1// Copyright 2012 the V8 project authors. All rights reserved.
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3// modification, are permitted provided that the following conditions are
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27
28#include "v8.h"
29
30#include "codegen.h"
31#include "deoptimizer.h"
32#include "full-codegen.h"
33#include "safepoint-table.h"
34
35namespace v8 {
36namespace internal {
37
38const int Deoptimizer::table_entry_size_ = 16;
39
40
41int Deoptimizer::patch_size() {
42  const int kCallInstructionSizeInWords = 3;
43  return kCallInstructionSizeInWords * Assembler::kInstrSize;
44}
45
46
47void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
48  HandleScope scope;
49  AssertNoAllocation no_allocation;
50
51  if (!function->IsOptimized()) return;
52
53  // Get the optimized code.
54  Code* code = function->code();
55  Address code_start_address = code->instruction_start();
56
57  // Invalidate the relocation information, as it will become invalid by the
58  // code patching below, and is not needed any more.
59  code->InvalidateRelocation();
60
61  // For each LLazyBailout instruction insert a call to the corresponding
62  // deoptimization entry.
63  DeoptimizationInputData* deopt_data =
64      DeoptimizationInputData::cast(code->deoptimization_data());
65#ifdef DEBUG
66  Address prev_call_address = NULL;
67#endif
68  for (int i = 0; i < deopt_data->DeoptCount(); i++) {
69    if (deopt_data->Pc(i)->value() == -1) continue;
70    Address call_address = code_start_address + deopt_data->Pc(i)->value();
71    Address deopt_entry = GetDeoptimizationEntry(i, LAZY);
72    int call_size_in_bytes = MacroAssembler::CallSize(deopt_entry,
73                                                      RelocInfo::NONE);
74    int call_size_in_words = call_size_in_bytes / Assembler::kInstrSize;
75    ASSERT(call_size_in_bytes % Assembler::kInstrSize == 0);
76    ASSERT(call_size_in_bytes <= patch_size());
77    CodePatcher patcher(call_address, call_size_in_words);
78    patcher.masm()->Call(deopt_entry, RelocInfo::NONE);
79    ASSERT(prev_call_address == NULL ||
80           call_address >= prev_call_address + patch_size());
81    ASSERT(call_address + patch_size() <= code->instruction_end());
82#ifdef DEBUG
83    prev_call_address = call_address;
84#endif
85  }
86
87  Isolate* isolate = code->GetIsolate();
88
89  // Add the deoptimizing code to the list.
90  DeoptimizingCodeListNode* node = new DeoptimizingCodeListNode(code);
91  DeoptimizerData* data = isolate->deoptimizer_data();
92  node->set_next(data->deoptimizing_code_list_);
93  data->deoptimizing_code_list_ = node;
94
95  // We might be in the middle of incremental marking with compaction.
96  // Tell collector to treat this code object in a special way and
97  // ignore all slots that might have been recorded on it.
98  isolate->heap()->mark_compact_collector()->InvalidateCode(code);
99
100  // Set the code for the function to non-optimized version.
101  function->ReplaceCode(function->shared()->code());
102
103  if (FLAG_trace_deopt) {
104    PrintF("[forced deoptimization: ");
105    function->PrintName();
106    PrintF(" / %x]\n", reinterpret_cast<uint32_t>(function));
107  }
108}
109
110
111static const int32_t kBranchBeforeStackCheck = 0x2a000001;
112static const int32_t kBranchBeforeInterrupt =  0x5a000004;
113
114
115void Deoptimizer::PatchStackCheckCodeAt(Code* unoptimized_code,
116                                        Address pc_after,
117                                        Code* check_code,
118                                        Code* replacement_code) {
119  const int kInstrSize = Assembler::kInstrSize;
120  // The call of the stack guard check has the following form:
121  //  e1 5d 00 0c       cmp sp, <limit>
122  //  2a 00 00 01       bcs ok
123  //  e5 9f c? ??       ldr ip, [pc, <stack guard address>]
124  //  e1 2f ff 3c       blx ip
125  ASSERT(Memory::int32_at(pc_after - kInstrSize) == kBlxIp);
126  ASSERT(Assembler::IsLdrPcImmediateOffset(
127      Assembler::instr_at(pc_after - 2 * kInstrSize)));
128  if (FLAG_count_based_interrupts) {
129    ASSERT_EQ(kBranchBeforeInterrupt,
130              Memory::int32_at(pc_after - 3 * kInstrSize));
131  } else {
132    ASSERT_EQ(kBranchBeforeStackCheck,
133              Memory::int32_at(pc_after - 3 * kInstrSize));
134  }
135
136  // We patch the code to the following form:
137  //  e1 5d 00 0c       cmp sp, <limit>
138  //  e1 a0 00 00       mov r0, r0 (NOP)
139  //  e5 9f c? ??       ldr ip, [pc, <on-stack replacement address>]
140  //  e1 2f ff 3c       blx ip
141  // and overwrite the constant containing the
142  // address of the stack check stub.
143
144  // Replace conditional jump with NOP.
145  CodePatcher patcher(pc_after - 3 * kInstrSize, 1);
146  patcher.masm()->nop();
147
148  // Replace the stack check address in the constant pool
149  // with the entry address of the replacement code.
