1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
9 #include "src/codegen.h"
10 #include "src/deoptimizer.h"
11 #include "src/full-codegen.h"
12 #include "src/safepoint-table.h"
18 const int Deoptimizer::table_entry_size_ = 10;
21 int Deoptimizer::patch_size() {
22 return Assembler::kCallSequenceLength;
26 void Deoptimizer::EnsureRelocSpaceForLazyDeoptimization(Handle<Code> code) {
27 // Empty because there is no need for relocation information for the code
28 // patching in Deoptimizer::PatchCodeForDeoptimization below.
32 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
33 // Invalidate the relocation information, as it will become invalid by the
34 // code patching below, and is not needed any more.
35 code->InvalidateRelocation();
37 if (FLAG_zap_code_space) {
38 // Fail hard and early if we enter this code object again.
39 byte* pointer = code->FindCodeAgeSequence();
40 if (pointer != NULL) {
41 pointer += kNoCodeAgeSequenceLength;
43 pointer = code->instruction_start();
45 CodePatcher patcher(pointer, 1);
46 patcher.masm()->int3();
48 DeoptimizationInputData* data =
49 DeoptimizationInputData::cast(code->deoptimization_data());
50 int osr_offset = data->OsrPcOffset()->value();
52 CodePatcher osr_patcher(code->instruction_start() + osr_offset, 1);
53 osr_patcher.masm()->int3();
57 // For each LLazyBailout instruction insert a absolute call to the
58 // corresponding deoptimization entry, or a short call to an absolute
59 // jump if space is short. The absolute jumps are put in a table just
60 // before the safepoint table (space was allocated there when the Code
61 // object was created, if necessary).
63 Address instruction_start = code->instruction_start();
65 Address prev_call_address = NULL;
67 DeoptimizationInputData* deopt_data =
68 DeoptimizationInputData::cast(code->deoptimization_data());
69 deopt_data->SetSharedFunctionInfo(Smi::FromInt(0));
70 // For each LLazyBailout instruction insert a call to the corresponding
71 // deoptimization entry.
72 for (int i = 0; i < deopt_data->DeoptCount(); i++) {
73 if (deopt_data->Pc(i)->value() == -1) continue;
74 // Position where Call will be patched in.
75 Address call_address = instruction_start + deopt_data->Pc(i)->value();
76 // There is room enough to write a long call instruction because we pad
77 // LLazyBailout instructions with nops if necessary.
78 CodePatcher patcher(call_address, Assembler::kCallSequenceLength);
79 patcher.masm()->Call(GetDeoptimizationEntry(isolate, i, LAZY),
80 Assembler::RelocInfoNone());
81 DCHECK(prev_call_address == NULL ||
82 call_address >= prev_call_address + patch_size());
83 DCHECK(call_address + patch_size() <= code->instruction_end());
85 prev_call_address = call_address;
91 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
92 // Set the register values. The values are not important as there are no
93 // callee saved registers in JavaScript frames, so all registers are
94 // spilled. Registers rbp and rsp are set to the correct values though.
95 for (int i = 0; i < Register::kNumRegisters; i++) {
96 input_->SetRegister(i, i * 4);
98 input_->SetRegister(rsp.code(), reinterpret_cast<intptr_t>(frame->sp()));
99 input_->SetRegister(rbp.code(), reinterpret_cast<intptr_t>(frame->fp()));
100 for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); i++) {
101 input_->SetDoubleRegister(i, 0.0);
104 // Fill the frame content from the actual data on the frame.
105 for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
106 input_->SetFrameSlot(i, Memory::uintptr_at(tos + i));
111 void Deoptimizer::SetPlatformCompiledStubRegisters(
112 FrameDescription* output_frame, CodeStubDescriptor* descriptor) {
114 reinterpret_cast<intptr_t>(descriptor->deoptimization_handler());
115 int params = descriptor->GetHandlerParameterCount();
116 output_frame->SetRegister(rax.code(), params);
117 output_frame->SetRegister(rbx.code(), handler);
121 void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
122 for (int i = 0; i < XMMRegister::NumAllocatableRegisters(); ++i) {
123 double double_value = input_->GetDoubleRegister(i);
124 output_frame->SetDoubleRegister(i, double_value);
129 bool Deoptimizer::HasAlignmentPadding(JSFunction* function) {
130 // There is no dynamic alignment padding on x64 in the input frame.
