2 // Copyright 2011 the V8 project authors. All rights reserved.
3 // Use of this source code is governed by a BSD-style license that can be
4 // found in the LICENSE file.
8 #include "src/codegen.h"
9 #include "src/deoptimizer.h"
10 #include "src/full-codegen.h"
11 #include "src/safepoint-table.h"
17 int Deoptimizer::patch_size() {
18 const int kCallInstructionSizeInWords = 4;
19 return kCallInstructionSizeInWords * Assembler::kInstrSize;
23 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
24 Address code_start_address = code->instruction_start();
25 // Invalidate the relocation information, as it will become invalid by the
26 // code patching below, and is not needed any more.
27 code->InvalidateRelocation();
29 if (FLAG_zap_code_space) {
30 // Fail hard and early if we enter this code object again.
31 byte* pointer = code->FindCodeAgeSequence();
32 if (pointer != NULL) {
33 pointer += kNoCodeAgeSequenceLength;
35 pointer = code->instruction_start();
37 CodePatcher patcher(pointer, 1);
38 patcher.masm()->break_(0xCC);
40 DeoptimizationInputData* data =
41 DeoptimizationInputData::cast(code->deoptimization_data());
42 int osr_offset = data->OsrPcOffset()->value();
44 CodePatcher osr_patcher(code->instruction_start() + osr_offset, 1);
45 osr_patcher.masm()->break_(0xCC);
49 DeoptimizationInputData* deopt_data =
50 DeoptimizationInputData::cast(code->deoptimization_data());
52 Address prev_call_address = NULL;
54 // For each LLazyBailout instruction insert a call to the corresponding
55 // deoptimization entry.
56 for (int i = 0; i < deopt_data->DeoptCount(); i++) {
57 if (deopt_data->Pc(i)->value() == -1) continue;
58 Address call_address = code_start_address + deopt_data->Pc(i)->value();
59 Address deopt_entry = GetDeoptimizationEntry(isolate, i, LAZY);
60 int call_size_in_bytes = MacroAssembler::CallSize(deopt_entry,
62 int call_size_in_words = call_size_in_bytes / Assembler::kInstrSize;
63 DCHECK(call_size_in_bytes % Assembler::kInstrSize == 0);
64 DCHECK(call_size_in_bytes <= patch_size());
65 CodePatcher patcher(call_address, call_size_in_words);
66 patcher.masm()->Call(deopt_entry, RelocInfo::NONE32);
67 DCHECK(prev_call_address == NULL ||
68 call_address >= prev_call_address + patch_size());
69 DCHECK(call_address + patch_size() <= code->instruction_end());
72 prev_call_address = call_address;
78 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
79 // Set the register values. The values are not important as there are no
80 // callee saved registers in JavaScript frames, so all registers are
81 // spilled. Registers fp and sp are set to the correct values though.
83 for (int i = 0; i < Register::kNumRegisters; i++) {
84 input_->SetRegister(i, i * 4);
86 input_->SetRegister(sp.code(), reinterpret_cast<intptr_t>(frame->sp()));
87 input_->SetRegister(fp.code(), reinterpret_cast<intptr_t>(frame->fp()));
88 for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); i++) {
89 input_->SetDoubleRegister(i, 0.0);
92 // Fill the frame content from the actual data on the frame.
93 for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
94 input_->SetFrameSlot(i, Memory::uint32_at(tos + i));
99 void Deoptimizer::SetPlatformCompiledStubRegisters(
100 FrameDescription* output_frame, CodeStubDescriptor* descriptor) {
101 ApiFunction function(descriptor->deoptimization_handler());
102 ExternalReference xref(&function, ExternalReference::BUILTIN_CALL, isolate_);
103 intptr_t handler = reinterpret_cast<intptr_t>(xref.address());
104 int params = descriptor->GetHandlerParameterCount();
105 output_frame->SetRegister(a0.code(), params);
106 output_frame->SetRegister(a1.code(), handler);
110 void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
111 for (int i = 0; i < DoubleRegister::kMaxNumRegisters; ++i) {
112 double double_value = input_->GetDoubleRegister(i);
113 output_frame->SetDoubleRegister(i, double_value);
118 void Deoptimizer::CopySIMD128Registers(FrameDescription* output_frame) {
122 bool Deoptimizer::HasAlignmentPadding(JSFunction* function) {
123 // There is no dynamic alignment padding on MIPS in the input frame.
