[interpreter] A few code coverage improvements.

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

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/factory.h"
 #include "src/handles-inl.h"
 #include "src/interpreter/constant-array-builder.h"
 #include "src/isolate.h"
@@ skipping 21 matching lines @@
   ConstantArrayBuilder builder(isolate(), zone());
   for (size_t i = 0; i < k16BitCapacity; i++) {
     builder.Insert(handle(Smi::FromInt(static_cast<int>(i)), isolate()));
   }
   CHECK_EQ(builder.size(), k16BitCapacity);
   for (size_t i = 0; i < k16BitCapacity; i++) {
     CHECK_EQ(Handle<Smi>::cast(builder.At(i))->value(), i);
   }
 }
 
-
 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();
       CHECK(operand_size == OperandSize::kByte);
     }
     for (size_t i = 0; i < 2 * k8BitCapacity; i++) {
       Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
       builder.Insert(object);
@@ skipping 141 matching lines @@
   }
   for (size_t i = 0; i < k8BitCapacity; i++) {
     Handle<Object> original = builder.At(k8BitCapacity + i);
     Handle<Object> duplicate = builder.At(i);
     CHECK(original->SameValue(*duplicate));
     Handle<Object> reference = isolate()->factory()->NewNumberFromSize(i);
     CHECK(original->SameValue(*reference));
   }
 }
 
-
 TEST_F(ConstantArrayBuilderTest, GapNotFilledWhenLowReservationDiscarded) {
   ConstantArrayBuilder builder(isolate(), zone());
   for (size_t i = 0; i < k8BitCapacity; i++) {
     OperandSize operand_size = builder.CreateReservedEntry();
     CHECK(OperandSize::kByte == operand_size);
     CHECK_EQ(builder.size(), 0);
   }
   for (size_t i = 0; i < k8BitCapacity; i++) {
     Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
     builder.Insert(object);
     CHECK_EQ(builder.size(), i + k8BitCapacity + 1);
   }
   for (size_t i = 0; i < k8BitCapacity; i++) {
     builder.DiscardReservedEntry(OperandSize::kByte);
     builder.Insert(builder.At(i + k8BitCapacity));
     CHECK_EQ(builder.size(), 2 * k8BitCapacity);
   }
   for (size_t i = 0; i < k8BitCapacity; i++) {
     Handle<Object> reference = isolate()->factory()->NewNumberFromSize(i);
     Handle<Object> original = builder.At(k8BitCapacity + i);
     CHECK(original->SameValue(*reference));
     Handle<Object> duplicate = builder.At(i);
     CHECK(duplicate->SameValue(*isolate()->factory()->the_hole_value()));
   }
 }
 
+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);
+  }
+  for (int i = 0; i < 128; ++i) {
+    CHECK_EQ(builder.Insert(isolate()->factory()->NewNumber(i)), i);
+  }
+  CHECK_EQ(builder.Insert(isolate()->factory()->NewNumber(256)), 256);
+
+  Handle<FixedArray> constant_array = builder.ToFixedArray();
+  CHECK_EQ(constant_array->length(), 257);
+  for (int i = 128; i < 256; i++) {
+    CHECK(constant_array->get(i)->SameValue(
+        *isolate()->factory()->the_hole_value()));
+  }
+  CHECK(!constant_array->get(127)->SameValue(
+      *isolate()->factory()->the_hole_value()));
+  CHECK(!constant_array->get(256)->SameValue(
+      *isolate()->factory()->the_hole_value()));
+}
+
+TEST_F(ConstantArrayBuilderTest, ReservationsAtAllScales) {
+  ConstantArrayBuilder builder(isolate(), zone());
+  for (int i = 0; i < 256; i++) {
+    CHECK_EQ(builder.CreateReservedEntry(), OperandSize::kByte);
+  }
+  for (int i = 256; i < 65536; ++i) {
+    CHECK_EQ(builder.CreateReservedEntry(), OperandSize::kShort);
+  }
+  for (int i = 65536; i < 131072; ++i) {
+    CHECK_EQ(builder.CreateReservedEntry(), OperandSize::kQuad);
+  }
+  CHECK_EQ(builder.CommitReservedEntry(OperandSize::kByte,
+                                       isolate()->factory()->NewNumber(1)),
+           0);
+  CHECK_EQ(builder.CommitReservedEntry(OperandSize::kShort,
+                                       isolate()->factory()->NewNumber(2)),
+           256);
+  CHECK_EQ(builder.CommitReservedEntry(OperandSize::kQuad,
+                                       isolate()->factory()->NewNumber(3)),
+           65536);
+  Handle<FixedArray> constant_array = builder.ToFixedArray();
+  CHECK_EQ(constant_array->length(), 65537);
+  int count = 1;
+  for (int i = 0; i < constant_array->length(); ++i) {
+    Handle<Object> expected;
+    if (i == 0 || i == 256 || i == 65536) {
+      expected = isolate()->factory()->NewNumber(count++);
+    } else {
+      expected = isolate()->factory()->the_hole_value();
+    }
+    CHECK(constant_array->get(i)->SameValue(*expected));
+  }
+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8