[turbofan] Implemented the TruncateFloat64ToUint64 TurboFan operator.

test/cctest/compiler/test-run-machops.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.
 
 // TODO(jochen): Remove this after the setting is turned on globally.
 #define V8_IMMINENT_DEPRECATION_WARNINGS
 
 #include <cmath>
 #include <functional>
 #include <limits>
@@ skipping 5346 matching lines @@
   BufferedRawMachineAssemblerTester<int64_t> m(kMachFloat64);
   m.Return(m.ChangeFloat64ToInt64(m.Parameter(0)));
 
   FOR_INT64_INPUTS(i) {
     double input = static_cast<double>(*i);
     CHECK_EQ(static_cast<int64_t>(input), m.Call(input));
   }
 }
 
 
+TEST(RunTruncateFloat64ToUint64) {
+  BufferedRawMachineAssemblerTester<uint64_t> m(kMachFloat64);
+  m.Return(m.TruncateFloat64ToUint64(m.Parameter(0)));
+
+  FOR_UINT64_INPUTS(j) {
+    double input = static_cast<double>(*j);
+
+    if (input < 18446744073709551616.0) {
+      CHECK_EQ(static_cast<uint64_t>(input), m.Call(input));
+    }
+  }
+
+  FOR_FLOAT64_INPUTS(i) {
+    if (*i < 18446744073709551616.0 && *i >= 0) {
+      CHECK_EQ(static_cast<uint64_t>(*i), m.Call(*i));
+    }
+  }
+}
+
+
 TEST(RunRoundInt64ToFloat32) {
   BufferedRawMachineAssemblerTester<float> m(kMachInt64);
   m.Return(m.RoundInt64ToFloat32(m.Parameter(0)));
   FOR_INT64_INPUTS(i) { CHECK_EQ(static_cast<float>(*i), m.Call(*i)); }
 }
 
 
 TEST(RunRoundInt64ToFloat64) {
   BufferedRawMachineAssemblerTester<double> m(kMachInt64);
   m.Return(m.RoundInt64ToFloat64(m.Parameter(0)));
@@ skipping 258 matching lines @@
   Node* call = r.AddNode(r.common()->Call(desc), phi);
   r.Return(call);
 
   CHECK_EQ(33, r.Call(1));
   CHECK_EQ(44, r.Call(0));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8