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1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 //     * Redistributions of source code must retain the above copyright
7 //       notice, this list of conditions and the following disclaimer.
8 //     * Redistributions in binary form must reproduce the above
9 //       copyright notice, this list of conditions and the following
10 //       disclaimer in the documentation and/or other materials provided
11 //       with the distribution.
12 //     * Neither the name of Google Inc. nor the names of its
13 //       contributors may be used to endorse or promote products derived
14 //       from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 
28 #include "v8.h"
29 
30 #if defined(V8_TARGET_ARCH_X64)
31 
32 #include "codegen.h"
33 #include "deoptimizer.h"
34 #include "full-codegen.h"
35 #include "safepoint-table.h"
36 
37 namespace v8 {
38 namespace internal {
39 
40 
41 const int Deoptimizer::table_entry_size_ = 10;
42 
43 
patch_size()44 int Deoptimizer::patch_size() {
45   return Assembler::kCallInstructionLength;
46 }
47 
48 
DeoptimizeFunction(JSFunction * function)49 void Deoptimizer::DeoptimizeFunction(JSFunction* function) {
50   HandleScope scope;
51   AssertNoAllocation no_allocation;
52 
53   if (!function->IsOptimized()) return;
54 
55   // Get the optimized code.
56   Code* code = function->code();
57 
58   // Invalidate the relocation information, as it will become invalid by the
59   // code patching below, and is not needed any more.
60   code->InvalidateRelocation();
61 
62   // For each LLazyBailout instruction insert a absolute call to the
63   // corresponding deoptimization entry, or a short call to an absolute
64   // jump if space is short. The absolute jumps are put in a table just
65   // before the safepoint table (space was allocated there when the Code
66   // object was created, if necessary).
67 
68   Address instruction_start = function->code()->instruction_start();
69 #ifdef DEBUG
70   Address prev_call_address = NULL;
71 #endif
72   DeoptimizationInputData* deopt_data =
73       DeoptimizationInputData::cast(code->deoptimization_data());
74   for (int i = 0; i < deopt_data->DeoptCount(); i++) {
75     if (deopt_data->Pc(i)->value() == -1) continue;
76     // Position where Call will be patched in.
77     Address call_address = instruction_start + deopt_data->Pc(i)->value();
78     // There is room enough to write a long call instruction because we pad
79     // LLazyBailout instructions with nops if necessary.
80     CodePatcher patcher(call_address, Assembler::kCallInstructionLength);
81     patcher.masm()->Call(GetDeoptimizationEntry(i, LAZY), RelocInfo::NONE);
82     ASSERT(prev_call_address == NULL ||
83            call_address >= prev_call_address + patch_size());
84     ASSERT(call_address + patch_size() <= code->instruction_end());
85 #ifdef DEBUG
86     prev_call_address = call_address;
87 #endif
88   }
89 
90   Isolate* isolate = code->GetIsolate();
91 
92   // Add the deoptimizing code to the list.
93   DeoptimizingCodeListNode* node = new DeoptimizingCodeListNode(code);
94   DeoptimizerData* data = isolate->deoptimizer_data();
95   node->set_next(data->deoptimizing_code_list_);
96   data->deoptimizing_code_list_ = node;
97 
98   // We might be in the middle of incremental marking with compaction.
99   // Tell collector to treat this code object in a special way and
100   // ignore all slots that might have been recorded on it.
101   isolate->heap()->mark_compact_collector()->InvalidateCode(code);
102 
103   // Set the code for the function to non-optimized version.
104   function->ReplaceCode(function->shared()->code());
105 
106   if (FLAG_trace_deopt) {
107     PrintF("[forced deoptimization: ");
108     function->PrintName();
109     PrintF(" / %" V8PRIxPTR "]\n", reinterpret_cast<intptr_t>(function));
110   }
111 }
112 
113 
PatchStackCheckCodeAt(Code * unoptimized_code,Address pc_after,Code * check_code,Code * replacement_code)114 void Deoptimizer::PatchStackCheckCodeAt(Code* unoptimized_code,
115                                         Address pc_after,
116                                         Code* check_code,
117                                         Code* replacement_code) {
118   Address call_target_address = pc_after - kIntSize;
119   ASSERT(check_code->entry() ==
120          Assembler::target_address_at(call_target_address));
121   // The stack check code matches the pattern:
122   //
123   //     cmp rsp, <limit>
124   //     jae ok
125   //     call <stack guard>
126   //     test rax, <loop nesting depth>
127   // ok: ...