131 // This code tries to be close to ia32 code so that any changes can be
133 void Deoptimizer::EntryGenerator::Generate() {
136 // Unlike on ARM we don't save all the registers, just the useful ones.
137 // For the rest, there are gaps on the stack, so the offsets remain the same.
138 const int kNumberOfRegisters = Register::kNumRegisters;
140 RegList restored_regs = kJSCallerSaved | kCalleeSaved;
141 RegList saved_regs = restored_regs | sp.bit() | ra.bit();
143 const int kDoubleRegsSize =
144 kDoubleSize * FPURegister::kMaxNumAllocatableRegisters;
146 // Save all FPU registers before messing with them.
147 __ Subu(sp, sp, Operand(kDoubleRegsSize));
148 for (int i = 0; i < FPURegister::kMaxNumAllocatableRegisters; ++i) {
149 FPURegister fpu_reg = FPURegister::FromAllocationIndex(i);
150 int offset = i * kDoubleSize;
151 __ sdc1(fpu_reg, MemOperand(sp, offset));
154 // Push saved_regs (needed to populate FrameDescription::registers_).
155 // Leave gaps for other registers.
156 __ Subu(sp, sp, kNumberOfRegisters * kPointerSize);
157 for (int16_t i = kNumberOfRegisters - 1; i >= 0; i--) {
158 if ((saved_regs & (1 << i)) != 0) {
159 __ sw(ToRegister(i), MemOperand(sp, kPointerSize * i));
163 const int kSavedRegistersAreaSize =
164 (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
166 // Get the bailout id from the stack.
167 __ lw(a2, MemOperand(sp, kSavedRegistersAreaSize));
169 // Get the address of the location in the code object (a3) (return
170 // address for lazy deoptimization) and compute the fp-to-sp delta in
173 // Correct one word for bailout id.
174 __ Addu(t0, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
178 // Allocate a new deoptimizer object.
179 // Pass four arguments in a0 to a3 and fifth & sixth arguments on stack.
180 __ PrepareCallCFunction(6, t1);
181 __ lw(a0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
182 __ li(a1, Operand(type())); // bailout type,
183 // a2: bailout id already loaded.
184 // a3: code address or 0 already loaded.
185 __ sw(t0, CFunctionArgumentOperand(5)); // Fp-to-sp delta.
186 __ li(t1, Operand(ExternalReference::isolate_address(isolate())));
187 __ sw(t1, CFunctionArgumentOperand(6)); // Isolate.
188 // Call Deoptimizer::New().
190 AllowExternalCallThatCantCauseGC scope(masm());
191 __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6);
194 // Preserve "deoptimizer" object in register v0 and get the input
195 // frame descriptor pointer to a1 (deoptimizer->input_);
196 // Move deopt-obj to a0 for call to Deoptimizer::ComputeOutputFrames() below.
198 __ lw(a1, MemOperand(v0, Deoptimizer::input_offset()));
200 // Copy core registers into FrameDescription::registers_[kNumRegisters].
