// Copyright 2006-2009 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 "bootstrapper.h"
#include "codegen-inl.h"
#include "debug.h"
#include "runtime.h"
#include "serialize.h"
namespace v8 {
namespace internal {
// -------------------------------------------------------------------------
// MacroAssembler implementation.
MacroAssembler::MacroAssembler(void* buffer, int size)
: Assembler(buffer, size),
generating_stub_(false),
allow_stub_calls_(true),
code_object_(Heap::undefined_value()) {
}
static void RecordWriteHelper(MacroAssembler* masm,
Register object,
Register addr,
Register scratch) {
Label fast;
// Compute the page start address from the heap object pointer, and reuse
// the 'object' register for it.
masm->and_(object, ~Page::kPageAlignmentMask);
Register page_start = object;
// Compute the bit addr in the remembered set/index of the pointer in the
// page. Reuse 'addr' as pointer_offset.
masm->sub(addr, Operand(page_start));
masm->shr(addr, kObjectAlignmentBits);
Register pointer_offset = addr;
// If the bit offset lies beyond the normal remembered set range, it is in
// the extra remembered set area of a large object.
masm->cmp(pointer_offset, Page::kPageSize / kPointerSize);
masm->j(less, &fast);
// Adjust 'page_start' so that addressing using 'pointer_offset' hits the
// extra remembered set after the large object.
// Find the length of the large object (FixedArray).
masm->mov(scratch, Operand(page_start, Page::kObjectStartOffset
+ FixedArray::kLengthOffset));
Register array_length = scratch;
// Extra remembered set starts right after the large object (a FixedArray), at
// page_start + kObjectStartOffset + objectSize
// where objectSize is FixedArray::kHeaderSize + kPointerSize * array_length.
// Add the delta between the end of the normal RSet and the start of the
// extra RSet to 'page_start', so that addressing the bit using
// 'pointer_offset' hits the extra RSet words.
masm->lea(page_start,
Operand(page_start, array_length, times_pointer_size,
Page::kObjectStartOffset + FixedArray::kHeaderSize
- Page::kRSetEndOffset));
// NOTE: For now, we use the bit-test-and-set (bts) x86 instruction
// to limit code size. We should probably evaluate this decision by
// measuring the performance of an equivalent implementation using
// "simpler" instructions
masm->bind(&fast);
masm->bts(Operand(page_start, Page::kRSetOffset), pointer_offset);
}
class RecordWriteStub : public CodeStub {
public:
RecordWriteStub(Register object, Register addr, Register scratch)
: object_(object), addr_(addr), scratch_(scratch) { }
void Generate(MacroAssembler* masm);
private:
Register object_;
Register addr_;
Register scratch_;
#ifdef DEBUG
void Print() {
PrintF("RecordWriteStub (object reg %d), (addr reg %d), (scratch reg %d)\n",
object_.code(), addr_.code(), scratch_.code());
}
#endif
// Minor key encoding in 12 bits of three registers (object, address and
// scratch) OOOOAAAASSSS.
class ScratchBits: public BitField<uint32_t, 0, 4> {};
class AddressBits: public BitField<uint32_t, 4, 4> {};
class ObjectBits: public BitField<uint32_t, 8, 4> {};
Major MajorKey() { return RecordWrite; }
int MinorKey() {
// Encode the registers.
return ObjectBits::encode(object_.code()) |
AddressBits::encode(addr_.code()) |
ScratchBits::encode(scratch_.code());
}
};
void RecordWriteStub::Generate(MacroAssembler* masm) {
RecordWriteHelper(masm, object_, addr_, scratch_);
masm->ret(0);
}
// Set the remembered set bit for [object+offset].
// object is the object being stored into, value is the object being stored.
// If offset is zero, then the scratch register contains the array index into
// the elements array represented as a Smi.
// All registers are clobbered by the operation.
void MacroAssembler::RecordWrite(Register object, int offset,
Register value, Register scratch) {
// The compiled code assumes that record write doesn't change the
// context register, so we check that none of the clobbered
// registers are esi.
ASSERT(!object.is(esi) && !value.is(esi) && !scratch.is(esi));
// First, check if a remembered set write is even needed. The tests below
// catch stores of Smis and stores into young gen (which does not have space
// for the remembered set bits.
