Remove relocation lock.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 7acec8bcd5ebc3e2e0757d312ee591f5e5174e72..b4a4a932292be74ce8ae46176aec4fd356ef2373 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -234,14 +234,6 @@ class LChunkBuilder;
   virtual Opcode opcode() const { return HValue::k##type; }
 
 
-#ifdef DEBUG
-#define ASSERT_ALLOCATION_DISABLED                                       \
-  ASSERT(isolate()->optimizing_compiler_thread()->IsOptimizerThread() || \
-         !isolate()->heap()->IsAllocationAllowed())
-#else
-#define ASSERT_ALLOCATION_DISABLED do {} while (0)
-#endif
-
 class Range: public ZoneObject {
  public:
   Range()
@@ -1057,6 +1049,10 @@ class HValue: public ZoneObject {
   bool Equals(HValue* other);
   virtual intptr_t Hashcode();
 
+  // Some instructions' hash code is dependent on object addresses and are not
+  // safe regarding GC and parallel recompilation.  Compute the hash upfront.
+  virtual void FinalizeHashcode() { }
+
   // Printing support.
   virtual void PrintTo(StringStream* stream) = 0;
   void PrintNameTo(StringStream* stream);
@@ -2856,7 +2852,11 @@ class HCheckPrototypeMaps: public HTemplateInstruction<0> {
  public:
   HCheckPrototypeMaps(Handle<JSObject> prototype,
                       Handle<JSObject> holder,
-                      Zone* zone) : prototypes_(2, zone), maps_(2, zone) {
+                      Zone* zone)
+      : prototypes_(2, zone),
+        maps_(2, zone),
+        first_prototype_(NULL),
+        last_prototype_(NULL) {
     SetFlag(kUseGVN);
     SetGVNFlag(kDependsOnMaps);
     // Keep a list of all objects on the prototype chain up to the holder
@@ -2882,18 +2882,18 @@ class HCheckPrototypeMaps: public HTemplateInstruction<0> {
   virtual void PrintDataTo(StringStream* stream);
 
   virtual intptr_t Hashcode() {
-    ASSERT_ALLOCATION_DISABLED;
-    // Dereferencing to use the object's raw address for hashing is safe.
-    HandleDereferenceGuard allow_handle_deref(isolate(),
-                                              HandleDereferenceGuard::ALLOW);
-    SLOW_ASSERT(Heap::RelocationLock::IsLocked(isolate()->heap()) ||
-                !isolate()->optimizing_compiler_thread()->IsOptimizerThread());
-    intptr_t hash = 0;
-    for (int i = 0; i < prototypes_.length(); i++) {
-      hash = 17 * hash + reinterpret_cast<intptr_t>(*prototypes_[i]);
-      hash = 17 * hash + reinterpret_cast<intptr_t>(*maps_[i]);
-    }
-    return hash;
+    ASSERT_NE(NULL, first_prototype_);
+    return reinterpret_cast<intptr_t>(first_prototype_) * 17 +
+        reinterpret_cast<intptr_t>(last_prototype_);
+  }
+
+  virtual void FinalizeHashcode() {
+    ASSERT(first_prototype_ == 0 ||
+           first_prototype_ == reinterpret_cast<Address>(*prototypes_.first()));
+    first_prototype_ = reinterpret_cast<Address>(*prototypes_.first());
+    ASSERT(last_prototype_ == 0 ||
+           last_prototype_ == reinterpret_cast<Address>(*prototypes_.last()));
+    last_prototype_ = reinterpret_cast<Address>(*prototypes_.last());
   }
 
   bool CanOmitPrototypeChecks() {
@@ -2906,22 +2906,16 @@ class HCheckPrototypeMaps: public HTemplateInstruction<0> {
  protected:
   virtual bool DataEquals(HValue* other) {
     HCheckPrototypeMaps* b = HCheckPrototypeMaps::cast(other);
-#ifdef DEBUG
-    if (prototypes_.length() != b->prototypes()->length()) return false;
-    for (int i = 0; i < prototypes_.length(); i++) {
-      if (!prototypes_[i].is_identical_to(b->prototypes()->at(i))) return false;
-      if (!maps_[i].is_identical_to(b->maps()->at(i))) return false;
-    }
-    return true;
-#else
-    return prototypes_.first().is_identical_to(b->prototypes()->first()) &&
-           prototypes_.last().is_identical_to(b->prototypes()->last());
-#endif  // DEBUG
+    ASSERT_NE(0, first_prototype_);
+    return first_prototype_ == b->first_prototype_ &&
+           last_prototype_ == b->last_prototype_;
   }
 
  private:
   ZoneList<Handle<JSObject> > prototypes_;
   ZoneList<Handle<Map> > maps_;
+  Address first_prototype_;
+  Address last_prototype_;
 };
 