128   //
129   // We will patch away the branch so the code is:
130   //
131   //     cmp rsp, <limit>  ;; Not changed
132   //     nop
133   //     nop
134   //     call <on-stack replacment>
135   //     test rax, <loop nesting depth>
136   // ok:
137   //
138   ASSERT(*(call_target_address - 3) == 0x73 &&  // jae
139          *(call_target_address - 2) == 0x07 &&  // offset
140          *(call_target_address - 1) == 0xe8);   // call
141   *(call_target_address - 3) = 0x66;  // 2 byte nop part 1
142   *(call_target_address - 2) = 0x90;  // 2 byte nop part 2
143   Assembler::set_target_address_at(call_target_address,
144                                    replacement_code->entry());
145 
146   unoptimized_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
147       unoptimized_code, call_target_address, replacement_code);
148 }
149 
150 
RevertStackCheckCodeAt(Code * unoptimized_code,Address pc_after,Code * check_code,Code * replacement_code)151 void Deoptimizer::RevertStackCheckCodeAt(Code* unoptimized_code,
152                                          Address pc_after,
153                                          Code* check_code,
154                                          Code* replacement_code) {
155   Address call_target_address = pc_after - kIntSize;
156   ASSERT(replacement_code->entry() ==
157          Assembler::target_address_at(call_target_address));
158   // Replace the nops from patching (Deoptimizer::PatchStackCheckCode) to
159   // restore the conditional branch.
160   ASSERT(*(call_target_address - 3) == 0x66 &&  // 2 byte nop part 1
161          *(call_target_address - 2) == 0x90 &&  // 2 byte nop part 2
162          *(call_target_address - 1) == 0xe8);   // call
163   *(call_target_address - 3) = 0x73;  // jae
164   *(call_target_address - 2) = 0x07;  // offset
165   Assembler::set_target_address_at(call_target_address,
166                                    check_code->entry());
167 
168   check_code->GetHeap()->incremental_marking()->RecordCodeTargetPatch(
169       unoptimized_code, call_target_address, check_code);
170 }
171 
172 
LookupBailoutId(DeoptimizationInputData * data,unsigned ast_id)173 static int LookupBailoutId(DeoptimizationInputData* data, unsigned ast_id) {
174   ByteArray* translations = data->TranslationByteArray();
175   int length = data->DeoptCount();
176   for (int i = 0; i < length; i++) {
177     if (static_cast<unsigned>(data->AstId(i)->value()) == ast_id) {
178       TranslationIterator it(translations,  data->TranslationIndex(i)->value());
179       int value = it.Next();
180       ASSERT(Translation::BEGIN == static_cast<Translation::Opcode>(value));
181       // Read the number of frames.
182       value = it.Next();
183       if (value == 1) return i;
184     }
185   }
186   UNREACHABLE();
187   return -1;
188 }
189 
190 
DoComputeOsrOutputFrame()191 void Deoptimizer::DoComputeOsrOutputFrame() {
192   DeoptimizationInputData* data = DeoptimizationInputData::cast(
193       optimized_code_->deoptimization_data());
194   unsigned ast_id = data->OsrAstId()->value();
195   // TODO(kasperl): This should not be the bailout_id_. It should be
196   // the ast id. Confusing.
197   ASSERT(bailout_id_ == ast_id);
198 
199   int bailout_id = LookupBailoutId(data, ast_id);
200   unsigned translation_index = data->TranslationIndex(bailout_id)->value();
201   ByteArray* translations = data->TranslationByteArray();
202 
203   TranslationIterator iterator(translations, translation_index);
204   Translation::Opcode opcode =
205       static_cast<Translation::Opcode>(iterator.Next());
206   ASSERT(Translation::BEGIN == opcode);
207   USE(opcode);
208   int count = iterator.Next();
209   iterator.Skip(1);  // Drop JS frame count.
210   ASSERT(count == 1);
211   USE(count);
212 
213   opcode = static_cast<Translation::Opcode>(iterator.Next());
214   USE(opcode);
215   ASSERT(Translation::JS_FRAME == opcode);
216   unsigned node_id = iterator.Next();
217   USE(node_id);
218   ASSERT(node_id == ast_id);
219   JSFunction* function = JSFunction::cast(ComputeLiteral(iterator.Next()));
220   USE(function);
221   ASSERT(function == function_);
222   unsigned height = iterator.Next();
223   unsigned height_in_bytes = height * kPointerSize;
224   USE(height_in_bytes);
225 
226   unsigned fixed_size = ComputeFixedSize(function_);
227   unsigned input_frame_size = input_->GetFrameSize();
228   ASSERT(fixed_size + height_in_bytes == input_frame_size);
229 
230   unsigned stack_slot_size = optimized_code_->stack_slots() * kPointerSize;
231   unsigned outgoing_height = data->ArgumentsStackHeight(bailout_id)->value();
232   unsigned outgoing_size = outgoing_height * kPointerSize;
233   unsigned output_frame_size = fixed_size + stack_slot_size + outgoing_size;
234   ASSERT(outgoing_size == 0);  // OSR does not happen in the middle of a call.
235 
236   if (FLAG_trace_osr) {
237     PrintF("[on-stack replacement: begin 0x%08" V8PRIxPTR " ",
238            reinterpret_cast<intptr_t>(function_));
239     function_->PrintName();
240     PrintF(" => node=%u, frame=%d->%d]\n",
241            ast_id,
242            input_frame_size,
243            output_frame_size);
244   }
245 
246   // There's only one output frame in the OSR case.
247   output_count_ = 1;
248   output_ = new FrameDescription*[1];
249   output_[0] = new(output_frame_size) FrameDescription(
250       output_frame_size, function_);
251   output_[0]->SetFrameType(StackFrame::JAVA_SCRIPT);
252 
253   // Clear the incoming parameters in the optimized frame to avoid
254   // confusing the garbage collector.
