[Interpreter] Avoid allocating pairs array in VisitDeclarations.

test/unittests/interpreter/constant-array-builder-unittest.cc

Index: test/unittests/interpreter/constant-array-builder-unittest.cc
diff --git a/test/unittests/interpreter/constant-array-builder-unittest.cc b/test/unittests/interpreter/constant-array-builder-unittest.cc
index c48ac58738c18d8a1f4eb4bbdc1e1a82678c50fb..1233aa4843d826ea10f6d9277f0c437a0e2275a7 100644
--- a/test/unittests/interpreter/constant-array-builder-unittest.cc
+++ b/test/unittests/interpreter/constant-array-builder-unittest.cc
@@ -43,7 +43,7 @@ TEST_F(ConstantArrayBuilderTest, AllocateEntriesWithIdx8Reservations) {
   for (size_t reserved = 1; reserved < k8BitCapacity; reserved *= 3) {
     ConstantArrayBuilder builder(isolate(), zone());
     for (size_t i = 0; i < reserved; i++) {
-      OperandSize operand_size = builder.CreateReservedEntry();
+      OperandSize operand_size = builder.CreateDiscardableReservedEntry();
       CHECK(operand_size == OperandSize::kByte);
     }
     for (size_t i = 0; i < 2 * k8BitCapacity; i++) {
@@ -94,7 +94,7 @@ TEST_F(ConstantArrayBuilderTest, AllocateEntriesWithIdx8Reservations) {
 
     // Now make reservations, and commit them with unique entries.
     for (size_t i = 0; i < duplicates_in_idx8_space; i++) {
-      OperandSize operand_size = builder.CreateReservedEntry();
+      OperandSize operand_size = builder.CreateDiscardableReservedEntry();
       CHECK(operand_size == OperandSize::kByte);
     }
     for (size_t i = 0; i < duplicates_in_idx8_space; i++) {
@@ -118,7 +118,7 @@ TEST_F(ConstantArrayBuilderTest, AllocateEntriesWithWideReservations) {
       CHECK_EQ(builder.size(), i + 1);
     }
     for (size_t i = 0; i < reserved; i++) {
-      OperandSize operand_size = builder.CreateReservedEntry();
+      OperandSize operand_size = builder.CreateDiscardableReservedEntry();
       CHECK(operand_size == OperandSize::kShort);
       CHECK_EQ(builder.size(), k8BitCapacity);
     }
@@ -127,14 +127,14 @@ TEST_F(ConstantArrayBuilderTest, AllocateEntriesWithWideReservations) {
       CHECK_EQ(builder.size(), k8BitCapacity);
     }
     for (size_t i = 0; i < reserved; i++) {
-      OperandSize operand_size = builder.CreateReservedEntry();
+      OperandSize operand_size = builder.CreateDiscardableReservedEntry();
       CHECK(operand_size == OperandSize::kShort);
       Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
       builder.CommitReservedEntry(operand_size, object);
       CHECK_EQ(builder.size(), k8BitCapacity);
     }
     for (size_t i = k8BitCapacity; i < k8BitCapacity + reserved; i++) {
-      OperandSize operand_size = builder.CreateReservedEntry();
+      OperandSize operand_size = builder.CreateDiscardableReservedEntry();
       CHECK(operand_size == OperandSize::kShort);
       Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
       builder.CommitReservedEntry(operand_size, object);
@@ -177,7 +177,7 @@ TEST_F(ConstantArrayBuilderTest, ToLargeFixedArray) {
 TEST_F(ConstantArrayBuilderTest, GapFilledWhenLowReservationCommitted) {
   ConstantArrayBuilder builder(isolate(), zone());
   for (size_t i = 0; i < k8BitCapacity; i++) {
-    OperandSize operand_size = builder.CreateReservedEntry();
+    OperandSize operand_size = builder.CreateDiscardableReservedEntry();
     CHECK(OperandSize::kByte == operand_size);
     CHECK_EQ(builder.size(), 0);
   }
@@ -203,7 +203,7 @@ TEST_F(ConstantArrayBuilderTest, GapFilledWhenLowReservationCommitted) {
 TEST_F(ConstantArrayBuilderTest, GapNotFilledWhenLowReservationDiscarded) {
   ConstantArrayBuilder builder(isolate(), zone());
   for (size_t i = 0; i < k8BitCapacity; i++) {
-    OperandSize operand_size = builder.CreateReservedEntry();
+    OperandSize operand_size = builder.CreateDiscardableReservedEntry();
     CHECK(OperandSize::kByte == operand_size);
     CHECK_EQ(builder.size(), 0);
   }
@@ -230,7 +230,7 @@ TEST_F(ConstantArrayBuilderTest, HolesWithUnusedReservations) {
   static int kNumberOfHoles = 128;
   ConstantArrayBuilder builder(isolate(), zone());
   for (int i = 0; i < kNumberOfHoles; ++i) {
-    CHECK_EQ(builder.CreateReservedEntry(), OperandSize::kByte);
+    CHECK_EQ(builder.CreateDiscardableReservedEntry(), OperandSize::kByte);
   }
   for (int i = 0; i < 128; ++i) {
     CHECK_EQ(builder.Insert(isolate()->factory()->NewNumber(i)), i);
@@ -252,13 +252,13 @@ TEST_F(ConstantArrayBuilderTest, HolesWithUnusedReservations) {
 TEST_F(ConstantArrayBuilderTest, ReservationsAtAllScales) {
   ConstantArrayBuilder builder(isolate(), zone());
   for (int i = 0; i < 256; i++) {
-    CHECK_EQ(builder.CreateReservedEntry(), OperandSize::kByte);
+    CHECK_EQ(builder.CreateDiscardableReservedEntry(), OperandSize::kByte);
   }
   for (int i = 256; i < 65536; ++i) {
-    CHECK_EQ(builder.CreateReservedEntry(), OperandSize::kShort);
+    CHECK_EQ(builder.CreateDiscardableReservedEntry(), OperandSize::kShort);
   }
   for (int i = 65536; i < 131072; ++i) {
-    CHECK_EQ(builder.CreateReservedEntry(), OperandSize::kQuad);
+    CHECK_EQ(builder.CreateDiscardableReservedEntry(), OperandSize::kQuad);
   }
   CHECK_EQ(builder.CommitReservedEntry(OperandSize::kByte,
                                        isolate()->factory()->NewNumber(1)),
@@ -283,6 +283,40 @@ TEST_F(ConstantArrayBuilderTest, ReservationsAtAllScales) {
   }
 }
 
