action == OMIT_REMEMBERED_SET &&
!FLAG_incremental_marking) {
return;
}
if (FLAG_debug_code) {
Label ok;
cmp(value, Operand(address, 0));
j(equal, &ok, Label::kNear);
int3();
bind(&ok);
}
// First, check if a write barrier is even needed. The tests below
// catch stores of Smis and stores into young gen.
Label done;
if (smi_check == INLINE_SMI_CHECK) {
// Skip barrier if writing a smi.
JumpIfSmi(value, &done, Label::kNear);
}
CheckPageFlag(value,
value, // Used as scratch.
MemoryChunk::kPointersToHereAreInterestingMask,
zero,
&done,
Label::kNear);
CheckPageFlag(object,
value, // Used as scratch.
MemoryChunk::kPointersFromHereAreInterestingMask,
zero,
&done,
Label::kNear);
RecordWriteStub stub(object, value, address, remembered_set_action, fp_mode);
CallStub(&stub);
bind(&done);
// Clobber clobbered registers when running with the debug-code flag
// turned on to provoke errors.
if (emit_debug_code()) {
mov(address, Immediate(BitCast<int32_t>(kZapValue)));
mov(value, Immediate(BitCast<int32_t>(kZapValue)));
}
}
#ifdef ENABLE_DEBUGGER_SUPPORT
void MacroAssembler::DebugBreak() {
Set(eax, Immediate(0));
mov(ebx, Immediate(ExternalReference(Runtime::kDebugBreak, isolate())));
CEntryStub ces(1);
call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
}
#endif
void MacroAssembler::Set(Register dst, const Immediate& x) {
if (x.is_zero()) {
xor_(dst, dst); // Shorter than mov.
} else {
mov(dst, x);
}
}
void MacroAssembler::Set(const Operand& dst, const Immediate& x) {
mov(dst, x);
}
bool MacroAssembler::IsUnsafeImmediate(const Immediate& x) {
static const int kMaxImmediateBits = 17;
if (x.rmode_ != RelocInfo::NONE) return false;
return !is_intn(x.x_, kMaxImmediateBits);
}
void MacroAssembler::SafeSet(Register dst, const Immediate& x) {
if (IsUnsafeImmediate(x) && jit_cookie() != 0) {
Set(dst, Immediate(x.x_ ^ jit_cookie()));
xor_(dst, jit_cookie());
} else {
Set(dst, x);
}
}
void MacroAssembler::SafePush(const Immediate& x) {
if (IsUnsafeImmediate(x) && jit_cookie() != 0) {
push(Immediate(x.x_ ^ jit_cookie()));
xor_(Operand(esp, 0), Immediate(jit_cookie()));
} else {
push(x);
}
}
void MacroAssembler::CompareRoot(Register with, Heap::RootListIndex index) {
// see ROOT_ACCESSOR macro in factory.h
Handle<Object> value(&isolate()->heap()->roots_array_start()[index]);
cmp(with, value);
}
void MacroAssembler::CompareRoot(const Operand& with,
Heap::RootListIndex index) {
// see ROOT_ACCESSOR macro in factory.h
Handle<Object> value(&isolate()->heap()->roots_array_start()[index]);
cmp(with, value);
}
void MacroAssembler::CmpObjectType(Register heap_object,
InstanceType type,
Register map) {
mov(map, FieldOperand(heap_object, HeapObject::kMapOffset));
CmpInstanceType(map, type);
}
void MacroAssembler::CmpInstanceType(Register map, InstanceType type) {
cmpb(FieldOperand(map, Map::kInstanceTypeOffset),
static_cast<int8_t>(type));
}
void MacroAssembler::CheckFastElements(Register map,
Label* fail,
Label::Distance distance) {
STATIC_ASSERT(FAST_SMI_ONLY_ELEMENTS == 0);
STATIC_ASSERT(FAST_ELEMENTS == 1);
cmpb(FieldOperand(map, Map::kBitField2Offset),
Map::kMaximumBitField2FastElementValue);
j(above, fail, distance);
}
void MacroAssembler::CheckFastObjectElements(Register map,
Label* fail,
Label::Distance distance) {
STATIC_ASSERT(FAST_SMI_ONLY_ELEMENTS == 0);
STATIC_ASSERT(FAST_ELEMENTS == 1);
cmpb(FieldOperand(map, Map::kBitField2Offset),
Map::kMaximumBitField2FastSmiOnlyElementValue);
j(below_equal, fail, distance);
cmpb(FieldOperand(map, Map::kBitField2Offset),
Map::kMaximumBitField2FastElementValue);
j(above, fail, distance);
}
void MacroAssembler::CheckFastSmiOnlyElements(Register map,
Label* fail,
Label::Distance distance) {
STATIC_ASSERT(FAST_SMI_ONLY_ELEMENTS == 0);
cmpb(FieldOperand(map, Map::kBitField2Offset),
Map::kMaximumBitField2FastSmiOnlyElementValue);
j(above, fail, distance);
}
void MacroAssembler::StoreNumberToDoubleElements(
Register maybe_number,
Register elements,
Register key,
Register scratch1,
XMMRegister scratch2,
Label* fail,
bool specialize_for_processor) {
Label smi_value, done, maybe_nan, not_nan, is_nan, have_double_value;
JumpIfSmi(maybe_number, &smi_value, Label::kNear);
CheckMap(maybe_number,
isolate()->factory()->heap_number_map(),
fail,
DONT_DO_SMI_CHECK);
// Double value, canonicalize NaN.
uint32_t offset = HeapNumber::kValueOffset + sizeof(kHoleNanLower32);
cmp(FieldOperand(maybe_number, offset),
Immediate(kNaNOrInfinityLowerBoundUpper32));
j(greater_equal, &maybe_nan, Label::kNear);
bind(¬_nan);
ExternalReference canonical_nan_reference =
ExternalReference::address_of_canonical_non_hole_nan();
if (CpuFeatures::IsSupported(SSE2) && specialize_for_processor) {
CpuFeatures::Scope use_sse2(SSE2);
movdbl(scratch2, FieldOperand(maybe_number, HeapNumber::kValueOffset));
bind(&have_double_value);
movdbl(FieldOperand(elements, key, times_4, FixedDoubleArray::kHeaderSize),
scratch2);
} else {
fld_d(FieldOperand(maybe_number, HeapNumber::kValueOffset));
bind(&have_double_value);
fstp_d(FieldOperand(elements, key, times_4, FixedDoubleArray::kHeaderSize));
}
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.
j(greater, &is_nan, Label::kNear);
cmp(FieldOperand(maybe_number, HeapNumber::kValueOffset), Immediate(0));
j(zero, ¬_nan);
bind(&is_nan);
if (CpuFeatures::IsSupported(SSE2) && specialize_for_processor) {
CpuFeatures::Scope use_sse2(SSE2);
movdbl(scratch2, Operand::StaticVariable(canonical_nan_reference));
} else {
fld_d(Operand::StaticVariable(canonical_nan_reference));
}
jmp(&have_double_value, Label::kNear);
bind(&smi_value);
// Value is a smi. Convert to a double and store.
// Preserve original value.