137 void Deoptimizer::EntryGenerator::Generate() {
140 // Save all general purpose registers before messing with them.
141 const int kNumberOfRegisters = Register::kNumRegisters;
143 const int kDoubleRegsSize = kDoubleSize *
144 XMMRegister::NumAllocatableRegisters();
145 __ subp(rsp, Immediate(kDoubleRegsSize));
147 for (int i = 0; i < XMMRegister::NumAllocatableRegisters(); ++i) {
148 XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i);
149 int offset = i * kDoubleSize;
150 __ movsd(Operand(rsp, offset), xmm_reg);
153 // We push all registers onto the stack, even though we do not need
154 // to restore all later.
155 for (int i = 0; i < kNumberOfRegisters; i++) {
156 Register r = Register::from_code(i);
160 const int kSavedRegistersAreaSize = kNumberOfRegisters * kRegisterSize +
163 __ Store(ExternalReference(Isolate::kCEntryFPAddress, isolate()), rbp);
165 // We use this to keep the value of the fifth argument temporarily.
166 // Unfortunately we can't store it directly in r8 (used for passing
167 // this on linux), since it is another parameter passing register on windows.
170 // Get the bailout id from the stack.
171 __ movp(arg_reg_3, Operand(rsp, kSavedRegistersAreaSize));
173 // Get the address of the location in the code object
174 // and compute the fp-to-sp delta in register arg5.
175 __ movp(arg_reg_4, Operand(rsp, kSavedRegistersAreaSize + 1 * kRegisterSize));
176 __ leap(arg5, Operand(rsp, kSavedRegistersAreaSize + 1 * kRegisterSize +
182 // Allocate a new deoptimizer object.
183 __ PrepareCallCFunction(6);
184 __ movp(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
185 __ movp(arg_reg_1, rax);
186 __ Set(arg_reg_2, type());
187 // Args 3 and 4 are already in the right registers.
189 // On windows put the arguments on the stack (PrepareCallCFunction
190 // has created space for this). On linux pass the arguments in r8 and r9.
192 __ movq(Operand(rsp, 4 * kRegisterSize), arg5);
193 __ LoadAddress(arg5, ExternalReference::isolate_address(isolate()));
194 __ movq(Operand(rsp, 5 * kRegisterSize), arg5);
197 __ LoadAddress(r9, ExternalReference::isolate_address(isolate()));
200 { AllowExternalCallThatCantCauseGC scope(masm());
201 __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6);
203 // Preserve deoptimizer object in register rax and get the input
204 // frame descriptor pointer.
205 __ movp(rbx, Operand(rax, Deoptimizer::input_offset()));
207 // Fill in the input registers.
208 for (int i = kNumberOfRegisters -1; i >= 0; i--) {
209 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
210 __ PopQuad(Operand(rbx, offset));
213 // Fill in the double input registers.
214 int double_regs_offset = FrameDescription::double_registers_offset();
215 for (int i = 0; i < XMMRegister::NumAllocatableRegisters(); i++) {
216 int dst_offset = i * kDoubleSize + double_regs_offset;
217 __ popq(Operand(rbx, dst_offset));
220 // Remove the bailout id and return address from the stack.
221 __ addp(rsp, Immediate(1 * kRegisterSize + kPCOnStackSize));
223 // Compute a pointer to the unwinding limit in register rcx; that is
224 // the first stack slot not part of the input frame.
225 __ movp(rcx, Operand(rbx, FrameDescription::frame_size_offset()));
228 // Unwind the stack down to - but not including - the unwinding
229 // limit and copy the contents of the activation frame to the input
230 // frame description.
