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.
7 #include "src/codegen.h"
8 #include "src/deoptimizer.h"
9 #include "src/full-codegen.h"
10 #include "src/safepoint-table.h"
15 const int Deoptimizer::table_entry_size_ = 8;
18 int Deoptimizer::patch_size() {
19 const int kCallInstructionSizeInWords = 3;
20 return kCallInstructionSizeInWords * Assembler::kInstrSize;
24 void Deoptimizer::EnsureRelocSpaceForLazyDeoptimization(Handle<Code> code) {
25 // Empty because there is no need for relocation information for the code
26 // patching in Deoptimizer::PatchCodeForDeoptimization below.
30 void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
31 Address code_start_address = code->instruction_start();
32 // Invalidate the relocation information, as it will become invalid by the
33 // code patching below, and is not needed any more.
34 code->InvalidateRelocation();
36 if (FLAG_zap_code_space) {
37 // Fail hard and early if we enter this code object again.
38 byte* pointer = code->FindCodeAgeSequence();
39 if (pointer != NULL) {
40 pointer += kNoCodeAgeSequenceLength;
42 pointer = code->instruction_start();
44 CodePatcher patcher(pointer, 1);
45 patcher.masm()->bkpt(0);
47 DeoptimizationInputData* data =
48 DeoptimizationInputData::cast(code->deoptimization_data());
49 int osr_offset = data->OsrPcOffset()->value();
51 CodePatcher osr_patcher(code->instruction_start() + osr_offset, 1);
52 osr_patcher.masm()->bkpt(0);
56 DeoptimizationInputData* deopt_data =
57 DeoptimizationInputData::cast(code->deoptimization_data());
59 Address prev_call_address = NULL;
61 // For each LLazyBailout instruction insert a call to the corresponding
62 // deoptimization entry.
63 for (int i = 0; i < deopt_data->DeoptCount(); i++) {
64 if (deopt_data->Pc(i)->value() == -1) continue;
65 Address call_address = code_start_address + deopt_data->Pc(i)->value();
66 Address deopt_entry = GetDeoptimizationEntry(isolate, i, LAZY);
67 // We need calls to have a predictable size in the unoptimized code, but
68 // this is optimized code, so we don't have to have a predictable size.
69 int call_size_in_bytes =
70 MacroAssembler::CallSizeNotPredictableCodeSize(isolate,
73 int call_size_in_words = call_size_in_bytes / Assembler::kInstrSize;
74 DCHECK(call_size_in_bytes % Assembler::kInstrSize == 0);
75 DCHECK(call_size_in_bytes <= patch_size());
76 CodePatcher patcher(call_address, call_size_in_words);
77 patcher.masm()->Call(deopt_entry, RelocInfo::NONE32);
78 DCHECK(prev_call_address == NULL ||
79 call_address >= prev_call_address + patch_size());
80 DCHECK(call_address + patch_size() <= code->instruction_end());
82 prev_call_address = call_address;
88 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
89 // Set the register values. The values are not important as there are no
90 // callee saved registers in JavaScript frames, so all registers are
91 // spilled. Registers fp and sp are set to the correct values though.
93 for (int i = 0; i < Register::kNumRegisters; i++) {
94 input_->SetRegister(i, i * 4);
96 input_->SetRegister(sp.code(), reinterpret_cast<intptr_t>(frame->sp()));
97 input_->SetRegister(fp.code(), reinterpret_cast<intptr_t>(frame->fp()));
98 for (int i = 0; i < DoubleRegister::NumAllocatableRegisters(); i++) {
99 input_->SetDoubleRegister(i, 0.0);
102 // Fill the frame content from the actual data on the frame.
103 for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
104 input_->SetFrameSlot(i, Memory::uint32_at(tos + i));
109 void Deoptimizer::SetPlatformCompiledStubRegisters(
110 FrameDescription* output_frame, CodeStubDescriptor* descriptor) {
111 ApiFunction function(descriptor->deoptimization_handler());
112 ExternalReference xref(&function, ExternalReference::BUILTIN_CALL, isolate_);
113 intptr_t handler = reinterpret_cast<intptr_t>(xref.address());
114 int params = descriptor->GetHandlerParameterCount();
115 output_frame->SetRegister(r0.code(), params);
116 output_frame->SetRegister(r1.code(), handler);
120 void Deoptimizer::CopyDoubleRegisters(FrameDescription* output_frame) {
121 for (int i = 0; i < DwVfpRegister::kMaxNumRegisters; ++i) {
122 double double_value = input_->GetDoubleRegister(i);
123 output_frame->SetDoubleRegister(i, double_value);
128 bool Deoptimizer::HasAlignmentPadding(JSFunction* function) {
129 // There is no dynamic alignment padding on ARM in the input frame.
