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31 #include "deoptimizer.h"
32 #include "full-codegen.h"
33 #include "safepoint-table.h"
38 const int Deoptimizer::table_entry_size_ = 12;
41 int Deoptimizer::patch_size() {
42 const int kCallInstructionSizeInWords = 3;
43 return kCallInstructionSizeInWords * Assembler::kInstrSize;
47 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
48 Address code_start_address = code->instruction_start();
49 // Invalidate the relocation information, as it will become invalid by the
50 // code patching below, and is not needed any more.
51 code->InvalidateRelocation();
53 // For each LLazyBailout instruction insert a call to the corresponding
54 // deoptimization entry.
55 DeoptimizationInputData* deopt_data =
56 DeoptimizationInputData::cast(code->deoptimization_data());
58 Address prev_call_address = NULL;
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(deopt_entry,
69 int call_size_in_words = call_size_in_bytes / Assembler::kInstrSize;
70 ASSERT(call_size_in_bytes % Assembler::kInstrSize == 0);
71 ASSERT(call_size_in_bytes <= patch_size());
72 CodePatcher patcher(call_address, call_size_in_words);
73 patcher.masm()->Call(deopt_entry, RelocInfo::NONE32);
74 ASSERT(prev_call_address == NULL ||
75 call_address >= prev_call_address + patch_size());
76 ASSERT(call_address + patch_size() <= code->instruction_end());
78 prev_call_address = call_address;
84 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
85 // Set the register values. The values are not important as there are no
86 // callee saved registers in JavaScript frames, so all registers are
87 // spilled. Registers fp and sp are set to the correct values though.
89 for (int i = 0; i < Register::kNumRegisters; i++) {
90 input_->SetRegister(i, i * 4);
92 input_->SetRegister(sp.code(), reinterpret_cast<intptr_t>(frame->sp()));
93 input_->SetRegister(fp.code(), reinterpret_cast<intptr_t>(frame->fp()));
94 for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); i++) {
95 input_->SetDoubleRegister(i, 0.0);
98 // Fill the frame content from the actual data on the frame.
99 for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
100 input_->SetFrameSlot(i, Memory::uint32_at(tos + i));
105 void Deoptimizer::SetPlatformCompiledStubRegisters(
106 FrameDescription* output_frame, CodeStubInterfaceDescriptor* descriptor) {
107 ApiFunction function(descriptor->deoptimization_handler_);
108 ExternalReference xref(&function, ExternalReference::BUILTIN_CALL, isolate_);
109 intptr_t handler = reinterpret_cast<intptr_t>(xref.address());
110 int params = descriptor->environment_length();
111 output_frame->SetRegister(r0.code(), params);
112 output_frame->SetRegister(r1.code(), handler);
116 void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
117 for (int i = 0; i < DwVfpRegister::kMaxNumRegisters; ++i) {
118 double double_value = input_->GetDoubleRegister(i);
119 output_frame->SetDoubleRegister(i, double_value);
124 bool Deoptimizer::HasAlignmentPadding(JSFunction* function) {
125 // There is no dynamic alignment padding on ARM in the input frame.
132 // This code tries to be close to ia32 code so that any changes can be
134 void Deoptimizer::EntryGenerator::Generate() {
137 // Save all general purpose registers before messing with them.
138 const int kNumberOfRegisters = Register::kNumRegisters;
140 // Everything but pc, lr and ip which will be saved but not restored.
141 RegList restored_regs = kJSCallerSaved | kCalleeSaved | ip.bit();
143 const int kDoubleRegsSize =
144 kDoubleSize * DwVfpRegister::kMaxNumAllocatableRegisters;
146 // Save all allocatable VFP registers before messing with them.
147 ASSERT(kDoubleRegZero.code() == 14);
148 ASSERT(kScratchDoubleReg.code() == 15);
150 // Check CPU flags for number of registers, setting the Z condition flag.
151 __ CheckFor32DRegs(ip);
153 // Push registers d0-d13, and possibly d16-d31, on the stack.
154 // If d16-d31 are not pushed, decrease the stack pointer instead.
155 __ vstm(db_w, sp, d16, d31, ne);
156 __ sub(sp, sp, Operand(16 * kDoubleSize), LeaveCC, eq);
157 __ vstm(db_w, sp, d0, d13);
159 // Push all 16 registers (needed to populate FrameDescription::registers_).
160 // TODO(1588) Note that using pc with stm is deprecated, so we should perhaps
161 // handle this a bit differently.
162 __ stm(db_w, sp, restored_regs | sp.bit() | lr.bit() | pc.bit());
164 const int kSavedRegistersAreaSize =
165 (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
167 // Get the bailout id from the stack.
168 __ ldr(r2, MemOperand(sp, kSavedRegistersAreaSize));
170 // Get the address of the location in the code object (r3) (return
171 // address for lazy deoptimization) and compute the fp-to-sp delta in
174 // Correct one word for bailout id.
175 __ add(r4, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
178 // Allocate a new deoptimizer object.
179 // Pass four arguments in r0 to r3 and fifth argument on stack.
180 __ PrepareCallCFunction(6, r5);
181 __ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
182 __ mov(r1, Operand(type())); // bailout type,
183 // r2: bailout id already loaded.
184 // r3: code address or 0 already loaded.
185 __ str(r4, MemOperand(sp, 0 * kPointerSize)); // Fp-to-sp delta.
186 __ mov(r5, Operand(ExternalReference::isolate_address(isolate())));
187 __ str(r5, MemOperand(sp, 1 * kPointerSize)); // Isolate.
188 // Call Deoptimizer::New().
