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.
8 #include "deoptimizer.h"
9 #include "full-codegen.h"
10 #include "safepoint-table.h"
15 const int Deoptimizer::table_entry_size_ = 12;
18 int Deoptimizer::patch_size() {
19 const int kCallInstructionSizeInWords = 3;
20 return kCallInstructionSizeInWords * Assembler::kInstrSize;
24 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
25 Address code_start_address = code->instruction_start();
26 // Invalidate the relocation information, as it will become invalid by the
27 // code patching below, and is not needed any more.
28 code->InvalidateRelocation();
30 if (FLAG_zap_code_space) {
31 // Fail hard and early if we enter this code object again.
32 byte* pointer = code->FindCodeAgeSequence();
33 if (pointer != NULL) {
34 pointer += kNoCodeAgeSequenceLength * Assembler::kInstrSize;
36 pointer = code->instruction_start();
38 CodePatcher patcher(pointer, 1);
39 patcher.masm()->bkpt(0);
41 DeoptimizationInputData* data =
42 DeoptimizationInputData::cast(code->deoptimization_data());
43 int osr_offset = data->OsrPcOffset()->value();
45 CodePatcher osr_patcher(code->instruction_start() + osr_offset, 1);
46 osr_patcher.masm()->bkpt(0);
50 DeoptimizationInputData* deopt_data =
51 DeoptimizationInputData::cast(code->deoptimization_data());
52 SharedFunctionInfo* shared =
53 SharedFunctionInfo::cast(deopt_data->SharedFunctionInfo());
54 shared->EvictFromOptimizedCodeMap(code, "deoptimized code");
56 Address prev_call_address = NULL;
58 // For each LLazyBailout instruction insert a call to the corresponding
59 // deoptimization entry.
60 for (int i = 0; i < deopt_data->DeoptCount(); i++) {
61 if (deopt_data->Pc(i)->value() == -1) continue;
62 Address call_address = code_start_address + deopt_data->Pc(i)->value();
63 Address deopt_entry = GetDeoptimizationEntry(isolate, i, LAZY);
64 // We need calls to have a predictable size in the unoptimized code, but
65 // this is optimized code, so we don't have to have a predictable size.
66 int call_size_in_bytes =
67 MacroAssembler::CallSizeNotPredictableCodeSize(isolate,
70 int call_size_in_words = call_size_in_bytes / Assembler::kInstrSize;
71 ASSERT(call_size_in_bytes % Assembler::kInstrSize == 0);
72 ASSERT(call_size_in_bytes <= patch_size());
73 CodePatcher patcher(call_address, call_size_in_words);
74 patcher.masm()->Call(deopt_entry, RelocInfo::NONE32);
75 ASSERT(prev_call_address == NULL ||
76 call_address >= prev_call_address + patch_size());
77 ASSERT(call_address + patch_size() <= code->instruction_end());
79 prev_call_address = call_address;
85 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
86 // Set the register values. The values are not important as there are no
87 // callee saved registers in JavaScript frames, so all registers are
88 // spilled. Registers fp and sp are set to the correct values though.
90 for (int i = 0; i < Register::kNumRegisters; i++) {
91 input_->SetRegister(i, i * 4);
93 input_->SetRegister(sp.code(), reinterpret_cast<intptr_t>(frame->sp()));
94 input_->SetRegister(fp.code(), reinterpret_cast<intptr_t>(frame->fp()));
95 for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); i++) {
96 input_->SetDoubleRegister(i, 0.0);
99 // Fill the frame content from the actual data on the frame.
100 for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
101 input_->SetFrameSlot(i, Memory::uint32_at(tos + i));
106 void Deoptimizer::SetPlatformCompiledStubRegisters(
107 FrameDescription* output_frame, CodeStubInterfaceDescriptor* descriptor) {
108 ApiFunction function(descriptor->deoptimization_handler_);
109 ExternalReference xref(&function, ExternalReference::BUILTIN_CALL, isolate_);
110 intptr_t handler = reinterpret_cast<intptr_t>(xref.address());
111 int params = descriptor->GetHandlerParameterCount();
112 output_frame->SetRegister(r0.code(), params);
113 output_frame->SetRegister(r1.code(), handler);
117 void Deoptimizer::CopySIMD128Registers(FrameDescription* output_frame) {
118 for (int i = 0; i < DwVfpRegister::kMaxNumRegisters; ++i) {
119 double double_value = input_->GetDoubleRegister(i);
120 output_frame->SetDoubleRegister(i, double_value);
125 bool Deoptimizer::HasAlignmentPadding(JSFunction* function) {
126 // There is no dynamic alignment padding on ARM in the input frame.
