| // Copyright 2013 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() { |
| // Size of the code used to patch lazy bailout points. |
| // Patching is done by Deoptimizer::DeoptimizeFunction. |
| return 4 * kInstructionSize; |
| } |
| |
| |
| void Deoptimizer::EnsureRelocSpaceForLazyDeoptimization(Handle<Code> code) { |
| // Empty because there is no need for relocation information for the code |
| // patching in Deoptimizer::PatchCodeForDeoptimization below. |
| } |
| |
| |
| 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(); |
| |
| // TODO(jkummerow): if (FLAG_zap_code_space), make the code object's |
| // entry sequence unusable (see other architectures). |
| |
| DeoptimizationInputData* deopt_data = |
| DeoptimizationInputData::cast(code->deoptimization_data()); |
| Address code_start_address = code->instruction_start(); |
| #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); |
| |
| PatchingAssembler patcher(call_address, patch_size() / kInstructionSize); |
| patcher.ldr_pcrel(ip0, (2 * kInstructionSize) >> kLoadLiteralScaleLog2); |
| patcher.blr(ip0); |
| patcher.dc64(reinterpret_cast<intptr_t>(deopt_entry)); |
| |
| 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::NumRegisters(); i++) { |
| input_->SetRegister(i, 0); |
| } |
| |
| // TODO(all): Do we also need to set a value to csp? |
| input_->SetRegister(jssp.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)); |
| } |
| } |
| |
| |
| bool Deoptimizer::HasAlignmentPadding(JSFunction* function) { |
| // There is no dynamic alignment padding on ARM64 in the input frame. |
| return false; |
| } |
| |
| |
| 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(x0.code(), params); |
| output_frame->SetRegister(x1.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); |
| } |
| } |
| |
| |
| |
| #define __ masm()-> |
| |
| void Deoptimizer::EntryGenerator::Generate() { |
| GeneratePrologue(); |
| |
| // TODO(all): This code needs to be revisited. We probably only need to save |
| // caller-saved registers here. Callee-saved registers can be stored directly |
| // in the input frame. |
| |
| // Save all allocatable floating point registers. |
| CPURegList saved_fp_registers(CPURegister::kFPRegister, kDRegSizeInBits, |
| FPRegister::kAllocatableFPRegisters); |
| __ PushCPURegList(saved_fp_registers); |
| |
| // We save all the registers expcept jssp, sp and lr. |
| CPURegList saved_registers(CPURegister::kRegister, kXRegSizeInBits, 0, 27); |
| saved_registers.Combine(fp); |
| __ PushCPURegList(saved_registers); |
| |
| const int kSavedRegistersAreaSize = |
| (saved_registers.Count() * kXRegSize) + |
| (saved_fp_registers.Count() * kDRegSize); |
| |
| // Floating point registers are saved on the stack above core registers. |
| const int kFPRegistersOffset = saved_registers.Count() * kXRegSize; |
| |
| // Get the bailout id from the stack. |
| Register bailout_id = x2; |
| __ Peek(bailout_id, kSavedRegistersAreaSize); |
| |
| Register code_object = x3; |
| Register fp_to_sp = x4; |
| // Get the address of the location in the code object. This is the return |
| // address for lazy deoptimization. |
| __ Mov(code_object, lr); |
| // Compute the fp-to-sp delta, and correct one word for bailout id. |
| __ Add(fp_to_sp, masm()->StackPointer(), |
| kSavedRegistersAreaSize + (1 * kPointerSize)); |
| __ Sub(fp_to_sp, fp, fp_to_sp); |
| |
| // Allocate a new deoptimizer object. |
| __ Ldr(x0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset)); |