150  uint32_t stack_check_address_offset = Memory::uint16_at(pc_after -
151      2 * kInstrSize) & 0xfff;
152  Address stack_check_address_pointer = pc_after + stack_check_address_offset;
153  ASSERT(Memory::uint32_at(stack_check_address_pointer) ==
154         reinterpret_cast<uint32_t>(check_code->entry()));
155  Memory::uint32_at(stack_check_address_pointer) =
156      reinterpret_cast<uint32_t>(replacement_code->entry());
157
158  unoptimized_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
159      unoptimized_code, pc_after - 2 * kInstrSize, replacement_code);
160}
161
162
163void Deoptimizer::RevertStackCheckCodeAt(Code* unoptimized_code,
164                                         Address pc_after,
165                                         Code* check_code,
166                                         Code* replacement_code) {
167  const int kInstrSize = Assembler::kInstrSize;
168  ASSERT(Memory::int32_at(pc_after - kInstrSize) == kBlxIp);
169  ASSERT(Assembler::IsLdrPcImmediateOffset(
170      Assembler::instr_at(pc_after - 2 * kInstrSize)));
171
172  // Replace NOP with conditional jump.
173  CodePatcher patcher(pc_after - 3 * kInstrSize, 1);
174  if (FLAG_count_based_interrupts) {
175    patcher.masm()->b(+16, pl);
176    ASSERT_EQ(kBranchBeforeInterrupt,
177              Memory::int32_at(pc_after - 3 * kInstrSize));
178  } else {
179    patcher.masm()->b(+4, cs);
180    ASSERT_EQ(kBranchBeforeStackCheck,
181              Memory::int32_at(pc_after - 3 * kInstrSize));
182  }
183
184  // Replace the stack check address in the constant pool
185  // with the entry address of the replacement code.
186  uint32_t stack_check_address_offset = Memory::uint16_at(pc_after -
187      2 * kInstrSize) & 0xfff;
188  Address stack_check_address_pointer = pc_after + stack_check_address_offset;
189  ASSERT(Memory::uint32_at(stack_check_address_pointer) ==
190         reinterpret_cast<uint32_t>(replacement_code->entry()));
191  Memory::uint32_at(stack_check_address_pointer) =
192      reinterpret_cast<uint32_t>(check_code->entry());
193
194  check_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
195      unoptimized_code, pc_after - 2 * kInstrSize, check_code);
196}
197
198
199static int LookupBailoutId(DeoptimizationInputData* data, unsigned ast_id) {
200  ByteArray* translations = data->TranslationByteArray();
201  int length = data->DeoptCount();
202  for (int i = 0; i < length; i++) {
203    if (static_cast<unsigned>(data->AstId(i)->value()) == ast_id) {
204      TranslationIterator it(translations,  data->TranslationIndex(i)->value());
205      int value = it.Next();
206      ASSERT(Translation::BEGIN == static_cast<Translation::Opcode>(value));
207      // Read the number of frames.
208      value = it.Next();
209      if (value == 1) return i;
210    }
211  }
212  UNREACHABLE();
213  return -1;
214}
215
216
217void Deoptimizer::DoComputeOsrOutputFrame() {
218  DeoptimizationInputData* data = DeoptimizationInputData::cast(
219      optimized_code_->deoptimization_data());
220  unsigned ast_id = data->OsrAstId()->value();
221
222  int bailout_id = LookupBailoutId(data, ast_id);
223  unsigned translation_index = data->TranslationIndex(bailout_id)->value();
224  ByteArray* translations = data->TranslationByteArray();
225
226  TranslationIterator iterator(translations, translation_index);
227  Translation::Opcode opcode =
228      static_cast<Translation::Opcode>(iterator.Next());
229  ASSERT(Translation::BEGIN == opcode);
230  USE(opcode);
231  int count = iterator.Next();
232  iterator.Skip(1);  // Drop JS frame count.
233  ASSERT(count == 1);
234  USE(count);
235
236  opcode = static_cast<Translation::Opcode>(iterator.Next());
237  USE(opcode);
238  ASSERT(Translation::JS_FRAME == opcode);
239  unsigned node_id = iterator.Next();
240  USE(node_id);
241  ASSERT(node_id == ast_id);
242  JSFunction* function = JSFunction::cast(ComputeLiteral(iterator.Next()));
243  USE(function);
244  ASSERT(function == function_);
245  unsigned height = iterator.Next();
246  unsigned height_in_bytes = height * kPointerSize;
247  USE(height_in_bytes);
248
249  unsigned fixed_size = ComputeFixedSize(function_);
250  unsigned input_frame_size = input_->GetFrameSize();
251  ASSERT(fixed_size + height_in_bytes == input_frame_size);
252
253  unsigned stack_slot_size = optimized_code_->stack_slots() * kPointerSize;
254  unsigned outgoing_height = data->ArgumentsStackHeight(bailout_id)->value();
255  unsigned outgoing_size = outgoing_height * kPointerSize;
256  unsigned output_frame_size = fixed_size + stack_slot_size + outgoing_size;
257  ASSERT(outgoing_size == 0);  // OSR does not happen in the middle of a call.
258
259  if (FLAG_trace_osr) {
260    PrintF("[on-stack replacement: begin 0x%08" V8PRIxPTR " ",
261           reinterpret_cast<intptr_t>(function_));
262    function_->PrintName();
263    PrintF(" => node=%u, frame=%d->%d]\n",
264           ast_id,
265           input_frame_size,
266           output_frame_size);
267  }
268
269  // There's only one output frame in the OSR case.