 
@@ -3176,6 +3170,7 @@ class HConstant: public HTemplateInstruction<0> {
             Representation r,
             Handle<Object> optional_handle = Handle<Object>::null());
   HConstant(Handle<Object> handle,
+            Address raw_address,
             Representation r,
             HType type,
             bool is_internalized_string,
@@ -3189,8 +3184,6 @@ class HConstant: public HTemplateInstruction<0> {
     return handle_;
   }
 
-  bool InOldSpace() const { return !HEAP->InNewSpace(*handle_); }
-
   bool IsSpecialDouble() const {
     return has_double_value_ &&
         (BitCast<int64_t>(double_value_) == BitCast<int64_t>(-0.0) ||
@@ -3211,19 +3204,16 @@ class HConstant: public HTemplateInstruction<0> {
 
     ASSERT(!handle_.is_null());
     Heap* heap = isolate()->heap();
-    // We should have handled minus_zero_value and nan_value in the
-    // has_double_value_ clause above.
-    // Dereferencing is safe to compare against immovable singletons.
-    HandleDereferenceGuard allow_handle_deref(isolate(),
-                                              HandleDereferenceGuard::ALLOW);
-    ASSERT(*handle_ != heap->minus_zero_value());
-    ASSERT(*handle_ != heap->nan_value());
-    return *handle_ == heap->undefined_value() ||
-           *handle_ == heap->null_value() ||
-           *handle_ == heap->true_value() ||
-           *handle_ == heap->false_value() ||
-           *handle_ == heap->the_hole_value() ||
-           *handle_ == heap->empty_string();
+    // The raw address is sufficient to compare against root list entries.
+    Object* obj = reinterpret_cast<Object*>(raw_address_);
+    ASSERT(obj != heap->minus_zero_value());
+    ASSERT(obj != heap->nan_value());
+    return obj == heap->undefined_value() ||
+           obj == heap->null_value() ||
+           obj == heap->true_value() ||
+           obj == heap->false_value() ||
+           obj == heap->the_hole_value() ||
+           obj == heap->empty_string();
   }
 
   virtual Representation RequiredInputRepresentation(int index) {
@@ -3293,24 +3283,25 @@ class HConstant: public HTemplateInstruction<0> {
   }
 
   virtual intptr_t Hashcode() {
-    ASSERT_ALLOCATION_DISABLED;
-    intptr_t hash;
-
     if (has_int32_value_) {
-      hash = static_cast<intptr_t>(int32_value_);
+      return static_cast<intptr_t>(int32_value_);
     } else if (has_double_value_) {
-      hash = static_cast<intptr_t>(BitCast<int64_t>(double_value_));
+      return static_cast<intptr_t>(BitCast<int64_t>(double_value_));
     } else {
       ASSERT(!handle_.is_null());
-      // Dereferencing to use the object's raw address for hashing is safe.
-      HandleDereferenceGuard allow_handle_deref(isolate(),
-                                                HandleDereferenceGuard::ALLOW);
-      SLOW_ASSERT(Heap::RelocationLock::IsLocked(isolate()->heap()) ||
-                 !isolate()->optimizing_compiler_thread()->IsOptimizerThread());
-      hash = reinterpret_cast<intptr_t>(*handle_);
+      ASSERT_NE(NULL, raw_address_);
+      return reinterpret_cast<intptr_t>(raw_address_);
     }
+  }
 
-    return hash;
+  virtual void FinalizeHashcode() {
+    if (!has_double_value_) {

[Sven Panne, 2013/04/12 11:30:53]

What about has_int32_value_?

[Yang, 2013/04/15 13:55:31]

Done.

