[Interpreter] Avoid allocating pairs array in VisitDeclarations.

src/interpreter/constant-array-builder.h

Index: src/interpreter/constant-array-builder.h
diff --git a/src/interpreter/constant-array-builder.h b/src/interpreter/constant-array-builder.h
index 1a68646251f1f4360f72668bb91ff9fb48593de6..5aa442e4d716002794666c78569da27e74f50ded 100644
--- a/src/interpreter/constant-array-builder.h
+++ b/src/interpreter/constant-array-builder.h
@@ -48,10 +48,18 @@ class ConstantArrayBuilder final BASE_EMBEDDED {
   // present. Returns the array index associated with the object.
   size_t Insert(Handle<Object> object);
 
+  // Reserves a entry which cannot later be discarded, and returns the array
+  // index associated with the reservation.
+  size_t ReserveEntry();
+
+  // Commits an undiscardable reserved entry and updates the entry with the
+  // given object.
+  void InsertReservedEntry(size_t index, Handle<Object> object);
+
   // Creates a reserved entry in the constant pool and returns
   // the size of the operand that'll be required to hold the entry
   // when committed.
-  OperandSize CreateReservedEntry();
+  OperandSize CreateDiscardableReservedEntry();

[oth, 2016/07/22 10:22:10]

The names here used to align to give a hint that it was a group of related
methods, e.g. CreateReservedEntry, CommitReservedEntry, DiscardReservedEntry.

How about something like:

s/ReserveEntry/AllocateEntry/
s/InsertReservedEntry/BindAllocatedEntry/
s/CreateDiscardableReservedEntry/CreateReservedEntry/

[rmcilroy, 2016/07/25 10:55:29]

SGTM (/s/BindAllocatedEntry/InsertAllocatedEntry). Done.

 
   // Commit reserved entry and returns the constant pool index for the
   // object.
@@ -64,6 +72,7 @@ class ConstantArrayBuilder final BASE_EMBEDDED {
   typedef uint32_t index_t;
 
   index_t AllocateEntry(Handle<Object> object);
+  index_t AllocateIndex(Handle<Object> object);
 
   struct ConstantArraySlice final : public ZoneObject {
     ConstantArraySlice(Zone* zone, size_t start_index, size_t capacity,
@@ -72,6 +81,7 @@ class ConstantArrayBuilder final BASE_EMBEDDED {
     void Unreserve();
     size_t Allocate(Handle<Object> object);
     Handle<Object> At(size_t index) const;
+    void Update(size_t index, Handle<Object> object);
 
     inline size_t available() const { return capacity() - reserved() - size(); }
     inline size_t reserved() const { return reserved_; }
@@ -91,7 +101,7 @@ class ConstantArrayBuilder final BASE_EMBEDDED {
     DISALLOW_COPY_AND_ASSIGN(ConstantArraySlice);
   };
 
-  const ConstantArraySlice* IndexToSlice(size_t index) const;
+  ConstantArraySlice* IndexToSlice(size_t index) const;
   ConstantArraySlice* OperandSizeToSlice(OperandSize operand_size) const;
 
   IdentityMap<index_t>* constants_map() { return &constants_map_; }