270  output_count_ = 1;
271  output_ = new FrameDescription*[1];
272  output_[0] = new(output_frame_size) FrameDescription(
273      output_frame_size, function_);
274  output_[0]->SetFrameType(StackFrame::JAVA_SCRIPT);
275
276  // Clear the incoming parameters in the optimized frame to avoid
277  // confusing the garbage collector.
278  unsigned output_offset = output_frame_size - kPointerSize;
279  int parameter_count = function_->shared()->formal_parameter_count() + 1;
280  for (int i = 0; i < parameter_count; ++i) {
281    output_[0]->SetFrameSlot(output_offset, 0);
282    output_offset -= kPointerSize;
283  }
284
285  // Translate the incoming parameters. This may overwrite some of the
286  // incoming argument slots we've just cleared.
287  int input_offset = input_frame_size - kPointerSize;
288  bool ok = true;
289  int limit = input_offset - (parameter_count * kPointerSize);
290  while (ok && input_offset > limit) {
291    ok = DoOsrTranslateCommand(&iterator, &input_offset);
292  }
293
294  // There are no translation commands for the caller's pc and fp, the
295  // context, and the function.  Set them up explicitly.
296  for (int i =  StandardFrameConstants::kCallerPCOffset;
297       ok && i >=  StandardFrameConstants::kMarkerOffset;
298       i -= kPointerSize) {
299    uint32_t input_value = input_->GetFrameSlot(input_offset);
300    if (FLAG_trace_osr) {
301      const char* name = "UNKNOWN";
302      switch (i) {
303        case StandardFrameConstants::kCallerPCOffset:
304          name = "caller's pc";
305          break;
306        case StandardFrameConstants::kCallerFPOffset:
307          name = "fp";
308          break;
309        case StandardFrameConstants::kContextOffset:
310          name = "context";
311          break;
312        case StandardFrameConstants::kMarkerOffset:
313          name = "function";
314          break;
315      }
316      PrintF("    [sp + %d] <- 0x%08x ; [sp + %d] (fixed part - %s)\n",
317             output_offset,
318             input_value,
319             input_offset,
320             name);
321    }
322
323    output_[0]->SetFrameSlot(output_offset, input_->GetFrameSlot(input_offset));
324    input_offset -= kPointerSize;
325    output_offset -= kPointerSize;
326  }
327
328  // Translate the rest of the frame.
329  while (ok && input_offset >= 0) {
330    ok = DoOsrTranslateCommand(&iterator, &input_offset);
331  }
332
333  // If translation of any command failed, continue using the input frame.
334  if (!ok) {
335    delete output_[0];
336    output_[0] = input_;
337    output_[0]->SetPc(reinterpret_cast<uint32_t>(from_));
338  } else {
339    // Set up the frame pointer and the context pointer.
340    output_[0]->SetRegister(fp.code(), input_->GetRegister(fp.code()));
341    output_[0]->SetRegister(cp.code(), input_->GetRegister(cp.code()));
342
343    unsigned pc_offset = data->OsrPcOffset()->value();
344    uint32_t pc = reinterpret_cast<uint32_t>(
345        optimized_code_->entry() + pc_offset);
346    output_[0]->SetPc(pc);
347  }
348  Code* continuation = isolate_->builtins()->builtin(Builtins::kNotifyOSR);
349  output_[0]->SetContinuation(
350      reinterpret_cast<uint32_t>(continuation->entry()));
351
352  if (FLAG_trace_osr) {
353    PrintF("[on-stack replacement translation %s: 0x%08" V8PRIxPTR " ",
354           ok ? "finished" : "aborted",
355           reinterpret_cast<intptr_t>(function));
356    function->PrintName();
357    PrintF(" => pc=0x%0x]\n", output_[0]->GetPc());
358  }
359}
360
361
362void Deoptimizer::DoComputeArgumentsAdaptorFrame(TranslationIterator* iterator,
363                                                 int frame_index) {
364  JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
365  unsigned height = iterator->Next();
366  unsigned height_in_bytes = height * kPointerSize;
367  if (FLAG_trace_deopt) {
368    PrintF("  translating arguments adaptor => height=%d\n", height_in_bytes);
369  }
370
371  unsigned fixed_frame_size = ArgumentsAdaptorFrameConstants::kFrameSize;
372  unsigned output_frame_size = height_in_bytes + fixed_frame_size;
373
374  // Allocate and store the output frame description.
375  FrameDescription* output_frame =
376      new(output_frame_size) FrameDescription(output_frame_size, function);
377  output_frame->SetFrameType(StackFrame::ARGUMENTS_ADAPTOR);
378
379  // Arguments adaptor can not be topmost or bottommost.
380  ASSERT(frame_index > 0 && frame_index < output_count_ - 1);
381  ASSERT(output_[frame_index] == NULL);
382  output_[frame_index] = output_frame;
383
384  // The top address of the frame is computed from the previous
385  // frame's top and this frame's size.
386  uint32_t top_address;
387  top_address = output_[frame_index - 1]->GetTop() - output_frame_size;
388  output_frame->SetTop(top_address);
389
390  // Compute the incoming parameter translation.