+      ASSERT(!handle_.is_null());
+      // Hash code has not been set, or already set to the same value.
+      ASSERT(raw_address_ == NULL ||
+             raw_address_ == reinterpret_cast<Address>(*handle_));
+      raw_address_ = reinterpret_cast<Address>(*handle_);
+    }
   }
 
 #ifdef DEBUG
@@ -3333,8 +3324,9 @@ class HConstant: public HTemplateInstruction<0> {
           BitCast<int64_t>(other_constant->double_value_);
     } else {
       ASSERT(!handle_.is_null());
+      ASSERT_NE(NULL, raw_address_);
       return !other_constant->handle_.is_null() &&
-          handle_.is_identical_to(other_constant->handle_);
+             raw_address_ == other_constant->raw_address_;
     }
   }
 
@@ -3358,7 +3350,12 @@ class HConstant: public HTemplateInstruction<0> {
   bool has_double_value_ : 1;
   bool is_internalized_string_ : 1;  // TODO(yangguo): make this part of HType.
   bool boolean_value_ : 1;
-  int32_t int32_value_;
+  // An extra hash code is only necessary if the value is not a number.
+  // So has_double_value_ governs how to interpret the union.

[Sven Panne, 2013/04/12 11:30:53]

This is a bit obscure. Wouldn't it be better if we had some enum (perhaps stored
in a bitfield tag for space reasons) with 3 values
HAS_{INT32,DOUBLE,OBJECT}_VALUE and include the double in the union?

[Yang, 2013/04/15 13:55:31]

Skipping this comment as discussed offline.

+  union {
+    int32_t int32_value_;
+    Address raw_address_;
+  };
   double double_value_;
   HType type_from_value_;
 };
@@ -4759,7 +4756,7 @@ class HUnknownOSRValue: public HTemplateInstruction<0> {
 class HLoadGlobalCell: public HTemplateInstruction<0> {
  public:
   HLoadGlobalCell(Handle<JSGlobalPropertyCell> cell, PropertyDetails details)
-      : cell_(cell), details_(details) {
+      : cell_(cell), details_(details), hash_code_(0) {
     set_representation(Representation::Tagged());
     SetFlag(kUseGVN);
     SetGVNFlag(kDependsOnGlobalVars);
@@ -4771,13 +4768,15 @@ class HLoadGlobalCell: public HTemplateInstruction<0> {
   virtual void PrintDataTo(StringStream* stream);
 
   virtual intptr_t Hashcode() {
-    ASSERT_ALLOCATION_DISABLED;
-    // Dereferencing to use the object's raw address for hashing is safe.
-    HandleDereferenceGuard allow_handle_deref(isolate(),
-                                              HandleDereferenceGuard::ALLOW);
-    SLOW_ASSERT(Heap::RelocationLock::IsLocked(isolate()->heap()) ||
-               !isolate()->optimizing_compiler_thread()->IsOptimizerThread());
-    return reinterpret_cast<intptr_t>(*cell_);
+    ASSERT_NE(0, hash_code_);
+    return hash_code_;
+  }
+
+  virtual void FinalizeHashcode() {
+    // Hash code has not been set, or already set to the same value.
+    ASSERT(hash_code_ == 0 ||
+           hash_code_ == reinterpret_cast<intptr_t>(*cell_));
+    hash_code_ = reinterpret_cast<intptr_t>(*cell_);
   }
 
   virtual Representation RequiredInputRepresentation(int index) {
@@ -4789,7 +4788,8 @@ class HLoadGlobalCell: public HTemplateInstruction<0> {
  protected:
   virtual bool DataEquals(HValue* other) {
     HLoadGlobalCell* b = HLoadGlobalCell::cast(other);
-    return cell_.is_identical_to(b->cell());
+    ASSERT_NE(0, hash_code_);
+    return hash_code_ == b->hash_code_;
   }
 
  private:
@@ -4797,6 +4797,7 @@ class HLoadGlobalCell: public HTemplateInstruction<0> {
 
   Handle<JSGlobalPropertyCell> cell_;
   PropertyDetails details_;
+  intptr_t hash_code_;

[Sven Panne, 2013/04/12 11:30:53]

Renaming this to something like 'unique_id_' makes it a bit clearer that it is
actually a bit more than a hash value.

[Yang, 2013/04/15 13:55:31]

Done.

 };