Speed up object-keyed Map and Set by giving out sequential hash codes

src/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.
 
 var rngstate;  // Initialized to a Uint32Array during genesis.
 
 (function(global, utils) {
 "use strict";
 
 %CheckIsBootstrapping();
@@ skipping 119 matching lines @@
 function MathRandom() {
   var r0 = (MathImul(18030, rngstate[0] & 0xFFFF) + (rngstate[0] >>> 16)) | 0;
   rngstate[0] = r0;
   var r1 = (MathImul(36969, rngstate[1] & 0xFFFF) + (rngstate[1] >>> 16)) | 0;
   rngstate[1] = r1;
   var x = ((r0 << 16) + (r1 & 0xFFFF)) | 0;
   // Division by 0x100000000 through multiplication by reciprocal.
   return (x < 0 ? (x + 0x100000000) : x) * 2.3283064365386962890625e-10;
 }
 
-function MathRandomRaw() {
-  var r0 = (MathImul(18030, rngstate[0] & 0xFFFF) + (rngstate[0] >>> 16)) | 0;
-  rngstate[0] = r0;
-  var r1 = (MathImul(36969, rngstate[1] & 0xFFFF) + (rngstate[1] >>> 16)) | 0;
-  rngstate[1] = r1;
-  var x = ((r0 << 16) + (r1 & 0xFFFF)) | 0;
-  return x & 0x3fffffff;
-}
 
 // ECMA 262 - 15.8.2.15
 function MathRound(x) {
   return %RoundNumber(TO_NUMBER_INLINE(x));
 }
 
 // ECMA 262 - 15.8.2.17
 function MathSqrtJS(x) {
   return %_MathSqrt(+x);
 }
@@ skipping 201 matching lines @@
 %SetForceInlineFlag(MathSqrtJS);
 %SetForceInlineFlag(MathTrunc);
 
 // -------------------------------------------------------------------
 // Exports
 
 utils.Export(function(to) {
   to.MathAbs = MathAbs;
   to.MathExp = MathExp;
   to.MathFloor = MathFloorJS;
-  to.IntRandom = MathRandomRaw;
   to.MathMax = MathMax;
   to.MathMin = MathMin;
 });
 
 })