391  int parameter_count = height;
392  unsigned output_offset = output_frame_size;
393  for (int i = 0; i < parameter_count; ++i) {
394    output_offset -= kPointerSize;
395    DoTranslateCommand(iterator, frame_index, output_offset);
396  }
397
398  // Read caller's PC from the previous frame.
399  output_offset -= kPointerSize;
400  intptr_t callers_pc = output_[frame_index - 1]->GetPc();
401  output_frame->SetFrameSlot(output_offset, callers_pc);
402  if (FLAG_trace_deopt) {
403    PrintF("    0x%08x: [top + %d] <- 0x%08x ; caller's pc\n",
404           top_address + output_offset, output_offset, callers_pc);
405  }
406
407  // Read caller's FP from the previous frame, and set this frame's FP.
408  output_offset -= kPointerSize;
409  intptr_t value = output_[frame_index - 1]->GetFp();
410  output_frame->SetFrameSlot(output_offset, value);
411  intptr_t fp_value = top_address + output_offset;
412  output_frame->SetFp(fp_value);
413  if (FLAG_trace_deopt) {
414    PrintF("    0x%08x: [top + %d] <- 0x%08x ; caller's fp\n",
415           fp_value, output_offset, value);
416  }
417
418  // A marker value is used in place of the context.
419  output_offset -= kPointerSize;
420  intptr_t context = reinterpret_cast<intptr_t>(
421      Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
422  output_frame->SetFrameSlot(output_offset, context);
423  if (FLAG_trace_deopt) {
424    PrintF("    0x%08x: [top + %d] <- 0x%08x ; context (adaptor sentinel)\n",
425           top_address + output_offset, output_offset, context);
426  }
427
428  // The function was mentioned explicitly in the ARGUMENTS_ADAPTOR_FRAME.
429  output_offset -= kPointerSize;
430  value = reinterpret_cast<intptr_t>(function);
431  output_frame->SetFrameSlot(output_offset, value);
432  if (FLAG_trace_deopt) {
433    PrintF("    0x%08x: [top + %d] <- 0x%08x ; function\n",
434           top_address + output_offset, output_offset, value);
435  }
436
437  // Number of incoming arguments.
438  output_offset -= kPointerSize;
439  value = reinterpret_cast<uint32_t>(Smi::FromInt(height - 1));
440  output_frame->SetFrameSlot(output_offset, value);
441  if (FLAG_trace_deopt) {
442    PrintF("    0x%08x: [top + %d] <- 0x%08x ; argc (%d)\n",
443           top_address + output_offset, output_offset, value, height - 1);
444  }
445
446  ASSERT(0 == output_offset);
447
448  Builtins* builtins = isolate_->builtins();
449  Code* adaptor_trampoline =
450      builtins->builtin(Builtins::kArgumentsAdaptorTrampoline);
451  uint32_t pc = reinterpret_cast<uint32_t>(
452      adaptor_trampoline->instruction_start() +
453      isolate_->heap()->arguments_adaptor_deopt_pc_offset()->value());
454  output_frame->SetPc(pc);
455}
456
457
458void Deoptimizer::DoComputeConstructStubFrame(TranslationIterator* iterator,
459                                              int frame_index) {
460  Builtins* builtins = isolate_->builtins();
461  Code* construct_stub = builtins->builtin(Builtins::kJSConstructStubGeneric);
462  JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
463  unsigned height = iterator->Next();
464  unsigned height_in_bytes = height * kPointerSize;
465  if (FLAG_trace_deopt) {
466    PrintF("  translating construct stub => height=%d\n", height_in_bytes);
467  }
468
469  unsigned fixed_frame_size = 8 * kPointerSize;
470  unsigned output_frame_size = height_in_bytes + fixed_frame_size;
471
472  // Allocate and store the output frame description.
473  FrameDescription* output_frame =
474      new(output_frame_size) FrameDescription(output_frame_size, function);
475  output_frame->SetFrameType(StackFrame::CONSTRUCT);
476
477  // Construct stub can not be topmost or bottommost.
478  ASSERT(frame_index > 0 && frame_index < output_count_ - 1);
479  ASSERT(output_[frame_index] == NULL);
480  output_[frame_index] = output_frame;
481
482  // The top address of the frame is computed from the previous
483  // frame's top and this frame's size.
484  uint32_t top_address;
485  top_address = output_[frame_index - 1]->GetTop() - output_frame_size;
486  output_frame->SetTop(top_address);
487
488  // Compute the incoming parameter translation.
489  int parameter_count = height;
490  unsigned output_offset = output_frame_size;
491  for (int i = 0; i < parameter_count; ++i) {
492    output_offset -= kPointerSize;
493    DoTranslateCommand(iterator, frame_index, output_offset);
494  }
495
496  // Read caller's PC from the previous frame.
497  output_offset -= kPointerSize;
498  intptr_t callers_pc = output_[frame_index - 1]->GetPc();
499  output_frame->SetFrameSlot(output_offset, callers_pc);
500  if (FLAG_trace_deopt) {
501    PrintF("    0x%08x: [top + %d] <- 0x%08x ; caller's pc\n",
502           top_address + output_offset, output_offset, callers_pc);
503  }
504
505  // Read caller's FP from the previous frame, and set this frame's FP.