+TEST_F(ConstantArrayBuilderTest, AllocateEntriesWithFixedReservations) {
+  ConstantArrayBuilder builder(isolate(), zone());
+  for (size_t i = 0; i < k16BitCapacity; i++) {
+    if ((i % 2) == 0) {
+      CHECK_EQ(i, builder.ReserveEntry());
+    } else {
+      builder.Insert(handle(Smi::FromInt(static_cast<int>(i)), isolate()));
+    }
+  }
+  CHECK_EQ(builder.size(), k16BitCapacity);
+
+  // Check values before reserved entries are inserted.
+  for (size_t i = 0; i < k16BitCapacity; i++) {
+    if ((i % 2) == 0) {
+      // Check reserved values are the hole.
+      Handle<Object> empty = builder.At(i);
+      CHECK(empty->SameValue(isolate()->heap()->the_hole_value()));
+    } else {
+      CHECK_EQ(Handle<Smi>::cast(builder.At(i))->value(), i);
+    }
+  }
+
+  // Insert reserved entries.
+  for (size_t i = 0; i < k16BitCapacity; i += 2) {
+    builder.InsertReservedEntry(
+        i, handle(Smi::FromInt(static_cast<int>(i)), isolate()));
+  }
+
+  // Check values after reserved entries are inserted.
+  for (size_t i = 0; i < k16BitCapacity; i++) {
+    CHECK_EQ(Handle<Smi>::cast(builder.At(i))->value(), i);
+  }
+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8