// 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_X64 #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::kCallSequenceLength; } void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) { // Invalidate the relocation information, as it will become invalid by the // code patching below, and is not needed any more. code->InvalidateRelocation(); 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(); } } // For each LLazyBailout instruction insert a absolute call to the // corresponding deoptimization entry, or a short call to an absolute // jump if space is short. The absolute jumps are put in a table just // before the safepoint table (space was allocated there when the Code // object was created, if necessary). Address instruction_start = code->instruction_start(); #ifdef DEBUG Address prev_call_address = NULL; #endif DeoptimizationInputData* deopt_data = DeoptimizationInputData::cast(code->deoptimization_data()); SharedFunctionInfo* shared = SharedFunctionInfo::cast(deopt_data->SharedFunctionInfo()); shared->EvictFromOptimizedCodeMap(code, "deoptimized code"); deopt_data->SetSharedFunctionInfo(Smi::FromInt(0)); // 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; // Position where Call will be patched in. Address call_address = instruction_start + deopt_data->Pc(i)->value(); // There is room enough to write a long call instruction because we pad // LLazyBailout instructions with nops if necessary. CodePatcher patcher(call_address, Assembler::kCallSequenceLength); patcher.masm()->Call(GetDeoptimizationEntry(isolate, i, LAZY), Assembler::RelocInfoNone()); ASSERT(prev_call_address == NULL || call_address >= prev_call_address + patch_size()); ASSERT(call_address + patch_size() <= code->instruction_end()); #ifdef DEBUG prev_call_address = call_address; #endif } } 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 rbp and rsp are set to the correct values though. for (int i = 0; i < Register::kNumRegisters; i++) { input_->SetRegister(i, i * 4); } input_->SetRegister(rsp.code(), reinterpret_cast<intptr_t>(frame->sp())); input_->SetRegister(rbp.code(), reinterpret_cast<intptr_t>(frame->fp())); for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); 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::uintptr_at(tos + i)); } } void Deoptimizer::SetPlatformCompiledStubRegisters( FrameDescription* output_frame, CodeStubInterfaceDescriptor* descriptor) { intptr_t handler = reinterpret_cast<intptr_t>(descriptor->deoptimization_handler()); int params = descriptor->GetHandlerParameterCount(); output_frame->SetRegister(rax.code(), params); output_frame->SetRegister(rbx.code(), handler); } void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) { for (int i = 0; i < XMMRegister::NumAllocatableRegisters(); ++i) { double double_value = input_->GetDoubleRegister(i); output_frame->SetDoubleRegister(i, double_value); } } bool Deoptimizer::HasAlignmentPadding(JSFunction* function) { // There is no dynamic alignment padding on x64 in the input frame. return false; } #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::NumAllocatableRegisters(); __ subp(rsp, Immediate(kDoubleRegsSize)); for (int i = 0; i < XMMRegister::NumAllocatableRegisters(); ++i) { XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i); int offset = i * kDoubleSize; __ movsd(Operand(rsp, offset), xmm_reg); } // We push all registers onto the stack, even though we do not need // to restore all later. for (int i = 0; i < kNumberOfRegisters; i++) { Register r = Register::from_code(i); __ pushq(r); } const int kSavedRegistersAreaSize = kNumberOfRegisters * kRegisterSize + kDoubleRegsSize; // We use this to keep the value of the fifth argument temporarily. // Unfortunately we can't store it directly in r8 (used for passing // this on linux), since it is another parameter passing register on windows. Register arg5 = r11; // Get the bailout id from the stack. __ movp(arg_reg_3, Operand(rsp, kSavedRegistersAreaSize)); // Get the address of the location in the code object // and compute the fp-to-sp delta in register arg5. __ movp(arg_reg_4, Operand(rsp, kSavedRegistersAreaSize + 1 * kRegisterSize)); __ leap(arg5, Operand(rsp, kSavedRegistersAreaSize + 1 * kRegisterSize + kPCOnStackSize)); __ subp(arg5, rbp); __ negp(arg5); // Allocate a new deoptimizer object. __ PrepareCallCFunction(6); __ movp(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset)); __ movp(arg_reg_1, rax); __ Set(arg_reg_2, type()); // Args 3 and 4 are already in the right registers. // On windows put the arguments on the stack (PrepareCallCFunction // has created space for this). On linux pass the arguments in r8 and r9. #ifdef _WIN64 __ movq(Operand(rsp, 