Encode any deoptimizer entry in serialized data.

This removes kDeoptTableSerializeEntryCount heuristic constant.

Review-Url: https://codereview.chromium.org/2790573002
Cr-Commit-Position: refs/heads/master@{#44379}

src/external-reference-table.cc

@@ -45,7 +45,6 @@ ExternalReferenceTable::ExternalReferenceTable(Isolate* isolate) {
   AddIsolateAddresses(isolate);
   AddAccessors(isolate);
   AddStubCache(isolate);
-  AddDeoptEntries(isolate);
   // API references must be added last.
   AddApiReferences(isolate);
 }
@@ -436,19 +435,6 @@ void ExternalReferenceTable::AddStubCache(Isolate* isolate) {
       "Store StubCache::secondary_->map");
 }
 
-void ExternalReferenceTable::AddDeoptEntries(Isolate* isolate) {
-  // Add a small set of deopt entry addresses to encoder without generating
-  // the
-  // deopt table code, which isn't possible at deserialization time.
-  HandleScope scope(isolate);
-  for (int entry = 0; entry < kDeoptTableSerializeEntryCount; ++entry) {
-    Address address = Deoptimizer::GetDeoptimizationEntry(
-        isolate, entry, Deoptimizer::LAZY,
-        Deoptimizer::CALCULATE_ENTRY_ADDRESS);
-    Add(address, "lazy_deopt");
-  }
-}
-
 void ExternalReferenceTable::AddApiReferences(Isolate* isolate) {
   // Add external references provided by the embedder (a null-terminated
   // array).

src/external-reference-table.h

@@ -34,8 +34,6 @@ class ExternalReferenceTable {
 
   static const char* ResolveSymbol(void* address);
 
-  static const int kDeoptTableSerializeEntryCount = 64;
-
  private:
   struct ExternalReferenceEntry {
     Address address;
@@ -62,7 +60,6 @@ class ExternalReferenceTable {
   void AddIsolateAddresses(Isolate* isolate);
   void AddAccessors(Isolate* isolate);
   void AddStubCache(Isolate* isolate);
-  void AddDeoptEntries(Isolate* isolate);
   void AddApiReferences(Isolate* isolate);
 
   List<ExternalReferenceEntry> refs_;

src/isolate.cc

@@ -2731,16 +2731,6 @@ bool Isolate::Init(Deserializer* des) {
     ast_string_constants_ = new AstStringConstants(this, heap()->HashSeed());
   }
 
-  if (!create_heap_objects) {
-    // Now that the heap is consistent, it's OK to generate the code for the
-    // deopt entry table that might have been referred to by optimized code in
-    // the snapshot.
-    HandleScope scope(this);
-    Deoptimizer::EnsureCodeForDeoptimizationEntry(
-        this, Deoptimizer::LAZY,
-        ExternalReferenceTable::kDeoptTableSerializeEntryCount - 1);
-  }
-
   if (!serializer_enabled()) {
     // Ensure that all stubs which need to be generated ahead of time, but
     // cannot be serialized into the snapshot have been generated.

src/snapshot/deserializer.cc

@@ -7,6 +7,7 @@
 #include "src/api.h"
 #include "src/assembler-inl.h"
 #include "src/bootstrapper.h"
+#include "src/deoptimizer.h"
 #include "src/external-reference-table.h"
 #include "src/heap/heap-inl.h"
 #include "src/isolate.h"
@@ -732,6 +733,33 @@ bool Deserializer::ReadData(Object** current, Object** limit, int source_space,
         break;
       }
 
+      case kDeoptimizerEntryFromCode:
+      case kDeoptimizerEntryPlain: {
+        int skip = source_.GetInt();
+        current = reinterpret_cast<Object**>(
+            reinterpret_cast<intptr_t>(current) + skip);
+        Deoptimizer::BailoutType bailout_type =
+            static_cast<Deoptimizer::BailoutType>(source_.Get());
+        int entry_id = source_.GetInt();
+        HandleScope scope(isolate);
+        Address address = Deoptimizer::GetDeoptimizationEntry(
+            isolate_, entry_id, bailout_type, Deoptimizer::ENSURE_ENTRY_CODE);
+        if (data == kDeoptimizerEntryFromCode) {
+          Address location_of_branch_data = reinterpret_cast<Address>(current);
+          Assembler::deserialization_set_special_target_at(
+              isolate, location_of_branch_data,
+              Code::cast(HeapObject::FromAddress(current_object_address)),
+              address);
+          location_of_branch_data += Assembler::kSpecialTargetSize;
+          current = reinterpret_cast<Object**>(location_of_branch_data);
+        } else {
+          Object* new_object = reinterpret_cast<Object*>(address);
+          UnalignedCopy(current, &new_object);
+          current++;
+        }
+        break;
+      }
+
       case kInternalReferenceEncoded:
       case kInternalReference: {
         // Internal reference address is not encoded via skip, but by offset

src/snapshot/serializer-common.h

@@ -184,7 +184,10 @@ class SerializerDeserializer : public ObjectVisitor {
   static const int kHotObjectWithSkip = 0x58;
   static const int kHotObjectMask = 0x07;
 
-  // 0x35..0x37, 0x55..0x57, 0x75..0x7f unused.
+  static const int kDeoptimizerEntryPlain = 0x35;
+  static const int kDeoptimizerEntryFromCode = 0x36;
+
+  // 0x37, 0x55..0x57, 0x75..0x7f unused.
 