506  output_offset -= kPointerSize;
507  intptr_t value = output_[frame_index - 1]->GetFp();
508  output_frame->SetFrameSlot(output_offset, value);
509  intptr_t fp_value = top_address + output_offset;
510  output_frame->SetFp(fp_value);
511  if (FLAG_trace_deopt) {
512    PrintF("    0x%08x: [top + %d] <- 0x%08x ; caller's fp\n",
513           fp_value, output_offset, value);
514  }
515
516  // The context can be gotten from the previous frame.
517  output_offset -= kPointerSize;
518  value = output_[frame_index - 1]->GetContext();
519  output_frame->SetFrameSlot(output_offset, value);
520  if (FLAG_trace_deopt) {
521    PrintF("    0x%08x: [top + %d] <- 0x%08x ; context\n",
522           top_address + output_offset, output_offset, value);
523  }
524
525  // A marker value is used in place of the function.
526  output_offset -= kPointerSize;
527  value = reinterpret_cast<intptr_t>(Smi::FromInt(StackFrame::CONSTRUCT));
528  output_frame->SetFrameSlot(output_offset, value);
529  if (FLAG_trace_deopt) {
530    PrintF("    0x%08x: [top + %d] <- 0x%08x ; function (construct sentinel)\n",
531           top_address + output_offset, output_offset, value);
532  }
533
534  // The output frame reflects a JSConstructStubGeneric frame.
535  output_offset -= kPointerSize;
536  value = reinterpret_cast<intptr_t>(construct_stub);
537  output_frame->SetFrameSlot(output_offset, value);
538  if (FLAG_trace_deopt) {
539    PrintF("    0x%08x: [top + %d] <- 0x%08x ; code object\n",
540           top_address + output_offset, output_offset, value);
541  }
542
543  // Number of incoming arguments.
544  output_offset -= kPointerSize;
545  value = reinterpret_cast<uint32_t>(Smi::FromInt(height - 1));
546  output_frame->SetFrameSlot(output_offset, value);
547  if (FLAG_trace_deopt) {
548    PrintF("    0x%08x: [top + %d] <- 0x%08x ; argc (%d)\n",
549           top_address + output_offset, output_offset, value, height - 1);
550  }
551
552  // Constructor function being invoked by the stub.
553  output_offset -= kPointerSize;
554  value = reinterpret_cast<intptr_t>(function);
555  output_frame->SetFrameSlot(output_offset, value);
556  if (FLAG_trace_deopt) {
557    PrintF("    0x%08x: [top + %d] <- 0x%08x ; constructor function\n",
558           top_address + output_offset, output_offset, value);
559  }
560
561  // The newly allocated object was passed as receiver in the artificial
562  // constructor stub environment created by HEnvironment::CopyForInlining().
563  output_offset -= kPointerSize;
564  value = output_frame->GetFrameSlot(output_frame_size - kPointerSize);
565  output_frame->SetFrameSlot(output_offset, value);
566  if (FLAG_trace_deopt) {
567    PrintF("    0x%08x: [top + %d] <- 0x%08x ; allocated receiver\n",
568           top_address + output_offset, output_offset, value);
569  }
570
571  ASSERT(0 == output_offset);
572
573  uint32_t pc = reinterpret_cast<uint32_t>(
574      construct_stub->instruction_start() +
575      isolate_->heap()->construct_stub_deopt_pc_offset()->value());
576  output_frame->SetPc(pc);
577}
578
579
580// This code is very similar to ia32 code, but relies on register names (fp, sp)
581// and how the frame is laid out.
582void Deoptimizer::DoComputeJSFrame(TranslationIterator* iterator,
583                                   int frame_index) {
584  // Read the ast node id, function, and frame height for this output frame.
585  int node_id = iterator->Next();
586  JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
587  unsigned height = iterator->Next();
588  unsigned height_in_bytes = height * kPointerSize;
589  if (FLAG_trace_deopt) {
590    PrintF("  translating ");
591    function->PrintName();
592    PrintF(" => node=%d, height=%d\n", node_id, height_in_bytes);
593  }
594
595  // The 'fixed' part of the frame consists of the incoming parameters and
596  // the part described by JavaScriptFrameConstants.
597  unsigned fixed_frame_size = ComputeFixedSize(function);
598  unsigned input_frame_size = input_->GetFrameSize();
599  unsigned output_frame_size = height_in_bytes + fixed_frame_size;
600
601  // Allocate and store the output frame description.
602  FrameDescription* output_frame =
603      new(output_frame_size) FrameDescription(output_frame_size, function);
604  output_frame->SetFrameType(StackFrame::JAVA_SCRIPT);
605
606  bool is_bottommost = (0 == frame_index);
607  bool is_topmost = (output_count_ - 1 == frame_index);
608  ASSERT(frame_index >= 0 && frame_index < output_count_);
609  ASSERT(output_[frame_index] == NULL);
610  output_[frame_index] = output_frame;
611
612  // The top address for the bottommost output frame can be computed from
613  // the input frame pointer and the output frame's height.  For all
614  // subsequent output frames, it can be computed from the previous one's
615  // top address and the current frame's size.
616  uint32_t top_address;
617  if (is_bottommost) {
618    // 2 = context and function in the frame.
619    top_address =
620        input_->GetRegister(fp.code()) - (2 * kPointerSize) - height_in_bytes;
621  } else {
622    top_address = output_[frame_index - 1]->GetTop() - output_frame_size;
623  }
624  output_frame->SetTop(top_address);
625
626  // Compute the incoming parameter translation.