255   unsigned output_offset = output_frame_size - kPointerSize;
256   int parameter_count = function_->shared()->formal_parameter_count() + 1;
257   for (int i = 0; i < parameter_count; ++i) {
258     output_[0]->SetFrameSlot(output_offset, 0);
259     output_offset -= kPointerSize;
260   }
261 
262   // Translate the incoming parameters. This may overwrite some of the
263   // incoming argument slots we've just cleared.
264   int input_offset = input_frame_size - kPointerSize;
265   bool ok = true;
266   int limit = input_offset - (parameter_count * kPointerSize);
267   while (ok && input_offset > limit) {
268     ok = DoOsrTranslateCommand(&iterator, &input_offset);
269   }
270 
271   // There are no translation commands for the caller's pc and fp, the
272   // context, and the function.  Set them up explicitly.
273   for (int i = StandardFrameConstants::kCallerPCOffset;
274        ok && i >=  StandardFrameConstants::kMarkerOffset;
275        i -= kPointerSize) {
276     intptr_t input_value = input_->GetFrameSlot(input_offset);
277     if (FLAG_trace_osr) {
278       const char* name = "UNKNOWN";
279       switch (i) {
280         case StandardFrameConstants::kCallerPCOffset:
281           name = "caller's pc";
282           break;
283         case StandardFrameConstants::kCallerFPOffset:
284           name = "fp";
285           break;
286         case StandardFrameConstants::kContextOffset:
287           name = "context";
288           break;
289         case StandardFrameConstants::kMarkerOffset:
290           name = "function";
291           break;
292       }
293       PrintF("    [rsp + %d] <- 0x%08" V8PRIxPTR " ; [rsp + %d] "
294              "(fixed part - %s)\n",
295              output_offset,
296              input_value,
297              input_offset,
298              name);
299     }
300     output_[0]->SetFrameSlot(output_offset, input_->GetFrameSlot(input_offset));
301     input_offset -= kPointerSize;
302     output_offset -= kPointerSize;
303   }
304 
305   // Translate the rest of the frame.
306   while (ok && input_offset >= 0) {
307     ok = DoOsrTranslateCommand(&iterator, &input_offset);
308   }
309 
310   // If translation of any command failed, continue using the input frame.
311   if (!ok) {
312     delete output_[0];
313     output_[0] = input_;
314     output_[0]->SetPc(reinterpret_cast<intptr_t>(from_));
315   } else {
316     // Set up the frame pointer and the context pointer.
317     output_[0]->SetRegister(rbp.code(), input_->GetRegister(rbp.code()));
318     output_[0]->SetRegister(rsi.code(), input_->GetRegister(rsi.code()));
319 
320     unsigned pc_offset = data->OsrPcOffset()->value();
321     intptr_t pc = reinterpret_cast<intptr_t>(
322         optimized_code_->entry() + pc_offset);
323     output_[0]->SetPc(pc);
324   }
325   Code* continuation =
326       function->GetIsolate()->builtins()->builtin(Builtins::kNotifyOSR);
327   output_[0]->SetContinuation(
328       reinterpret_cast<intptr_t>(continuation->entry()));
329 
330   if (FLAG_trace_osr) {
331     PrintF("[on-stack replacement translation %s: 0x%08" V8PRIxPTR " ",
332            ok ? "finished" : "aborted",
333            reinterpret_cast<intptr_t>(function));
334     function->PrintName();
335     PrintF(" => pc=0x%0" V8PRIxPTR "]\n", output_[0]->GetPc());
336   }
337 }
338 
339 
DoComputeArgumentsAdaptorFrame(TranslationIterator * iterator,int frame_index)340 void Deoptimizer::DoComputeArgumentsAdaptorFrame(TranslationIterator* iterator,
341                                                  int frame_index) {
342   JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
343   unsigned height = iterator->Next();
344   unsigned height_in_bytes = height * kPointerSize;
345   if (FLAG_trace_deopt) {
346     PrintF("  translating arguments adaptor => height=%d\n", height_in_bytes);
347   }
348 
349   unsigned fixed_frame_size = ArgumentsAdaptorFrameConstants::kFrameSize;
350   unsigned output_frame_size = height_in_bytes + fixed_frame_size;
351 
352   // Allocate and store the output frame description.
353   FrameDescription* output_frame =
354       new(output_frame_size) FrameDescription(output_frame_size, function);
355   output_frame->SetFrameType(StackFrame::ARGUMENTS_ADAPTOR);
356 
357   // Arguments adaptor can not be topmost or bottommost.
358   ASSERT(frame_index > 0 && frame_index < output_count_ - 1);
359   ASSERT(output_[frame_index] == NULL);
360   output_[frame_index] = output_frame;
361 
362   // The top address of the frame is computed from the previous
363   // frame's top and this frame's size.
364   intptr_t top_address;
365   top_address = output_[frame_index - 1]->GetTop() - output_frame_size;
366   output_frame->SetTop(top_address);
367 
368   // Compute the incoming parameter translation.