   // ---------- byte code range 0x80..0xff ----------
   // First 32 root array items.

src/snapshot/serializer.cc

@@ -5,6 +5,7 @@
 #include "src/snapshot/serializer.h"
 
 #include "src/assembler-inl.h"
+#include "src/deoptimizer.h"
 #include "src/heap/heap-inl.h"
 #include "src/macro-assembler.h"
 #include "src/snapshot/natives.h"
@@ -334,6 +335,25 @@ bool Serializer::HasNotExceededFirstPageOfEachSpace() {
   return true;
 }
 
+bool Serializer::ObjectSerializer::TryEncodeDeoptimizationEntry(
+    HowToCode how_to_code, Address target, int skip) {
+  for (int bailout_type = 0; bailout_type <= Deoptimizer::kLastBailoutType;
+       ++bailout_type) {
+    int id = Deoptimizer::GetDeoptimizationId(
+        serializer_->isolate(), target,
+        static_cast<Deoptimizer::BailoutType>(bailout_type));
+    if (id == Deoptimizer::kNotDeoptimizationEntry) continue;
+    sink_->Put(how_to_code == kPlain ? kDeoptimizerEntryPlain
+                                     : kDeoptimizerEntryFromCode,
+               "DeoptimizationEntry");
+    sink_->PutInt(skip, "SkipB4DeoptimizationEntry");
+    sink_->Put(bailout_type, "BailoutType");
+    sink_->PutInt(id, "EntryId");
+    return true;
+  }
+  return false;
+}
+
 void Serializer::ObjectSerializer::SerializePrologue(AllocationSpace space,
                                                      int size, Map* map) {
   if (serializer_->code_address_map_) {
@@ -611,10 +631,12 @@ void Serializer::ObjectSerializer::VisitEmbeddedPointer(RelocInfo* rinfo) {
 void Serializer::ObjectSerializer::VisitExternalReference(Address* p) {
   int skip = OutputRawData(reinterpret_cast<Address>(p),
                            kCanReturnSkipInsteadOfSkipping);
+  Address target = *p;
+  if (!TryEncodeDeoptimizationEntry(kPlain, target, skip)) {
     sink_->Put(kExternalReference + kPlain + kStartOfObject, "ExternalRef");
     sink_->PutInt(skip, "SkipB4ExternalRef");
-  Address target = *p;
     sink_->PutInt(serializer_->EncodeExternalReference(target), "reference id");
+  }
   bytes_processed_so_far_ += kPointerSize;
 }
 
@@ -622,11 +644,14 @@ void Serializer::ObjectSerializer::VisitExternalReference(RelocInfo* rinfo) {
   int skip = OutputRawData(rinfo->target_address_address(),
                            kCanReturnSkipInsteadOfSkipping);
   HowToCode how_to_code = rinfo->IsCodedSpecially() ? kFromCode : kPlain;
-  sink_->Put(kExternalReference + how_to_code + kStartOfObject, "ExternalRef");
-  sink_->PutInt(skip, "SkipB4ExternalRef");
   Address target = rinfo->target_external_reference();
+  if (!TryEncodeDeoptimizationEntry(how_to_code, target, skip)) {
+    sink_->Put(kExternalReference + how_to_code + kStartOfObject,
+               "ExternalRef");
+    sink_->PutInt(skip, "SkipB4ExternalRef");
     DCHECK_NOT_NULL(target);  // Code does not reference null.
     sink_->PutInt(serializer_->EncodeExternalReference(target), "reference id");
+  }
   bytes_processed_so_far_ += rinfo->target_address_size();
 }
 
@@ -658,10 +683,13 @@ void Serializer::ObjectSerializer::VisitRuntimeEntry(RelocInfo* rinfo) {
   int skip = OutputRawData(rinfo->target_address_address(),
                            kCanReturnSkipInsteadOfSkipping);
   HowToCode how_to_code = rinfo->IsCodedSpecially() ? kFromCode : kPlain;
-  sink_->Put(kExternalReference + how_to_code + kStartOfObject, "ExternalRef");
-  sink_->PutInt(skip, "SkipB4ExternalRef");
   Address target = rinfo->target_address();
+  if (!TryEncodeDeoptimizationEntry(how_to_code, target, skip)) {
+    sink_->Put(kExternalReference + how_to_code + kStartOfObject,
+               "ExternalRef");
+    sink_->PutInt(skip, "SkipB4ExternalRef");
     sink_->PutInt(serializer_->EncodeExternalReference(target), "reference id");
+  }
   bytes_processed_so_far_ += rinfo->target_address_size();
 }
 

src/snapshot/serializer.h

@@ -300,6 +300,8 @@ class Serializer::ObjectSerializer : public ObjectVisitor {
   }
 
  private:
+  bool TryEncodeDeoptimizationEntry(HowToCode how_to_code, Address target,
+                                    int skip);
   void SerializePrologue(AllocationSpace space, int size, Map* map);
 
   bool SerializeExternalNativeSourceString(