Label done;
// Skip barrier if writing a smi.
ASSERT_EQ(0, kSmiTag);
test(value, Immediate(kSmiTagMask));
j(zero, &done);
if (Serializer::enabled()) {
// Can't do arithmetic on external references if it might get serialized.
mov(value, Operand(object));
// The mask isn't really an address. We load it as an external reference in
// case the size of the new space is different between the snapshot maker
// and the running system.
and_(Operand(value), Immediate(ExternalReference::new_space_mask()));
cmp(Operand(value), Immediate(ExternalReference::new_space_start()));
j(equal, &done);
} else {
int32_t new_space_start = reinterpret_cast<int32_t>(
ExternalReference::new_space_start().address());
lea(value, Operand(object, -new_space_start));
and_(value, Heap::NewSpaceMask());
j(equal, &done);
}
if ((offset > 0) && (offset < Page::kMaxHeapObjectSize)) {
// Compute the bit offset in the remembered set, leave it in 'value'.
lea(value, Operand(object, offset));
and_(value, Page::kPageAlignmentMask);
shr(value, kPointerSizeLog2);
// Compute the page address from the heap object pointer, leave it in
// 'object'.
and_(object, ~Page::kPageAlignmentMask);
// NOTE: For now, we use the bit-test-and-set (bts) x86 instruction
// to limit code size. We should probably evaluate this decision by
// measuring the performance of an equivalent implementation using
// "simpler" instructions
bts(Operand(object, Page::kRSetOffset), value);
} else {
Register dst = scratch;
if (offset != 0) {
lea(dst, Operand(object, offset));
} else {
// 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.
ASSERT_EQ(1, kSmiTagSize);
ASSERT_EQ(0, kSmiTag);
lea(dst, Operand(object, dst, times_half_pointer_size,
FixedArray::kHeaderSize - kHeapObjectTag));
}
// If we are already generating a shared stub, not inlining the
// record write code isn't going to save us any memory.
if (generating_stub()) {
RecordWriteHelper(this, object, dst, value);
} else {
RecordWriteStub stub(object, dst, value);
CallStub(&stub);
}
}
bind(&done);
// Clobber all input registers when running with the debug-code flag
// turned on to provoke errors.
if (FLAG_debug_code) {
mov(object, Immediate(bit_cast<int32_t>(kZapValue)));
mov(value, Immediate(bit_cast<int32_t>(kZapValue)));
mov(scratch, Immediate(bit_cast<int32_t>(kZapValue)));
}
}
void MacroAssembler::StackLimitCheck(Label* on_stack_overflow) {
cmp(esp,
Operand::StaticVariable(ExternalReference::address_of_stack_limit()));
j(below, on_stack_overflow);
}
#ifdef ENABLE_DEBUGGER_SUPPORT
void MacroAssembler::SaveRegistersToMemory(RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Copy the content of registers to memory location.
for (int i = 0; i < kNumJSCallerSaved; i++) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
Register reg = { r };
ExternalReference reg_addr =
ExternalReference(Debug_Address::Register(i));
mov(Operand::StaticVariable(reg_addr), reg);
}
}
}
void MacroAssembler::RestoreRegistersFromMemory(RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Copy the content of memory location to registers.
for (int i = kNumJSCallerSaved; --i >= 0;) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
Register reg = { r };
ExternalReference reg_addr =
ExternalReference(Debug_Address::Register(i));
mov(reg, Operand::StaticVariable(reg_addr));
}
}
}
void MacroAssembler::PushRegistersFromMemory(RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Push the content of the memory location to the stack.
for (int i = 0; i < kNumJSCallerSaved; i++) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
ExternalReference reg_addr =
ExternalReference(Debug_Address::Register(i));
push(Operand::StaticVariable(reg_addr));
}
}
}
void MacroAssembler::PopRegistersToMemory(RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Pop the content from the stack to the memory location.
for (int i = kNumJSCallerSaved; --i >= 0;) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
ExternalReference reg_addr =
ExternalReference(Debug_Address::Register(i));
pop(Operand::StaticVariable(reg_addr));
}
}
}
void MacroAssembler::CopyRegistersFromStackToMemory(Register base,
Register scratch,
RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Copy the content of the stack to the memory location and adjust base.
