[turbofan] Implemented the optional Float32RoundDown 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 5126 matching lines @@
                            -two_52,
                            -two_52 - 0.1,
                            -two_52 - 0.5,
                            -two_52 - 0.7,
                            -two_52 + 1,
                            -two_52 + 1 - 0.1,
                            -two_52 + 1 - 0.5,
                            -two_52 + 1 - 0.7};
 
 
+TEST(RunFloat32RoundDown) {
+  BufferedRawMachineAssemblerTester<float> m(kMachFloat32);
+  if (!m.machine()->Float32RoundDown().IsSupported()) return;
+
+  m.Return(m.Float32RoundDown(m.Parameter(0)));
+
+  FOR_FLOAT32_INPUTS(i) { CheckFloatEq(floorf(*i), m.Call(*i)); }

[jbramley, 2015/11/25 10:46:16]

Again, why not std::floor?

+}
+
+
 TEST(RunFloat64RoundDown1) {
   BufferedRawMachineAssemblerTester<double> m(kMachFloat64);
   if (!m.machine()->Float64RoundDown().IsSupported()) return;
 
   m.Return(m.Float64RoundDown(m.Parameter(0)));
 
   FOR_FLOAT64_INPUTS(i) { CheckDoubleEq(std::floor(*i), m.Call(*i)); }
 }
 
 
@@ skipping 498 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