231 __ leap(rdx, Operand(rbx, FrameDescription::frame_content_offset()));
232 Label pop_loop_header;
233 __ jmp(&pop_loop_header);
236 __ Pop(Operand(rdx, 0));
237 __ addp(rdx, Immediate(sizeof(intptr_t)));
238 __ bind(&pop_loop_header);
240 __ j(not_equal, &pop_loop);
242 // Compute the output frame in the deoptimizer.
244 __ PrepareCallCFunction(2);
245 __ movp(arg_reg_1, rax);
246 __ LoadAddress(arg_reg_2, ExternalReference::isolate_address(isolate()));
248 AllowExternalCallThatCantCauseGC scope(masm());
250 ExternalReference::compute_output_frames_function(isolate()), 2);
254 // Replace the current frame with the output frames.
255 Label outer_push_loop, inner_push_loop,
256 outer_loop_header, inner_loop_header;
257 // Outer loop state: rax = current FrameDescription**, rdx = one past the
258 // last FrameDescription**.
259 __ movl(rdx, Operand(rax, Deoptimizer::output_count_offset()));
260 __ movp(rax, Operand(rax, Deoptimizer::output_offset()));
261 __ leap(rdx, Operand(rax, rdx, times_pointer_size, 0));
262 __ jmp(&outer_loop_header);
263 __ bind(&outer_push_loop);
264 // Inner loop state: rbx = current FrameDescription*, rcx = loop index.
265 __ movp(rbx, Operand(rax, 0));
266 __ movp(rcx, Operand(rbx, FrameDescription::frame_size_offset()));
267 __ jmp(&inner_loop_header);
268 __ bind(&inner_push_loop);
269 __ subp(rcx, Immediate(sizeof(intptr_t)));
270 __ Push(Operand(rbx, rcx, times_1, FrameDescription::frame_content_offset()));
271 __ bind(&inner_loop_header);
273 __ j(not_zero, &inner_push_loop);
274 __ addp(rax, Immediate(kPointerSize));
275 __ bind(&outer_loop_header);
277 __ j(below, &outer_push_loop);
279 for (int i = 0; i < XMMRegister::NumAllocatableRegisters(); ++i) {
280 XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i);
281 int src_offset = i * kDoubleSize + double_regs_offset;
282 __ movsd(xmm_reg, Operand(rbx, src_offset));
285 // Push state, pc, and continuation from the last output frame.
286 __ Push(Operand(rbx, FrameDescription::state_offset()));
287 __ PushQuad(Operand(rbx, FrameDescription::pc_offset()));
288 __ PushQuad(Operand(rbx, FrameDescription::continuation_offset()));
290 // Push the registers from the last output frame.
291 for (int i = 0; i < kNumberOfRegisters; i++) {
292 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
293 __ PushQuad(Operand(rbx, offset));
296 // Restore the registers from the stack.
297 for (int i = kNumberOfRegisters - 1; i >= 0 ; i--) {
298 Register r = Register::from_code(i);
299 // Do not restore rsp, simply pop the value into the next register
300 // and overwrite this afterwards.
303 r = Register::from_code(i - 1);
308 // Set up the roots register.
309 __ InitializeRootRegister();
310 __ InitializeSmiConstantRegister();
312 // Return to the continuation point.
317 void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
318 // Create a sequence of deoptimization entries.
320 for (int i = 0; i < count(); i++) {
321 int start = masm()->pc_offset();
325 DCHECK(masm()->pc_offset() - start == table_entry_size_);
331 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
332 if (kPCOnStackSize == 2 * kPointerSize) {
333 // Zero out the high-32 bit of PC for x32 port.
334 SetFrameSlot(offset + kPointerSize, 0);
336 SetFrameSlot(offset, value);
340 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
341 if (kFPOnStackSize == 2 * kPointerSize) {
342 // Zero out the high-32 bit of FP for x32 port.
343 SetFrameSlot(offset + kPointerSize, 0);
345 SetFrameSlot(offset, value);
349 void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
350 // No out-of-line constant pool support.
358 } } // namespace v8::internal
360 #endif // V8_TARGET_ARCH_X64