for (int i = kNumJSCallerSaved; --i >= 0;) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
mov(scratch, Operand(base, 0));
ExternalReference reg_addr =
ExternalReference(Debug_Address::Register(i));
mov(Operand::StaticVariable(reg_addr), scratch);
lea(base, Operand(base, kPointerSize));
}
}
}
void MacroAssembler::DebugBreak() {
Set(eax, Immediate(0));
mov(ebx, Immediate(ExternalReference(Runtime::kDebugBreak)));
CEntryStub ces(1);
call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
}
#endif
void MacroAssembler::Set(Register dst, const Immediate& x) {
if (x.is_zero()) {
xor_(dst, Operand(dst)); // shorter than mov
} else {
mov(dst, x);
}
}
void MacroAssembler::Set(const Operand& dst, const Immediate& x) {
mov(dst, x);
}
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::CheckMap(Register obj,
Handle<Map> map,
Label* fail,
bool is_heap_object) {
if (!is_heap_object) {
test(obj, Immediate(kSmiTagMask));
j(zero, fail);
}
cmp(FieldOperand(obj, HeapObject::kMapOffset), Immediate(map));
j(not_equal, 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));
ASSERT(kNotStringTag != 0);
test(instance_type, Immediate(kIsNotStringMask));
return zero;
}
void MacroAssembler::FCmp() {
if (CpuFeatures::IsSupported(CMOV)) {
fucomip();
ffree(0);
fincstp();
} else {
fucompp();
push(eax);
fnstsw_ax();
sahf();
pop(eax);
}
}
void MacroAssembler::AbortIfNotNumber(Register object, const char* msg) {
Label ok;
test(object, Immediate(kSmiTagMask));
j(zero, &ok);
cmp(FieldOperand(object, HeapObject::kMapOffset),
Factory::heap_number_map());
Assert(equal, msg);
bind(&ok);
}
void MacroAssembler::EnterFrame(StackFrame::Type type) {
push(ebp);
mov(ebp, Operand(esp));
push(esi);
push(Immediate(Smi::FromInt(type)));
push(Immediate(CodeObject()));
if (FLAG_debug_code) {
cmp(Operand(esp, 0), Immediate(Factory::undefined_value()));
Check(not_equal, "code object not properly patched");
}
}
void MacroAssembler::LeaveFrame(StackFrame::Type type) {
if (FLAG_debug_code) {
cmp(Operand(ebp, StandardFrameConstants::kMarkerOffset),
Immediate(Smi::FromInt(type)));
Check(equal, "stack frame types must match");
}
leave();
}
void MacroAssembler::EnterExitFramePrologue(ExitFrame::Mode mode) {
// Setup 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, Operand(esp));
// Reserve room for entry stack pointer and push the debug marker.
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(Top::k_c_entry_fp_address);
ExternalReference context_address(Top::k_context_address);
mov(Operand::StaticVariable(c_entry_fp_address), ebp);
mov(Operand::StaticVariable(context_address), esi);
}
void MacroAssembler::EnterExitFrameEpilogue(ExitFrame::Mode mode, int argc) {
#ifdef ENABLE_DEBUGGER_SUPPORT
// Save the state of all registers to the stack from the memory
// location. This is needed to allow nested break points.
if (mode == ExitFrame::MODE_DEBUG) {
// TODO(1243899): This should be symmetric to
// CopyRegistersFromStackToMemory() but it isn't! esp is assumed
// correct here, but computed for the other call. Very error
// prone! FIX THIS. Actually there are deeper problems with
// register saving than this asymmetry (see the bug report
// associated with this issue).