369   int parameter_count = height;
370   unsigned output_offset = output_frame_size;
371   for (int i = 0; i < parameter_count; ++i) {
372     output_offset -= kPointerSize;
373     DoTranslateCommand(iterator, frame_index, output_offset);
374   }
375 
376   // Read caller's PC from the previous frame.
377   output_offset -= kPointerSize;
378   intptr_t callers_pc = output_[frame_index - 1]->GetPc();
379   output_frame->SetFrameSlot(output_offset, callers_pc);
380   if (FLAG_trace_deopt) {
381     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
382            V8PRIxPTR " ; caller's pc\n",
383            top_address + output_offset, output_offset, callers_pc);
384   }
385 
386   // Read caller's FP from the previous frame, and set this frame's FP.
387   output_offset -= kPointerSize;
388   intptr_t value = output_[frame_index - 1]->GetFp();
389   output_frame->SetFrameSlot(output_offset, value);
390   intptr_t fp_value = top_address + output_offset;
391   output_frame->SetFp(fp_value);
392   if (FLAG_trace_deopt) {
393     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
394            V8PRIxPTR " ; caller's fp\n",
395            fp_value, output_offset, value);
396   }
397 
398   // A marker value is used in place of the context.
399   output_offset -= kPointerSize;
400   intptr_t context = reinterpret_cast<intptr_t>(
401       Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
402   output_frame->SetFrameSlot(output_offset, context);
403   if (FLAG_trace_deopt) {
404     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
405            V8PRIxPTR " ; context (adaptor sentinel)\n",
406            top_address + output_offset, output_offset, context);
407   }
408 
409   // The function was mentioned explicitly in the ARGUMENTS_ADAPTOR_FRAME.
410   output_offset -= kPointerSize;
411   value = reinterpret_cast<intptr_t>(function);
412   output_frame->SetFrameSlot(output_offset, value);
413   if (FLAG_trace_deopt) {
414     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
415            V8PRIxPTR " ; function\n",
416            top_address + output_offset, output_offset, value);
417   }
418 
419   // Number of incoming arguments.
420   output_offset -= kPointerSize;
421   value = reinterpret_cast<intptr_t>(Smi::FromInt(height - 1));
422   output_frame->SetFrameSlot(output_offset, value);
423   if (FLAG_trace_deopt) {
424     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
425            V8PRIxPTR " ; argc (%d)\n",
426            top_address + output_offset, output_offset, value, height - 1);
427   }
428 
429   ASSERT(0 == output_offset);
430 
431   Builtins* builtins = isolate_->builtins();
432   Code* adaptor_trampoline =
433       builtins->builtin(Builtins::kArgumentsAdaptorTrampoline);
434   intptr_t pc_value = reinterpret_cast<intptr_t>(
435       adaptor_trampoline->instruction_start() +
436       isolate_->heap()->arguments_adaptor_deopt_pc_offset()->value());
437   output_frame->SetPc(pc_value);
438 }
439 
440 
DoComputeConstructStubFrame(TranslationIterator * iterator,int frame_index)441 void Deoptimizer::DoComputeConstructStubFrame(TranslationIterator* iterator,
442                                               int frame_index) {
443   Builtins* builtins = isolate_->builtins();
444   Code* construct_stub = builtins->builtin(Builtins::kJSConstructStubGeneric);
445   JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
446   unsigned height = iterator->Next();
447   unsigned height_in_bytes = height * kPointerSize;
448   if (FLAG_trace_deopt) {
449     PrintF("  translating construct stub => height=%d\n", height_in_bytes);
450   }
451 
452   unsigned fixed_frame_size = 7 * kPointerSize;
453   unsigned output_frame_size = height_in_bytes + fixed_frame_size;
454 
455   // Allocate and store the output frame description.
456   FrameDescription* output_frame =
457       new(output_frame_size) FrameDescription(output_frame_size, function);
458   output_frame->SetFrameType(StackFrame::CONSTRUCT);
459 
460   // Construct stub can not be topmost or bottommost.
461   ASSERT(frame_index > 0 && frame_index < output_count_ - 1);
462   ASSERT(output_[frame_index] == NULL);
463   output_[frame_index] = output_frame;
464 
465   // The top address of the frame is computed from the previous
466   // frame's top and this frame's size.
467   intptr_t top_address;
468   top_address = output_[frame_index - 1]->GetTop() - output_frame_size;
469   output_frame->SetTop(top_address);
470 
471   // Compute the incoming parameter translation.
472   int parameter_count = height;
473   unsigned output_offset = output_frame_size;
474   for (int i = 0; i < parameter_count; ++i) {
475     output_offset -= kPointerSize;
476     DoTranslateCommand(iterator, frame_index, output_offset);
477   }
478 
479   // Read caller's PC from the previous frame.
480   output_offset -= kPointerSize;
481   intptr_t callers_pc = output_[frame_index - 1]->GetPc();
482   output_frame->SetFrameSlot(output_offset, callers_pc);
483   if (FLAG_trace_deopt) {
484     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
485            V8PRIxPTR " ; caller's pc\n",
486            top_address + output_offset, output_offset, callers_pc);
487   }
488 
489   // Read caller's FP from the previous frame, and set this frame's FP.