mov(scratch1, maybe_number);
SmiUntag(scratch1);
if (CpuFeatures::IsSupported(SSE2) && specialize_for_processor) {
CpuFeatures::Scope fscope(SSE2);
cvtsi2sd(scratch2, scratch1);
movdbl(FieldOperand(elements, key, times_4, FixedDoubleArray::kHeaderSize),
scratch2);
} else {
push(scratch1);
fild_s(Operand(esp, 0));
pop(scratch1);
fstp_d(FieldOperand(elements, key, times_4, FixedDoubleArray::kHeaderSize));
}
bind(&done);
}
void MacroAssembler::CompareMap(Register obj,
Handle<Map> map,
Label* early_success,
CompareMapMode mode) {
cmp(FieldOperand(obj, HeapObject::kMapOffset), map);
if (mode == ALLOW_ELEMENT_TRANSITION_MAPS) {
Map* transitioned_fast_element_map(
map->LookupElementsTransitionMap(FAST_ELEMENTS, NULL));
ASSERT(transitioned_fast_element_map == NULL ||
map->elements_kind() != FAST_ELEMENTS);
if (transitioned_fast_element_map != NULL) {
j(equal, early_success, Label::kNear);
cmp(FieldOperand(obj, HeapObject::kMapOffset),
Handle<Map>(transitioned_fast_element_map));
}
Map* transitioned_double_map(
map->LookupElementsTransitionMap(FAST_DOUBLE_ELEMENTS, NULL));
ASSERT(transitioned_double_map == NULL ||
map->elements_kind() == FAST_SMI_ONLY_ELEMENTS);
if (transitioned_double_map != NULL) {
j(equal, early_success, Label::kNear);
cmp(FieldOperand(obj, HeapObject::kMapOffset),
Handle<Map>(transitioned_double_map));
}
}
}
void MacroAssembler::CheckMap(Register obj,
Handle<Map> map,
Label* fail,
SmiCheckType smi_check_type,
CompareMapMode mode) {
if (smi_check_type == DO_SMI_CHECK) {
JumpIfSmi(obj, fail);
}
Label success;
CompareMap(obj, map, &success, mode);
j(not_equal, fail);
bind(&success);
}
void MacroAssembler::DispatchMap(Register obj,
Handle<Map> map,
Handle<Code> success,
SmiCheckType smi_check_type) {
Label fail;
if (smi_check_type == DO_SMI_CHECK) {
JumpIfSmi(obj, &fail);
}
cmp(FieldOperand(obj, HeapObject::kMapOffset), Immediate(map));
j(equal, success);
bind(&fail);
}
Condition MacroAssembler::IsObjectStringType(Register heap_object,
Register map,
Register instance_type) {
mov(map, FieldOperand(heap_object, HeapObject::kMapOffset));
movzx_b(instance_type, FieldOperand(map, Map::kInstanceTypeOffset));
STATIC_ASSERT(kNotStringTag != 0);
test(instance_type, Immediate(kIsNotStringMask));
return zero;
}
void MacroAssembler::IsObjectJSObjectType(Register heap_object,
Register map,
Register scratch,
Label* fail) {
mov(map, FieldOperand(heap_object, HeapObject::kMapOffset));
IsInstanceJSObjectType(map, scratch, fail);
}
void MacroAssembler::IsInstanceJSObjectType(Register map,
Register scratch,
Label* fail) {
movzx_b(scratch, FieldOperand(map, Map::kInstanceTypeOffset));
sub(scratch, Immediate(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
cmp(scratch,
LAST_NONCALLABLE_SPEC_OBJECT_TYPE - FIRST_NONCALLABLE_SPEC_OBJECT_TYPE);
j(above, fail);
}
void MacroAssembler::FCmp() {
if (CpuFeatures::IsSupported(CMOV)) {
fucomip();
fstp(0);
} else {
fucompp();
push(eax);
fnstsw_ax();
sahf();
pop(eax);
}
}
void MacroAssembler::AbortIfNotNumber(Register object) {
Label ok;
JumpIfSmi(object, &ok);
cmp(FieldOperand(object, HeapObject::kMapOffset),
isolate()->factory()->heap_number_map());
Assert(equal, "Operand not a number");
bind(&ok);
}
void MacroAssembler::AbortIfNotSmi(Register object) {
test(object, Immediate(kSmiTagMask));
Assert(equal, "Operand is not a smi");
}
void MacroAssembler::AbortIfNotString(Register object) {
test(object, Immediate(kSmiTagMask));
Assert(not_equal, "Operand is not a string");
push(object);
mov(object, FieldOperand(object, HeapObject::kMapOffset));
CmpInstanceType(object, FIRST_NONSTRING_TYPE);
pop(object);
Assert(below, "Operand is not a string");
}
void MacroAssembler::AbortIfSmi(Register object) {
test(object, Immediate(kSmiTagMask));
Assert(not_equal, "Operand is a smi");
}
void MacroAssembler::EnterFrame(StackFrame::Type type) {
push(ebp);
mov(ebp, esp);
push(esi);
push(Immediate(Smi::FromInt(type)));
push(Immediate(CodeObject()));
if (emit_debug_code()) {
cmp(Operand(esp, 0), Immediate(isolate()->factory()->undefined_value()));
Check(not_equal, "code object not properly patched");
}
}
void MacroAssembler::LeaveFrame(StackFrame::Type type) {
if (emit_debug_code()) {
cmp(Operand(ebp, StandardFrameConstants::kMarkerOffset),
Immediate(Smi::FromInt(type)));
Check(equal, "stack frame types must match");
}
leave();
}
void MacroAssembler::EnterExitFramePrologue() {
// Set up the frame structure on the stack.
ASSERT(ExitFrameConstants::kCallerSPDisplacement == +2 * kPointerSize);
ASSERT(ExitFrameConstants::kCallerPCOffset == +1 * kPointerSize);
ASSERT(ExitFrameConstants::kCallerFPOffset == 0 * kPointerSize);
push(ebp);
mov(ebp, esp);
// Reserve room for entry stack pointer and push the code object.
ASSERT(ExitFrameConstants::kSPOffset == -1 * kPointerSize);
push(Immediate(0)); // Saved entry sp, patched before call.
push(Immediate(CodeObject())); // Accessed from ExitFrame::code_slot.
// Save the frame pointer and the context in top.
ExternalReference c_entry_fp_address(Isolate::kCEntryFPAddress,
isolate());
ExternalReference context_address(Isolate::kContextAddress,
isolate());
mov(Operand::StaticVariable(c_entry_fp_address), ebp);
mov(Operand::StaticVariable(context_address), esi);
}
void MacroAssembler::EnterExitFrameEpilogue(int argc, bool save_doubles) {
// Optionally save all XMM registers.
if (save_doubles) {
CpuFeatures::Scope scope(SSE2);
int space = XMMRegister::kNumRegisters * kDoubleSize + argc * kPointerSize;
sub(esp, Immediate(space));
const int offset = -2 * kPointerSize;
for (int i = 0; i < XMMRegister::kNumRegisters; i++) {
XMMRegister reg = XMMRegister::from_code(i);
movdbl(Operand(ebp, offset - ((i + 1) * kDoubleSize)), reg);
}
} else {
sub(esp, Immediate(argc * kPointerSize));
}
// Get the required frame alignment for the OS.
const int kFrameAlignment = OS::ActivationFrameAlignment();
if (kFrameAlignment > 0) {
ASSERT(IsPowerOf2(kFrameAlignment));
and_(esp, -kFrameAlignment);
}
// Patch the saved entry sp.
mov(Operand(ebp, ExitFrameConstants::kSPOffset), esp);
}
void MacroAssembler::EnterExitFrame(bool save_doubles) {
EnterExitFramePrologue();
// Set up argc and argv in callee-saved registers.
int offset = StandardFrameConstants::kCallerSPOffset - kPointerSize;
mov(edi, eax);
lea(esi, Operand(ebp, eax, times_4, offset));
// Reserve space for argc, argv and isolate.
EnterExitFrameEpilogue(3, save_doubles);
}
void MacroAssembler::EnterApiExitFrame(int argc) {
EnterExitFramePrologue();
EnterExitFrameEpilogue(argc, false);
}
void MacroAssembler::LeaveExitFrame(bool save_doubles) {
// Optionally restore all XMM registers.
if (save_doubles) {
CpuFeatures::Scope scope(SSE2);
const int offset = -2 * kPointerSize;
for (int i = 0; i < XMMRegister::kNumRegisters; i++) {
XMMRegister reg = XMMRegister::from_code(i);
movdbl(reg, Operand(ebp, offset - ((i + 1) * kDoubleSize)));
}
}
// Get the return address from the stack and restore the frame pointer.
mov(ecx, Operand(ebp, 1 * kPointerSize));
mov(ebp, Operand(ebp, 0 * kPointerSize));
// Pop the arguments and the receiver from the caller stack.
lea(esp, Operand(esi, 1 * kPointerSize));
// Push the return address to get ready to return.
push(ecx);
LeaveExitFrameEpilogue();
}
void MacroAssembler::LeaveExitFrameEpilogue() {
// Restore current context from top and clear it in debug mode.
ExternalReference context_address(Isolate::kContextAddress, isolate());
mov(esi, Operand::StaticVariable(context_address));
#ifdef DEBUG
mov(Operand::StaticVariable(context_address), Immediate(0));
#endif
// Clear the top frame.
ExternalReference c_entry_fp_address(Isolate::kCEntryFPAddress,
isolate());
mov(Operand::StaticVariable(c_entry_fp_address), Immediate(0));
}
void MacroAssembler::LeaveApiExitFrame() {
mov(esp, ebp);
pop(ebp);
LeaveExitFrameEpilogue();
}
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);
STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);
// We will build up the handler from the bottom by pushing on the stack.
// First push the frame pointer and context.
if (kind == StackHandler::JS_ENTRY) {
// The frame pointer does not point to a JS frame so we save NULL for
// ebp. We expect the code throwing an exception to check ebp before
// dereferencing it to restore the context.
push(Immediate(0)); // NULL frame pointer.
push(Immediate(Smi::FromInt(0))); // No context.
} else {
push(ebp);
push(esi);
}
// Push the state and the code object.
unsigned state =
StackHandler::IndexField::encode(handler_index) |
StackHandler::KindField::encode(kind);
push(Immediate(state));
Push(CodeObject());
// Link the current handler as the next handler.
ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
push(Operand::StaticVariable(handler_address));
// Set this new handler as the current one.
mov(Operand::StaticVariable(handler_address), esp);
}
void MacroAssembler::PopTryHandler() {
STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
pop(Operand::StaticVariable(handler_address));
add(esp, Immediate(StackHandlerConstants::kSize - kPointerSize));
}
void MacroAssembler::JumpToHandlerEntry() {
// Compute the handler entry address and jump to it. The handler table is
// a fixed array of (smi-tagged) code offsets.
// eax = exception, edi = code object, edx = state.
mov(ebx, FieldOperand(edi, Code::kHandlerTableOffset));
shr(edx, StackHandler::kKindWidth);
mov(edx, FieldOperand(ebx, edx, times_4, FixedArray::kHeaderSize));
SmiUntag(edx);
lea(edi, FieldOperand(edi, edx, times_1, Code::kHeaderSize));
jmp(edi);
}
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 eax.
if (!value.is(eax)) {
mov(eax, value);
}
// Drop the stack pointer to the top of the top handler.
ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
mov(esp, Operand::StaticVariable(handler_address));
// Restore the next handler.
pop(Operand::StaticVariable(handler_address));
// Remove the code object and state, compute the handler address in edi.
pop(edi); // Code object.
pop(edx); // Index and state.
// Restore the context and frame pointer.
pop(esi); // Context.
pop(ebp); // Frame pointer.
// If the handler is a JS frame, restore the context to the frame.
// (kind == ENTRY) == (ebp == 0) == (esi == 0), so we could test either
// ebp or esi.
Label skip;
test(esi, esi);
j(zero, &skip, Label::kNear);
mov(Operand(ebp, StandardFrameConstants::kContextOffset), esi);
bind(&skip);
JumpToHandlerEntry();
}
void MacroAssembler::ThrowUncatchable(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 eax.
if (!value.is(eax)) {
mov(eax, value);
}
// Drop the stack pointer to the top of the top stack handler.
ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
mov(esp, Operand::StaticVariable(handler_address));
// Unwind the handlers until the top ENTRY handler is found.
Label fetch_next, check_kind;
jmp(&check_kind, Label::kNear);
bind(&fetch_next);
mov(esp, Operand(esp, StackHandlerConstants::kNextOffset));
bind(&check_kind);
STATIC_ASSERT(StackHandler::JS_ENTRY == 0);
test(Operand(esp, StackHandlerConstants::kStateOffset),
Immediate(StackHandler::KindField::kMask));
j(not_zero, &fetch_next);
// Set the top handler address to next handler past the top ENTRY handler.
pop(Operand::StaticVariable(handler_address));
// Remove the code object and state, compute the handler address in edi.
pop(edi); // Code object.
pop(edx); // Index and state.
// Clear the context pointer and frame pointer (0 was saved in the handler).
pop(esi);
pop(ebp);
JumpToHandlerEntry();
}
void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
Register scratch,
Label* miss) {
Label same_contexts;
ASSERT(!holder_reg.is(scratch));
// Load current lexical context from the stack frame.
mov(scratch, Operand(ebp, StandardFrameConstants::kContextOffset));
// When generating debug code, make sure the lexical context is set.
if (emit_debug_code()) {
cmp(scratch, Immediate(0));
Check(not_equal, "we should not have an empty lexical context");
}
// Load the global context of the current context.
int offset = Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
mov(scratch, FieldOperand(scratch, offset));
mov(scratch, FieldOperand(scratch, GlobalObject::kGlobalContextOffset));
// Check the context is a global context.
if (emit_debug_code()) {
push(scratch);
// Read the first word and compare to global_context_map.
mov(scratch, FieldOperand(scratch, HeapObject::kMapOffset));
cmp(scratch, isolate()->factory()->global_context_map());
Check(equal, "JSGlobalObject::global_context should be a global context.");
pop(scratch);
}
// Check if both contexts are the same.
cmp(scratch, FieldOperand(holder_reg, JSGlobalProxy::kContextOffset));
j(equal, &same_contexts);
// Compare security tokens, save holder_reg on the stack so we can use it
// as a temporary register.
//
// TODO(119): avoid push(holder_reg)/pop(holder_reg)
push(holder_reg);
// Check that the security token in the calling global object is
// compatible with the security token in the receiving global
// object.
mov(holder_reg, FieldOperand(holder_reg, JSGlobalProxy::kContextOffset));
// Check the context is a global context.
if (emit_debug_code()) {
cmp(holder_reg, isolate()->factory()->null_value());
Check(not_equal, "JSGlobalProxy::context() should not be null.");
push(holder_reg);
// Read the first word and compare to global_context_map(),
mov(holder_reg, FieldOperand(holder_reg, HeapObject::kMapOffset));
cmp(holder_reg, isolate()->factory()->global_context_map());
Check(equal, "JSGlobalObject::global_context should be a global context.");
pop(holder_reg);
}
int token_offset = Context::kHeaderSize +
Context::SECURITY_TOKEN_INDEX * kPointerSize;
mov(scratch, FieldOperand(scratch, token_offset));
cmp(scratch, FieldOperand(holder_reg, token_offset));
pop(holder_reg);
j(not_equal, miss);
bind(&same_contexts);
}
// Compute the hash code from the untagged key. This must be kept in sync
// with ComputeIntegerHash in utils.h.
//
// Note: r0 will contain hash code
void MacroAssembler::GetNumberHash(Register r0, Register scratch) {
// Xor original key with a seed.
if (Serializer::enabled()) {
ExternalReference roots_array_start =
ExternalReference::roots_array_start(isolate());
mov(scratch, Immediate(Heap::kHashSeedRootIndex));
mov(scratch,
Operand::StaticArray(scratch, times_pointer_size, roots_array_start));
SmiUntag(scratch);
xor_(r0, scratch);
} else {
int32_t seed = isolate()->heap()->HashSeed();
xor_(r0, Immediate(seed));
}
// hash = ~hash + (hash << 15);
mov(scratch, r0);
not_(r0);
shl(scratch, 15);
add(r0, scratch);
// hash = hash ^ (hash >> 12);
mov(scratch, r0);
shr(scratch, 12);
xor_(r0, scratch);
// hash = hash + (hash << 2);
lea(r0, Operand(r0, r0, times_4, 0));
// hash = hash ^ (hash >> 4);
mov(scratch, r0);
shr(scratch, 4);
xor_(r0, scratch);
// hash = hash * 2057;
imul(r0, r0, 2057);
// hash = hash ^ (hash >> 16);
mov(scratch, r0);
shr(scratch, 16);
xor_(r0, scratch);
}
void MacroAssembler::LoadFromNumberDictionary(Label* miss,
Register elements,
Register key,
Register r0,
Register r1,
Register r2,
Register result) {
// Register use:
//
// elements - holds the slow-case elements of the receiver and is unchanged.
//
// key - holds the smi key on entry and is unchanged.
//
// Scratch registers:
//
// r0 - holds the untagged key on entry and holds the hash once computed.
//
// r1 - used to hold the capacity mask of the dictionary
//
// r2 - used for the index into the dictionary.
//
// result - holds the result on exit if the load succeeds and we fall through.
Label done;
GetNumberHash(r0, r1);
// Compute capacity mask.
mov(r1, FieldOperand(elements, SeededNumberDictionary::kCapacityOffset));
shr(r1, kSmiTagSize); // convert smi to int
dec(r1);
// Generate an unrolled loop that performs a few probes before giving up.
const int kProbes = 4;
for (int i = 0; i < kProbes; i++) {
// Use r2 for index calculations and keep the hash intact in r0.
mov(r2, r0);
// Compute the masked index: (hash + i + i * i) & mask.
if (i > 0) {
add(r2, Immediate(SeededNumberDictionary::GetProbeOffset(i)));
}
and_(r2, r1);
// Scale the index by multiplying by the entry size.
ASSERT(SeededNumberDictionary::kEntrySize == 3);
lea(r2, Operand(r2, r2, times_2, 0)); // r2 = r2 * 3
// Check if the key matches.
cmp(key, FieldOperand(elements,
r2,
times_pointer_size,
SeededNumberDictionary::kElementsStartOffset));
if (i != (kProbes - 1)) {
j(equal, &done);
} else {
j(not_equal, miss);
}
}
bind(&done);
// Check that the value is a normal propety.
const int kDetailsOffset =
SeededNumberDictionary::kElementsStartOffset + 2 * kPointerSize;
ASSERT_EQ(NORMAL, 0);
test(FieldOperand(elements, r2, times_pointer_size, kDetailsOffset),
Immediate(PropertyDetails::TypeField::kMask << kSmiTagSize));
j(not_zero, miss);
// Get the value at the masked, scaled index.
const int kValueOffset =
SeededNumberDictionary::kElementsStartOffset + kPointerSize;
mov(result, FieldOperand(elements, r2, times_pointer_size, kValueOffset));
}
void MacroAssembler::LoadAllocationTopHelper(Register result,
Register scratch,
AllocationFlags flags) {
ExternalReference new_space_allocation_top =
ExternalReference::new_space_allocation_top_address(isolate());
// Just return if allocation top is already known.
if ((flags & RESULT_CONTAINS_TOP) != 0) {
// No use of scratch if allocation top is provided.
