今このタイミングでFlash9のArrayの挙動については100%誰も興味が無い．
id:keim_at_Si:20080523の続き．as3のArrayはかなり気持ち悪いので，自分のプログラムでも，ボトルネックになりそうなところではほとんど使ってません．Flash10のVector調べる前にArrayの気持ち悪さを再確認してみましょう．しかし，ほんとキモいなー，これ．
Array ベンチマーク for int
Array ベンチマーク for Number
少し止まったあと，各ループの処理時間が表示されます．環境依存激しそうなので皆さん自分の環境でやってみてください．プレイヤーが古いですがうちの1GHzノートの場合，
for int
デバッガの結果．
Windows XP/StandAlone/WIN 9,0,115,0/debugger
862[ms] { array[i] += t1; }
846[ms] { array[i] = array[i] + t1; }
1047[ms] { array[i] = int(array[i]) + t1; }
494[ms] { t0 = array[i]; t0 += t1; array[i] = t0; }
491[ms] { t0 = array[i]; t0 = t0 + t1; array[i] = t0; }
583[ms] { t0 = array[i]; array[i] = t0 + t1; }
685[ms] { array[i] = array[i + t1]; }
417[ms] { t0 = i + t1; array[i] = array[t0]; }ie上での結果．
Windows XP/ActiveX/WIN 9,0,115,0/normal
695[ms] { array[i] += t1; }
698[ms] { array[i] = array[i] + t1; }
451[ms] { array[i] = int(array[i]) + t1; }
376[ms] { t0 = array[i]; t0 += t1; array[i] = t0; }
374[ms] { t0 = array[i]; t0 = t0 + t1; array[i] = t0; }
449[ms] { t0 = array[i]; array[i] = t0 + t1; }
529[ms] { array[i] = array[i + t1]; }
321[ms] { t0 = i + t1; array[i] = array[t0]; }
for Number
デバッガの結果．
Windows XP/StandAlone/WIN 9,0,115,0/debugger
919[ms] { array[i] += t1; }
932[ms] { array[i] = array[i] + t1; }
1080[ms] { array[i] = Number(array[i]) + t1; }
604[ms] { t0 = array[i]; t0 += t1; array[i] = t0; }
613[ms] { t0 = array[i]; t0 = t0 + t1; array[i] = t0; }
644[ms] { t0 = array[i]; array[i] = t0 + t1; }ie上での結果．
Windows XP/ActiveX/WIN 9,0,115,0/normal
769[ms] { array[i] += t1; }
770[ms] { array[i] = array[i] + t1; }
502[ms] { array[i] = Number(array[i]) + t1; }
505[ms] { t0 = array[i]; t0 += t1; array[i] = t0; }
508[ms] { t0 = array[i]; t0 = t0 + t1; array[i] = t0; }
512[ms] { t0 = array[i]; array[i] = t0 + t1; }
4,5,6行目の高速化も十分気持ち悪いんだけど，特にArrayの異常さを感じたのは for int の7,8行目かな．だれかTamarinソースによる合理的な説明を求む．あと3行目のデバッガとブラウザでの速度差に震撼．キャストしておくとJITコンパイラで最適化されるよって話を，たしかAdobeのプレゼン資料で読んだ気はしてたんだけど，デバッガ上では最適化されてないみたい．うわー．
とりあえずArrayは計算式内で直接使わずローカル変数に代入して使う．あとインデックスもあらかじめ計算しておく．
結論，Arrayきもい．
以下ソース
for int．
package { import flash.text.TextField; import flash.display.*; import flash.utils.getTimer; import flash.system.Capabilities; [SWF(width="640", height="480", backgroundColor='#ffffff')] public class main extends Sprite { function main() { var i:int, imax:int = 4999999; var time:int, array:Array = new Array(imax); var res:String = Capabilities.os+"/"; res += Capabilities.playerType+"/"; res += Capabilities.version+"/"; res += (Capabilities.isDebugger?"debugger":"normal")+"\n"; //----test start var t0:int, t1:int; for (i=0; i<imax; i++) { array[i] = int(0); } imax--; t1 = 1; time = getTimer(); for (i=0; i<imax; i++) { array[i] += t1; } res += String(getTimer() - time) + '[ms] { array[i] += t1; }\n'; time = getTimer(); for (i=0; i<imax; i++) { array[i] = array[i] + t1; } res += String(getTimer() - time) + '[ms] { array[i] = array[i] + t1; }\n'; time = getTimer(); for (i=0; i<imax; i++) { array[i] = int(array[i]) + t1; } res += String(getTimer() - time) + '[ms] { array[i] = int(array[i]) + t1; }\n'; time = getTimer(); for (i=0; i<imax; i++) { t0 = array[i]; t0 += t1; array[i] = t0; } res += String(getTimer() - time) + '[ms] { t0 = array[i]; t0 += t1; array[i] = t0; }\n'; time = getTimer(); for (i=0; i<imax; i++) { t0 = array[i]; t0 = t0 + t1; array[i] = t0; } res += String(getTimer() - time) + '[ms] { t0 = array[i]; t0 = t0 + t1; array[i] = t0; }\n'; time = getTimer(); for (i=0; i<imax; i++) { t0 = array[i]; array[i] = t0 + t1; } res += String(getTimer() - time) + '[ms] { t0 = array[i]; array[i] = t0 + t1; }\n'; time = getTimer(); for (i=0; i<imax; i++) { array[i] = array[i + t1]; } res += String(getTimer() - time) + '[ms] { array[i] = array[i + t1]; }\n'; time = getTimer(); for (i=0; i<imax; i++) { t0 = i + t1; array[i] = array[t0]; } res += String(getTimer() - time) + '[ms] { t0 = i + t1; array[i] = array[t0]; }\n'; //----test end var tf:TextField = new TextField(); tf.multiline = true; tf.width = 640; tf.height = 480; tf.selectable = true; tf.textColor = 0x000000; tf.text = res; addChild(tf); stage.scaleMode = StageScaleMode.NO_SCALE; } } }
for Number．
//----test start var t0:Number, t1:Number; for (i=0; i<imax; i++) { array[i] = Number(0); } imax--; t1 = 1; time = getTimer(); for (i=0; i<imax; i++) { array[i] += t1; } res += String(getTimer() - time) + '[ms] { array[i] += t1; }\n'; time = getTimer(); for (i=0; i<imax; i++) { array[i] = array[i] + t1; } res += String(getTimer() - time) + '[ms] { array[i] = array[i] + t1; }\n'; time = getTimer(); for (i=0; i<imax; i++) { array[i] = Number(array[i]) + t1; } res += String(getTimer() - time) + '[ms] { array[i] = Number(array[i]) + t1; }\n'; time = getTimer(); for (i=0; i<imax; i++) { t0 = array[i]; t0 += t1; array[i] = t0; } res += String(getTimer() - time) + '[ms] { t0 = array[i]; t0 += t1; array[i] = t0; }\n'; time = getTimer(); for (i=0; i<imax; i++) { t0 = array[i]; t0 = t0 + t1; array[i] = t0; } res += String(getTimer() - time) + '[ms] { t0 = array[i]; t0 = t0 + t1; array[i] = t0; }\n'; time = getTimer(); for (i=0; i<imax; i++) { t0 = array[i]; array[i] = t0 + t1; } res += String(getTimer() - time) + '[ms] { t0 = array[i]; array[i] = t0 + t1; }\n'; //----test end
