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_ = 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;
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::CopyDoubleRegisters(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.
133 // This code tries to be close to ia32 code so that any changes can be
135 void Deoptimizer::EntryGenerator::Generate() {
138 // Save all general purpose registers before messing with them.
139 const int kNumberOfRegisters = Register::kNumRegisters;
141 // Everything but pc, lr and ip which will be saved but not restored.
142 RegList restored_regs = kJSCallerSaved | kCalleeSaved | ip.bit();
144 const int kDoubleRegsSize =
145 kDoubleSize * DwVfpRegister::kMaxNumAllocatableRegisters;
147 // Save all allocatable VFP registers before messing with them.
148 ASSERT(kDoubleRegZero.code() == 14);
149 ASSERT(kScratchDoubleReg.code() == 15);
151 // Check CPU flags for number of registers, setting the Z condition flag.
152 __ CheckFor32DRegs(ip);
154 // Push registers d0-d13, and possibly d16-d31, on the stack.
155 // If d16-d31 are not pushed, decrease the stack pointer instead.
156 __ vstm(db_w, sp, d16, d31, ne);
157 __ sub(sp, sp, Operand(16 * kDoubleSize), LeaveCC, eq);
158 __ vstm(db_w, sp, d0, d13);
160 // Push all 16 registers (needed to populate FrameDescription::registers_).
161 // TODO(1588) Note that using pc with stm is deprecated, so we should perhaps
162 // handle this a bit differently.
163 __ stm(db_w, sp, restored_regs | sp.bit() | lr.bit() | pc.bit());
165 const int kSavedRegistersAreaSize =
166 (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
168 // Get the bailout id from the stack.
169 __ ldr(r2, MemOperand(sp, kSavedRegistersAreaSize));
171 // Get the address of the location in the code object (r3) (return
172 // address for lazy deoptimization) and compute the fp-to-sp delta in
175 // Correct one word for bailout id.
176 __ add(r4, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
179 // Allocate a new deoptimizer object.
180 // Pass four arguments in r0 to r3 and fifth argument on stack.
181 __ PrepareCallCFunction(6, r5);
182 __ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
183 __ mov(r1, Operand(type())); // bailout type,
184 // r2: bailout id already loaded.
185 // r3: code address or 0 already loaded.
186 __ str(r4, MemOperand(sp, 0 * kPointerSize)); // Fp-to-sp delta.
187 __ mov(r5, Operand(ExternalReference::isolate_address(isolate())));
188 __ str(r5, MemOperand(sp, 1 * kPointerSize)); // Isolate.
189 // Call Deoptimizer::New().
191 AllowExternalCallThatCantCauseGC scope(masm());
192 __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate()), 6);
195 // Preserve "deoptimizer" object in register r0 and get the input
196 // frame descriptor pointer to r1 (deoptimizer->input_);
197 __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
199 // Copy core registers into FrameDescription::registers_[kNumRegisters].
200 ASSERT(Register::kNumRegisters == kNumberOfRegisters);
201 for (int i = 0; i < kNumberOfRegisters; i++) {
202 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
203 __ ldr(r2, MemOperand(sp, i * kPointerSize));
204 __ str(r2, MemOperand(r1, offset));
207 // Copy VFP registers to
208 // double_registers_[DoubleRegister::kMaxNumAllocatableRegisters]
209 int double_regs_offset = FrameDescription::double_registers_offset();
210 for (int i = 0; i < DwVfpRegister::kMaxNumAllocatableRegisters; ++i) {
211 int dst_offset = i * kDoubleSize + double_regs_offset;
212 int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
213 __ vldr(d0, sp, src_offset);
214 __ vstr(d0, r1, dst_offset);
217 // Remove the bailout id and the saved registers from the stack.
218 __ add(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
220 // Compute a pointer to the unwinding limit in register r2; that is
221 // the first stack slot not part of the input frame.
222 __ ldr(r2, MemOperand(r1, FrameDescription::frame_size_offset()));
225 // Unwind the stack down to - but not including - the unwinding
226 // limit and copy the contents of the activation frame to the input
227 // frame description.
228 __ add(r3, r1, Operand(FrameDescription::frame_content_offset()));
230 Label pop_loop_header;
231 __ b(&pop_loop_header);
234 __ str(r4, MemOperand(r3, 0));
235 __ add(r3, r3, Operand(sizeof(uint32_t)));
236 __ bind(&pop_loop_header);
240 // Compute the output frame in the deoptimizer.