ASSERT(scratch.is(no_reg));
#ifdef DEBUG
// Assert that result actually contains top on entry.
cmp(result, Operand::StaticVariable(new_space_allocation_top));
Check(equal, "Unexpected allocation top");
#endif
return;
}
// Move address of new object to result. Use scratch register if available.
if (scratch.is(no_reg)) {
mov(result, Operand::StaticVariable(new_space_allocation_top));
} else {
mov(scratch, Immediate(new_space_allocation_top));
mov(result, Operand(scratch, 0));
}
}
void MacroAssembler::UpdateAllocationTopHelper(Register result_end,
Register scratch) {
if (emit_debug_code()) {
test(result_end, Immediate(kObjectAlignmentMask));
Check(zero, "Unaligned allocation in new space");
}
ExternalReference new_space_allocation_top =
ExternalReference::new_space_allocation_top_address(isolate());
// Update new top. Use scratch if available.
if (scratch.is(no_reg)) {
mov(Operand::StaticVariable(new_space_allocation_top), result_end);
} else {
mov(Operand(scratch, 0), result_end);
}
}
void MacroAssembler::AllocateInNewSpace(int object_size,
Register result,
Register result_end,
Register scratch,
Label* gc_required,
AllocationFlags flags) {
if (!FLAG_inline_new) {
if (emit_debug_code()) {
// Trash the registers to simulate an allocation failure.
mov(result, Immediate(0x7091));
if (result_end.is_valid()) {
mov(result_end, Immediate(0x7191));
}
if (scratch.is_valid()) {
mov(scratch, Immediate(0x7291));
}
}
jmp(gc_required);
return;
}
ASSERT(!result.is(result_end));
// Load address of new object into result.
LoadAllocationTopHelper(result, scratch, flags);
Register top_reg = result_end.is_valid() ? result_end : result;
// Calculate new top and bail out if new space is exhausted.
ExternalReference new_space_allocation_limit =
ExternalReference::new_space_allocation_limit_address(isolate());
if (!top_reg.is(result)) {
mov(top_reg, result);
}
add(top_reg, Immediate(object_size));
j(carry, gc_required);
cmp(top_reg, Operand::StaticVariable(new_space_allocation_limit));
j(above, gc_required);
// Update allocation top.
UpdateAllocationTopHelper(top_reg, scratch);
// Tag result if requested.
if (top_reg.is(result)) {
if ((flags & TAG_OBJECT) != 0) {
sub(result, Immediate(object_size - kHeapObjectTag));
} else {
sub(result, Immediate(object_size));
}
} else if ((flags & TAG_OBJECT) != 0) {
add(result, Immediate(kHeapObjectTag));
}
}
void MacroAssembler::AllocateInNewSpace(int header_size,
ScaleFactor element_size,
Register element_count,
Register result,
Register result_end,
Register scratch,
Label* gc_required,
AllocationFlags flags) {
if (!FLAG_inline_new) {
if (emit_debug_code()) {
// Trash the registers to simulate an allocation failure.
mov(result, Immediate(0x7091));
mov(result_end, Immediate(0x7191));
if (scratch.is_valid()) {
mov(scratch, Immediate(0x7291));
}
// Register element_count is not modified by the function.
}
jmp(gc_required);
return;
}
ASSERT(!result.is(result_end));
// Load address of new object into result.
LoadAllocationTopHelper(result, scratch, flags);
// Calculate new top and bail out if new space is exhausted.
ExternalReference new_space_allocation_limit =
ExternalReference::new_space_allocation_limit_address(isolate());
// We assume that element_count*element_size + header_size does not
// overflow.
lea(result_end, Operand(element_count, element_size, header_size));
add(result_end, result);
j(carry, gc_required);
cmp(result_end, Operand::StaticVariable(new_space_allocation_limit));
j(above, gc_required);
// Tag result if requested.
if ((flags & TAG_OBJECT) != 0) {
lea(result, Operand(result, kHeapObjectTag));
}
// Update allocation top.
UpdateAllocationTopHelper(result_end, scratch);
}
void MacroAssembler::AllocateInNewSpace(Register object_size,
Register result,
Register result_end,
Register scratch,
Label* gc_required,
AllocationFlags flags) {
if (!FLAG_inline_new) {
if (emit_debug_code()) {
// Trash the registers to simulate an allocation failure.
mov(result, Immediate(0x7091));
mov(result_end, Immediate(0x7191));
if (scratch.is_valid()) {
mov(scratch, Immediate(0x7291));
}
// object_size is left unchanged by this function.
}
jmp(gc_required);
return;
}
ASSERT(!result.is(result_end));
// Load address of new object into result.
LoadAllocationTopHelper(result, scratch, flags);
// Calculate new top and bail out if new space is exhausted.
ExternalReference new_space_allocation_limit =
ExternalReference::new_space_allocation_limit_address(isolate());
if (!object_size.is(result_end)) {
mov(result_end, object_size);
}
add(result_end, result);
j(carry, gc_required);
cmp(result_end, Operand::StaticVariable(new_space_allocation_limit));
j(above, gc_required);
// Tag result if requested.
if ((flags & TAG_OBJECT) != 0) {
lea(result, Operand(result, kHeapObjectTag));
}
// Update allocation top.
UpdateAllocationTopHelper(result_end, scratch);
}
void MacroAssembler::UndoAllocationInNewSpace(Register object) {
ExternalReference new_space_allocation_top =
ExternalReference::new_space_allocation_top_address(isolate());
// Make sure the object has no tag before resetting top.
and_(object, Immediate(~kHeapObjectTagMask));
#ifdef DEBUG
cmp(object, Operand::StaticVariable(new_space_allocation_top));
Check(below, "Undo allocation of non allocated memory");
#endif
mov(Operand::StaticVariable(new_space_allocation_top), object);
}
void MacroAssembler::AllocateHeapNumber(Register result,
Register scratch1,
Register scratch2,
Label* gc_required) {
// Allocate heap number in new space.
AllocateInNewSpace(HeapNumber::kSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
// Set the map.
mov(FieldOperand(result, HeapObject::kMapOffset),
Immediate(isolate()->factory()->heap_number_map()));
}
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);
ASSERT(kShortSize == 2);
// scratch1 = length * 2 + kObjectAlignmentMask.
lea(scratch1, Operand(length, length, times_1, kObjectAlignmentMask));
and_(scratch1, Immediate(~kObjectAlignmentMask));
// Allocate two byte string in new space.
AllocateInNewSpace(SeqTwoByteString::kHeaderSize,
times_1,
scratch1,
result,
scratch2,
scratch3,
gc_required,
TAG_OBJECT);
// Set the map, length and hash field.
mov(FieldOperand(result, HeapObject::kMapOffset),
Immediate(isolate()->factory()->string_map()));
mov(scratch1, length);
SmiTag(scratch1);
mov(FieldOperand(result, String::kLengthOffset), scratch1);
mov(FieldOperand(result, String::kHashFieldOffset),
Immediate(String::kEmptyHashField));
}
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);
mov(scratch1, length);
ASSERT(kCharSize == 1);
add(scratch1, Immediate(kObjectAlignmentMask));
and_(scratch1, Immediate(~kObjectAlignmentMask));
// Allocate ASCII string in new space.
AllocateInNewSpace(SeqAsciiString::kHeaderSize,
times_1,
scratch1,
result,
scratch2,
scratch3,
gc_required,
TAG_OBJECT);
// Set the map, length and hash field.
mov(FieldOperand(result, HeapObject::kMapOffset),
Immediate(isolate()->factory()->ascii_string_map()));
mov(scratch1, length);
SmiTag(scratch1);
mov(FieldOperand(result, String::kLengthOffset), scratch1);
mov(FieldOperand(result, String::kHashFieldOffset),
Immediate(String::kEmptyHashField));
}
void MacroAssembler::AllocateAsciiString(Register result,
int length,
Register scratch1,
Register scratch2,
Label* gc_required) {
ASSERT(length > 0);
// Allocate ASCII string in new space.
AllocateInNewSpace(SeqAsciiString::SizeFor(length),
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
// Set the map, length and hash field.
mov(FieldOperand(result, HeapObject::kMapOffset),
Immediate(isolate()->factory()->ascii_string_map()));
mov(FieldOperand(result, String::kLengthOffset),
Immediate(Smi::FromInt(length)));
mov(FieldOperand(result, String::kHashFieldOffset),
Immediate(String::kEmptyHashField));
}
void MacroAssembler::AllocateTwoByteConsString(Register result,
Register scratch1,
Register scratch2,
Label* gc_required) {
// Allocate heap number in new space.
AllocateInNewSpace(ConsString::kSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
// Set the map. The other fields are left uninitialized.
mov(FieldOperand(result, HeapObject::kMapOffset),
Immediate(isolate()->factory()->cons_string_map()));
}
void MacroAssembler::AllocateAsciiConsString(Register result,
Register scratch1,
Register scratch2,
Label* gc_required) {
// Allocate heap number in new space.
AllocateInNewSpace(ConsString::kSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
// Set the map. The other fields are left uninitialized.
mov(FieldOperand(result, HeapObject::kMapOffset),
Immediate(isolate()->factory()->cons_ascii_string_map()));
}
void MacroAssembler::AllocateTwoByteSlicedString(Register result,
Register scratch1,
Register scratch2,
Label* gc_required) {
// Allocate heap number in new space.
AllocateInNewSpace(SlicedString::kSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
// Set the map. The other fields are left uninitialized.
mov(FieldOperand(result, HeapObject::kMapOffset),
Immediate(isolate()->factory()->sliced_string_map()));
}
void MacroAssembler::AllocateAsciiSlicedString(Register result,
Register scratch1,
Register scratch2,
Label* gc_required) {
// Allocate heap number in new space.
AllocateInNewSpace(SlicedString::kSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
// Set the map. The other fields are left uninitialized.
mov(FieldOperand(result, HeapObject::kMapOffset),
Immediate(isolate()->factory()->sliced_ascii_string_map()));
}
// Copy memory, byte-by-byte, from source to destination. Not optimized for
// long or aligned copies. The contents of scratch and length are destroyed.
