Use signaling NaN for holes in fixed double arrays.

test/unittests/base/math-unittest.cc

+// Copyright 2015 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 <limits>
+
+#include "src/base/math.h"
+#include "testing/gtest-support.h"
+
+namespace v8 {
+namespace base {
+
+TEST(Math, IsQuietNaN) {
+  EXPECT_FALSE(IsQuietNaN(0.0f));
+  EXPECT_FALSE(IsQuietNaN(0.0));
+  EXPECT_TRUE(IsQuietNaN(std::numeric_limits<float>::quiet_NaN()));
+  EXPECT_TRUE(IsQuietNaN(std::numeric_limits<double>::quiet_NaN()));
+  EXPECT_FALSE(IsQuietNaN(std::numeric_limits<float>::signaling_NaN()));
+  EXPECT_FALSE(IsQuietNaN(std::numeric_limits<double>::signaling_NaN()));
+  EXPECT_FALSE(IsQuietNaN(std::numeric_limits<float>::infinity()));
+  EXPECT_FALSE(IsQuietNaN(std::numeric_limits<double>::infinity()));
+}
+
+
+TEST(Math, IsSignalingNaN) {
+  EXPECT_FALSE(IsSignalingNaN(0.0f));
+  EXPECT_FALSE(IsSignalingNaN(0.0));
+  EXPECT_TRUE(IsSignalingNaN(std::numeric_limits<float>::signaling_NaN()));
+  EXPECT_TRUE(IsSignalingNaN(std::numeric_limits<double>::signaling_NaN()));
+  EXPECT_FALSE(IsSignalingNaN(std::numeric_limits<float>::quiet_NaN()));
+  EXPECT_FALSE(IsSignalingNaN(std::numeric_limits<double>::quiet_NaN()));
+  EXPECT_FALSE(IsSignalingNaN(std::numeric_limits<float>::infinity()));
+  EXPECT_FALSE(IsSignalingNaN(std::numeric_limits<double>::infinity()));
+}
+
+}  // namespace base
+}  // namespace v8