136 // This code tries to be close to ia32 code so that any changes can be
138 void Deoptimizer::EntryGenerator::Generate() {
141 // Save all general purpose registers before messing with them.
142 const int kNumberOfRegisters = Register::kNumRegisters;
144 // Everything but pc, lr and ip which will be saved but not restored.
145 RegList restored_regs = kJSCallerSaved | kCalleeSaved | ip.bit();
147 const int kDoubleRegsSize =
148 kDoubleSize * DwVfpRegister::kMaxNumAllocatableRegisters;
150 // Save all allocatable VFP registers before messing with them.
151 DCHECK(kDoubleRegZero.code() == 14);
152 DCHECK(kScratchDoubleReg.code() == 15);
154 // Check CPU flags for number of registers, setting the Z condition flag.
155 __ CheckFor32DRegs(ip);
157 // Push registers d0-d13, and possibly d16-d31, on the stack.
158 // If d16-d31 are not pushed, decrease the stack pointer instead.
159 __ vstm(db_w, sp, d16, d31, ne);
160 __ sub(sp, sp, Operand(16 * kDoubleSize), LeaveCC, eq);
161 __ vstm(db_w, sp, d0, d13);
163 // Push all 16 registers (needed to populate FrameDescription::registers_).
164 // TODO(1588) Note that using pc with stm is deprecated, so we should perhaps
165 // handle this a bit differently.
166 __ stm(db_w, sp, restored_regs | sp.bit() | lr.bit() | pc.bit());
168 __ mov(ip, Operand(ExternalReference(Isolate::kCEntryFPAddress, isolate())));
169 __ str(fp, MemOperand(ip));
171 const int kSavedRegistersAreaSize =
172 (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
174 // Get the bailout id from the stack.
175 __ ldr(r2, MemOperand(sp, kSavedRegistersAreaSize));
177 // Get the address of the location in the code object (r3) (return
178 // address for lazy deoptimization) and compute the fp-to-sp delta in
181 // Correct one word for bailout id.
182 __ add(r4, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
185 // Allocate a new deoptimizer object.
186 // Pass four arguments in r0 to r3 and fifth argument on stack.
187 __ PrepareCallCFunction(6, r5);
188 __ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
189 __ mov(r1, Operand(type())); // bailout type,
190 // r2: bailout id already loaded.
191 // r3: code address or 0 already loaded.
192 __ str(r4, MemOperand(sp, 0 * kPointerSize)); // Fp-to-sp delta.
193 __ mov(r5, Operand(ExternalReference::isolate_address(isolate())));
194 __ str(r5, MemOperand(sp, 1 * kPointerSize)); // Isolate.
195 // Call Deoptimizer::New().
197 AllowExternalCallThatCantCauseGC scope(masm());
198 __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6);
201 // Preserve "deoptimizer" object in register r0 and get the input
202 // frame descriptor pointer to r1 (deoptimizer->input_);
203 __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
205 // Copy core registers into FrameDescription::registers_[kNumRegisters].
206 DCHECK(Register::kNumRegisters == kNumberOfRegisters);
207 for (int i = 0; i < kNumberOfRegisters; i++) {
208 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
209 __ ldr(r2, MemOperand(sp, i * kPointerSize));
210 __ str(r2, MemOperand(r1, offset));
213 // Copy VFP registers to
214 // double_registers_[DoubleRegister::kMaxNumAllocatableRegisters]
215 int double_regs_offset = FrameDescription::double_registers_offset();
216 for (int i = 0; i < DwVfpRegister::kMaxNumAllocatableRegisters; ++i) {
217 int dst_offset = i * kDoubleSize + double_regs_offset;
218 int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
219 __ vldr(d0, sp, src_offset);
220 __ vstr(d0, r1, dst_offset);
223 // Remove the bailout id and the saved registers from the stack.
224 __ add(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
226 // Compute a pointer to the unwinding limit in register r2; that is
227 // the first stack slot not part of the input frame.