201 DCHECK(Register::kNumRegisters == kNumberOfRegisters);
202 for (int i = 0; i < kNumberOfRegisters; i++) {
203 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
204 if ((saved_regs & (1 << i)) != 0) {
205 __ lw(a2, MemOperand(sp, i * kPointerSize));
206 __ sw(a2, MemOperand(a1, offset));
207 } else if (FLAG_debug_code) {
208 __ li(a2, kDebugZapValue);
209 __ sw(a2, MemOperand(a1, offset));
213 int double_regs_offset = FrameDescription::double_registers_offset();
214 // Copy FPU registers to
215 // double_registers_[DoubleRegister::kNumAllocatableRegisters]
216 for (int i = 0; i < FPURegister::NumAllocatableRegisters(); ++i) {
217 int dst_offset = i * kDoubleSize + double_regs_offset;
218 int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
219 __ ldc1(f0, MemOperand(sp, src_offset));
220 __ sdc1(f0, MemOperand(a1, dst_offset));
223 // Remove the bailout id and the saved registers from the stack.
224 __ Addu(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
226 // Compute a pointer to the unwinding limit in register a2; that is
227 // the first stack slot not part of the input frame.
228 __ lw(a2, MemOperand(a1, FrameDescription::frame_size_offset()));
231 // Unwind the stack down to - but not including - the unwinding
232 // limit and copy the contents of the activation frame to the input
233 // frame description.
234 __ Addu(a3, a1, Operand(FrameDescription::frame_content_offset()));
236 Label pop_loop_header;
237 __ BranchShort(&pop_loop_header);
240 __ sw(t0, MemOperand(a3, 0));
241 __ addiu(a3, a3, sizeof(uint32_t));
242 __ bind(&pop_loop_header);
243 __ BranchShort(&pop_loop, ne, a2, Operand(sp));
245 // Compute the output frame in the deoptimizer.
246 __ push(a0); // Preserve deoptimizer object across call.
247 // a0: deoptimizer object; a1: scratch.
248 __ PrepareCallCFunction(1, a1);
249 // Call Deoptimizer::ComputeOutputFrames().
251 AllowExternalCallThatCantCauseGC scope(masm());
253 ExternalReference::compute_output_frames_function(isolate()), 1);
255 __ pop(a0); // Restore deoptimizer object (class Deoptimizer).
257 // Replace the current (input) frame with the output frames.
258 Label outer_push_loop, inner_push_loop,
259 outer_loop_header, inner_loop_header;
260 // Outer loop state: t0 = current "FrameDescription** output_",
261 // a1 = one past the last FrameDescription**.
262 __ lw(a1, MemOperand(a0, Deoptimizer::output_count_offset()));
263 __ lw(t0, MemOperand(a0, Deoptimizer::output_offset())); // t0 is output_.
264 __ sll(a1, a1, kPointerSizeLog2); // Count to offset.
265 __ addu(a1, t0, a1); // a1 = one past the last FrameDescription**.
266 __ jmp(&outer_loop_header);
267 __ bind(&outer_push_loop);
268 // Inner loop state: a2 = current FrameDescription*, a3 = loop index.
269 __ lw(a2, MemOperand(t0, 0)); // output_[ix]
270 __ lw(a3, MemOperand(a2, FrameDescription::frame_size_offset()));
271 __ jmp(&inner_loop_header);
272 __ bind(&inner_push_loop);
273 __ Subu(a3, a3, Operand(sizeof(uint32_t)));
274 __ Addu(t2, a2, Operand(a3));
275 __ lw(t3, MemOperand(t2, FrameDescription::frame_content_offset()));
277 __ bind(&inner_loop_header);
278 __ BranchShort(&inner_push_loop, ne, a3, Operand(zero_reg));
280 __ Addu(t0, t0, Operand(kPointerSize));
281 __ bind(&outer_loop_header);
282 __ BranchShort(&outer_push_loop, lt, t0, Operand(a1));
284 __ lw(a1, MemOperand(a0, Deoptimizer::input_offset()));
285 for (int i = 0; i < FPURegister::kMaxNumAllocatableRegisters; ++i) {
286 const FPURegister fpu_reg = FPURegister::FromAllocationIndex(i);
287 int src_offset = i * kDoubleSize + double_regs_offset;
288 __ ldc1(fpu_reg, MemOperand(a1, src_offset));
291 // Push state, pc, and continuation from the last output frame.
