[builtins] Introduce proper Float64Tan operator.

src/builtins.cc

 // Copyright 2012 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 "src/builtins.h"
 
 #include "src/api-arguments.h"
 #include "src/api-natives.h"
 #include "src/api.h"
 #include "src/base/ieee754.h"
@@ skipping 2543 matching lines @@
   using compiler::Node;
 
   Node* x = assembler->Parameter(1);
   Node* context = assembler->Parameter(4);
   Node* x_value = assembler->TruncateTaggedToFloat64(context, x);
   Node* value = assembler->Float64Sqrt(x_value);
   Node* result = assembler->ChangeFloat64ToTagged(value);
   assembler->Return(result);
 }
 
+// ES6 section 20.2.2.33 Math.tan ( x )
+void Builtins::Generate_MathTan(CodeStubAssembler* assembler) {
+  using compiler::Node;
+
+  Node* x = assembler->Parameter(1);
+  Node* context = assembler->Parameter(4);
+  Node* x_value = assembler->TruncateTaggedToFloat64(context, x);
+  Node* value = assembler->Float64Tan(x_value);
+  Node* result = assembler->ChangeFloat64ToTagged(value);
+  assembler->Return(result);
+}
+
 // ES6 section 20.2.2.35 Math.trunc ( x )
 void Builtins::Generate_MathTrunc(CodeStubAssembler* assembler) {
   Generate_MathRoundingOperation(assembler, &CodeStubAssembler::Float64Trunc);
 }
 
 // -----------------------------------------------------------------------------
 // ES6 section 19.2 Function Objects
 
 // ES6 section 19.2.3.6 Function.prototype [ @@hasInstance ] ( V )
 void Builtins::Generate_FunctionPrototypeHasInstance(
@@ skipping 3479 matching lines @@
 BUILTIN_LIST_H(DEFINE_BUILTIN_ACCESSOR_H)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 #undef DEFINE_BUILTIN_ACCESSOR_T
 #undef DEFINE_BUILTIN_ACCESSOR_S
 #undef DEFINE_BUILTIN_ACCESSOR_H
 
 }  // namespace internal
 }  // namespace v8