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

src/js/math.js

 // 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.
 
 (function(global, utils) {
 "use strict";
 
 %CheckIsBootstrapping();
 
 // -------------------------------------------------------------------
 // Imports
 
 // The first two slots are reserved to persist PRNG state.
 define kRandomNumberStart = 2;
 
-var GlobalFloat64Array = global.Float64Array;
 var GlobalMath = global.Math;
-var GlobalObject = global.Object;
 var NaN = %GetRootNaN();
 var nextRandomIndex = 0;
 var randomNumbers = UNDEFINED;
 var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 
 //-------------------------------------------------------------------
-
-// ECMA 262 - 15.8.2.1
-function MathAbs(x) {
-  x = +x;
-  return (x > 0) ? x : 0 - x;
-}
-
 // ECMA 262 - 15.8.2.14
 function MathRandom() {
   // While creating a startup snapshot, %GenerateRandomNumbers returns a
   // normal array containing a single random number, and has to be called for
   // every new random number.
   // Otherwise, it returns a pre-populated typed array of random numbers. The
   // first two elements are reserved for the PRNG state.
   if (nextRandomIndex <= kRandomNumberStart) {
     randomNumbers = %GenerateRandomNumbers(randomNumbers);
     if (%_IsTypedArray(randomNumbers)) {
@@ skipping 34 matching lines @@
 }
 
 // ES6 draft 09-27-13, section 20.2.2.17.
 function MathHypot(x, y) {  // Function length is 2.
   // We may want to introduce fast paths for two arguments and when
   // normalization to avoid overflow is not necessary.  For now, we
   // simply assume the general case.
   var length = arguments.length;
   var max = 0;
   for (var i = 0; i < length; i++) {
-    var n = MathAbs(arguments[i]);
+    var n = %math_abs(arguments[i]);
     if (n > max) max = n;
     arguments[i] = n;
   }
   if (max === INFINITY) return INFINITY;
 
   // Kahan summation to avoid rounding errors.
   // Normalize the numbers to the largest one to avoid overflow.
   if (max === 0) max = 1;
   var sum = 0;
   var compensation = 0;
@@ skipping 15 matching lines @@
 utils.InstallConstants(GlobalMath, [
   "PI", 3.1415926535897932,
   "SQRT1_2", 0.7071067811865476,
   "SQRT2", 1.4142135623730951
 ]);
 
 // Set up non-enumerable functions of the Math object and
 // set their names.
 utils.InstallFunctions(GlobalMath, DONT_ENUM, [
   "random", MathRandom,
-  "abs", MathAbs,
   "sign", MathSign,
   "asinh", MathAsinh,
   "acosh", MathAcosh,
   "hypot", MathHypot,
 ]);
 
 %SetForceInlineFlag(MathRandom);
 %SetForceInlineFlag(MathSign);
 
 // -------------------------------------------------------------------
 // Exports
 
 utils.Export(function(to) {
-  to.MathAbs = MathAbs;
   to.MathRandom = MathRandom;
 });
 
 })