4 * kRegisterSize), arg5); __ LoadAddress(arg5, ExternalReference::isolate_address(isolate())); __ movq(Operand(rsp, 5 * kRegisterSize), arg5); #else __ movp(r8, arg5); __ LoadAddress(r9, ExternalReference::isolate_address(isolate())); #endif { AllowExternalCallThatCantCauseGC scope(masm()); __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6); } // Preserve deoptimizer object in register rax and get the input // frame descriptor pointer. __ movp(rbx, Operand(rax, Deoptimizer::input_offset())); // Fill in the input registers. for (int i = kNumberOfRegisters -1; i >= 0; i--) { int offset = (i * kPointerSize) + FrameDescription::registers_offset(); __ PopQuad(Operand(rbx, offset)); } // Fill in the double input registers. int double_regs_offset = FrameDescription::double_registers_offset(); for (int i = 0; i < XMMRegister::NumAllocatableRegisters(); i++) { int dst_offset = i * kDoubleSize + double_regs_offset; __ popq(Operand(rbx, dst_offset)); } // Remove the bailout id and return address from the stack. __ addp(rsp, Immediate(1 * kRegisterSize + kPCOnStackSize)); // Compute a pointer to the unwinding limit in register rcx; that is // the first stack slot not part of the input frame. __ movp(rcx, Operand(rbx, FrameDescription::frame_size_offset())); __ addp(rcx, rsp); // Unwind the stack down to - but not including - the unwinding // limit and copy the contents of the activation frame to the input // frame description. __ leap(rdx, Operand(rbx, FrameDescription::frame_content_offset())); Label pop_loop_header; __ jmp(&pop_loop_header); Label pop_loop; __ bind(&pop_loop); __ Pop(Operand(rdx, 0)); __ addp(rdx, Immediate(sizeof(intptr_t))); __ bind(&pop_loop_header); __ cmpp(rcx, rsp); __ j(not_equal, &pop_loop); // Compute the output frame in the deoptimizer. __ pushq(rax); __ PrepareCallCFunction(2); __ movp(arg_reg_1, rax); __ LoadAddress(arg_reg_2, ExternalReference::isolate_address(isolate())); { AllowExternalCallThatCantCauseGC scope(masm()); __ CallCFunction( ExternalReference::compute_output_frames_function(isolate()), 2); } __ popq(rax); // Replace the current frame with the output frames. Label outer_push_loop, inner_push_loop, outer_loop_header, inner_loop_header; // Outer loop state: rax = current FrameDescription**, rdx = one past the // last FrameDescription**. __ movl(rdx, Operand(rax, Deoptimizer::output_count_offset())); __ movp(rax, Operand(rax, Deoptimizer::output_offset())); __ leap(rdx, Operand(rax, rdx, times_pointer_size, 0)); __ jmp(&outer_loop_header); __ bind(&outer_push_loop); // Inner loop state: rbx = current FrameDescription*, rcx = loop index. __ movp(rbx, Operand(rax, 0)); __ movp(rcx, Operand(rbx, FrameDescription::frame_size_offset())); __ jmp(&inner_loop_header); __ bind(&inner_push_loop); __ subp(rcx, Immediate(sizeof(intptr_t))); __ Push(Operand(rbx, rcx, times_1, FrameDescription::frame_content_offset())); __ bind(&inner_loop_header); __ testp(rcx, rcx); __ j(not_zero, &inner_push_loop); __ addp(rax, Immediate(kPointerSize)); __ bind(&outer_loop_header); __ cmpp(rax, rdx); __ j(below, &outer_push_loop); for (int i = 0; i < XMMRegister::NumAllocatableRegisters(); ++i) { XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i); int src_offset = i * kDoubleSize + double_regs_offset; __ movsd(xmm_reg, Operand(rbx, src_offset)); } // Push state, pc, and continuation from the last output frame. __ Push(Operand(rbx, FrameDescription::state_offset())); __ PushQuad(Operand(rbx, FrameDescription::pc_offset())); __ PushQuad(Operand(rbx, 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(); __ PushQuad(Operand(rbx, offset)); } // Restore the registers from the stack. for (int i = kNumberOfRegisters - 1; i >= 0 ; i--) { Register r = Register::from_code(i); // Do not restore rsp, simply pop the value into the next register // and overwrite this afterwards. if (r.is(rsp)) { ASSERT(i > 0); r = Register::from_code(i - 1); } __ popq(r); } // Set up the roots register. __ InitializeRootRegister(); __ InitializeSmiConstantRegister(); // 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); __ pushq_imm32(i); __ jmp(&done); ASSERT(masm()->pc_offset() - start == table_entry_size_); } __ bind(&done); } void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) { if (kPCOnStackSize == 2 * kPointerSize) { // Zero out the high-32 bit of PC for x32 port. SetFrameSlot(offset + kPointerSize, 0); } SetFrameSlot(offset, value); } void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) { if (kFPOnStackSize == 2 * kPointerSize) { // Zero out the high-32 bit of FP for x32 port. SetFrameSlot(offset + kPointerSize, 0); } 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_X64