| // Copyright 2011 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" |
| |
| #include "src/codegen.h" |
| #include "src/deoptimizer.h" |
| #include "src/full-codegen.h" |
| #include "src/safepoint-table.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| int Deoptimizer::patch_size() { |
| const int kCallInstructionSizeInWords = 6; |
| return kCallInstructionSizeInWords * Assembler::kInstrSize; |
| } |
| |
| |
| void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) { |
| Address code_start_address = code->instruction_start(); |
| // 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()->break_(0xCC); |
| |
| 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()->break_(0xCC); |
| } |
| } |
| |
| 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; |
| Address call_address = code_start_address + deopt_data->Pc(i)->value(); |
| Address deopt_entry = GetDeoptimizationEntry(isolate, i, LAZY); |
| int call_size_in_bytes = MacroAssembler::CallSize(deopt_entry, |
| RelocInfo::NONE32); |
| int call_size_in_words = call_size_in_bytes / Assembler::kInstrSize; |
| DCHECK(call_size_in_bytes % Assembler::kInstrSize == 0); |
| DCHECK(call_size_in_bytes <= patch_size()); |
| CodePatcher patcher(call_address, call_size_in_words); |
| patcher.masm()->Call(deopt_entry, RelocInfo::NONE32); |
| 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 |
| } |
| } |
| |
| |
| 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 fp and sp are set to the correct values though. |
| |
| for (int i = 0; i < Register::kNumRegisters; i++) { |
| input_->SetRegister(i, i * 4); |
| } |
| input_->SetRegister(sp.code(), reinterpret_cast<intptr_t>(frame->sp())); |
| input_->SetRegister(fp.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::uint64_at(tos + i)); |
| } |
| } |
| |
| |
| void Deoptimizer::SetPlatformCompiledStubRegisters( |
| FrameDescription* output_frame, CodeStubDescriptor* descriptor) { |
| ApiFunction function(descriptor->deoptimization_handler()); |
| ExternalReference xref(&function, ExternalReference::BUILTIN_CALL, isolate_); |
| intptr_t handler = reinterpret_cast<intptr_t>(xref.address()); |
| int params = descriptor->GetHandlerParameterCount(); |
| output_frame->SetRegister(s0.code(), params); |
| output_frame->SetRegister(s1.code(), (params - 1) * kPointerSize); |
| output_frame->SetRegister(s2.code(), handler); |
| } |
| |
| |
| void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) { |
| for (int i = 0; i < DoubleRegister::kMaxNumRegisters; ++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 MIPS in the input frame. |
| return false; |
| } |
| |
| |
| #define __ masm()-> |
| |
| |
| // This code tries to be close to ia32 code so that any changes can be |
| // easily ported. |
| void Deoptimizer::EntryGenerator::Generate() { |
| GeneratePrologue(); |
| |
| // Unlike on ARM we don't save all the registers, just the useful ones. |
| // For the rest, there are gaps on the stack, so the offsets remain the same. |
| const int kNumberOfRegisters = Register::kNumRegisters; |
| |
| RegList restored_regs = kJSCallerSaved | kCalleeSaved; |
| RegList saved_regs = restored_regs | sp.bit() | ra.bit(); |
| |
| const int kDoubleRegsSize = |
| kDoubleSize * FPURegister::kMaxNumAllocatableRegisters; |
| |
| // Save all FPU registers before messing with them. |
| __ Dsubu(sp, sp, Operand(kDoubleRegsSize)); |
| for (int i = 0; i < FPURegister::kMaxNumAllocatableRegisters; ++i) { |
| FPURegister fpu_reg = FPURegister::FromAllocationIndex(i); |
| int offset = i * kDoubleSize; |
| __ sdc1(fpu_reg, MemOperand(sp, offset)); |
| } |
| |
| // Push saved_regs (needed to populate FrameDescription::registers_). |
| // Leave gaps for other registers. |
| __ Dsubu(sp, sp, kNumberOfRegisters * kPointerSize); |
| for (int16_t i = kNumberOfRegisters - 1; i >= 0; i--) { |
| if ((saved_regs & (1 << i)) != 0) { |
| __ sd(ToRegister(i), MemOperand(sp, kPointerSize * i)); |
| } |
| } |
| |
| const int kSavedRegistersAreaSize = |
| (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize; |