// Source and destination are incremented by length.
// Many variants of movsb, loop unrolling, word moves, and indexed operands
// have been tried here already, and this is fastest.
// A simpler loop is faster on small copies, but 30% slower on large ones.
// The cld() instruction must have been emitted, to set the direction flag(),
// before calling this function.
void MacroAssembler::CopyBytes(Register source,
Register destination,
Register length,
Register scratch) {
Label loop, done, short_string, short_loop;
// Experimentation shows that the short string loop is faster if length < 10.
cmp(length, Immediate(10));
j(less_equal, &short_string);
ASSERT(source.is(esi));
ASSERT(destination.is(edi));
ASSERT(length.is(ecx));
// Because source is 4-byte aligned in our uses of this function,
// we keep source aligned for the rep_movs call by copying the odd bytes
// at the end of the ranges.
mov(scratch, Operand(source, length, times_1, -4));
mov(Operand(destination, length, times_1, -4), scratch);
mov(scratch, ecx);
shr(ecx, 2);
rep_movs();
and_(scratch, Immediate(0x3));
add(destination, scratch);
jmp(&done);
bind(&short_string);
test(length, length);
j(zero, &done);
bind(&short_loop);
mov_b(scratch, Operand(source, 0));
mov_b(Operand(destination, 0), scratch);
inc(source);
inc(destination);
dec(length);
j(not_zero, &short_loop);
bind(&done);
}
void MacroAssembler::InitializeFieldsWithFiller(Register start_offset,
Register end_offset,
Register filler) {
Label loop, entry;
jmp(&entry);
bind(&loop);
mov(Operand(start_offset, 0), filler);
add(start_offset, Immediate(kPointerSize));
bind(&entry);
cmp(start_offset, end_offset);
j(less, &loop);
}
void MacroAssembler::BooleanBitTest(Register object,
int field_offset,
int bit_index) {
bit_index += kSmiTagSize + kSmiShiftSize;
ASSERT(IsPowerOf2(kBitsPerByte));
int byte_index = bit_index / kBitsPerByte;
int byte_bit_index = bit_index & (kBitsPerByte - 1);
test_b(FieldOperand(object, field_offset + byte_index),
static_cast<byte>(1 << byte_bit_index));
}
void MacroAssembler::NegativeZeroTest(Register result,
Register op,
Label* then_label) {
Label ok;
test(result, result);
j(not_zero, &ok);
test(op, op);
j(sign, then_label);
bind(&ok);
}
void MacroAssembler::NegativeZeroTest(Register result,
Register op1,
Register op2,
Register scratch,
Label* then_label) {
Label ok;
test(result, result);
j(not_zero, &ok);
mov(scratch, op1);
or_(scratch, op2);
j(sign, then_label);
bind(&ok);
}
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.
CmpObjectType(function, JS_FUNCTION_TYPE, result);
j(not_equal, miss);
if (miss_on_bound_function) {
// If a bound function, go to miss label.
mov(scratch,
FieldOperand(function, JSFunction::kSharedFunctionInfoOffset));
BooleanBitTest(scratch, SharedFunctionInfo::kCompilerHintsOffset,
SharedFunctionInfo::kBoundFunction);
j(not_zero, miss);
}
// Make sure that the function has an instance prototype.
Label non_instance;
movzx_b(scratch, FieldOperand(result, Map::kBitFieldOffset));
test(scratch, Immediate(1 << Map::kHasNonInstancePrototype));
j(not_zero, &non_instance);
// Get the prototype or initial map from the function.
mov(result,
FieldOperand(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.
cmp(result, Immediate(isolate()->factory()->the_hole_value()));
j(equal, miss);
// If the function does not have an initial map, we're done.
Label done;
CmpObjectType(result, MAP_TYPE, scratch);
j(not_equal, &done);
// Get the prototype from the initial map.
mov(result, FieldOperand(result, Map::kPrototypeOffset));
jmp(&done);
// Non-instance prototype: Fetch prototype from constructor field
// in initial map.
bind(&non_instance);
mov(result, FieldOperand(result, Map::kConstructorOffset));
// All done.
bind(&done);
}
void MacroAssembler::CallStub(CodeStub* stub, unsigned ast_id) {
ASSERT(AllowThisStubCall(stub)); // Calls are not allowed in some stubs.
call(stub->GetCode(), RelocInfo::CODE_TARGET, ast_id);
}
void MacroAssembler::TailCallStub(CodeStub* stub) {
ASSERT(allow_stub_calls_ || stub->CompilingCallsToThisStubIsGCSafe());
jmp(stub->GetCode(), RelocInfo::CODE_TARGET);
}
void MacroAssembler::StubReturn(int argc) {
ASSERT(argc >= 1 && generating_stub());
ret((argc - 1) * kPointerSize);
}
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) {
add(esp, Immediate(num_arguments * kPointerSize));
}
mov(eax, Immediate(isolate()->factory()->undefined_value()));
}
void MacroAssembler::IndexFromHash(Register hash, Register index) {
// 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.
and_(hash, String::kArrayIndexValueMask);
STATIC_ASSERT(String::kHashShift >= kSmiTagSize && kSmiTag == 0);
if (String::kHashShift > kSmiTagSize) {
shr(hash, String::kHashShift - kSmiTagSize);
}
if (!index.is(hash)) {
mov(index, hash);
}
}
void MacroAssembler::CallRuntime(Runtime::FunctionId id, int num_arguments) {
CallRuntime(Runtime::FunctionForId(id), num_arguments);
}
void MacroAssembler::CallRuntimeSaveDoubles(Runtime::FunctionId id) {
const Runtime::Function* function = Runtime::FunctionForId(id);
Set(eax, Immediate(function->nargs));
mov(ebx, Immediate(ExternalReference(function, isolate())));
CEntryStub ces(1, kSaveFPRegs);
CallStub(&ces);
}
void MacroAssembler::CallRuntime(const Runtime::Function* f,
int num_arguments) {
// 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.
Set(eax, Immediate(num_arguments));
mov(ebx, Immediate(ExternalReference(f, isolate())));
CEntryStub ces(1);
CallStub(&ces);
}
void MacroAssembler::CallExternalReference(ExternalReference ref,
int num_arguments) {
mov(eax, Immediate(num_arguments));
mov(ebx, Immediate(ref));
CEntryStub stub(1);
CallStub(&stub);
}
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.
Set(eax, Immediate(num_arguments));
JumpToExternalReference(ext);
}
void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid,
int num_arguments,
int result_size) {
TailCallExternalReference(ExternalReference(fid, isolate()),
num_arguments,
result_size);
}
// If true, a Handle<T> returned by value from a function with cdecl calling
// convention will be returned directly as a value of location_ field in a
// register eax.
// If false, it is returned as a pointer to a preallocated by caller memory
// region. Pointer to this region should be passed to a function as an
// implicit first argument.
#if defined(USING_BSD_ABI) || defined(__MINGW32__) || defined(__CYGWIN__)
static const bool kReturnHandlesDirectly = true;
#else
static const bool kReturnHandlesDirectly = false;
#endif
Operand ApiParameterOperand(int index) {
return Operand(
esp, (index + (kReturnHandlesDirectly ? 0 : 1)) * kPointerSize);
}
void MacroAssembler::PrepareCallApiFunction(int argc) {
if (kReturnHandlesDirectly) {
EnterApiExitFrame(argc);
// When handles are returned directly we don't have to allocate extra
// space for and pass an out parameter.
if (emit_debug_code()) {
mov(esi, Immediate(BitCast<int32_t>(kZapValue)));
}
} else {
// We allocate two additional slots: return value and pointer to it.
EnterApiExitFrame(argc + 2);
// The argument slots are filled as follows:
//
// n + 1: output slot
// n: arg n
// ...
// 1: arg1
// 0: pointer to the output slot
lea(esi, Operand(esp, (argc + 1) * kPointerSize));
mov(Operand(esp, 0 * kPointerSize), esi);
if (emit_debug_code()) {
mov(Operand(esi, 0), Immediate(0));
}
}
}
void MacroAssembler::CallApiFunctionAndReturn(Address function_address,
int stack_space) {
ExternalReference next_address =
ExternalReference::handle_scope_next_address();
ExternalReference limit_address =
ExternalReference::handle_scope_limit_address();
ExternalReference level_address =
ExternalReference::handle_scope_level_address();
// Allocate HandleScope in callee-save registers.
mov(ebx, Operand::StaticVariable(next_address));
mov(edi, Operand::StaticVariable(limit_address));
add(Operand::StaticVariable(level_address), Immediate(1));
// Call the api function.
call(function_address, RelocInfo::RUNTIME_ENTRY);
if (!kReturnHandlesDirectly) {
// PrepareCallApiFunction saved pointer to the output slot into
// callee-save register esi.
mov(eax, Operand(esi, 0));
}
Label empty_handle;
Label prologue;
Label promote_scheduled_exception;
Label delete_allocated_handles;
Label leave_exit_frame;
// Check if the result handle holds 0.
test(eax, eax);
j(zero, &empty_handle);
// It was non-zero. Dereference to get the result value.
mov(eax, Operand(eax, 0));
bind(&prologue);
// No more valid handles (the result handle was the last one). Restore
// previous handle scope.
mov(Operand::StaticVariable(next_address), ebx);
sub(Operand::StaticVariable(level_address), Immediate(1));
Assert(above_equal, "Invalid HandleScope level");
cmp(edi, Operand::StaticVariable(limit_address));
j(not_equal, &delete_allocated_handles);
bind(&leave_exit_frame);
// Check if the function scheduled an exception.
