| // Copyright 2012 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/v8.h" |
| |
| #if V8_TARGET_ARCH_IA32 |
| |
| #include "src/codegen.h" |
| #include "src/deoptimizer.h" |
| #include "src/full-codegen.h" |
| #include "src/safepoint-table.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| const int Deoptimizer::table_entry_size_ = 10; |
| |
| |
| int Deoptimizer::patch_size() { |
| return Assembler::kCallInstructionLength; |
| } |
| |
| |
| void Deoptimizer::EnsureRelocSpaceForLazyDeoptimization(Handle<Code> code) { |
| Isolate* isolate = code->GetIsolate(); |
| HandleScope scope(isolate); |
| |
| // Compute the size of relocation information needed for the code |
| // patching in Deoptimizer::DeoptimizeFunction. |
| int min_reloc_size = 0; |
| int prev_pc_offset = 0; |
| DeoptimizationInputData* deopt_data = |
| DeoptimizationInputData::cast(code->deoptimization_data()); |
| for (int i = 0; i < deopt_data->DeoptCount(); i++) { |
| int pc_offset = deopt_data->Pc(i)->value(); |
| if (pc_offset == -1) continue; |
| DCHECK_GE(pc_offset, prev_pc_offset); |
| int pc_delta = pc_offset - prev_pc_offset; |
| // We use RUNTIME_ENTRY reloc info which has a size of 2 bytes |
| // if encodable with small pc delta encoding and up to 6 bytes |
| // otherwise. |
| if (pc_delta <= RelocInfo::kMaxSmallPCDelta) { |
| min_reloc_size += 2; |
| } else { |
| min_reloc_size += 6; |
| } |
| prev_pc_offset = pc_offset; |
| } |
| |
| // If the relocation information is not big enough we create a new |
| // relocation info object that is padded with comments to make it |
| // big enough for lazy doptimization. |
| int reloc_length = code->relocation_info()->length(); |
| if (min_reloc_size > reloc_length) { |
| int comment_reloc_size = RelocInfo::kMinRelocCommentSize; |
| // Padding needed. |
| int min_padding = min_reloc_size - reloc_length; |
| // Number of comments needed to take up at least that much space. |
| int additional_comments = |
| (min_padding + comment_reloc_size - 1) / comment_reloc_size; |
| // Actual padding size. |
| int padding = additional_comments * comment_reloc_size; |
| // Allocate new relocation info and copy old relocation to the end |
| // of the new relocation info array because relocation info is |
| // written and read backwards. |
| Factory* factory = isolate->factory(); |
| Handle<ByteArray> new_reloc = |
| factory->NewByteArray(reloc_length + padding, TENURED); |
| MemCopy(new_reloc->GetDataStartAddress() + padding, |
| code->relocation_info()->GetDataStartAddress(), reloc_length); |
| // Create a relocation writer to write the comments in the padding |
| // space. Use position 0 for everything to ensure short encoding. |
| RelocInfoWriter reloc_info_writer( |
| new_reloc->GetDataStartAddress() + padding, 0); |
| intptr_t comment_string |
| = reinterpret_cast<intptr_t>(RelocInfo::kFillerCommentString); |
| RelocInfo rinfo(0, RelocInfo::COMMENT, comment_string, NULL); |
| for (int i = 0; i < additional_comments; ++i) { |
| #ifdef DEBUG |
| byte* pos_before = reloc_info_writer.pos(); |
| #endif |
| reloc_info_writer.Write(&rinfo); |
| DCHECK(RelocInfo::kMinRelocCommentSize == |
| pos_before - reloc_info_writer.pos()); |
| } |
| // Replace relocation information on the code object. |
| code->set_relocation_info(*new_reloc); |
| } |
| } |
| |
| |
| void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) { |
| Address code_start_address = code->instruction_start(); |
| |
| if (FLAG_zap_code_space) { |
| // Fail hard and early if we enter this code object again. |
| byte* pointer = code->FindCodeAgeSequence(); |
| if (pointer != NULL) { |
| pointer += kNoCodeAgeSequenceLength; |
| } else { |
| pointer = code->instruction_start(); |
| } |
| CodePatcher patcher(pointer, 1); |
| patcher.masm()->int3(); |
| |
| DeoptimizationInputData* data = |
| DeoptimizationInputData::cast(code->deoptimization_data()); |
| int osr_offset = data->OsrPcOffset()->value(); |
| if (osr_offset > 0) { |
| CodePatcher osr_patcher(code->instruction_start() + osr_offset, 1); |
| osr_patcher.masm()->int3(); |