PushRegistersFromMemory(kJSCallerSaved);
}
#endif
// Reserve space for arguments.
sub(Operand(esp), Immediate(argc * kPointerSize));
// Get the required frame alignment for the OS.
static 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(ExitFrame::Mode mode) {
EnterExitFramePrologue(mode);
// Setup argc and argv in callee-saved registers.
int offset = StandardFrameConstants::kCallerSPOffset - kPointerSize;
mov(edi, Operand(eax));
lea(esi, Operand(ebp, eax, times_4, offset));
EnterExitFrameEpilogue(mode, 2);
}
void MacroAssembler::EnterApiExitFrame(ExitFrame::Mode mode,
int stack_space,
int argc) {
EnterExitFramePrologue(mode);
int offset = StandardFrameConstants::kCallerSPOffset - kPointerSize;
lea(esi, Operand(ebp, (stack_space * kPointerSize) + offset));
EnterExitFrameEpilogue(mode, argc);
}
void MacroAssembler::LeaveExitFrame(ExitFrame::Mode mode) {
#ifdef ENABLE_DEBUGGER_SUPPORT
// Restore the memory copy of the registers by digging them out from
// the stack. This is needed to allow nested break points.
if (mode == ExitFrame::MODE_DEBUG) {
// It's okay to clobber register ebx below because we don't need
// the function pointer after this.
const int kCallerSavedSize = kNumJSCallerSaved * kPointerSize;
int kOffset = ExitFrameConstants::kCodeOffset - kCallerSavedSize;
lea(ebx, Operand(ebp, kOffset));
CopyRegistersFromStackToMemory(ebx, ecx, kJSCallerSaved);
}
#endif
// 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));
// Restore current context from top and clear it in debug mode.
ExternalReference context_address(Top::k_context_address);
mov(esi, Operand::StaticVariable(context_address));
#ifdef DEBUG
mov(Operand::StaticVariable(context_address), Immediate(0));
#endif
// Push the return address to get ready to return.
push(ecx);
// Clear the top frame.
ExternalReference c_entry_fp_address(Top::k_c_entry_fp_address);
mov(Operand::StaticVariable(c_entry_fp_address), Immediate(0));
}
void MacroAssembler::PushTryHandler(CodeLocation try_location,
HandlerType type) {
// Adjust this code if not the case.
ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
// The pc (return address) is already on TOS.
if (try_location == IN_JAVASCRIPT) {
if (type == TRY_CATCH_HANDLER) {
push(Immediate(StackHandler::TRY_CATCH));
} else {
push(Immediate(StackHandler::TRY_FINALLY));
}
push(ebp);
} else {
ASSERT(try_location == IN_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(StackHandler::ENTRY));
push(Immediate(0)); // NULL frame pointer.
}
// Save the current handler as the next handler.
push(Operand::StaticVariable(ExternalReference(Top::k_handler_address)));
// Link this handler as the new current one.
mov(Operand::StaticVariable(ExternalReference(Top::k_handler_address)), esp);
}
void MacroAssembler::PopTryHandler() {
ASSERT_EQ(0, StackHandlerConstants::kNextOffset);
pop(Operand::StaticVariable(ExternalReference(Top::k_handler_address)));
add(Operand(esp), Immediate(StackHandlerConstants::kSize - kPointerSize));
}
Register MacroAssembler::CheckMaps(JSObject* object, Register object_reg,
JSObject* holder, Register holder_reg,
Register scratch,
int save_at_depth,
Label* miss) {
// Make sure there's no overlap between scratch and the other
// registers.
ASSERT(!scratch.is(object_reg) && !scratch.is(holder_reg));
// Keep track of the current object in register reg.
Register reg = object_reg;
int depth = 0;
if (save_at_depth == depth) {
mov(Operand(esp, kPointerSize), object_reg);
}
// Check the maps in the prototype chain.
// Traverse the prototype chain from the object and do map checks.
while (object != holder) {
depth++;
// Only global objects and objects that do not require access
// checks are allowed in stubs.
ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded());
JSObject* prototype = JSObject::cast(object->GetPrototype());
if (Heap::InNewSpace(prototype)) {
// Get the map of the current object.
mov(scratch, FieldOperand(reg, HeapObject::kMapOffset));
cmp(Operand(scratch), Immediate(Handle<Map>(object->map())));
// Branch on the result of the map check.
j(not_equal, miss, not_taken);
// Check access rights to the global object. This has to happen
// after the map check so that we know that the object is
// actually a global object.
if (object->IsJSGlobalProxy()) {
CheckAccessGlobalProxy(reg, scratch, miss);
// Restore scratch register to be the map of the object.