490   output_offset -= kPointerSize;
491   intptr_t value = output_[frame_index - 1]->GetFp();
492   output_frame->SetFrameSlot(output_offset, value);
493   intptr_t fp_value = top_address + output_offset;
494   output_frame->SetFp(fp_value);
495   if (FLAG_trace_deopt) {
496     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
497            V8PRIxPTR " ; caller's fp\n",
498            fp_value, output_offset, value);
499   }
500 
501   // The context can be gotten from the previous frame.
502   output_offset -= kPointerSize;
503   value = output_[frame_index - 1]->GetContext();
504   output_frame->SetFrameSlot(output_offset, value);
505   if (FLAG_trace_deopt) {
506     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
507            V8PRIxPTR " ; context\n",
508            top_address + output_offset, output_offset, value);
509   }
510 
511   // A marker value is used in place of the function.
512   output_offset -= kPointerSize;
513   value = reinterpret_cast<intptr_t>(Smi::FromInt(StackFrame::CONSTRUCT));
514   output_frame->SetFrameSlot(output_offset, value);
515   if (FLAG_trace_deopt) {
516     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
517            V8PRIxPTR " ; function (construct sentinel)\n",
518            top_address + output_offset, output_offset, value);
519   }
520 
521   // The output frame reflects a JSConstructStubGeneric frame.
522   output_offset -= kPointerSize;
523   value = reinterpret_cast<intptr_t>(construct_stub);
524   output_frame->SetFrameSlot(output_offset, value);
525   if (FLAG_trace_deopt) {
526     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
527            V8PRIxPTR " ; code object\n",
528            top_address + output_offset, output_offset, value);
529   }
530 
531   // Number of incoming arguments.
532   output_offset -= kPointerSize;
533   value = reinterpret_cast<intptr_t>(Smi::FromInt(height - 1));
534   output_frame->SetFrameSlot(output_offset, value);
535   if (FLAG_trace_deopt) {
536     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
537            V8PRIxPTR " ; argc (%d)\n",
538            top_address + output_offset, output_offset, value, height - 1);
539   }
540 
541   // The newly allocated object was passed as receiver in the artificial
542   // constructor stub environment created by HEnvironment::CopyForInlining().
543   output_offset -= kPointerSize;
544   value = output_frame->GetFrameSlot(output_frame_size - kPointerSize);
545   output_frame->SetFrameSlot(output_offset, value);
546   if (FLAG_trace_deopt) {
547     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
548            V8PRIxPTR " ; allocated receiver\n",
549            top_address + output_offset, output_offset, value);
550   }
551 
552   ASSERT(0 == output_offset);
553 
554   intptr_t pc = reinterpret_cast<intptr_t>(
555       construct_stub->instruction_start() +
556       isolate_->heap()->construct_stub_deopt_pc_offset()->value());
557   output_frame->SetPc(pc);
558 }
559 
560 
DoComputeJSFrame(TranslationIterator * iterator,int frame_index)561 void Deoptimizer::DoComputeJSFrame(TranslationIterator* iterator,
562                                    int frame_index) {
563   int node_id = iterator->Next();
564   JSFunction* function = JSFunction::cast(ComputeLiteral(iterator->Next()));
565   unsigned height = iterator->Next();
566   unsigned height_in_bytes = height * kPointerSize;
567   if (FLAG_trace_deopt) {
568     PrintF("  translating ");
569     function->PrintName();
570     PrintF(" => node=%d, height=%d\n", node_id, height_in_bytes);
571   }
572 
573   // The 'fixed' part of the frame consists of the incoming parameters and
574   // the part described by JavaScriptFrameConstants.
575   unsigned fixed_frame_size = ComputeFixedSize(function);
576   unsigned input_frame_size = input_->GetFrameSize();
577   unsigned output_frame_size = height_in_bytes + fixed_frame_size;
578 
579   // Allocate and store the output frame description.
580   FrameDescription* output_frame =
581       new(output_frame_size) FrameDescription(output_frame_size, function);
582   output_frame->SetFrameType(StackFrame::JAVA_SCRIPT);
583 
584   bool is_bottommost = (0 == frame_index);
585   bool is_topmost = (output_count_ - 1 == frame_index);
586   ASSERT(frame_index >= 0 && frame_index < output_count_);
587   ASSERT(output_[frame_index] == NULL);
588   output_[frame_index] = output_frame;
589 
590   // The top address for the bottommost output frame can be computed from
591   // the input frame pointer and the output frame's height.  For all
592   // subsequent output frames, it can be computed from the previous one's
593   // top address and the current frame's size.
594   intptr_t top_address;
595   if (is_bottommost) {
596     // 2 = context and function in the frame.
597     top_address =
598         input_->GetRegister(rbp.code()) - (2 * kPointerSize) - height_in_bytes;
599   } else {
600     top_address = output_[frame_index - 1]->GetTop() - output_frame_size;
601   }
602   output_frame->SetTop(top_address);
603 
604   // Compute the incoming parameter translation.