190 AllowExternalCallThatCantCauseGC scope(masm());
191 __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6);
194 // Preserve "deoptimizer" object in register r0 and get the input
195 // frame descriptor pointer to r1 (deoptimizer->input_);
196 __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
198 // Copy core registers into FrameDescription::registers_[kNumRegisters].
199 ASSERT(Register::kNumRegisters == kNumberOfRegisters);
200 for (int i = 0; i < kNumberOfRegisters; i++) {
201 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
202 __ ldr(r2, MemOperand(sp, i * kPointerSize));
203 __ str(r2, MemOperand(r1, offset));
206 // Copy VFP registers to
207 // double_registers_[DoubleRegister::kMaxNumAllocatableRegisters]
208 int double_regs_offset = FrameDescription::double_registers_offset();
209 for (int i = 0; i < DwVfpRegister::kMaxNumAllocatableRegisters; ++i) {
210 int dst_offset = i * kDoubleSize + double_regs_offset;
211 int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
212 __ vldr(d0, sp, src_offset);
213 __ vstr(d0, r1, dst_offset);
216 // Remove the bailout id and the saved registers from the stack.
217 __ add(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
219 // Compute a pointer to the unwinding limit in register r2; that is
220 // the first stack slot not part of the input frame.
221 __ ldr(r2, MemOperand(r1, FrameDescription::frame_size_offset()));
224 // Unwind the stack down to - but not including - the unwinding
225 // limit and copy the contents of the activation frame to the input
226 // frame description.
227 __ add(r3, r1, Operand(FrameDescription::frame_content_offset()));
229 Label pop_loop_header;
230 __ b(&pop_loop_header);
233 __ str(r4, MemOperand(r3, 0));
234 __ add(r3, r3, Operand(sizeof(uint32_t)));
235 __ bind(&pop_loop_header);
239 // Compute the output frame in the deoptimizer.
240 __ push(r0); // Preserve deoptimizer object across call.
241 // r0: deoptimizer object; r1: scratch.
242 __ PrepareCallCFunction(1, r1);
243 // Call Deoptimizer::ComputeOutputFrames().
245 AllowExternalCallThatCantCauseGC scope(masm());
247 ExternalReference::compute_output_frames_function(isolate()), 1);
249 __ pop(r0); // Restore deoptimizer object (class Deoptimizer).
251 // Replace the current (input) frame with the output frames.
252 Label outer_push_loop, inner_push_loop,
253 outer_loop_header, inner_loop_header;
254 // Outer loop state: r4 = current "FrameDescription** output_",
255 // r1 = one past the last FrameDescription**.
256 __ ldr(r1, MemOperand(r0, Deoptimizer::output_count_offset()));
257 __ ldr(r4, MemOperand(r0, Deoptimizer::output_offset())); // r4 is output_.
258 __ add(r1, r4, Operand(r1, LSL, 2));
259 __ jmp(&outer_loop_header);
260 __ bind(&outer_push_loop);
261 // Inner loop state: r2 = current FrameDescription*, r3 = loop index.
262 __ ldr(r2, MemOperand(r4, 0)); // output_[ix]
263 __ ldr(r3, MemOperand(r2, FrameDescription::frame_size_offset()));
264 __ jmp(&inner_loop_header);
265 __ bind(&inner_push_loop);
266 __ sub(r3, r3, Operand(sizeof(uint32_t)));
267 __ add(r6, r2, Operand(r3));
268 __ ldr(r6, MemOperand(r6, FrameDescription::frame_content_offset()));
270 __ bind(&inner_loop_header);
271 __ cmp(r3, Operand::Zero());
272 __ b(ne, &inner_push_loop); // test for gt?
273 __ add(r4, r4, Operand(kPointerSize));
274 __ bind(&outer_loop_header);
276 __ b(lt, &outer_push_loop);
278 // Check CPU flags for number of registers, setting the Z condition flag.
279 __ CheckFor32DRegs(ip);
281 __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
282 int src_offset = FrameDescription::double_registers_offset();
283 for (int i = 0; i < DwVfpRegister::kMaxNumRegisters; ++i) {
284 if (i == kDoubleRegZero.code()) continue;
285 if (i == kScratchDoubleReg.code()) continue;
287 const DwVfpRegister reg = DwVfpRegister::from_code(i);
288 __ vldr(reg, r1, src_offset, i < 16 ? al : ne);
289 src_offset += kDoubleSize;
292 // Push state, pc, and continuation from the last output frame.
293 __ ldr(r6, MemOperand(r2, FrameDescription::state_offset()));
295 __ ldr(r6, MemOperand(r2, FrameDescription::pc_offset()));
297 __ ldr(r6, MemOperand(r2, FrameDescription::continuation_offset()));
300 // Push the registers from the last output frame.
301 for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
302 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
303 __ ldr(r6, MemOperand(r2, offset));
307 // Restore the registers from the stack.
308 __ ldm(ia_w, sp, restored_regs); // all but pc registers.
309 __ pop(ip); // remove sp
310 __ pop(ip); // remove lr
312 __ InitializeRootRegister();
314 __ pop(ip); // remove pc
315 __ pop(ip); // get continuation, leave pc on stack
318 __ stop("Unreachable.");
322 void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
323 // Create a sequence of deoptimization entries.
324 // Note that registers are still live when jumping to an entry.
326 for (int i = 0; i < count(); i++) {
327 int start = masm()->pc_offset();
329 __ mov(ip, Operand(i));
332 ASSERT(masm()->pc_offset() - start == table_entry_size_);
338 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
339 SetFrameSlot(offset, value);
343 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
344 SetFrameSlot(offset, value);
350 } } // namespace v8::internal