[builtins] Migrate Math.hypot() to C++ 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();
 
 // -------------------------------------------------------------------
@@ skipping 48 matching lines @@
 
 // ES6 draft 09-27-13, section 20.2.2.3.
 function MathAcosh(x) {
   x = TO_NUMBER(x);
   if (x < 1) return NaN;
   // Idempotent for NaN and +Infinity.
   if (!NUMBER_IS_FINITE(x)) return x;
   return %math_log(x + %math_sqrt(x + 1) * %math_sqrt(x - 1));
 }
 
-// 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 = %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;
-  for (var i = 0; i < length; i++) {
-    var n = arguments[i] / max;
-    var summand = n * n - compensation;
-    var preliminary = sum + summand;
-    compensation = (preliminary - sum) - summand;
-    sum = preliminary;
-  }
-  return %math_sqrt(sum) * max;
-}
 
 // -------------------------------------------------------------------
 
 %AddNamedProperty(GlobalMath, toStringTagSymbol, "Math", READ_ONLY | DONT_ENUM);
 
 // Set up math constants.
 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,
   "sign", MathSign,
   "asinh", MathAsinh,
-  "acosh", MathAcosh,
-  "hypot", MathHypot,
+  "acosh", MathAcosh
 ]);
 
 %SetForceInlineFlag(MathRandom);
 %SetForceInlineFlag(MathSign);
 
 // -------------------------------------------------------------------
 // Exports
 
 utils.Export(function(to) {
   to.MathRandom = MathRandom;
 });
 
 })