[builtins] Introduce proper Float64Atan and Float64Atan2 operators.

test/unittests/compiler/js-builtin-reducer-unittest.cc

Index: test/unittests/compiler/js-builtin-reducer-unittest.cc
diff --git a/test/unittests/compiler/js-builtin-reducer-unittest.cc b/test/unittests/compiler/js-builtin-reducer-unittest.cc
index 017016be01163d5bddbfaad933a091732197aeac..552365b5cfca0c5ed0b7ad7d4a6b97ce89d04141 100644
--- a/test/unittests/compiler/js-builtin-reducer-unittest.cc
+++ b/test/unittests/compiler/js-builtin-reducer-unittest.cc
@@ -203,6 +203,53 @@ TEST_F(JSBuiltinReducerTest, MathFround) {
 }
 
 // -----------------------------------------------------------------------------
+// Math.atan
+
+TEST_F(JSBuiltinReducerTest, MathAtan) {
+  Node* function = MathFunction("atan");
+
+  Node* effect = graph()->start();
+  Node* control = graph()->start();
+  Node* context = UndefinedConstant();
+  Node* frame_state = graph()->start();
+  TRACED_FOREACH(Type*, t0, kNumberTypes) {
+    Node* p0 = Parameter(t0, 0);
+    Node* call = graph()->NewNode(javascript()->CallFunction(3), function,
+                                  UndefinedConstant(), p0, context, frame_state,
+                                  effect, control);
+    Reduction r = Reduce(call);
+
+    ASSERT_TRUE(r.Changed());
+    EXPECT_THAT(r.replacement(), IsNumberAtan(p0));
+  }
+}
+
+// -----------------------------------------------------------------------------
+// Math.atan2
+
+TEST_F(JSBuiltinReducerTest, MathAtan2) {
+  Node* function = MathFunction("atan2");
+
+  Node* effect = graph()->start();
+  Node* control = graph()->start();
+  Node* context = UndefinedConstant();
+  Node* frame_state = graph()->start();
+  TRACED_FOREACH(Type*, t0, kNumberTypes) {
+    Node* p0 = Parameter(t0, 0);
+    TRACED_FOREACH(Type*, t1, kNumberTypes) {
+      Node* p1 = Parameter(t1, 0);
+      Node* call = graph()->NewNode(javascript()->CallFunction(4), function,
+                                    UndefinedConstant(), p0, p1, context,
+                                    frame_state, effect, control);
+      Reduction r = Reduce(call);
+
+      ASSERT_TRUE(r.Changed());
+      EXPECT_THAT(r.replacement(), IsNumberAtan2(p0, p1));
+    }
+  }
+}
+
+// -----------------------------------------------------------------------------
 // Math.log
 
 TEST_F(JSBuiltinReducerTest, MathLog) {