131 Code* Deoptimizer::NotifyStubFailureBuiltin() {
132 return isolate_->builtins()->builtin(Builtins::kNotifyStubFailureSaveDoubles);
138 // This code tries to be close to ia32 code so that any changes can be
140 void Deoptimizer::EntryGenerator::Generate() {
143 // Save all general purpose registers before messing with them.
144 const int kNumberOfRegisters = Register::kNumRegisters;
146 // Everything but pc, lr and ip which will be saved but not restored.
147 RegList restored_regs = kJSCallerSaved | kCalleeSaved | ip.bit();
149 const int kDoubleRegsSize =
150 kDoubleSize * DwVfpRegister::kMaxNumAllocatableRegisters;
152 // Save all allocatable VFP registers before messing with them.
153 ASSERT(kDoubleRegZero.code() == 14);
154 ASSERT(kScratchDoubleReg.code() == 15);
156 // Check CPU flags for number of registers, setting the Z condition flag.
157 __ CheckFor32DRegs(ip);
159 // Push registers d0-d13, and possibly d16-d31, on the stack.
160 // If d16-d31 are not pushed, decrease the stack pointer instead.
161 __ vstm(db_w, sp, d16, d31, ne);
162 __ sub(sp, sp, Operand(16 * kDoubleSize), LeaveCC, eq);
163 __ vstm(db_w, sp, d0, d13);
165 // Push all 16 registers (needed to populate FrameDescription::registers_).
166 // TODO(1588) Note that using pc with stm is deprecated, so we should perhaps
167 // handle this a bit differently.
168 __ stm(db_w, sp, restored_regs | sp.bit() | lr.bit() | pc.bit());
170 const int kSavedRegistersAreaSize =
171 (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
173 // Get the bailout id from the stack.
174 __ ldr(r2, MemOperand(sp, kSavedRegistersAreaSize));
176 // Get the address of the location in the code object (r3) (return
177 // address for lazy deoptimization) and compute the fp-to-sp delta in
180 // Correct one word for bailout id.
181 __ add(r4, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
184 // Allocate a new deoptimizer object.
185 // Pass four arguments in r0 to r3 and fifth argument on stack.
186 __ PrepareCallCFunction(6, r5);
187 __ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
188 __ mov(r1, Operand(type())); // bailout type,
189 // r2: bailout id already loaded.
190 // r3: code address or 0 already loaded.
191 __ str(r4, MemOperand(sp, 0 * kPointerSize)); // Fp-to-sp delta.
192 __ mov(r5, Operand(ExternalReference::isolate_address(isolate())));
193 __ str(r5, MemOperand(sp, 1 * kPointerSize)); // Isolate.
194 // Call Deoptimizer::New().
196 AllowExternalCallThatCantCauseGC scope(masm());
197 __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6);
200 // Preserve "deoptimizer" object in register r0 and get the input
201 // frame descriptor pointer to r1 (deoptimizer->input_);
202 __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
204 // Copy core registers into FrameDescription::registers_[kNumRegisters].
205 ASSERT(Register::kNumRegisters == kNumberOfRegisters);
206 for (int i = 0; i < kNumberOfRegisters; i++) {
207 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
208 __ ldr(r2, MemOperand(sp, i * kPointerSize));
209 __ str(r2, MemOperand(r1, offset));
212 // Copy VFP registers to
213 // double_registers_[DoubleRegister::kMaxNumAllocatableRegisters]
214 int double_regs_offset = FrameDescription::simd128_registers_offset();
215 for (int i = 0; i < DwVfpRegister::kMaxNumAllocatableRegisters; ++i) {
216 int dst_offset = i * kDoubleSize + double_regs_offset;
217 int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
218 __ vldr(d0, sp, src_offset);
219 __ vstr(d0, r1, dst_offset);
222 // Remove the bailout id and the saved registers from the stack.
223 __ add(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
225 // Compute a pointer to the unwinding limit in register r2; that is
226 // the first stack slot not part of the input frame.
227 __ ldr(r2, MemOperand(r1, FrameDescription::frame_size_offset()));
230 // Unwind the stack down to - but not including - the unwinding
231 // limit and copy the contents of the activation frame to the input
232 // frame description.