| |
| // Get the bailout id from the stack. |
| __ ld(a2, MemOperand(sp, kSavedRegistersAreaSize)); |
| |
| // Get the address of the location in the code object (a3) (return |
| // address for lazy deoptimization) and compute the fp-to-sp delta in |
| // register a4. |
| __ mov(a3, ra); |
| // Correct one word for bailout id. |
| __ Daddu(a4, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize))); |
| |
| __ Dsubu(a4, fp, a4); |
| |
| // Allocate a new deoptimizer object. |
| __ PrepareCallCFunction(6, a5); |
| // Pass six arguments, according to O32 or n64 ABI. a0..a3 are same for both. |
| __ li(a1, Operand(type())); // bailout type, |
| __ ld(a0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset)); |
| // a2: bailout id already loaded. |
| // a3: code address or 0 already loaded. |
| if (kMipsAbi == kN64) { |
| // a4: already has fp-to-sp delta. |
| __ li(a5, Operand(ExternalReference::isolate_address(isolate()))); |
| } else { // O32 abi. |
| // Pass four arguments in a0 to a3 and fifth & sixth arguments on stack. |
| __ sd(a4, CFunctionArgumentOperand(5)); // Fp-to-sp delta. |
| __ li(a5, Operand(ExternalReference::isolate_address(isolate()))); |
| __ sd(a5, CFunctionArgumentOperand(6)); // Isolate. |
| } |
| // Call Deoptimizer::New(). |
| { |
| AllowExternalCallThatCantCauseGC scope(masm()); |
| __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6); |
| } |
| |
| // Preserve "deoptimizer" object in register v0 and get the input |
| // frame descriptor pointer to a1 (deoptimizer->input_); |
| // Move deopt-obj to a0 for call to Deoptimizer::ComputeOutputFrames() below. |
| __ mov(a0, v0); |
| __ ld(a1, MemOperand(v0, Deoptimizer::input_offset())); |
| |
| // Copy core registers into FrameDescription::registers_[kNumRegisters]. |
| DCHECK(Register::kNumRegisters == kNumberOfRegisters); |
| for (int i = 0; i < kNumberOfRegisters; i++) { |
| int offset = (i * kPointerSize) + FrameDescription::registers_offset(); |
| if ((saved_regs & (1 << i)) != 0) { |
| __ ld(a2, MemOperand(sp, i * kPointerSize)); |
| __ sd(a2, MemOperand(a1, offset)); |
| } else if (FLAG_debug_code) { |
| __ li(a2, kDebugZapValue); |
| __ sd(a2, MemOperand(a1, offset)); |
| } |
| } |
| |
| int double_regs_offset = FrameDescription::double_registers_offset(); |
| // Copy FPU registers to |
| // double_registers_[DoubleRegister::kNumAllocatableRegisters] |
| for (int i = 0; i < FPURegister::NumAllocatableRegisters(); ++i) { |
| int dst_offset = i * kDoubleSize + double_regs_offset; |
| int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize; |
| __ ldc1(f0, MemOperand(sp, src_offset)); |
| __ sdc1(f0, MemOperand(a1, dst_offset)); |
| } |
| |
| // Remove the bailout id and the saved registers from the stack. |
| __ Daddu(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize))); |
| |
| // Compute a pointer to the unwinding limit in register a2; that is |
| // the first stack slot not part of the input frame. |
| __ ld(a2, MemOperand(a1, FrameDescription::frame_size_offset())); |
| __ Daddu(a2, a2, sp); |
| |
| // Unwind the stack down to - but not including - the unwinding |
| // limit and copy the contents of the activation frame to the input |
| // frame description. |
| __ Daddu(a3, a1, Operand(FrameDescription::frame_content_offset())); |
| Label pop_loop; |
| Label pop_loop_header; |
| __ BranchShort(&pop_loop_header); |
| __ bind(&pop_loop); |
| __ pop(a4); |
| __ sd(a4, MemOperand(a3, 0)); |
| __ daddiu(a3, a3, sizeof(uint64_t)); |
| __ bind(&pop_loop_header); |
| __ BranchShort(&pop_loop, ne, a2, Operand(sp)); |
| // Compute the output frame in the deoptimizer. |
| __ push(a0); // Preserve deoptimizer object across call. |
| // a0: deoptimizer object; a1: scratch. |
| __ PrepareCallCFunction(1, a1); |
| // Call Deoptimizer::ComputeOutputFrames(). |
| { |
| AllowExternalCallThatCantCauseGC scope(masm()); |
| __ CallCFunction( |
| ExternalReference::compute_output_frames_function(isolate()), 1); |
| } |
| __ pop(a0); // Restore deoptimizer object (class Deoptimizer). |