605   int parameter_count = function->shared()->formal_parameter_count() + 1;
606   unsigned output_offset = output_frame_size;
607   unsigned input_offset = input_frame_size;
608   for (int i = 0; i < parameter_count; ++i) {
609     output_offset -= kPointerSize;
610     DoTranslateCommand(iterator, frame_index, output_offset);
611   }
612   input_offset -= (parameter_count * kPointerSize);
613 
614   // There are no translation commands for the caller's pc and fp, the
615   // context, and the function.  Synthesize their values and set them up
616   // explicitly.
617   //
618   // The caller's pc for the bottommost output frame is the same as in the
619   // input frame.  For all subsequent output frames, it can be read from the
620   // previous one.  This frame's pc can be computed from the non-optimized
621   // function code and AST id of the bailout.
622   output_offset -= kPointerSize;
623   input_offset -= kPointerSize;
624   intptr_t value;
625   if (is_bottommost) {
626     value = input_->GetFrameSlot(input_offset);
627   } else {
628     value = output_[frame_index - 1]->GetPc();
629   }
630   output_frame->SetFrameSlot(output_offset, value);
631   if (FLAG_trace_deopt) {
632     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
633            V8PRIxPTR  " ; caller's pc\n",
634            top_address + output_offset, output_offset, value);
635   }
636 
637   // The caller's frame pointer for the bottommost output frame is the same
638   // as in the input frame.  For all subsequent output frames, it can be
639   // read from the previous one.  Also compute and set this frame's frame
640   // pointer.
641   output_offset -= kPointerSize;
642   input_offset -= kPointerSize;
643   if (is_bottommost) {
644     value = input_->GetFrameSlot(input_offset);
645   } else {
646     value = output_[frame_index - 1]->GetFp();
647   }
648   output_frame->SetFrameSlot(output_offset, value);
649   intptr_t fp_value = top_address + output_offset;
650   ASSERT(!is_bottommost || input_->GetRegister(rbp.code()) == fp_value);
651   output_frame->SetFp(fp_value);
652   if (is_topmost) output_frame->SetRegister(rbp.code(), fp_value);
653   if (FLAG_trace_deopt) {
654     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
655            V8PRIxPTR " ; caller's fp\n",
656            fp_value, output_offset, value);
657   }
658 
659   // For the bottommost output frame the context can be gotten from the input
660   // frame. For all subsequent output frames it can be gotten from the function
661   // so long as we don't inline functions that need local contexts.
662   output_offset -= kPointerSize;
663   input_offset -= kPointerSize;
664   if (is_bottommost) {
665     value = input_->GetFrameSlot(input_offset);
666   } else {
667     value = reinterpret_cast<intptr_t>(function->context());
668   }
669   output_frame->SetFrameSlot(output_offset, value);
670   output_frame->SetContext(value);
671   if (is_topmost) output_frame->SetRegister(rsi.code(), value);
672   if (FLAG_trace_deopt) {
673     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
674            V8PRIxPTR "; context\n",
675            top_address + output_offset, output_offset, value);
676   }
677 
678   // The function was mentioned explicitly in the BEGIN_FRAME.
679   output_offset -= kPointerSize;
680   input_offset -= kPointerSize;
681   value = reinterpret_cast<intptr_t>(function);
682   // The function for the bottommost output frame should also agree with the
683   // input frame.
684   ASSERT(!is_bottommost || input_->GetFrameSlot(input_offset) == value);
685   output_frame->SetFrameSlot(output_offset, value);
686   if (FLAG_trace_deopt) {
687     PrintF("    0x%08" V8PRIxPTR ": [top + %d] <- 0x%08"
688            V8PRIxPTR "; function\n",
689            top_address + output_offset, output_offset, value);
690   }
691 
692   // Translate the rest of the frame.
693   for (unsigned i = 0; i < height; ++i) {
694     output_offset -= kPointerSize;
695     DoTranslateCommand(iterator, frame_index, output_offset);
696   }
697   ASSERT(0 == output_offset);
698 
699   // Compute this frame's PC, state, and continuation.
700   Code* non_optimized_code = function->shared()->code();
701   FixedArray* raw_data = non_optimized_code->deoptimization_data();
702   DeoptimizationOutputData* data = DeoptimizationOutputData::cast(raw_data);
703   Address start = non_optimized_code->instruction_start();
704   unsigned pc_and_state = GetOutputInfo(data, node_id, function->shared());
705   unsigned pc_offset = FullCodeGenerator::PcField::decode(pc_and_state);
706   intptr_t pc_value = reinterpret_cast<intptr_t>(start + pc_offset);
707   output_frame->SetPc(pc_value);
708 
709   FullCodeGenerator::State state =
710       FullCodeGenerator::StateField::decode(pc_and_state);
711   output_frame->SetState(Smi::FromInt(state));
712 
713   // Set the continuation for the topmost frame.
714   if (is_topmost && bailout_type_ != DEBUGGER) {
715     Code* continuation = (bailout_type_ == EAGER)
716         ? isolate_->builtins()->builtin(Builtins::kNotifyDeoptimized)
717         : isolate_->builtins()->builtin(Builtins::kNotifyLazyDeoptimized);
718     output_frame->SetContinuation(
719         reinterpret_cast<intptr_t>(continuation->entry()));
720   }
721 }
722 
723 
FillInputFrame(Address tos,JavaScriptFrame * frame)724 void Deoptimizer::FillInputFrame(Address tos, JavaScriptFrame* frame) {
725   // Set the register values. The values are not important as there are no
726   // callee saved registers in JavaScript frames, so all registers are
727   // spilled. Registers rbp and rsp are set to the correct values though.