// We load the prototype from the map in the scratch register.
mov(scratch, FieldOperand(reg, HeapObject::kMapOffset));
}
// The prototype is in new space; we cannot store a reference
// to it in the code. Load it from the map.
reg = holder_reg; // from now the object is in holder_reg
mov(reg, FieldOperand(scratch, Map::kPrototypeOffset));
} else {
// Check the map of the current object.
cmp(FieldOperand(reg, HeapObject::kMapOffset),
Immediate(Handle<Map>(object->map())));
// Branch on the result of the map check.
j(not_equal, miss, not_taken);
// Check access rights to the global object. This has to happen
// after the map check so that we know that the object is
// actually a global object.
if (object->IsJSGlobalProxy()) {
CheckAccessGlobalProxy(reg, scratch, miss);
}
// The prototype is in old space; load it directly.
reg = holder_reg; // from now the object is in holder_reg
mov(reg, Handle<JSObject>(prototype));
}
if (save_at_depth == depth) {
mov(Operand(esp, kPointerSize), reg);
}
// Go to the next object in the prototype chain.
object = prototype;
}
// Check the holder map.
cmp(FieldOperand(reg, HeapObject::kMapOffset),
Immediate(Handle<Map>(holder->map())));
j(not_equal, miss, not_taken);
// Log the check depth.
LOG(IntEvent("check-maps-depth", depth + 1));
// Perform security check for access to the global object and return
// the holder register.
ASSERT(object == holder);
ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded());
if (object->IsJSGlobalProxy()) {
CheckAccessGlobalProxy(reg, scratch, miss);
}
return reg;
}
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 (FLAG_debug_code) {
cmp(Operand(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 (FLAG_debug_code) {
push(scratch);
// Read the first word and compare to global_context_map.
mov(scratch, FieldOperand(scratch, HeapObject::kMapOffset));
cmp(scratch, 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, taken);
// 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 (FLAG_debug_code) {
cmp(holder_reg, 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, 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, not_taken);
bind(&same_contexts);
}
void MacroAssembler::LoadAllocationTopHelper(Register result,
Register result_end,
Register scratch,
AllocationFlags flags) {
ExternalReference new_space_allocation_top =
ExternalReference::new_space_allocation_top_address();
// 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 {
ASSERT(!scratch.is(result_end));
mov(Operand(scratch), Immediate(new_space_allocation_top));
mov(result, Operand(scratch, 0));
}
}
void MacroAssembler::UpdateAllocationTopHelper(Register result_end,
Register scratch) {
if (FLAG_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();
// 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) {
ASSERT(!result.is(result_end));
// Load address of new object into result.
LoadAllocationTopHelper(result, result_end, scratch, flags);
// Calculate new top and bail out if new space is exhausted.
ExternalReference new_space_allocation_limit =
ExternalReference::new_space_allocation_limit_address();
lea(result_end, Operand(result, object_size));
cmp(result_end, Operand::StaticVariable(new_space_allocation_limit));
j(above, gc_required, not_taken);
// Tag result if requested.
if ((flags & TAG_OBJECT) != 0) {
lea(result, Operand(result, kHeapObjectTag));
}
// Update allocation top.
UpdateAllocationTopHelper(result_end, scratch);
}
void MacroAssembler::AllocateInNewSpace(int header_size,
ScaleFactor element_size,
Register element_count,
Register result,
Register result_end,
Register scratch,
Label* gc_required,
AllocationFlags flags) {
ASSERT(!result.is(result_end));
// Load address of new object into result.
LoadAllocationTopHelper(result, result_end, scratch, flags);
// Calculate new top and bail out if new space is exhausted.
ExternalReference new_space_allocation_limit =
ExternalReference::new_space_allocation_limit_address();
lea(result_end, Operand(result, element_count, element_size, header_size));
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) {
ASSERT(!result.is(result_end));
// Load address of new object into result.
LoadAllocationTopHelper(result, result_end, scratch, flags);
// Calculate new top and bail out if new space is exhausted.