627  int parameter_count = function->shared()->formal_parameter_count() + 1;
628  unsigned output_offset = output_frame_size;
629  unsigned input_offset = input_frame_size;
630  for (int i = 0; i < parameter_count; ++i) {
631    output_offset -= kPointerSize;
632    DoTranslateCommand(iterator, frame_index, output_offset);
633  }
634  input_offset -= (parameter_count * kPointerSize);
635
636  // There are no translation commands for the caller's pc and fp, the
637  // context, and the function.  Synthesize their values and set them up
638  // explicitly.
639  //
640  // The caller's pc for the bottommost output frame is the same as in the
641  // input frame.  For all subsequent output frames, it can be read from the
642  // previous one.  This frame's pc can be computed from the non-optimized
643  // function code and AST id of the bailout.
644  output_offset -= kPointerSize;
645  input_offset -= kPointerSize;
646  intptr_t value;
647  if (is_bottommost) {
648    value = input_->GetFrameSlot(input_offset);
649  } else {
650    value = output_[frame_index - 1]->GetPc();
651  }
652  output_frame->SetFrameSlot(output_offset, value);
653  if (FLAG_trace_deopt) {
654    PrintF("    0x%08x: [top + %d] <- 0x%08x ; caller's pc\n",
655           top_address + output_offset, output_offset, value);
656  }
657
658  // The caller's frame pointer for the bottommost output frame is the same
659  // as in the input frame.  For all subsequent output frames, it can be
660  // read from the previous one.  Also compute and set this frame's frame
661  // pointer.
662  output_offset -= kPointerSize;
663  input_offset -= kPointerSize;
664  if (is_bottommost) {
665    value = input_->GetFrameSlot(input_offset);
666  } else {
667    value = output_[frame_index - 1]->GetFp();
668  }
669  output_frame->SetFrameSlot(output_offset, value);
670  intptr_t fp_value = top_address + output_offset;
671  ASSERT(!is_bottommost || input_->GetRegister(fp.code()) == fp_value);
672  output_frame->SetFp(fp_value);
673  if (is_topmost) {
674    output_frame->SetRegister(fp.code(), fp_value);
675  }
676  if (FLAG_trace_deopt) {
677    PrintF("    0x%08x: [top + %d] <- 0x%08x ; caller's fp\n",
678           fp_value, output_offset, value);
679  }
680
681  // For the bottommost output frame the context can be gotten from the input
682  // frame. For all subsequent output frames it can be gotten from the function
683  // so long as we don't inline functions that need local contexts.
684  output_offset -= kPointerSize;
685  input_offset -= kPointerSize;
686  if (is_bottommost) {
687    value = input_->GetFrameSlot(input_offset);
688  } else {
689    value = reinterpret_cast<intptr_t>(function->context());
690  }
691  output_frame->SetFrameSlot(output_offset, value);
692  output_frame->SetContext(value);
693  if (is_topmost) output_frame->SetRegister(cp.code(), value);
694  if (FLAG_trace_deopt) {
695    PrintF("    0x%08x: [top + %d] <- 0x%08x ; context\n",
696           top_address + output_offset, output_offset, value);
697  }
698
699  // The function was mentioned explicitly in the BEGIN_FRAME.
700  output_offset -= kPointerSize;
701  input_offset -= kPointerSize;
702  value = reinterpret_cast<uint32_t>(function);
703  // The function for the bottommost output frame should also agree with the
704  // input frame.
705  ASSERT(!is_bottommost || input_->GetFrameSlot(input_offset) == value);
706  output_frame->SetFrameSlot(output_offset, value);
707  if (FLAG_trace_deopt) {
708    PrintF("    0x%08x: [top + %d] <- 0x%08x ; function\n",
709           top_address + output_offset, output_offset, value);
710  }
711
712  // Translate the rest of the frame.
713  for (unsigned i = 0; i < height; ++i) {
714    output_offset -= kPointerSize;
715    DoTranslateCommand(iterator, frame_index, output_offset);
716  }
717  ASSERT(0 == output_offset);
718
719  // Compute this frame's PC, state, and continuation.
720  Code* non_optimized_code = function->shared()->code();
721  FixedArray* raw_data = non_optimized_code->deoptimization_data();
722  DeoptimizationOutputData* data = DeoptimizationOutputData::cast(raw_data);
723  Address start = non_optimized_code->instruction_start();
724  unsigned pc_and_state = GetOutputInfo(data, node_id, function->shared());
725  unsigned pc_offset = FullCodeGenerator::PcField::decode(pc_and_state);
726  uint32_t pc_value = reinterpret_cast<uint32_t>(start + pc_offset);
727  output_frame->SetPc(pc_value);
728  if (is_topmost) {
729    output_frame->SetRegister(pc.code(), pc_value);
730  }
731
732  FullCodeGenerator::State state =
733      FullCodeGenerator::StateField::decode(pc_and_state);
734  output_frame->SetState(Smi::FromInt(state));
735
736
737  // Set the continuation for the topmost frame.
738  if (is_topmost && bailout_type_ != DEBUGGER) {
739    Builtins* builtins = isolate_->builtins();
740    Code* continuation = (bailout_type_ == EAGER)
741        ? builtins->builtin(Builtins::kNotifyDeoptimized)
742        : builtins->builtin(Builtins::kNotifyLazyDeoptimized);
743    output_frame->SetContinuation(
744        reinterpret_cast<uint32_t>(continuation->entry()));
745  }
746}
747
748
749void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
750  // Set the register values. The values are not important as there are no
751  // callee saved registers in JavaScript frames, so all registers are
752  // spilled. Registers fp and sp are set to the correct values though.