| __ Mov(x1, type()); |
| // Following arguments are already loaded: |
| // - x2: bailout id |
| // - x3: code object address |
| // - x4: fp-to-sp delta |
| __ Mov(x5, ExternalReference::isolate_address(isolate())); |
| |
| { |
| // Call Deoptimizer::New(). |
| AllowExternalCallThatCantCauseGC scope(masm()); |
| __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6); |
| } |
| |
| // Preserve "deoptimizer" object in register x0. |
| Register deoptimizer = x0; |
| |
| // Get the input frame descriptor pointer. |
| __ Ldr(x1, MemOperand(deoptimizer, Deoptimizer::input_offset())); |
| |
| // Copy core registers into the input frame. |
| CPURegList copy_to_input = saved_registers; |
| for (int i = 0; i < saved_registers.Count(); i++) { |
| __ Peek(x2, i * kPointerSize); |
| CPURegister current_reg = copy_to_input.PopLowestIndex(); |
| int offset = (current_reg.code() * kPointerSize) + |
| FrameDescription::registers_offset(); |
| __ Str(x2, MemOperand(x1, offset)); |
| } |
| |
| // Copy FP registers to the input frame. |
| for (int i = 0; i < saved_fp_registers.Count(); i++) { |
| int dst_offset = FrameDescription::double_registers_offset() + |
| (i * kDoubleSize); |
| int src_offset = kFPRegistersOffset + (i * kDoubleSize); |
| __ Peek(x2, src_offset); |
| __ Str(x2, MemOperand(x1, dst_offset)); |
| } |
| |
| // Remove the bailout id and the saved registers from the stack. |
| __ Drop(1 + (kSavedRegistersAreaSize / kXRegSize)); |
| |
| // Compute a pointer to the unwinding limit in register x2; that is |
| // the first stack slot not part of the input frame. |
| Register unwind_limit = x2; |
| __ Ldr(unwind_limit, MemOperand(x1, FrameDescription::frame_size_offset())); |
| __ Add(unwind_limit, unwind_limit, __ StackPointer()); |
| |
| // Unwind the stack down to - but not including - the unwinding |
| // limit and copy the contents of the activation frame to the input |
| // frame description. |
| __ Add(x3, x1, FrameDescription::frame_content_offset()); |
| Label pop_loop; |
| Label pop_loop_header; |
| __ B(&pop_loop_header); |
| __ Bind(&pop_loop); |
| __ Pop(x4); |
| __ Str(x4, MemOperand(x3, kPointerSize, PostIndex)); |
| __ Bind(&pop_loop_header); |
| __ Cmp(unwind_limit, __ StackPointer()); |
| __ B(ne, &pop_loop); |
| |
| // Compute the output frame in the deoptimizer. |
| __ Push(x0); // Preserve deoptimizer object across call. |
| |
| { |
| // Call Deoptimizer::ComputeOutputFrames(). |
| AllowExternalCallThatCantCauseGC scope(masm()); |
| __ CallCFunction( |
| ExternalReference::compute_output_frames_function(isolate()), 1); |
| } |
| __ Pop(x4); // 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; |
| __ Ldrsw(x1, MemOperand(x4, Deoptimizer::output_count_offset())); |
| __ Ldr(x0, MemOperand(x4, Deoptimizer::output_offset())); |
| __ Add(x1, x0, Operand(x1, LSL, kPointerSizeLog2)); |
| __ B(&outer_loop_header); |
| |
| __ Bind(&outer_push_loop); |
| Register current_frame = x2; |
| __ Ldr(current_frame, MemOperand(x0, 0)); |
| __ Ldr(x3, MemOperand(current_frame, FrameDescription::frame_size_offset())); |
| __ B(&inner_loop_header); |
| |
| __ Bind(&inner_push_loop); |
| __ Sub(x3, x3, kPointerSize); |
| __ Add(x6, current_frame, x3); |
| __ Ldr(x7, MemOperand(x6, FrameDescription::frame_content_offset())); |
| __ Push(x7); |
| __ Bind(&inner_loop_header); |
| __ Cbnz(x3, &inner_push_loop); |
| |
| __ Add(x0, x0, kPointerSize); |
| __ Bind(&outer_loop_header); |
| __ Cmp(x0, x1); |