ExternalReference scheduled_exception_address =
ExternalReference::scheduled_exception_address(isolate());
cmp(Operand::StaticVariable(scheduled_exception_address),
Immediate(isolate()->factory()->the_hole_value()));
j(not_equal, &promote_scheduled_exception);
LeaveApiExitFrame();
ret(stack_space * kPointerSize);
bind(&promote_scheduled_exception);
TailCallRuntime(Runtime::kPromoteScheduledException, 0, 1);
bind(&empty_handle);
// It was zero; the result is undefined.
mov(eax, isolate()->factory()->undefined_value());
jmp(&prologue);
// HandleScope limit has changed. Delete allocated extensions.
ExternalReference delete_extensions =
ExternalReference::delete_handle_scope_extensions(isolate());
bind(&delete_allocated_handles);
mov(Operand::StaticVariable(limit_address), edi);
mov(edi, eax);
mov(Operand(esp, 0), Immediate(ExternalReference::isolate_address()));
mov(eax, Immediate(delete_extensions));
call(eax);
mov(eax, edi);
jmp(&leave_exit_frame);
}
void MacroAssembler::JumpToExternalReference(const ExternalReference& ext) {
// Set the entry point and jump to the C entry runtime stub.
mov(ebx, Immediate(ext));
CEntryStub ces(1);
jmp(ces.GetCode(), RelocInfo::CODE_TARGET);
}
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 ecx to
// follow the calling convention which requires the call type to be
// in ecx.
ASSERT(dst.is(ecx));
if (call_kind == CALL_AS_FUNCTION) {
// Set to some non-zero smi by updating the least significant
// byte.
mov_b(dst, 1 << kSmiTagSize);
} else {
// Set to smi zero by clearing the register.
xor_(dst, dst);
}
}
void MacroAssembler::InvokePrologue(const ParameterCount& expected,
const ParameterCount& actual,
Handle<Code> code_constant,
const Operand& code_operand,
Label* done,
bool* definitely_mismatches,
InvokeFlag flag,
Label::Distance done_near,
const CallWrapper& call_wrapper,
CallKind call_kind) {
bool definitely_matches = false;
*definitely_mismatches = false;
Label invoke;
if (expected.is_immediate()) {
ASSERT(actual.is_immediate());
if (expected.immediate() == actual.immediate()) {
definitely_matches = true;
} else {
mov(eax, 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;
mov(ebx, expected.immediate());
}
}
} else {
if (actual.is_immediate()) {
// Expected is in register, actual is immediate. This is the
// case when we invoke function values without going through the
// IC mechanism.
cmp(expected.reg(), actual.immediate());
j(equal, &invoke);
ASSERT(expected.reg().is(ebx));
mov(eax, actual.immediate());
} else if (!expected.reg().is(actual.reg())) {
// Both expected and actual are in (different) registers. This
// is the case when we invoke functions using call and apply.
cmp(expected.reg(), actual.reg());
j(equal, &invoke);
ASSERT(actual.reg().is(eax));
ASSERT(expected.reg().is(ebx));
}
}
if (!definitely_matches) {
Handle<Code> adaptor =
isolate()->builtins()->ArgumentsAdaptorTrampoline();
if (!code_constant.is_null()) {
mov(edx, Immediate(code_constant));
add(edx, Immediate(Code::kHeaderSize - kHeapObjectTag));
} else if (!code_operand.is_reg(edx)) {
mov(edx, code_operand);
}
if (flag == CALL_FUNCTION) {
call_wrapper.BeforeCall(CallSize(adaptor, RelocInfo::CODE_TARGET));
SetCallKind(ecx, call_kind);
call(adaptor, RelocInfo::CODE_TARGET);
call_wrapper.AfterCall();
if (!*definitely_mismatches) {
jmp(done, done_near);
}
} else {
SetCallKind(ecx, call_kind);
jmp(adaptor, RelocInfo::CODE_TARGET);
}
bind(&invoke);
}
}
void MacroAssembler::InvokeCode(const Operand& 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, Label::kNear,
call_wrapper, call_kind);
if (!definitely_mismatches) {
if (flag == CALL_FUNCTION) {
call_wrapper.BeforeCall(CallSize(code));
SetCallKind(ecx, call_kind);
call(code);
call_wrapper.AfterCall();
} else {
ASSERT(flag == JUMP_FUNCTION);
SetCallKind(ecx, call_kind);
jmp(code);
}
bind(&done);
}
}
void MacroAssembler::InvokeCode(Handle<Code> code,
const ParameterCount& expected,
const ParameterCount& actual,
RelocInfo::Mode rmode,
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;
Operand dummy(eax, 0);
bool definitely_mismatches = false;
InvokePrologue(expected, actual, code, dummy, &done, &definitely_mismatches,
flag, Label::kNear, call_wrapper, call_kind);
if (!definitely_mismatches) {
if (flag == CALL_FUNCTION) {
call_wrapper.BeforeCall(CallSize(code, rmode));
SetCallKind(ecx, call_kind);
call(code, rmode);
call_wrapper.AfterCall();
} else {
ASSERT(flag == JUMP_FUNCTION);
SetCallKind(ecx, call_kind);
jmp(code, rmode);
}
bind(&done);
}
}
void MacroAssembler::InvokeFunction(Register fun,
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());
ASSERT(fun.is(edi));
mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
mov(ebx, FieldOperand(edx, SharedFunctionInfo::kFormalParameterCountOffset));
SmiUntag(ebx);
ParameterCount expected(ebx);
InvokeCode(FieldOperand(edi, JSFunction::kCodeEntryOffset),
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(edi, function);
mov(esi, FieldOperand(edi, 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.
InvokeCode(FieldOperand(edi, JSFunction::kCodeEntryOffset),
expected, actual, flag, call_wrapper, call_kind);
}
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());
// Rely on the assertion to check that the number of provided
// arguments match the expected number of arguments. Fake a
// parameter count to avoid emitting code to do the check.
ParameterCount expected(0);
GetBuiltinFunction(edi, id);
InvokeCode(FieldOperand(edi, JSFunction::kCodeEntryOffset),
expected, expected, flag, call_wrapper, CALL_AS_METHOD);
}
void MacroAssembler::GetBuiltinFunction(Register target,
Builtins::JavaScript id) {
// Load the JavaScript builtin function from the builtins object.
mov(target, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
mov(target, FieldOperand(target, GlobalObject::kBuiltinsOffset));
mov(target, FieldOperand(target,
JSBuiltinsObject::OffsetOfFunctionWithId(id)));
}
void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) {
ASSERT(!target.is(edi));
// Load the JavaScript builtin function from the builtins object.
GetBuiltinFunction(edi, id);
// Load the code entry point from the function into the target register.
mov(target, FieldOperand(edi, JSFunction::kCodeEntryOffset));
}
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.
mov(dst, Operand(esi, Context::SlotOffset(Context::PREVIOUS_INDEX)));
for (int i = 1; i < context_chain_length; i++) {
mov(dst, Operand(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).
mov(dst, esi);
}
// We should not have found a with context by walking the context chain
// (i.e., the static scope chain and runtime context chain do not agree).
// A variable occurring in such a scope should have slot type LOOKUP and
// not CONTEXT.
if (emit_debug_code()) {
cmp(FieldOperand(dst, HeapObject::kMapOffset),
isolate()->factory()->with_context_map());
Check(not_equal, "Variable resolved to with context.");
}
}
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.
mov(scratch, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
mov(scratch, FieldOperand(scratch, GlobalObject::kGlobalContextOffset));
// Check that the function's map is the same as the expected cached map.
int expected_index =
Context::GetContextMapIndexFromElementsKind(expected_kind);
cmp(map_in_out, Operand(scratch, Context::SlotOffset(expected_index)));
j(not_equal, no_map_match);
// Use the transitioned cached map.
int trans_index =
Context::GetContextMapIndexFromElementsKind(transitioned_kind);
mov(map_in_out, Operand(scratch, Context::SlotOffset(trans_index)));
}
void MacroAssembler::LoadInitialArrayMap(
Register function_in, Register scratch, Register map_out) {
ASSERT(!function_in.is(map_out));
Label done;
mov(map_out, FieldOperand(function_in,
JSFunction::kPrototypeOrInitialMapOffset));
if (!FLAG_smi_only_arrays) {
LoadTransitionedArrayMapConditional(FAST_SMI_ONLY_ELEMENTS,
FAST_ELEMENTS,
map_out,
scratch,
&done);
}
bind(&done);
}
void MacroAssembler::LoadGlobalFunction(int index, Register function) {
// Load the global or builtins object from the current context.
mov(function, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
// Load the global context from the global or builtins object.