228 __ ldr(r2, MemOperand(r1, 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 __ add(r3, r1, Operand(FrameDescription::frame_content_offset()));
236 Label pop_loop_header;
237 __ b(&pop_loop_header);
240 __ str(r4, MemOperand(r3, 0));
241 __ add(r3, r3, Operand(sizeof(uint32_t)));
242 __ bind(&pop_loop_header);
246 // Compute the output frame in the deoptimizer.
247 __ push(r0); // Preserve deoptimizer object across call.
248 // r0: deoptimizer object; r1: scratch.
249 __ PrepareCallCFunction(1, r1);
250 // Call Deoptimizer::ComputeOutputFrames().
252 AllowExternalCallThatCantCauseGC scope(masm());
254 ExternalReference::compute_output_frames_function(isolate()), 1);
256 __ pop(r0); // Restore deoptimizer object (class Deoptimizer).
258 // Replace the current (input) frame with the output frames.
259 Label outer_push_loop, inner_push_loop,
260 outer_loop_header, inner_loop_header;
261 // Outer loop state: r4 = current "FrameDescription** output_",
262 // r1 = one past the last FrameDescription**.
263 __ ldr(r1, MemOperand(r0, Deoptimizer::output_count_offset()));
264 __ ldr(r4, MemOperand(r0, Deoptimizer::output_offset())); // r4 is output_.
265 __ add(r1, r4, Operand(r1, LSL, 2));
266 __ jmp(&outer_loop_header);
267 __ bind(&outer_push_loop);
268 // Inner loop state: r2 = current FrameDescription*, r3 = loop index.
269 __ ldr(r2, MemOperand(r4, 0)); // output_[ix]
270 __ ldr(r3, MemOperand(r2, FrameDescription::frame_size_offset()));
271 __ jmp(&inner_loop_header);
272 __ bind(&inner_push_loop);
273 __ sub(r3, r3, Operand(sizeof(uint32_t)));
274 __ add(r6, r2, Operand(r3));
275 __ ldr(r6, MemOperand(r6, FrameDescription::frame_content_offset()));
277 __ bind(&inner_loop_header);
278 __ cmp(r3, Operand::Zero());
279 __ b(ne, &inner_push_loop); // test for gt?
280 __ add(r4, r4, Operand(kPointerSize));
281 __ bind(&outer_loop_header);
283 __ b(lt, &outer_push_loop);
285 // Check CPU flags for number of registers, setting the Z condition flag.
286 __ CheckFor32DRegs(ip);
288 __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
289 int src_offset = FrameDescription::double_registers_offset();
290 for (int i = 0; i < DwVfpRegister::kMaxNumRegisters; ++i) {
291 if (i == kDoubleRegZero.code()) continue;
292 if (i == kScratchDoubleReg.code()) continue;
294 const DwVfpRegister reg = DwVfpRegister::from_code(i);
295 __ vldr(reg, r1, src_offset, i < 16 ? al : ne);
296 src_offset += kDoubleSize;
299 // Push state, pc, and continuation from the last output frame.
300 __ ldr(r6, MemOperand(r2, FrameDescription::state_offset()));
302 __ ldr(r6, MemOperand(r2, FrameDescription::pc_offset()));
304 __ ldr(r6, MemOperand(r2, FrameDescription::continuation_offset()));
307 // Push the registers from the last output frame.
308 for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
309 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
310 __ ldr(r6, MemOperand(r2, offset));
314 // Restore the registers from the stack.
315 __ ldm(ia_w, sp, restored_regs); // all but pc registers.
316 __ pop(ip); // remove sp
317 __ pop(ip); // remove lr
319 __ InitializeRootRegister();
321 __ pop(ip); // remove pc
322 __ pop(ip); // get continuation, leave pc on stack
325 __ stop("Unreachable.");
329 void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
330 // Create a sequence of deoptimization entries.
331 // Note that registers are still live when jumping to an entry.
333 for (int i = 0; i < count(); i++) {
334 int start = masm()->pc_offset();
336 __ mov(ip, Operand(i));
338 DCHECK(masm()->pc_offset() - start == table_entry_size_);
345 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
346 SetFrameSlot(offset, value);
350 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
351 SetFrameSlot(offset, value);
355 void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
356 DCHECK(FLAG_enable_ool_constant_pool);
357 SetFrameSlot(offset, value);
363 } } // namespace v8::internal