// 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), unresolved_(0), 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 {}; class AddressBits: public BitField {}; class ObjectBits: public BitField {}; 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) { // 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)); and_(value, Heap::NewSpaceMask()); cmp(Operand(value), Immediate(ExternalReference::new_space_start())); j(equal, &done); } else { int32_t new_space_start = reinterpret_cast( 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); } 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)); } } } #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(type)); } 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::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 if (mode == ExitFrame::MODE_DEBUG) { push(Immediate(0)); } else { push(Immediate(CodeObject())); } // 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, 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 = 1; // 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(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(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(prototype)); } // Go to the next object in the prototype chain. object = prototype; } // Check the holder map. cmp(FieldOperand(reg, HeapObject::kMapOffset), Immediate(Handle(holder->map()))); j(not_equal, miss, not_taken); // Log the check depth. LOG(IntEvent("check-maps-depth", depth)); // 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::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::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; } Runtime::FunctionId function_id = static_cast(f->stub_id); RuntimeStub stub(function_id, num_arguments); 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(); } Runtime::FunctionId function_id = static_cast(f->stub_id); RuntimeStub stub(function_id, num_arguments); return TryCallStub(&stub); } 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_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 adaptor = Handle(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::null(), code, &done, flag); if (flag == CALL_FUNCTION) { call(code); } else { ASSERT(flag == JUMP_FUNCTION); jmp(code); } bind(&done); } void MacroAssembler::InvokeCode(Handle 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::InvokeBuiltin(Builtins::JavaScript id, InvokeFlag flag) { bool resolved; Handle code = ResolveBuiltin(id, &resolved); // 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); InvokeCode(Handle(code), expected, expected, RelocInfo::CODE_TARGET, flag); const char* name = Builtins::GetName(id); int argc = Builtins::GetArgumentsCount(id); if (!resolved) { uint32_t flags = Bootstrapper::FixupFlagsArgumentsCount::encode(argc) | Bootstrapper::FixupFlagsUseCodeObject::encode(false); Unresolved entry = { pc_offset() - sizeof(int32_t), flags, name }; unresolved_.Add(entry); } } void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) { bool resolved; Handle code = ResolveBuiltin(id, &resolved); const char* name = Builtins::GetName(id); int argc = Builtins::GetArgumentsCount(id); mov(Operand(target), Immediate(code)); if (!resolved) { uint32_t flags = Bootstrapper::FixupFlagsArgumentsCount::encode(argc) | Bootstrapper::FixupFlagsUseCodeObject::encode(true); Unresolved entry = { pc_offset() - sizeof(int32_t), flags, name }; unresolved_.Add(entry); } add(Operand(target), Immediate(Code::kHeaderSize - kHeapObjectTag)); } Handle MacroAssembler::ResolveBuiltin(Builtins::JavaScript id, bool* resolved) { // Move the builtin function into the temporary function slot by // reading it from the builtins object. NOTE: We should be able to // reduce this to two instructions by putting the function table in // the global object instead of the "builtins" object and by using a // real register for the function. mov(edx, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX))); mov(edx, FieldOperand(edx, GlobalObject::kBuiltinsOffset)); int builtins_offset = JSBuiltinsObject::kJSBuiltinsOffset + (id * kPointerSize); mov(edi, FieldOperand(edx, builtins_offset)); return Builtins::GetCode(id, resolved); } 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 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::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(msg); intptr_t p0 = (p1 & ~kSmiTagMask) + kSmiTag; ASSERT(reinterpret_cast(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(Smi::FromInt(p1 - p0)))); CallRuntime(Runtime::kAbort, 2); // will not return here int3(); } 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