292 __ lw(t2, MemOperand(a2, FrameDescription::state_offset()));
295 __ lw(t2, MemOperand(a2, FrameDescription::pc_offset()));
297 __ lw(t2, MemOperand(a2, FrameDescription::continuation_offset()));
301 // Technically restoring 'at' should work unless zero_reg is also restored
302 // but it's safer to check for this.
303 DCHECK(!(at.bit() & restored_regs));
304 // Restore the registers from the last output frame.
306 for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
307 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
308 if ((restored_regs & (1 << i)) != 0) {
309 __ lw(ToRegister(i), MemOperand(at, offset));
313 __ InitializeRootRegister();
315 __ pop(at); // Get continuation, leave pc on stack.
318 __ stop("Unreachable.");
322 // Maximum size of a table entry generated below.
323 const int Deoptimizer::table_entry_size_ = 2 * Assembler::kInstrSize;
325 void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
326 Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm());
328 // Create a sequence of deoptimization entries.
329 // Note that registers are still live when jumping to an entry.
330 Label table_start, done, done_special, trampoline_jump;
331 __ bind(&table_start);
332 int kMaxEntriesBranchReach = (1 << (kImm16Bits - 2))/
333 (table_entry_size_ / Assembler::kInstrSize);
335 if (count() <= kMaxEntriesBranchReach) {
337 for (int i = 0; i < count(); i++) {
341 __ Branch(USE_DELAY_SLOT, &done); // Expose delay slot.
342 __ li(at, i); // In the delay slot.
344 DCHECK_EQ(table_entry_size_, masm()->SizeOfCodeGeneratedSince(&start));
347 DCHECK_EQ(masm()->SizeOfCodeGeneratedSince(&table_start),
348 count() * table_entry_size_);
352 // Uncommon case, the branch cannot reach.
353 // Create mini trampoline and adjust id constants to get proper value at
355 for (int i = kMaxEntriesBranchReach; i > 1; i--) {
359 __ Branch(USE_DELAY_SLOT, &trampoline_jump); // Expose delay slot.
360 __ li(at, - i); // In the delay slot.
361 DCHECK_EQ(table_entry_size_, masm()->SizeOfCodeGeneratedSince(&start));
363 // Entry with id == kMaxEntriesBranchReach - 1.
364 __ bind(&trampoline_jump);
365 __ Branch(USE_DELAY_SLOT, &done_special);
368 for (int i = kMaxEntriesBranchReach ; i < count(); i++) {
372 __ Branch(USE_DELAY_SLOT, &done); // Expose delay slot.
373 __ li(at, i); // In the delay slot.
376 DCHECK_EQ(masm()->SizeOfCodeGeneratedSince(&table_start),
377 count() * table_entry_size_);
378 __ bind(&done_special);
379 __ addiu(at, at, kMaxEntriesBranchReach);
386 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
387 SetFrameSlot(offset, value);
391 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
392 SetFrameSlot(offset, value);
396 void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
397 // No out-of-line constant pool support.
402 double FrameDescription::GetDoubleRegister(unsigned n) const {
403 DCHECK(n < arraysize(double_registers_));
404 return double_registers_[n];
408 void FrameDescription::SetDoubleRegister(unsigned n, double value) {
409 DCHECK(n < arraysize(double_registers_));
410 double_registers_[n] = value;
414 simd128_value_t FrameDescription::GetSIMD128Register(unsigned n) const {
416 simd128_value_t value;
421 void FrameDescription::SetSIMD128Register(unsigned n, simd128_value_t value) {
426 int FrameDescription::double_registers_offset() {
427 return OFFSET_OF(FrameDescription, double_registers_);
431 int FrameDescription::simd128_registers_offset() {
440 } } // namespace v8::internal