| |
| // Replace the current (input) frame with the output frames. |
| Label outer_push_loop, inner_push_loop, |
| outer_loop_header, inner_loop_header; |
| // Outer loop state: a4 = current "FrameDescription** output_", |
| // a1 = one past the last FrameDescription**. |
| __ lw(a1, MemOperand(a0, Deoptimizer::output_count_offset())); |
| __ ld(a4, MemOperand(a0, Deoptimizer::output_offset())); // a4 is output_. |
| __ dsll(a1, a1, kPointerSizeLog2); // Count to offset. |
| __ daddu(a1, a4, a1); // a1 = one past the last FrameDescription**. |
| __ jmp(&outer_loop_header); |
| __ bind(&outer_push_loop); |
| // Inner loop state: a2 = current FrameDescription*, a3 = loop index. |
| __ ld(a2, MemOperand(a4, 0)); // output_[ix] |
| __ ld(a3, MemOperand(a2, FrameDescription::frame_size_offset())); |
| __ jmp(&inner_loop_header); |
| __ bind(&inner_push_loop); |
| __ Dsubu(a3, a3, Operand(sizeof(uint64_t))); |
| __ Daddu(a6, a2, Operand(a3)); |
| __ ld(a7, MemOperand(a6, FrameDescription::frame_content_offset())); |
| __ push(a7); |
| __ bind(&inner_loop_header); |
| __ BranchShort(&inner_push_loop, ne, a3, Operand(zero_reg)); |
| |
| __ Daddu(a4, a4, Operand(kPointerSize)); |
| __ bind(&outer_loop_header); |
| __ BranchShort(&outer_push_loop, lt, a4, Operand(a1)); |
| |
| __ ld(a1, MemOperand(a0, Deoptimizer::input_offset())); |
| for (int i = 0; i < FPURegister::kMaxNumAllocatableRegisters; ++i) { |
| const FPURegister fpu_reg = FPURegister::FromAllocationIndex(i); |
| int src_offset = i * kDoubleSize + double_regs_offset; |
| __ ldc1(fpu_reg, MemOperand(a1, src_offset)); |
| } |
| |
| // Push state, pc, and continuation from the last output frame. |
| __ ld(a6, MemOperand(a2, FrameDescription::state_offset())); |
| __ push(a6); |
| |
| __ ld(a6, MemOperand(a2, FrameDescription::pc_offset())); |
| __ push(a6); |
| __ ld(a6, MemOperand(a2, FrameDescription::continuation_offset())); |
| __ push(a6); |
| |
| |
| // Technically restoring 'at' should work unless zero_reg is also restored |
| // but it's safer to check for this. |
| DCHECK(!(at.bit() & restored_regs)); |
| // Restore the registers from the last output frame. |
| __ mov(at, a2); |
| for (int i = kNumberOfRegisters - 1; i >= 0; i--) { |
| int offset = (i * kPointerSize) + FrameDescription::registers_offset(); |
| if ((restored_regs & (1 << i)) != 0) { |
| __ ld(ToRegister(i), MemOperand(at, offset)); |
| } |
| } |
| |
| __ InitializeRootRegister(); |
| |
| __ pop(at); // Get continuation, leave pc on stack. |
| __ pop(ra); |
| __ Jump(at); |
| __ stop("Unreachable."); |
| } |
| |
| |
| // Maximum size of a table entry generated below. |
| const int Deoptimizer::table_entry_size_ = 11 * Assembler::kInstrSize; |
| |
| void Deoptimizer::TableEntryGenerator::GeneratePrologue() { |
| Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm()); |
| |
| // Create a sequence of deoptimization entries. |
| // Note that registers are still live when jumping to an entry. |
| Label table_start; |
| __ bind(&table_start); |
| for (int i = 0; i < count(); i++) { |
| Label start; |
| __ bind(&start); |
| __ daddiu(sp, sp, -1 * kPointerSize); |
| // Jump over the remaining deopt entries (including this one). |
| // This code is always reached by calling Jump, which puts the target (label |
| // start) into t9. |
| const int remaining_entries = (count() - i) * table_entry_size_; |
| __ Daddu(t9, t9, remaining_entries); |
| // 'at' was clobbered so we can only load the current entry value here. |
| __ li(t8, i); |
| __ jr(t9); // Expose delay slot. |
| __ sd(t8, MemOperand(sp, 0 * kPointerSize)); // In the delay slot. |
| |
| // Pad the rest of the code. |
| while (table_entry_size_ > (masm()->SizeOfCodeGeneratedSince(&start))) { |
| __ nop(); |
| } |
| |
| DCHECK_EQ(table_entry_size_, masm()->SizeOfCodeGeneratedSince(&start)); |
| } |
| |
| DCHECK_EQ(masm()->SizeOfCodeGeneratedSince(&table_start), |
| count() * table_entry_size_); |
| } |
| |
| |
| 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 |