| } |
| } |
| |
| // We will overwrite the code's relocation info in-place. Relocation info |
| // is written backward. The relocation info is the payload of a byte |
| // array. Later on we will slide this to the start of the byte array and |
| // create a filler object in the remaining space. |
| ByteArray* reloc_info = code->relocation_info(); |
| Address reloc_end_address = reloc_info->address() + reloc_info->Size(); |
| RelocInfoWriter reloc_info_writer(reloc_end_address, code_start_address); |
| |
| // Since the call is a relative encoding, write new |
| // reloc info. We do not need any of the existing reloc info because the |
| // existing code will not be used again (we zap it in debug builds). |
| // |
| // Emit call to lazy deoptimization at all lazy deopt points. |
| DeoptimizationInputData* deopt_data = |
| DeoptimizationInputData::cast(code->deoptimization_data()); |
| #ifdef DEBUG |
| Address prev_call_address = NULL; |
| #endif |
| // For each LLazyBailout instruction insert a call to the corresponding |
| // deoptimization entry. |
| for (int i = 0; i < deopt_data->DeoptCount(); i++) { |
| if (deopt_data->Pc(i)->value() == -1) continue; |
| // Patch lazy deoptimization entry. |
| Address call_address = code_start_address + deopt_data->Pc(i)->value(); |
| CodePatcher patcher(call_address, patch_size()); |
| Address deopt_entry = GetDeoptimizationEntry(isolate, i, LAZY); |
| patcher.masm()->call(deopt_entry, RelocInfo::NONE32); |
| // We use RUNTIME_ENTRY for deoptimization bailouts. |
| RelocInfo rinfo(call_address + 1, // 1 after the call opcode. |
| RelocInfo::RUNTIME_ENTRY, |
| reinterpret_cast<intptr_t>(deopt_entry), |
| NULL); |
| reloc_info_writer.Write(&rinfo); |
| DCHECK_GE(reloc_info_writer.pos(), |
| reloc_info->address() + ByteArray::kHeaderSize); |
| DCHECK(prev_call_address == NULL || |
| call_address >= prev_call_address + patch_size()); |
| DCHECK(call_address + patch_size() <= code->instruction_end()); |
| #ifdef DEBUG |
| prev_call_address = call_address; |
| #endif |
| } |
| |
| // Move the relocation info to the beginning of the byte array. |
| int new_reloc_size = reloc_end_address - reloc_info_writer.pos(); |
| MemMove(code->relocation_start(), reloc_info_writer.pos(), new_reloc_size); |
| |
| // The relocation info is in place, update the size. |
| reloc_info->set_length(new_reloc_size); |
| |
| // Handle the junk part after the new relocation info. We will create |
| // a non-live object in the extra space at the end of the former reloc info. |
| Address junk_address = reloc_info->address() + reloc_info->Size(); |
| DCHECK(junk_address <= reloc_end_address); |
| isolate->heap()->CreateFillerObjectAt(junk_address, |
| reloc_end_address - junk_address); |
| } |
| |
| |
| void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) { |
| // Set the register values. The values are not important as there are no |
| // callee saved registers in JavaScript frames, so all registers are |
| // spilled. Registers ebp and esp are set to the correct values though. |
| |
| for (int i = 0; i < Register::kNumRegisters; i++) { |
| input_->SetRegister(i, i * 4); |
| } |
| input_->SetRegister(esp.code(), reinterpret_cast<intptr_t>(frame->sp())); |
| input_->SetRegister(ebp.code(), reinterpret_cast<intptr_t>(frame->fp())); |
| for (int i = 0; i < XMMRegister::kMaxNumAllocatableRegisters; i++) { |
| input_->SetDoubleRegister(i, 0.0); |
| } |
| |
| // Fill the frame content from the actual data on the frame. |
| for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) { |
| input_->SetFrameSlot(i, Memory::uint32_at(tos + i)); |
| } |
| } |
| |
| |
| void Deoptimizer::SetPlatformCompiledStubRegisters( |
| FrameDescription* output_frame, CodeStubDescriptor* descriptor) { |
| intptr_t handler = |
| reinterpret_cast<intptr_t>(descriptor->deoptimization_handler()); |
| int params = descriptor->GetHandlerParameterCount(); |
| output_frame->SetRegister(eax.code(), params); |
| output_frame->SetRegister(ebx.code(), handler); |
| } |
| |
| |
| void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) { |