ExternalReference new_space_allocation_limit =
ExternalReference::new_space_allocation_limit_address();
if (!object_size.is(result_end)) {
mov(result_end, object_size);
}
add(result_end, Operand(result));
cmp(result_end, Operand::StaticVariable(new_space_allocation_limit));
j(above, gc_required, not_taken);
// 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();
// Make sure the object has no tag before resetting top.
and_(Operand(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(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_(Operand(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(Factory::string_map()));
mov(FieldOperand(result, String::kLengthOffset), length);
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(Operand(scratch1), Immediate(kObjectAlignmentMask));
and_(Operand(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(Factory::ascii_string_map()));
mov(FieldOperand(result, String::kLengthOffset), length);
mov(FieldOperand(result, String::kHashFieldOffset),
Immediate(String::kEmptyHashField));
}
void MacroAssembler::AllocateConsString(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(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(Factory::cons_ascii_string_map()));
}
void MacroAssembler::NegativeZeroTest(CodeGenerator* cgen,
Register result,
Register op,
JumpTarget* then_target) {
JumpTarget ok;
test(result, Operand(result));
ok.Branch(not_zero, taken);
test(op, Operand(op));
then_target->Branch(sign, not_taken);
ok.Bind();
}
void MacroAssembler::NegativeZeroTest(Register result,
Register op,
Label* then_label) {
Label ok;
test(result, Operand(result));
j(not_zero, &ok, taken);
test(op, Operand(op));
j(sign, then_label, not_taken);
bind(&ok);
}
void MacroAssembler::NegativeZeroTest(Register result,
Register op1,
Register op2,
Register scratch,
Label* then_label) {
Label ok;
test(result, Operand(result));
j(not_zero, &ok, taken);
mov(scratch, Operand(op1));
or_(scratch, Operand(op2));
j(sign, then_label, not_taken);
bind(&ok);
}
void MacroAssembler::TryGetFunctionPrototype(Register function,
Register result,
Register scratch,
Label* miss) {
// Check that the receiver isn't a smi.
test(function, Immediate(kSmiTagMask));
j(zero, miss, not_taken);
// Check that the function really is a function.
CmpObjectType(function, JS_FUNCTION_TYPE, result);
j(not_equal, miss, not_taken);
// 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, not_taken);
// 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(Operand(result), Immediate(Factory::the_hole_value()));
j(equal, miss, not_taken);
// 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) {
ASSERT(allow_stub_calls()); // Calls are not allowed in some stubs.
call(stub->GetCode(), RelocInfo::CODE_TARGET);
}
Object* MacroAssembler::TryCallStub(CodeStub* stub) {
ASSERT(allow_stub_calls()); // Calls are not allowed in some stubs.
Object* result = stub->TryGetCode();
if (!result->IsFailure()) {
call(Handle<Code>(Code::cast(result)), RelocInfo::CODE_TARGET);
}
return result;
}
void MacroAssembler::TailCallStub(CodeStub* stub) {
ASSERT(allow_stub_calls()); // Calls are not allowed in some stubs.
jmp(stub->GetCode(), RelocInfo::CODE_TARGET);
}
Object* MacroAssembler::TryTailCallStub(CodeStub* stub) {
ASSERT(allow_stub_calls()); // Calls are not allowed in some stubs.
Object* result = stub->TryGetCode();
if (!result->IsFailure()) {
jmp(Handle<Code>(Code::cast(result)), RelocInfo::CODE_TARGET);
}
return result;
}
void MacroAssembler::StubReturn(int argc) {
ASSERT(argc >= 1 && generating_stub());
ret((argc - 1) * kPointerSize);
}
void MacroAssembler::IllegalOperation(int num_arguments) {
if (num_arguments > 0) {
add(Operand(esp), Immediate(num_arguments * kPointerSize));
}
mov(eax, Immediate(Factory::undefined_value()));
}
void MacroAssembler::CallRuntime(Runtime::FunctionId id, int num_arguments) {
CallRuntime(Runtime::FunctionForId(id), num_arguments);
}
Object* MacroAssembler::TryCallRuntime(Runtime::FunctionId id,
int num_arguments) {
return TryCallRuntime(Runtime::FunctionForId(id), num_arguments);
}
void MacroAssembler::CallRuntime(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)));
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);
}
Object* MacroAssembler::TryCallRuntime(Runtime::Function* f,
int num_arguments) {
if (f->nargs >= 0 && f->nargs != num_arguments) {
IllegalOperation(num_arguments);
// Since we did not call the stub, there was no allocation failure.