233 __ add(r3, r1, Operand(FrameDescription::frame_content_offset()));
235 Label pop_loop_header;
236 __ b(&pop_loop_header);
239 __ str(r4, MemOperand(r3, 0));
240 __ add(r3, r3, Operand(sizeof(uint32_t)));
241 __ bind(&pop_loop_header);
245 // Compute the output frame in the deoptimizer.
246 __ push(r0); // Preserve deoptimizer object across call.
247 // r0: deoptimizer object; r1: scratch.
248 __ PrepareCallCFunction(1, r1);
249 // Call Deoptimizer::ComputeOutputFrames().
251 AllowExternalCallThatCantCauseGC scope(masm());
253 ExternalReference::compute_output_frames_function(isolate()), 1);
255 __ pop(r0); // 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: r4 = current "FrameDescription** output_",
261 // r1 = one past the last FrameDescription**.
262 __ ldr(r1, MemOperand(r0, Deoptimizer::output_count_offset()));
263 __ ldr(r4, MemOperand(r0, Deoptimizer::output_offset())); // r4 is output_.
264 __ add(r1, r4, Operand(r1, LSL, 2));
265 __ jmp(&outer_loop_header);
266 __ bind(&outer_push_loop);
267 // Inner loop state: r2 = current FrameDescription*, r3 = loop index.
268 __ ldr(r2, MemOperand(r4, 0)); // output_[ix]
269 __ ldr(r3, MemOperand(r2, FrameDescription::frame_size_offset()));
270 __ jmp(&inner_loop_header);
271 __ bind(&inner_push_loop);
272 __ sub(r3, r3, Operand(sizeof(uint32_t)));
273 __ add(r6, r2, Operand(r3));
274 __ ldr(r6, MemOperand(r6, FrameDescription::frame_content_offset()));
276 __ bind(&inner_loop_header);
277 __ cmp(r3, Operand::Zero());
278 __ b(ne, &inner_push_loop); // test for gt?
279 __ add(r4, r4, Operand(kPointerSize));
280 __ bind(&outer_loop_header);
282 __ b(lt, &outer_push_loop);
284 // Check CPU flags for number of registers, setting the Z condition flag.
285 __ CheckFor32DRegs(ip);
287 __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
288 int src_offset = FrameDescription::simd128_registers_offset();
289 for (int i = 0; i < DwVfpRegister::kMaxNumRegisters; ++i) {
290 if (i == kDoubleRegZero.code()) continue;
291 if (i == kScratchDoubleReg.code()) continue;
293 const DwVfpRegister reg = DwVfpRegister::from_code(i);
294 __ vldr(reg, r1, src_offset, i < 16 ? al : ne);
295 src_offset += kDoubleSize;
298 // Push state, pc, and continuation from the last output frame.
299 __ ldr(r6, MemOperand(r2, FrameDescription::state_offset()));
301 __ ldr(r6, MemOperand(r2, FrameDescription::pc_offset()));
303 __ ldr(r6, MemOperand(r2, FrameDescription::continuation_offset()));
306 // Push the registers from the last output frame.
307 for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
308 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
309 __ ldr(r6, MemOperand(r2, offset));
313 // Restore the registers from the stack.
314 __ ldm(ia_w, sp, restored_regs); // all but pc registers.
315 __ pop(ip); // remove sp
316 __ pop(ip); // remove lr
318 __ InitializeRootRegister();
320 __ pop(ip); // remove pc
321 __ pop(ip); // get continuation, leave pc on stack
324 __ stop("Unreachable.");
328 void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
329 // Create a sequence of deoptimization entries.
330 // Note that registers are still live when jumping to an entry.
332 for (int i = 0; i < count(); i++) {
333 int start = masm()->pc_offset();
335 __ mov(ip, Operand(i));
338 ASSERT(masm()->pc_offset() - start == table_entry_size_);
344 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
345 SetFrameSlot(offset, value);
349 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
350 SetFrameSlot(offset, value);
354 void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
355 ASSERT(FLAG_enable_ool_constant_pool);
356 SetFrameSlot(offset, value);
360 double FrameDescription::GetDoubleRegister(unsigned n) const {
361 ASSERT(n < 2 * ARRAY_SIZE(simd128_registers_));
362 return simd128_registers_[n / 2].d[n % 2];
366 void FrameDescription::SetDoubleRegister(unsigned n, double value) {
367 ASSERT(n < 2 * ARRAY_SIZE(simd128_registers_));
368 simd128_registers_[n / 2].d[n % 2] = value;
374 } } // namespace v8::internal