| for (int i = 0; i < XMMRegister::kMaxNumAllocatableRegisters; ++i) { |
| double double_value = input_->GetDoubleRegister(i); |
| output_frame->SetDoubleRegister(i, double_value); |
| } |
| } |
| |
| |
| bool Deoptimizer::HasAlignmentPadding(JSFunction* function) { |
| int parameter_count = function->shared()->formal_parameter_count() + 1; |
| unsigned input_frame_size = input_->GetFrameSize(); |
| unsigned alignment_state_offset = |
| input_frame_size - parameter_count * kPointerSize - |
| StandardFrameConstants::kFixedFrameSize - |
| kPointerSize; |
| DCHECK(JavaScriptFrameConstants::kDynamicAlignmentStateOffset == |
| JavaScriptFrameConstants::kLocal0Offset); |
| int32_t alignment_state = input_->GetFrameSlot(alignment_state_offset); |
| return (alignment_state == kAlignmentPaddingPushed); |
| } |
| |
| |
| #define __ masm()-> |
| |
| void Deoptimizer::EntryGenerator::Generate() { |
| GeneratePrologue(); |
| |
| // Save all general purpose registers before messing with them. |
| const int kNumberOfRegisters = Register::kNumRegisters; |
| |
| const int kDoubleRegsSize = kDoubleSize * |
| XMMRegister::kMaxNumAllocatableRegisters; |
| __ sub(esp, Immediate(kDoubleRegsSize)); |
| for (int i = 0; i < XMMRegister::kMaxNumAllocatableRegisters; ++i) { |
| XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i); |
| int offset = i * kDoubleSize; |
| __ movsd(Operand(esp, offset), xmm_reg); |
| } |
| |
| __ pushad(); |
| |
| const int kSavedRegistersAreaSize = kNumberOfRegisters * kPointerSize + |
| kDoubleRegsSize; |
| |
| // Get the bailout id from the stack. |
| __ mov(ebx, Operand(esp, kSavedRegistersAreaSize)); |
| |
| // Get the address of the location in the code object |
| // and compute the fp-to-sp delta in register edx. |
| __ mov(ecx, Operand(esp, kSavedRegistersAreaSize + 1 * kPointerSize)); |
| __ lea(edx, Operand(esp, kSavedRegistersAreaSize + 2 * kPointerSize)); |
| |
| __ sub(edx, ebp); |
| __ neg(edx); |
| |
| // Allocate a new deoptimizer object. |
| __ PrepareCallCFunction(6, eax); |
| __ mov(eax, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset)); |
| __ mov(Operand(esp, 0 * kPointerSize), eax); // Function. |
| __ mov(Operand(esp, 1 * kPointerSize), Immediate(type())); // Bailout type. |
| __ mov(Operand(esp, 2 * kPointerSize), ebx); // Bailout id. |
| __ mov(Operand(esp, 3 * kPointerSize), ecx); // Code address or 0. |
| __ mov(Operand(esp, 4 * kPointerSize), edx); // Fp-to-sp delta. |
| __ mov(Operand(esp, 5 * kPointerSize), |
| Immediate(ExternalReference::isolate_address(isolate()))); |
| { |
| AllowExternalCallThatCantCauseGC scope(masm()); |
| __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6); |
| } |
| |
| // Preserve deoptimizer object in register eax and get the input |
| // frame descriptor pointer. |
| __ mov(ebx, Operand(eax, Deoptimizer::input_offset())); |
| |
| // Fill in the input registers. |
| for (int i = kNumberOfRegisters - 1; i >= 0; i--) { |
| int offset = (i * kPointerSize) + FrameDescription::registers_offset(); |
| __ pop(Operand(ebx, offset)); |
| } |
| |
| int double_regs_offset = FrameDescription::double_registers_offset(); |
| // Fill in the double input registers. |
| for (int i = 0; i < XMMRegister::kMaxNumAllocatableRegisters; ++i) { |
| int dst_offset = i * kDoubleSize + double_regs_offset; |
| int src_offset = i * kDoubleSize; |
| __ movsd(xmm0, Operand(esp, src_offset)); |
| __ movsd(Operand(ebx, dst_offset), xmm0); |
| } |
| |
| // Clear FPU all exceptions. |
| // TODO(ulan): Find out why the TOP register is not zero here in some cases, |
| // and check that the generated code never deoptimizes with unbalanced stack. |
| __ fnclex(); |
| |
| // Remove the bailout id, return address and the double registers. |
| __ add(esp, Immediate(kDoubleRegsSize + 2 * kPointerSize)); |
| |
| // Compute a pointer to the unwinding limit in register ecx; that is |
| // the first stack slot not part of the input frame. |
| __ mov(ecx, Operand(ebx, FrameDescription::frame_size_offset())); |
| __ add(ecx, esp); |
| |