753
754  for (int i = 0; i < Register::kNumRegisters; i++) {
755    input_->SetRegister(i, i * 4);
756  }
757  input_->SetRegister(sp.code(), reinterpret_cast<intptr_t>(frame->sp()));
758  input_->SetRegister(fp.code(), reinterpret_cast<intptr_t>(frame->fp()));
759  for (int i = 0; i < DoubleRegister::kNumAllocatableRegisters; i++) {
760    input_->SetDoubleRegister(i, 0.0);
761  }
762
763  // Fill the frame content from the actual data on the frame.
764  for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
765    input_->SetFrameSlot(i, Memory::uint32_at(tos + i));
766  }
767}
768
769
770#define __ masm()->
771
772// This code tries to be close to ia32 code so that any changes can be
773// easily ported.
774void Deoptimizer::EntryGenerator::Generate() {
775  GeneratePrologue();
776
777  Isolate* isolate = masm()->isolate();
778
779  CpuFeatures::Scope scope(VFP3);
780  // Save all general purpose registers before messing with them.
781  const int kNumberOfRegisters = Register::kNumRegisters;
782
783  // Everything but pc, lr and ip which will be saved but not restored.
784  RegList restored_regs = kJSCallerSaved | kCalleeSaved | ip.bit();
785
786  const int kDoubleRegsSize =
787      kDoubleSize * DwVfpRegister::kNumAllocatableRegisters;
788
789  // Save all VFP registers before messing with them.
790  DwVfpRegister first = DwVfpRegister::FromAllocationIndex(0);
791  DwVfpRegister last =
792      DwVfpRegister::FromAllocationIndex(
793          DwVfpRegister::kNumAllocatableRegisters - 1);
794  ASSERT(last.code() > first.code());
795  ASSERT((last.code() - first.code()) ==
796      (DwVfpRegister::kNumAllocatableRegisters - 1));
797#ifdef DEBUG
798  for (int i = 0; i <= (DwVfpRegister::kNumAllocatableRegisters - 1); i++) {
799    ASSERT((DwVfpRegister::FromAllocationIndex(i).code() <= last.code()) &&
800           (DwVfpRegister::FromAllocationIndex(i).code() >= first.code()));
801  }
802#endif
803  __ vstm(db_w, sp, first, last);
804
805  // Push all 16 registers (needed to populate FrameDescription::registers_).
806  // TODO(1588) Note that using pc with stm is deprecated, so we should perhaps
807  // handle this a bit differently.
808  __ stm(db_w, sp, restored_regs  | sp.bit() | lr.bit() | pc.bit());
809
810  const int kSavedRegistersAreaSize =
811      (kNumberOfRegisters * kPointerSize) + kDoubleRegsSize;
812
813  // Get the bailout id from the stack.
814  __ ldr(r2, MemOperand(sp, kSavedRegistersAreaSize));
815
816  // Get the address of the location in the code object if possible (r3) (return
817  // address for lazy deoptimization) and compute the fp-to-sp delta in
818  // register r4.
819  if (type() == EAGER) {
820    __ mov(r3, Operand(0));
821    // Correct one word for bailout id.
822    __ add(r4, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
823  } else if (type() == OSR) {
824    __ mov(r3, lr);
825    // Correct one word for bailout id.
826    __ add(r4, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
827  } else {
828    __ mov(r3, lr);
829    // Correct two words for bailout id and return address.
830    __ add(r4, sp, Operand(kSavedRegistersAreaSize + (2 * kPointerSize)));
831  }
832  __ sub(r4, fp, r4);
833
834  // Allocate a new deoptimizer object.
835  // Pass four arguments in r0 to r3 and fifth argument on stack.
836  __ PrepareCallCFunction(6, r5);
837  __ ldr(r0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
838  __ mov(r1, Operand(type()));  // bailout type,
839  // r2: bailout id already loaded.
840  // r3: code address or 0 already loaded.
841  __ str(r4, MemOperand(sp, 0 * kPointerSize));  // Fp-to-sp delta.
842  __ mov(r5, Operand(ExternalReference::isolate_address()));
843  __ str(r5, MemOperand(sp, 1 * kPointerSize));  // Isolate.
844  // Call Deoptimizer::New().
845  {
846    AllowExternalCallThatCantCauseGC scope(masm());
847    __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate), 6);
848  }
849
850  // Preserve "deoptimizer" object in register r0 and get the input
851  // frame descriptor pointer to r1 (deoptimizer->input_);
852  __ ldr(r1, MemOperand(r0, Deoptimizer::input_offset()));
853
854  // Copy core registers into FrameDescription::registers_[kNumRegisters].