mov(function, FieldOperand(function, GlobalObject::kGlobalContextOffset));
// Load the function from the global context.
mov(function, Operand(function, Context::SlotOffset(index)));
}
void MacroAssembler::LoadGlobalFunctionInitialMap(Register function,
Register map) {
// Load the initial map. The global functions all have initial maps.
mov(map, FieldOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
if (emit_debug_code()) {
Label ok, fail;
CheckMap(map, isolate()->factory()->meta_map(), &fail, DO_SMI_CHECK);
jmp(&ok);
bind(&fail);
Abort("Global functions must have initial map");
bind(&ok);
}
}
// Store the value in register src in the safepoint register stack
// slot for register dst.
void MacroAssembler::StoreToSafepointRegisterSlot(Register dst, Register src) {
mov(SafepointRegisterSlot(dst), src);
}
void MacroAssembler::StoreToSafepointRegisterSlot(Register dst, Immediate src) {
mov(SafepointRegisterSlot(dst), src);
}
void MacroAssembler::LoadFromSafepointRegisterSlot(Register dst, Register src) {
mov(dst, SafepointRegisterSlot(src));
}
Operand MacroAssembler::SafepointRegisterSlot(Register reg) {
return Operand(esp, SafepointRegisterStackIndex(reg.code()) * kPointerSize);
}
int MacroAssembler::SafepointRegisterStackIndex(int reg_code) {
// The registers are pushed starting with the lowest encoding,
// which means that lowest encodings are furthest away from
// the stack pointer.
ASSERT(reg_code >= 0 && reg_code < kNumSafepointRegisters);
return kNumSafepointRegisters - reg_code - 1;
}
void MacroAssembler::LoadHeapObject(Register result,
Handle<HeapObject> object) {
if (isolate()->heap()->InNewSpace(*object)) {
Handle<JSGlobalPropertyCell> cell =
isolate()->factory()->NewJSGlobalPropertyCell(object);
mov(result, Operand::Cell(cell));
} else {
mov(result, object);
}
}
void MacroAssembler::PushHeapObject(Handle<HeapObject> object) {
if (isolate()->heap()->InNewSpace(*object)) {
Handle<JSGlobalPropertyCell> cell =
isolate()->factory()->NewJSGlobalPropertyCell(object);
push(Operand::Cell(cell));
} else {
Push(object);
}
}
void MacroAssembler::Ret() {
ret(0);
}
void MacroAssembler::Ret(int bytes_dropped, Register scratch) {
if (is_uint16(bytes_dropped)) {
ret(bytes_dropped);
} else {
pop(scratch);
add(esp, Immediate(bytes_dropped));
push(scratch);
ret(0);
}
}
void MacroAssembler::Drop(int stack_elements) {
if (stack_elements > 0) {
add(esp, Immediate(stack_elements * kPointerSize));
}
}
void MacroAssembler::Move(Register dst, Register src) {
if (!dst.is(src)) {
mov(dst, src);
}
}
void MacroAssembler::SetCounter(StatsCounter* counter, int value) {
if (FLAG_native_code_counters && counter->Enabled()) {
mov(Operand::StaticVariable(ExternalReference(counter)), Immediate(value));
}
}
void MacroAssembler::IncrementCounter(StatsCounter* counter, int value) {
ASSERT(value > 0);
if (FLAG_native_code_counters && counter->Enabled()) {
Operand operand = Operand::StaticVariable(ExternalReference(counter));
if (value == 1) {
inc(operand);
} else {
add(operand, Immediate(value));
}
}
}
void MacroAssembler::DecrementCounter(StatsCounter* counter, int value) {
ASSERT(value > 0);
if (FLAG_native_code_counters && counter->Enabled()) {
Operand operand = Operand::StaticVariable(ExternalReference(counter));
if (value == 1) {
dec(operand);
} else {
sub(operand, Immediate(value));
}
}
}
void MacroAssembler::IncrementCounter(Condition cc,
StatsCounter* counter,
int value) {
ASSERT(value > 0);
if (FLAG_native_code_counters && counter->Enabled()) {
Label skip;
j(NegateCondition(cc), &skip);
pushfd();
IncrementCounter(counter, value);
popfd();
bind(&skip);
}
}
void MacroAssembler::DecrementCounter(Condition cc,
StatsCounter* counter,
int value) {
ASSERT(value > 0);
if (FLAG_native_code_counters && counter->Enabled()) {
Label skip;
j(NegateCondition(cc), &skip);
pushfd();
DecrementCounter(counter, value);
popfd();
bind(&skip);
}
}
void MacroAssembler::Assert(Condition cc, const char* msg) {
if (emit_debug_code()) Check(cc, msg);
}
void MacroAssembler::AssertFastElements(Register elements) {
if (emit_debug_code()) {
Factory* factory = isolate()->factory();
Label ok;
cmp(FieldOperand(elements, HeapObject::kMapOffset),
Immediate(factory->fixed_array_map()));
j(equal, &ok);
cmp(FieldOperand(elements, HeapObject::kMapOffset),
Immediate(factory->fixed_double_array_map()));
j(equal, &ok);
cmp(FieldOperand(elements, HeapObject::kMapOffset),
Immediate(factory->fixed_cow_array_map()));
j(equal, &ok);
Abort("JSObject with fast elements map has slow elements");
bind(&ok);
}
}
void MacroAssembler::Check(Condition cc, const char* msg) {
Label L;
j(cc, &L);
Abort(msg);
// will not return here
bind(&L);
}
void MacroAssembler::CheckStackAlignment() {
int frame_alignment = OS::ActivationFrameAlignment();
int frame_alignment_mask = frame_alignment - 1;
if (frame_alignment > kPointerSize) {
ASSERT(IsPowerOf2(frame_alignment));
Label alignment_as_expected;
test(esp, Immediate(frame_alignment_mask));
j(zero, &alignment_as_expected);
// Abort if stack is not aligned.
int3();
bind(&alignment_as_expected);
}
}
void MacroAssembler::Abort(const char* msg) {
// 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
push(eax);
push(Immediate(p0));
push(Immediate(reinterpret_cast<intptr_t>(Smi::FromInt(p1 - p0))));
// 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
int3();
}
void MacroAssembler::LoadInstanceDescriptors(Register map,
Register descriptors) {
mov(descriptors,
FieldOperand(map, Map::kInstanceDescriptorsOrBitField3Offset));
Label not_smi;
JumpIfNotSmi(descriptors, ¬_smi);
mov(descriptors, isolate()->factory()->empty_descriptor_array());
bind(¬_smi);
}
void MacroAssembler::LoadPowerOf2(XMMRegister dst,
Register scratch,
int power) {
ASSERT(is_uintn(power + HeapNumber::kExponentBias,
HeapNumber::kExponentBits));
mov(scratch, Immediate(power + HeapNumber::kExponentBias));
movd(dst, scratch);
psllq(dst, HeapNumber::kMantissaBits);
}
void MacroAssembler::JumpIfInstanceTypeIsNotSequentialAscii(
Register instance_type,
Register scratch,
Label* failure) {
if (!scratch.is(instance_type)) {
mov(scratch, instance_type);
}
and_(scratch,
kIsNotStringMask | kStringRepresentationMask | kStringEncodingMask);
cmp(scratch, kStringTag | kSeqStringTag | kAsciiStringTag);
j(not_equal, failure);
}
void MacroAssembler::JumpIfNotBothSequentialAsciiStrings(Register object1,
Register object2,
Register scratch1,
Register scratch2,
Label* failure) {
// Check that both objects are not smis.
STATIC_ASSERT(kSmiTag == 0);
mov(scratch1, object1);
and_(scratch1, object2);
JumpIfSmi(scratch1, failure);
// Load instance type for both strings.
mov(scratch1, FieldOperand(object1, HeapObject::kMapOffset));
mov(scratch2, FieldOperand(object2, HeapObject::kMapOffset));
movzx_b(scratch1, FieldOperand(scratch1, Map::kInstanceTypeOffset));
movzx_b(scratch2, FieldOperand(scratch2, Map::kInstanceTypeOffset));
// Check that both are flat ASCII strings.
const int kFlatAsciiStringMask =
kIsNotStringMask | kStringRepresentationMask | kStringEncodingMask;
const int kFlatAsciiStringTag = ASCII_STRING_TYPE;
// Interleave bits from both instance types and compare them in one check.