// Return some non-failure object.
return Heap::undefined_value();
}
// 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)));
CEntryStub ces(1);
return TryCallStub(&ces);
}
void MacroAssembler::TailCallRuntime(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));
JumpToRuntime(ext);
}
void MacroAssembler::PushHandleScope(Register scratch) {
// Push the number of extensions, smi-tagged so the gc will ignore it.
ExternalReference extensions_address =
ExternalReference::handle_scope_extensions_address();
mov(scratch, Operand::StaticVariable(extensions_address));
ASSERT_EQ(0, kSmiTag);
shl(scratch, kSmiTagSize);
push(scratch);
mov(Operand::StaticVariable(extensions_address), Immediate(0));
// Push next and limit pointers which will be wordsize aligned and
// hence automatically smi tagged.
ExternalReference next_address =
ExternalReference::handle_scope_next_address();
push(Operand::StaticVariable(next_address));
ExternalReference limit_address =
ExternalReference::handle_scope_limit_address();
push(Operand::StaticVariable(limit_address));
}
Object* MacroAssembler::PopHandleScopeHelper(Register saved,
Register scratch,
bool gc_allowed) {
Object* result = NULL;
ExternalReference extensions_address =
ExternalReference::handle_scope_extensions_address();
Label write_back;
mov(scratch, Operand::StaticVariable(extensions_address));
cmp(Operand(scratch), Immediate(0));
j(equal, &write_back);
// Calling a runtime function messes with registers so we save and
// restore any one we're asked not to change
if (saved.is_valid()) push(saved);
if (gc_allowed) {
CallRuntime(Runtime::kDeleteHandleScopeExtensions, 0);
} else {
result = TryCallRuntime(Runtime::kDeleteHandleScopeExtensions, 0);
if (result->IsFailure()) return result;
}
if (saved.is_valid()) pop(saved);
bind(&write_back);
ExternalReference limit_address =
ExternalReference::handle_scope_limit_address();
pop(Operand::StaticVariable(limit_address));
ExternalReference next_address =
ExternalReference::handle_scope_next_address();
pop(Operand::StaticVariable(next_address));
pop(scratch);
shr(scratch, kSmiTagSize);
mov(Operand::StaticVariable(extensions_address), scratch);
return result;
}
void MacroAssembler::PopHandleScope(Register saved, Register scratch) {
PopHandleScopeHelper(saved, scratch, true);
}
Object* MacroAssembler::TryPopHandleScope(Register saved, Register scratch) {
return PopHandleScopeHelper(saved, scratch, false);
}
void MacroAssembler::JumpToRuntime(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::InvokePrologue(const ParameterCount& expected,
const ParameterCount& actual,
Handle<Code> code_constant,
const Operand& code_operand,
Label* done,
InvokeFlag flag) {
bool definitely_matches = 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 {
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(), Operand(actual.reg()));
j(equal, &invoke);
ASSERT(actual.reg().is(eax));
ASSERT(expected.reg().is(ebx));
}
}
if (!definitely_matches) {
Handle<Code> adaptor =
Handle<Code>(Builtins::builtin(Builtins::ArgumentsAdaptorTrampoline));
if (!code_constant.is_null()) {
mov(edx, Immediate(code_constant));
add(Operand(edx), Immediate(Code::kHeaderSize - kHeapObjectTag));
} else if (!code_operand.is_reg(edx)) {
mov(edx, code_operand);
}
if (flag == CALL_FUNCTION) {
call(adaptor, RelocInfo::CODE_TARGET);
jmp(done);
} else {
jmp(adaptor, RelocInfo::CODE_TARGET);
}
bind(&invoke);
}
}
void MacroAssembler::InvokeCode(const Operand& code,
const ParameterCount& expected,
const ParameterCount& actual,
InvokeFlag flag) {
Label done;
InvokePrologue(expected, actual, Handle<Code>::null(), code, &done, flag);
if (flag == CALL_FUNCTION) {
call(code);
} else {
ASSERT(flag == JUMP_FUNCTION);
jmp(code);
}
bind(&done);
}
void MacroAssembler::InvokeCode(Handle<Code> code,
const ParameterCount& expected,
const ParameterCount& actual,
RelocInfo::Mode rmode,
InvokeFlag flag) {
Label done;
Operand dummy(eax);
InvokePrologue(expected, actual, code, dummy, &done, flag);
if (flag == CALL_FUNCTION) {
call(code, rmode);
} else {
ASSERT(flag == JUMP_FUNCTION);
jmp(code, rmode);
}
bind(&done);
}
void MacroAssembler::InvokeFunction(Register fun,
const ParameterCount& actual,
InvokeFlag flag) {
ASSERT(fun.is(edi));
mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
mov(ebx, FieldOperand(edx, SharedFunctionInfo::kFormalParameterCountOffset));
mov(edx, FieldOperand(edx, SharedFunctionInfo::kCodeOffset));
lea(edx, FieldOperand(edx, Code::kHeaderSize));
ParameterCount expected(ebx);
InvokeCode(Operand(edx), expected, actual, flag);
}
void MacroAssembler::InvokeFunction(JSFunction* function,
const ParameterCount& actual,
InvokeFlag flag) {
ASSERT(function->is_compiled());
// Get the function and setup the context.
