[turbofan] Add operators for float32 support.

src/compiler/machine-operator-reducer-unittest.cc

Index: src/compiler/machine-operator-reducer-unittest.cc
diff --git a/src/compiler/machine-operator-reducer-unittest.cc b/src/compiler/machine-operator-reducer-unittest.cc
index 6b27b12670432e4f9a75ae358166d7a3637d4ab7..f8849fe7a469f4cb97ecfd768f6caeca46403c39 100644
--- a/src/compiler/machine-operator-reducer-unittest.cc
+++ b/src/compiler/machine-operator-reducer-unittest.cc
@@ -315,6 +315,31 @@ TEST_F(MachineOperatorReducerTest, ChangeUint32ToUint64WithConstant) {
 
 
 // -----------------------------------------------------------------------------
+// TruncateFloat64ToFloat32
+
+
+TEST_F(MachineOperatorReducerTest,
+       TruncateFloat64ToFloat32WithChangeFloat32ToFloat64) {
+  Node* value = Parameter(0);
+  Reduction reduction = Reduce(graph()->NewNode(
+      machine()->TruncateFloat64ToFloat32(),
+      graph()->NewNode(machine()->ChangeFloat32ToFloat64(), value)));
+  ASSERT_TRUE(reduction.Changed());
+  EXPECT_EQ(value, reduction.replacement());
+}
+
+
+TEST_F(MachineOperatorReducerTest, TruncateFloat64ToFloat32WithConstant) {
+  TRACED_FOREACH(double, x, kFloat64Values) {
+    Reduction reduction = Reduce(graph()->NewNode(
+        machine()->TruncateFloat64ToFloat32(), Float64Constant(x)));
+    ASSERT_TRUE(reduction.Changed());
+    EXPECT_THAT(reduction.replacement(), IsFloat32Constant(DoubleToFloat32(x)));
+  }
+}
+
+
+// -----------------------------------------------------------------------------
 // TruncateFloat64ToInt32