ASSERT_EQ(0, kFlatAsciiStringMask & (kFlatAsciiStringMask << 3));
and_(scratch1, kFlatAsciiStringMask);
and_(scratch2, kFlatAsciiStringMask);
lea(scratch1, Operand(scratch1, scratch2, times_8, 0));
cmp(scratch1, kFlatAsciiStringTag | (kFlatAsciiStringTag << 3));
j(not_equal, failure);
}
void MacroAssembler::PrepareCallCFunction(int num_arguments, Register scratch) {
int frame_alignment = OS::ActivationFrameAlignment();
if (frame_alignment != 0) {
// Make stack end at alignment and make room for num_arguments words
// and the original value of esp.
mov(scratch, esp);
sub(esp, Immediate((num_arguments + 1) * kPointerSize));
ASSERT(IsPowerOf2(frame_alignment));
and_(esp, -frame_alignment);
mov(Operand(esp, num_arguments * kPointerSize), scratch);
} else {
sub(esp, Immediate(num_arguments * kPointerSize));
}
}
void MacroAssembler::CallCFunction(ExternalReference function,
int num_arguments) {
// Trashing eax is ok as it will be the return value.
mov(eax, Immediate(function));
CallCFunction(eax, num_arguments);
}
void MacroAssembler::CallCFunction(Register function,
int num_arguments) {
ASSERT(has_frame());
// Check stack alignment.
if (emit_debug_code()) {
CheckStackAlignment();
}
call(function);
if (OS::ActivationFrameAlignment() != 0) {
mov(esp, Operand(esp, num_arguments * kPointerSize));
} else {
add(esp, Immediate(num_arguments * kPointerSize));
}
}
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 size)
: address_(address),
size_(size),
masm_(Isolate::Current(), 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 MacroAssembler::CheckPageFlag(
Register object,
Register scratch,
int mask,
Condition cc,
Label* condition_met,
Label::Distance condition_met_distance) {
ASSERT(cc == zero || cc == not_zero);
if (scratch.is(object)) {
and_(scratch, Immediate(~Page::kPageAlignmentMask));
} else {
mov(scratch, Immediate(~Page::kPageAlignmentMask));
and_(scratch, object);
}
if (mask < (1 << kBitsPerByte)) {
test_b(Operand(scratch, MemoryChunk::kFlagsOffset),
static_cast<uint8_t>(mask));
} else {
test(Operand(scratch, MemoryChunk::kFlagsOffset), Immediate(mask));
}
j(cc, condition_met, condition_met_distance);
}
void MacroAssembler::JumpIfBlack(Register object,
Register scratch0,
Register scratch1,
Label* on_black,
Label::Distance on_black_near) {
HasColor(object, scratch0, scratch1,
on_black, on_black_near,
1, 0); // kBlackBitPattern.
ASSERT(strcmp(Marking::kBlackBitPattern, "10") == 0);
}
void MacroAssembler::HasColor(Register object,
Register bitmap_scratch,
Register mask_scratch,
Label* has_color,
Label::Distance has_color_distance,
int first_bit,
int second_bit) {
ASSERT(!AreAliased(object, bitmap_scratch, mask_scratch, ecx));
GetMarkBits(object, bitmap_scratch, mask_scratch);
Label other_color, word_boundary;
test(mask_scratch, Operand(bitmap_scratch, MemoryChunk::kHeaderSize));
j(first_bit == 1 ? zero : not_zero, &other_color, Label::kNear);
add(mask_scratch, mask_scratch); // Shift left 1 by adding.
j(zero, &word_boundary, Label::kNear);
test(mask_scratch, Operand(bitmap_scratch, MemoryChunk::kHeaderSize));
j(second_bit == 1 ? not_zero : zero, has_color, has_color_distance);
jmp(&other_color, Label::kNear);
bind(&word_boundary);
test_b(Operand(bitmap_scratch, MemoryChunk::kHeaderSize + kPointerSize), 1);
j(second_bit == 1 ? not_zero : zero, has_color, has_color_distance);
bind(&other_color);
}
void MacroAssembler::GetMarkBits(Register addr_reg,
Register bitmap_reg,
Register mask_reg) {
ASSERT(!AreAliased(addr_reg, mask_reg, bitmap_reg, ecx));
mov(bitmap_reg, Immediate(~Page::kPageAlignmentMask));
and_(bitmap_reg, addr_reg);
mov(ecx, addr_reg);
int shift =
Bitmap::kBitsPerCellLog2 + kPointerSizeLog2 - Bitmap::kBytesPerCellLog2;
shr(ecx, shift);
and_(ecx,
(Page::kPageAlignmentMask >> shift) & ~(Bitmap::kBytesPerCell - 1));
add(bitmap_reg, ecx);
mov(ecx, addr_reg);
shr(ecx, kPointerSizeLog2);
and_(ecx, (1 << Bitmap::kBitsPerCellLog2) - 1);
mov(mask_reg, Immediate(1));
shl_cl(mask_reg);
}
void MacroAssembler::EnsureNotWhite(
Register value,
Register bitmap_scratch,
Register mask_scratch,
Label* value_is_white_and_not_data,
Label::Distance distance) {
ASSERT(!AreAliased(value, bitmap_scratch, mask_scratch, ecx));
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.
test(mask_scratch, Operand(bitmap_scratch, MemoryChunk::kHeaderSize));
j(not_zero, &done, Label::kNear);
if (FLAG_debug_code) {
// Check for impossible bit pattern.
Label ok;
push(mask_scratch);
// shl. May overflow making the check conservative.
add(mask_scratch, mask_scratch);
test(mask_scratch, Operand(bitmap_scratch, MemoryChunk::kHeaderSize));
j(zero, &ok, Label::kNear);
int3();
bind(&ok);
pop(mask_scratch);
}
// 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 = ecx; // Holds map while checking type.
Register length = ecx; // Holds length of object after checking type.
Label not_heap_number;
Label is_data_object;
// Check for heap-number
mov(map, FieldOperand(value, HeapObject::kMapOffset));
cmp(map, FACTORY->heap_number_map());
j(not_equal, ¬_heap_number, Label::kNear);
mov(length, Immediate(HeapNumber::kSize));
jmp(&is_data_object, Label::kNear);
bind(¬_heap_number);
// 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 = ecx;
movzx_b(instance_type, FieldOperand(map, Map::kInstanceTypeOffset));
test_b(instance_type, kIsIndirectStringMask | kIsNotStringMask);
j(not_zero, value_is_white_and_not_data);
// 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).
Label not_external;
// External strings are the only ones with the kExternalStringTag bit
// set.
ASSERT_EQ(0, kSeqStringTag & kExternalStringTag);
ASSERT_EQ(0, kConsStringTag & kExternalStringTag);
test_b(instance_type, kExternalStringTag);
j(zero, ¬_external, Label::kNear);
mov(length, Immediate(ExternalString::kSize));
jmp(&is_data_object, Label::kNear);
bind(¬_external);
// Sequential string, either ASCII or UC16.
ASSERT(kAsciiStringTag == 0x04);
and_(length, Immediate(kStringEncodingMask));
xor_(length, Immediate(kStringEncodingMask));
add(length, Immediate(0x04));
// Value now either 4 (if ASCII) or 8 (if UC16), i.e., char-size shifted
// by 2. If we multiply the string length as smi by this, it still
// won't overflow a 32-bit value.
ASSERT_EQ(SeqAsciiString::kMaxSize, SeqTwoByteString::kMaxSize);
ASSERT(SeqAsciiString::kMaxSize <=
static_cast<int>(0xffffffffu >> (2 + kSmiTagSize)));
imul(length, FieldOperand(value, String::kLengthOffset));
shr(length, 2 + kSmiTagSize + kSmiShiftSize);
add(length, Immediate(SeqString::kHeaderSize + kObjectAlignmentMask));
and_(length, Immediate(~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.
or_(Operand(bitmap_scratch, MemoryChunk::kHeaderSize), mask_scratch);
and_(bitmap_scratch, Immediate(~Page::kPageAlignmentMask));
add(Operand(bitmap_scratch, MemoryChunk::kLiveBytesOffset),
length);
if (FLAG_debug_code) {
mov(length, Operand(bitmap_scratch, MemoryChunk::kLiveBytesOffset));
cmp(length, Operand(bitmap_scratch, MemoryChunk::kSizeOffset));
Check(less_equal, "Live Bytes Count overflow chunk size");
}
bind(&done);
}
void MacroAssembler::CheckEnumCache(Label* call_runtime) {
Label next;
mov(ecx, eax);
bind(&next);
// Check that there are no elements. Register ecx contains the
// current JS object we've reached through the prototype chain.
cmp(FieldOperand(ecx, JSObject::kElementsOffset),
isolate()->factory()->empty_fixed_array());
j(not_equal, call_runtime);
// Check that instance descriptors are not empty so that we can
// check for an enum cache. Leave the map in ebx for the subsequent
// prototype load.
mov(ebx, FieldOperand(ecx, HeapObject::kMapOffset));
mov(edx, FieldOperand(ebx, Map::kInstanceDescriptorsOrBitField3Offset));
JumpIfSmi(edx, call_runtime);
// Check that there is an enum cache in the non-empty instance
// descriptors (edx). This is the case if the next enumeration
// index field does not contain a smi.
mov(edx, FieldOperand(edx, DescriptorArray::kEnumerationIndexOffset));
JumpIfSmi(edx, call_runtime);
// For all objects but the receiver, check that the cache is empty.
Label check_prototype;
cmp(ecx, eax);
j(equal, &check_prototype, Label::kNear);
mov(edx, FieldOperand(edx, DescriptorArray::kEnumCacheBridgeCacheOffset));
cmp(edx, isolate()->factory()->empty_fixed_array());
j(not_equal, call_runtime);
// Load the prototype from the map and loop if non-null.
bind(&check_prototype);
mov(ecx, FieldOperand(ebx, Map::kPrototypeOffset));
cmp(ecx, isolate()->factory()->null_value());
j(not_equal, &next);
}
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_IA32