855  ASSERT(Register::kNumRegisters == kNumberOfRegisters);
856  for (int i = 0; i < kNumberOfRegisters; i++) {
857    int offset = (i * kPointerSize) + FrameDescription::registers_offset();
858    __ ldr(r2, MemOperand(sp, i * kPointerSize));
859    __ str(r2, MemOperand(r1, offset));
860  }
861
862  // Copy VFP registers to
863  // double_registers_[DoubleRegister::kNumAllocatableRegisters]
864  int double_regs_offset = FrameDescription::double_registers_offset();
865  for (int i = 0; i < DwVfpRegister::kNumAllocatableRegisters; ++i) {
866    int dst_offset = i * kDoubleSize + double_regs_offset;
867    int src_offset = i * kDoubleSize + kNumberOfRegisters * kPointerSize;
868    __ vldr(d0, sp, src_offset);
869    __ vstr(d0, r1, dst_offset);
870  }
871
872  // Remove the bailout id, eventually return address, and the saved registers
873  // from the stack.
874  if (type() == EAGER || type() == OSR) {
875    __ add(sp, sp, Operand(kSavedRegistersAreaSize + (1 * kPointerSize)));
876  } else {
877    __ add(sp, sp, Operand(kSavedRegistersAreaSize + (2 * kPointerSize)));
878  }
879
880  // Compute a pointer to the unwinding limit in register r2; that is
881  // the first stack slot not part of the input frame.
882  __ ldr(r2, MemOperand(r1, FrameDescription::frame_size_offset()));
883  __ add(r2, r2, sp);
884
885  // Unwind the stack down to - but not including - the unwinding
886  // limit and copy the contents of the activation frame to the input
887  // frame description.
888  __ add(r3,  r1, Operand(FrameDescription::frame_content_offset()));
889  Label pop_loop;
890  __ bind(&pop_loop);
891  __ pop(r4);
892  __ str(r4, MemOperand(r3, 0));
893  __ add(r3, r3, Operand(sizeof(uint32_t)));
894  __ cmp(r2, sp);
895  __ b(ne, &pop_loop);
896
897  // Compute the output frame in the deoptimizer.
898  __ push(r0);  // Preserve deoptimizer object across call.
899  // r0: deoptimizer object; r1: scratch.
900  __ PrepareCallCFunction(1, r1);
901  // Call Deoptimizer::ComputeOutputFrames().
902  {
903    AllowExternalCallThatCantCauseGC scope(masm());
904    __ CallCFunction(
905        ExternalReference::compute_output_frames_function(isolate), 1);
906  }
907  __ pop(r0);  // Restore deoptimizer object (class Deoptimizer).
908
909  // Replace the current (input) frame with the output frames.
910  Label outer_push_loop, inner_push_loop;
911  // Outer loop state: r0 = current "FrameDescription** output_",
912  // r1 = one past the last FrameDescription**.
913  __ ldr(r1, MemOperand(r0, Deoptimizer::output_count_offset()));
914  __ ldr(r0, MemOperand(r0, Deoptimizer::output_offset()));  // r0 is output_.
915  __ add(r1, r0, Operand(r1, LSL, 2));
916  __ bind(&outer_push_loop);
917  // Inner loop state: r2 = current FrameDescription*, r3 = loop index.
918  __ ldr(r2, MemOperand(r0, 0));  // output_[ix]
919  __ ldr(r3, MemOperand(r2, FrameDescription::frame_size_offset()));
920  __ bind(&inner_push_loop);
921  __ sub(r3, r3, Operand(sizeof(uint32_t)));
922  __ add(r6, r2, Operand(r3));
923  __ ldr(r7, MemOperand(r6, FrameDescription::frame_content_offset()));
924  __ push(r7);
925  __ cmp(r3, Operand(0));
926  __ b(ne, &inner_push_loop);  // test for gt?
927  __ add(r0, r0, Operand(kPointerSize));
928  __ cmp(r0, r1);
929  __ b(lt, &outer_push_loop);
930
931  // Push state, pc, and continuation from the last output frame.
932  if (type() != OSR) {
933    __ ldr(r6, MemOperand(r2, FrameDescription::state_offset()));
934    __ push(r6);
935  }
936
937  __ ldr(r6, MemOperand(r2, FrameDescription::pc_offset()));
938  __ push(r6);
939  __ ldr(r6, MemOperand(r2, FrameDescription::continuation_offset()));
940  __ push(r6);
941
942  // Push the registers from the last output frame.
943  for (int i = kNumberOfRegisters - 1; i >= 0; i--) {
944    int offset = (i * kPointerSize) + FrameDescription::registers_offset();
945    __ ldr(r6, MemOperand(r2, offset));
946    __ push(r6);
947  }
948
949  // Restore the registers from the stack.
950  __ ldm(ia_w, sp, restored_regs);  // all but pc registers.
951  __ pop(ip);  // remove sp
952  __ pop(ip);  // remove lr
953
954  __ InitializeRootRegister();
955
956  __ pop(ip);  // remove pc
957  __ pop(r7);  // get continuation, leave pc on stack
958  __ pop(lr);
959  __ Jump(r7);
960  __ stop("Unreachable.");
961}
962
963
964void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
965  // Create a sequence of deoptimization entries. Note that any
966  // registers may be still live.
967  Label done;
968  for (int i = 0; i < count(); i++) {
969    int start = masm()->pc_offset();
970    USE(start);
971    if (type() == EAGER) {
972      __ nop();
973    } else {
974      // Emulate ia32 like call by pushing return address to stack.
975      __ push(lr);
976    }
977    __ mov(ip, Operand(i));
978    __ push(ip);
979    __ b(&done);
980    ASSERT(masm()->pc_offset() - start == table_entry_size_);
981  }
982  __ bind(&done);
983}
984
985#undef __
986
987} }  // namespace v8::internal
988