| __ B(lt, &outer_push_loop); |
| |
| __ Ldr(x1, MemOperand(x4, Deoptimizer::input_offset())); |
| DCHECK(!saved_fp_registers.IncludesAliasOf(crankshaft_fp_scratch) && |
| !saved_fp_registers.IncludesAliasOf(fp_zero) && |
| !saved_fp_registers.IncludesAliasOf(fp_scratch)); |
| int src_offset = FrameDescription::double_registers_offset(); |
| while (!saved_fp_registers.IsEmpty()) { |
| const CPURegister reg = saved_fp_registers.PopLowestIndex(); |
| __ Ldr(reg, MemOperand(x1, src_offset)); |
| src_offset += kDoubleSize; |
| } |
| |
| // Push state from the last output frame. |
| __ Ldr(x6, MemOperand(current_frame, FrameDescription::state_offset())); |
| __ Push(x6); |
| |
| // TODO(all): ARM copies a lot (if not all) of the last output frame onto the |
| // stack, then pops it all into registers. Here, we try to load it directly |
| // into the relevant registers. Is this correct? If so, we should improve the |
| // ARM code. |
| |
| // TODO(all): This code needs to be revisited, We probably don't need to |
| // restore all the registers as fullcodegen does not keep live values in |
| // registers (note that at least fp must be restored though). |
| |
| // Restore registers from the last output frame. |
| // Note that lr is not in the list of saved_registers and will be restored |
| // later. We can use it to hold the address of last output frame while |
| // reloading the other registers. |
| DCHECK(!saved_registers.IncludesAliasOf(lr)); |
| Register last_output_frame = lr; |
| __ Mov(last_output_frame, current_frame); |
| |
| // We don't need to restore x7 as it will be clobbered later to hold the |
| // continuation address. |
| Register continuation = x7; |
| saved_registers.Remove(continuation); |
| |
| while (!saved_registers.IsEmpty()) { |
| // TODO(all): Look for opportunities to optimize this by using ldp. |
| CPURegister current_reg = saved_registers.PopLowestIndex(); |
| int offset = (current_reg.code() * kPointerSize) + |
| FrameDescription::registers_offset(); |
| __ Ldr(current_reg, MemOperand(last_output_frame, offset)); |
| } |
| |
| __ Ldr(continuation, MemOperand(last_output_frame, |
| FrameDescription::continuation_offset())); |
| __ Ldr(lr, MemOperand(last_output_frame, FrameDescription::pc_offset())); |
| __ InitializeRootRegister(); |
| __ Br(continuation); |
| } |
| |
| |
| // Size of an entry of the second level deopt table. |
| // This is the code size generated by GeneratePrologue for one entry. |
| const int Deoptimizer::table_entry_size_ = 2 * kInstructionSize; |
| |
| |
| void Deoptimizer::TableEntryGenerator::GeneratePrologue() { |
| UseScratchRegisterScope temps(masm()); |
| Register entry_id = temps.AcquireX(); |
| |
| // Create a sequence of deoptimization entries. |
| // Note that registers are still live when jumping to an entry. |
| Label done; |
| { |
| InstructionAccurateScope scope(masm()); |
| |
| // The number of entry will never exceed kMaxNumberOfEntries. |
| // As long as kMaxNumberOfEntries is a valid 16 bits immediate you can use |
| // a movz instruction to load the entry id. |
| DCHECK(is_uint16(Deoptimizer::kMaxNumberOfEntries)); |
| |
| for (int i = 0; i < count(); i++) { |
| int start = masm()->pc_offset(); |
| USE(start); |
| __ movz(entry_id, i); |
| __ b(&done); |
| DCHECK(masm()->pc_offset() - start == table_entry_size_); |
| } |
| } |
| __ Bind(&done); |
| __ Push(entry_id); |
| } |
| |
| |
| 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 |