[builtins] Migrate Math.abs() to TurboFan builtins.

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 2221 matching lines @@
   Handle<Object> object = args.atOrUndefined(isolate, 1);
   Handle<Object> replacer = args.atOrUndefined(isolate, 2);
   Handle<Object> indent = args.atOrUndefined(isolate, 3);
   RETURN_RESULT_OR_FAILURE(isolate,
                            stringifier.Stringify(object, replacer, indent));
 }
 
 // -----------------------------------------------------------------------------
 // ES6 section 20.2.2 Function Properties of the Math Object
 
+// ES6 section - 20.2.2.1 Math.abs ( x )
+void Builtins::Generate_MathAbs(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->Float64Abs(x_value);
+  Node* result = assembler->ChangeFloat64ToTagged(value);
+  assembler->Return(result);
+}
 
 // ES6 section 20.2.2.2 Math.acos ( x )
 BUILTIN(MathAcos) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
   Handle<Object> x = args.at<Object>(1);
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, x, Object::ToNumber(x));
   return *isolate->factory()->NewHeapNumber(std::acos(x->Number()));
 }
 
-
 // ES6 section 20.2.2.4 Math.asin ( x )
 BUILTIN(MathAsin) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
   Handle<Object> x = args.at<Object>(1);
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, x, Object::ToNumber(x));
   return *isolate->factory()->NewHeapNumber(std::asin(x->Number()));
 }
 
 // ES6 section 20.2.2.6 Math.atan ( x )
@@ skipping 4030 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