| // Unwind the stack down to - but not including - the unwinding |
| // limit and copy the contents of the activation frame to the input |
| // frame description. |
| __ lea(edx, Operand(ebx, FrameDescription::frame_content_offset())); |
| Label pop_loop_header; |
| __ jmp(&pop_loop_header); |
| Label pop_loop; |
| __ bind(&pop_loop); |
| __ pop(Operand(edx, 0)); |
| __ add(edx, Immediate(sizeof(uint32_t))); |
| __ bind(&pop_loop_header); |
| __ cmp(ecx, esp); |
| __ j(not_equal, &pop_loop); |
| |
| // Compute the output frame in the deoptimizer. |
| __ push(eax); |
| __ PrepareCallCFunction(1, ebx); |
| __ mov(Operand(esp, 0 * kPointerSize), eax); |
| { |
| AllowExternalCallThatCantCauseGC scope(masm()); |
| __ CallCFunction( |
| ExternalReference::compute_output_frames_function(isolate()), 1); |
| } |
| __ pop(eax); |
| |
| // If frame was dynamically aligned, pop padding. |
| Label no_padding; |
| __ cmp(Operand(eax, Deoptimizer::has_alignment_padding_offset()), |
| Immediate(0)); |
| __ j(equal, &no_padding); |
| __ pop(ecx); |
| if (FLAG_debug_code) { |
| __ cmp(ecx, Immediate(kAlignmentZapValue)); |
| __ Assert(equal, kAlignmentMarkerExpected); |
| } |
| __ bind(&no_padding); |
| |
| // Replace the current frame with the output frames. |
| Label outer_push_loop, inner_push_loop, |
| outer_loop_header, inner_loop_header; |
| // Outer loop state: eax = current FrameDescription**, edx = one past the |
| // last FrameDescription**. |
| __ mov(edx, Operand(eax, Deoptimizer::output_count_offset())); |
| __ mov(eax, Operand(eax, Deoptimizer::output_offset())); |
| __ lea(edx, Operand(eax, edx, times_4, 0)); |
| __ jmp(&outer_loop_header); |
| __ bind(&outer_push_loop); |
| // Inner loop state: ebx = current FrameDescription*, ecx = loop index. |
| __ mov(ebx, Operand(eax, 0)); |
| __ mov(ecx, Operand(ebx, FrameDescription::frame_size_offset())); |
| __ jmp(&inner_loop_header); |
| __ bind(&inner_push_loop); |
| __ sub(ecx, Immediate(sizeof(uint32_t))); |
| __ push(Operand(ebx, ecx, times_1, FrameDescription::frame_content_offset())); |
| __ bind(&inner_loop_header); |
| __ test(ecx, ecx); |
| __ j(not_zero, &inner_push_loop); |
| __ add(eax, Immediate(kPointerSize)); |
| __ bind(&outer_loop_header); |
| __ cmp(eax, edx); |
| __ j(below, &outer_push_loop); |
| |
| // In case of a failed STUB, we have to restore the XMM registers. |
| for (int i = 0; i < XMMRegister::kMaxNumAllocatableRegisters; ++i) { |
| XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i); |
| int src_offset = i * kDoubleSize + double_regs_offset; |
| __ movsd(xmm_reg, Operand(ebx, src_offset)); |
| } |
| |
| // Push state, pc, and continuation from the last output frame. |
| __ push(Operand(ebx, FrameDescription::state_offset())); |
| __ push(Operand(ebx, FrameDescription::pc_offset())); |
| __ push(Operand(ebx, FrameDescription::continuation_offset())); |
| |
| |
| // Push the registers from the last output frame. |
| for (int i = 0; i < kNumberOfRegisters; i++) { |
| int offset = (i * kPointerSize) + FrameDescription::registers_offset(); |
| __ push(Operand(ebx, offset)); |
| } |
| |
| // Restore the registers from the stack. |
| __ popad(); |
| |
| // Return to the continuation point. |
| __ ret(0); |
| } |
| |
| |
| void Deoptimizer::TableEntryGenerator::GeneratePrologue() { |
| // Create a sequence of deoptimization entries. |
| Label done; |
| for (int i = 0; i < count(); i++) { |
| int start = masm()->pc_offset(); |
| USE(start); |
| __ push_imm32(i); |
| __ jmp(&done); |
| DCHECK(masm()->pc_offset() - start == table_entry_size_); |
| } |
| __ bind(&done); |
| } |
| |
| |
| void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) { |
| SetFrameSlot(offset, value); |
| } |
| |
| |
| void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) { |
| SetFrameSlot(offset, value); |
| } |
| |
| |
| void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) { |
| // No out-of-line constant pool support. |
| UNREACHABLE(); |
| } |
| |
| |
| #undef __ |
| |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_TARGET_ARCH_IA32 |