728   for (int i = 0; i < Register::kNumRegisters; i++) {
729     input_->SetRegister(i, i * 4);
730   }
731   input_->SetRegister(rsp.code(), reinterpret_cast<intptr_t>(frame->sp()));
732   input_->SetRegister(rbp.code(), reinterpret_cast<intptr_t>(frame->fp()));
733   for (int i = 0; i < DoubleRegister::kNumAllocatableRegisters; i++) {
734     input_->SetDoubleRegister(i, 0.0);
735   }
736 
737   // Fill the frame content from the actual data on the frame.
738   for (unsigned i = 0; i < input_->GetFrameSize(); i += kPointerSize) {
739     input_->SetFrameSlot(i, Memory::uint64_at(tos + i));
740   }
741 }
742 
743 
744 #define __ masm()->
745 
Generate()746 void Deoptimizer::EntryGenerator::Generate() {
747   GeneratePrologue();
748 
749   // Save all general purpose registers before messing with them.
750   const int kNumberOfRegisters = Register::kNumRegisters;
751 
752   const int kDoubleRegsSize = kDoubleSize *
753                               XMMRegister::kNumAllocatableRegisters;
754   __ subq(rsp, Immediate(kDoubleRegsSize));
755 
756   for (int i = 0; i < XMMRegister::kNumAllocatableRegisters; ++i) {
757     XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i);
758     int offset = i * kDoubleSize;
759     __ movsd(Operand(rsp, offset), xmm_reg);
760   }
761 
762   // We push all registers onto the stack, even though we do not need
763   // to restore all later.
764   for (int i = 0; i < kNumberOfRegisters; i++) {
765     Register r = Register::from_code(i);
766     __ push(r);
767   }
768 
769   const int kSavedRegistersAreaSize = kNumberOfRegisters * kPointerSize +
770                                       kDoubleRegsSize;
771 
772   // When calling new_deoptimizer_function we need to pass the last argument
773   // on the stack on windows and in r8 on linux. The remaining arguments are
774   // all passed in registers (different ones on linux and windows though).
775 
776 #ifdef _WIN64
777   Register arg4 = r9;
778   Register arg3 = r8;
779   Register arg2 = rdx;
780   Register arg1 = rcx;
781 #else
782   Register arg4 = rcx;
783   Register arg3 = rdx;
784   Register arg2 = rsi;
785   Register arg1 = rdi;
786 #endif
787 
788   // We use this to keep the value of the fifth argument temporarily.
789   // Unfortunately we can't store it directly in r8 (used for passing
790   // this on linux), since it is another parameter passing register on windows.
791   Register arg5 = r11;
792 
793   // Get the bailout id from the stack.
794   __ movq(arg3, Operand(rsp, kSavedRegistersAreaSize));
795 
796   // Get the address of the location in the code object if possible
797   // and compute the fp-to-sp delta in register arg5.
798   if (type() == EAGER) {
799     __ Set(arg4, 0);
800     __ lea(arg5, Operand(rsp, kSavedRegistersAreaSize + 1 * kPointerSize));
801   } else {
802     __ movq(arg4, Operand(rsp, kSavedRegistersAreaSize + 1 * kPointerSize));
803     __ lea(arg5, Operand(rsp, kSavedRegistersAreaSize + 2 * kPointerSize));
804   }
805 
806   __ subq(arg5, rbp);
807   __ neg(arg5);
808 
809   // Allocate a new deoptimizer object.
810   __ PrepareCallCFunction(6);
811   __ movq(rax, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
812   __ movq(arg1, rax);
813   __ Set(arg2, type());
814   // Args 3 and 4 are already in the right registers.
815 
816   // On windows put the arguments on the stack (PrepareCallCFunction
817   // has created space for this). On linux pass the arguments in r8 and r9.
818 #ifdef _WIN64
819   __ movq(Operand(rsp, 4 * kPointerSize), arg5);
820   __ LoadAddress(arg5, ExternalReference::isolate_address());
821   __ movq(Operand(rsp, 5 * kPointerSize), arg5);
822 #else
823   __ movq(r8, arg5);
824   __ LoadAddress(r9, ExternalReference::isolate_address());
825 #endif
826 
827   Isolate* isolate = masm()->isolate();
828 
829   {
830     AllowExternalCallThatCantCauseGC scope(masm());
831     __ CallCFunction(ExternalReference::new_deoptimizer_function(isolate), 6);
832   }
833   // Preserve deoptimizer object in register rax and get the input
834   // frame descriptor pointer.
835   __ movq(rbx, Operand(rax, Deoptimizer::input_offset()));
836 
837   // Fill in the input registers.
838   for (int i = kNumberOfRegisters -1; i >= 0; i--) {
839     int offset = (i * kPointerSize) + FrameDescription::registers_offset();
840     __ pop(Operand(rbx, offset));
841   }
842 
843   // Fill in the double input registers.