mov(edi, Immediate(Handle<JSFunction>(function)));
mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
// Invoke the cached code.
Handle<Code> code(function->code());
ParameterCount expected(function->shared()->formal_parameter_count());
InvokeCode(code, expected, actual, RelocInfo::CODE_TARGET, flag);
}
void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id, InvokeFlag flag) {
// Calls are not allowed in some stubs.
ASSERT(flag == JUMP_FUNCTION || allow_stub_calls());
// 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);
GetBuiltinEntry(edx, id);
InvokeCode(Operand(edx), expected, expected, flag);
}
void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) {
// Load the JavaScript builtin function from the builtins object.
mov(edi, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
mov(edi, FieldOperand(edi, GlobalObject::kBuiltinsOffset));
int builtins_offset =
JSBuiltinsObject::kJSBuiltinsOffset + (id * kPointerSize);
mov(edi, FieldOperand(edi, builtins_offset));
// Load the code entry point from the function into the target register.
mov(target, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
mov(target, FieldOperand(target, SharedFunctionInfo::kCodeOffset));
add(Operand(target), Immediate(Code::kHeaderSize - kHeapObjectTag));
}
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::CLOSURE_INDEX)));
// Load the function context (which is the incoming, outer context).
mov(dst, FieldOperand(dst, JSFunction::kContextOffset));
for (int i = 1; i < context_chain_length; i++) {
mov(dst, Operand(dst, Context::SlotOffset(Context::CLOSURE_INDEX)));
mov(dst, FieldOperand(dst, JSFunction::kContextOffset));
}
// The context may be an intermediate context, not a function context.
mov(dst, Operand(dst, Context::SlotOffset(Context::FCONTEXT_INDEX)));
} else { // Slot is in the current function context.
// The context may be an intermediate context, not a function context.
mov(dst, Operand(esi, Context::SlotOffset(Context::FCONTEXT_INDEX)));
}
}
void MacroAssembler::Ret() {
ret(0);
}
void MacroAssembler::Drop(int stack_elements) {
if (stack_elements > 0) {
add(Operand(esp), Immediate(stack_elements * kPointerSize));
}
}
void MacroAssembler::Move(Register dst, Handle<Object> value) {
mov(dst, value);
}
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 (FLAG_debug_code) Check(cc, msg);
}
void MacroAssembler::Check(Condition cc, const char* msg) {
Label L;
j(cc, &L, taken);
Abort(msg);
// will not return here
bind(&L);
}
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
// Disable stub call restrictions to always allow calls to abort.
set_allow_stub_calls(true);
push(eax);
push(Immediate(p0));
push(Immediate(reinterpret_cast<intptr_t>(Smi::FromInt(p1 - p0))));
CallRuntime(Runtime::kAbort, 2);
// will not return here
int3();
}
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.
ASSERT_EQ(0, kSmiTag);
mov(scratch1, Operand(object1));
and_(scratch1, Operand(object2));
test(scratch1, Immediate(kSmiTagMask));
j(zero, 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);
}
CodePatcher::CodePatcher(byte* address, int size)
: address_(address), size_(size), masm_(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);
}
} } // namespace v8::internal