241 __ push(r0); // Preserve deoptimizer object across call.
242 // r0: deoptimizer object; r1: scratch.
243 __ PrepareCallCFunction(1, r1);
244 // Call Deoptimizer::ComputeOutputFrames().
246 AllowExternalCallThatCantCauseGC scope(masm());
248 ExternalReference::compute_output_frames_function(isolate()), 1);
250 __ pop(r0); // Restore deoptimizer object (class Deoptimizer).
252 // Replace the current (input) frame with the output frames.
253 Label outer_push_loop, inner_push_loop,
254 outer_loop_header, inner_loop_header;
255 // Outer loop state: r4 = current "FrameDescription** output_",
256 // r1 = one past the last FrameDescription**.
257 __ ldr(r1, MemOperand(r0, Deoptimizer::output_count_offset()));
258 __ ldr(r4, MemOperand(r0, Deoptimizer::output_offset())); // r4 is output_.
259 __ add(r1, r4, Operand(r1, LSL, 2));
260 __ jmp(&outer_loop_header);
261 __ bind(&outer_push_loop);
262 // Inner loop state: r2 = current FrameDescription*, r3 = loop index.
263 __ ldr(r2, MemOperand(r4, 0)); // output_[ix]
264 __ ldr(r3, MemOperand(r2, FrameDescription::frame_size_offset()));
265 __ jmp(&inner_loop_header);
266 __ bind(&inner_push_loop);
267 __ sub(r3, r3, Operand(sizeof(uint32_t)));
268 __ add(r6, r2, Operand(r3));
269 __ ldr(r6, MemOperand(r6, FrameDescription::frame_content_offset()));
271 __ bind(&inner_loop_header);
272 __ cmp(r3, Operand::Zero());
273 __ b(ne, &inner_push_loop); // test for gt?
274 __ add(r4, r4, Operand(kPointerSize));
275 __ bind(&outer_loop_header);
277 __ b(lt, &outer_push_loop);
279 // Check CPU flags for number of registers, setting the Z condition flag.
280 __ CheckFor32DRegs(ip);
282 __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
283 int src_offset = FrameDescription::double_registers_offset();
284 for (int i = 0; i < DwVfpRegister::kMaxNumRegisters; ++i) {
285 if (i == kDoubleRegZero.code()) continue;
286 if (i == kScratchDoubleReg.code()) continue;
288 const DwVfpRegister reg = DwVfpRegister::from_code(i);
289 __ vldr(reg, r1, src_offset, i < 16 ? al : ne);
290 src_offset += kDoubleSize;
293 // Push state, pc, and continuation from the last output frame.
294 __ ldr(r6, MemOperand(r2, FrameDescription::state_offset()));
296 __ ldr(r6, MemOperand(r2, FrameDescription::pc_offset()));
298 __ ldr(r6, MemOperand(r2, FrameDescription::continuation_offset()));
301 // Push the registers from the last output frame.
302 for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
303 int offset = (i * kPointerSize) + FrameDescription::registers_offset();
304 __ ldr(r6, MemOperand(r2, offset));
308 // Restore the registers from the stack.
309 __ ldm(ia_w, sp, restored_regs); // all but pc registers.
310 __ pop(ip); // remove sp
311 __ pop(ip); // remove lr
313 __ InitializeRootRegister();
315 __ pop(ip); // remove pc
316 __ pop(ip); // get continuation, leave pc on stack
319 __ stop("Unreachable.");
323 void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
324 // Create a sequence of deoptimization entries.
325 // Note that registers are still live when jumping to an entry.
327 for (int i = 0; i < count(); i++) {
328 int start = masm()->pc_offset();
330 __ mov(ip, Operand(i));
333 ASSERT(masm()->pc_offset() - start == table_entry_size_);
339 void FrameDescription::SetCallerPc(unsigned offset, intptr_t value) {
340 SetFrameSlot(offset, value);
344 void FrameDescription::SetCallerFp(unsigned offset, intptr_t value) {
345 SetFrameSlot(offset, value);
349 void FrameDescription::SetCallerConstantPool(unsigned offset, intptr_t value) {
350 ASSERT(FLAG_enable_ool_constant_pool);
351 SetFrameSlot(offset, value);
357 } } // namespace v8::internal