844   int double_regs_offset = FrameDescription::double_registers_offset();
845   for (int i = 0; i < XMMRegister::kNumAllocatableRegisters; i++) {
846     int dst_offset = i * kDoubleSize + double_regs_offset;
847     __ pop(Operand(rbx, dst_offset));
848   }
849 
850   // Remove the bailout id from the stack.
851   if (type() == EAGER) {
852     __ addq(rsp, Immediate(kPointerSize));
853   } else {
854     __ addq(rsp, Immediate(2 * kPointerSize));
855   }
856 
857   // Compute a pointer to the unwinding limit in register rcx; that is
858   // the first stack slot not part of the input frame.
859   __ movq(rcx, Operand(rbx, FrameDescription::frame_size_offset()));
860   __ addq(rcx, rsp);
861 
862   // Unwind the stack down to - but not including - the unwinding
863   // limit and copy the contents of the activation frame to the input
864   // frame description.
865   __ lea(rdx, Operand(rbx, FrameDescription::frame_content_offset()));
866   Label pop_loop;
867   __ bind(&pop_loop);
868   __ pop(Operand(rdx, 0));
869   __ addq(rdx, Immediate(sizeof(intptr_t)));
870   __ cmpq(rcx, rsp);
871   __ j(not_equal, &pop_loop);
872 
873   // Compute the output frame in the deoptimizer.
874   __ push(rax);
875   __ PrepareCallCFunction(2);
876   __ movq(arg1, rax);
877   __ LoadAddress(arg2, ExternalReference::isolate_address());
878   {
879     AllowExternalCallThatCantCauseGC scope(masm());
880     __ CallCFunction(
881         ExternalReference::compute_output_frames_function(isolate), 2);
882   }
883   __ pop(rax);
884 
885   // Replace the current frame with the output frames.
886   Label outer_push_loop, inner_push_loop;
887   // Outer loop state: rax = current FrameDescription**, rdx = one past the
888   // last FrameDescription**.
889   __ movl(rdx, Operand(rax, Deoptimizer::output_count_offset()));
890   __ movq(rax, Operand(rax, Deoptimizer::output_offset()));
891   __ lea(rdx, Operand(rax, rdx, times_8, 0));
892   __ bind(&outer_push_loop);
893   // Inner loop state: rbx = current FrameDescription*, rcx = loop index.
894   __ movq(rbx, Operand(rax, 0));
895   __ movq(rcx, Operand(rbx, FrameDescription::frame_size_offset()));
896   __ bind(&inner_push_loop);
897   __ subq(rcx, Immediate(sizeof(intptr_t)));
898   __ push(Operand(rbx, rcx, times_1, FrameDescription::frame_content_offset()));
899   __ testq(rcx, rcx);
900   __ j(not_zero, &inner_push_loop);
901   __ addq(rax, Immediate(kPointerSize));
902   __ cmpq(rax, rdx);
903   __ j(below, &outer_push_loop);
904 
905   // In case of OSR, we have to restore the XMM registers.
906   if (type() == OSR) {
907     for (int i = 0; i < XMMRegister::kNumAllocatableRegisters; ++i) {
908       XMMRegister xmm_reg = XMMRegister::FromAllocationIndex(i);
909       int src_offset = i * kDoubleSize + double_regs_offset;
910       __ movsd(xmm_reg, Operand(rbx, src_offset));
911     }
912   }
913 
914   // Push state, pc, and continuation from the last output frame.
915   if (type() != OSR) {
916     __ push(Operand(rbx, FrameDescription::state_offset()));
917   }
918   __ push(Operand(rbx, FrameDescription::pc_offset()));
919   __ push(Operand(rbx, FrameDescription::continuation_offset()));
920 
921   // Push the registers from the last output frame.
922   for (int i = 0; i < kNumberOfRegisters; i++) {
923     int offset = (i * kPointerSize) + FrameDescription::registers_offset();
924     __ push(Operand(rbx, offset));
925   }
926 
927   // Restore the registers from the stack.
928   for (int i = kNumberOfRegisters - 1; i >= 0 ; i--) {
929     Register r = Register::from_code(i);
930     // Do not restore rsp, simply pop the value into the next register
931     // and overwrite this afterwards.
932     if (r.is(rsp)) {
933       ASSERT(i > 0);
934       r = Register::from_code(i - 1);
935     }
936     __ pop(r);
937   }
938 
939   // Set up the roots register.
940   __ InitializeRootRegister();
941   __ InitializeSmiConstantRegister();
942 
943   // Return to the continuation point.
944   __ ret(0);
945 }
946 
947 
GeneratePrologue()948 void Deoptimizer::TableEntryGenerator::GeneratePrologue() {
949   // Create a sequence of deoptimization entries.
950   Label done;
951   for (int i = 0; i < count(); i++) {
952     int start = masm()->pc_offset();
953     USE(start);
954     __ push_imm32(i);
955     __ jmp(&done);
956     ASSERT(masm()->pc_offset() - start == table_entry_size_);
957   }
958   __ bind(&done);
959 }
960 
961 #undef __
962 
963 
964 } }  // namespace v8::internal
965 
966 #endif  // V8_TARGET_ARCH_X64
967