{"id":4155,"date":"2020-03-02T19:47:01","date_gmt":"2020-03-02T11:47:01","guid":{"rendered":"https:\/\/damogame.cn\/wordpress\/?p=4155"},"modified":"2020-03-02T19:47:01","modified_gmt":"2020-03-02T11:47:01","slug":"lualuajit","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/4155","title":{"rendered":"lua&#038;luaJit"},"content":{"rendered":"<div class=\"article-header-box\">\n<div class=\"article-header\">\n<div class=\"article-title-box\">\n<p class=\"title-article\"><a href=\"https:\/\/blog.csdn.net\/caolinqing1\/article\/details\/99724906\">\u539f\u6587\u5730\u5740<\/a><\/p>\n<p>&nbsp;<\/p>\n<\/div>\n<div class=\"article-info-box\">\n<div class=\"article-bar-top\"><span class=\"article-type type-4 float-left\">\u7ffb\u8bd1<\/span><a class=\"follow-nickName\" href=\"https:\/\/me.csdn.net\/caolinqing1\" target=\"_blank\" rel=\"noopener noreferrer\">\u8349\u7433\u60c5<\/a>\u00a0<span class=\"time\">\u6700\u540e\u53d1\u5e03\u4e8e2019-08-19 14:19:49\u00a0<\/span><span class=\"read-count\">\u9605\u8bfb\u6570 409<\/span>\u00a0<a id=\"blog_detail_zk_collection\" data-report-click=\"{&quot;mod&quot;:&quot;popu_823&quot;}\"><\/a>\u00a0\u6536\u85cf<\/div>\n<div class=\"operating\"><a class=\"href-article-edit slide-toggle\">\u5c55\u5f00<\/a><\/div>\n<\/div>\n<\/div>\n<\/div>\n<article class=\"baidu_pl\">\n<div id=\"article_content\" class=\"article_content clearfix\">\n<div id=\"content_views\" class=\"htmledit_views\">\n<p>lua\uff08www.lua.org\uff09\u5176\u5b9e\u5c31\u662f\u4e3a\u4e86\u5d4c\u5165\u5176\u5b83\u5e94\u7528\u7a0b\u5e8f\u800c\u5f00\u53d1\u7684\u4e00\u4e2a\u811a\u672c\u8bed\u8a00\uff0c<\/p>\n<p>luajit\uff08www.luajit.org\uff09\u662flua\u7684\u4e00\u4e2aJust-In-Time\u4e5f\u5c31\u662f\u8fd0\u884c\u65f6\u7f16\u8bd1\u5668\uff0c\u4e5f\u53ef\u4ee5\u8bf4\u662flua\u7684\u4e00\u4e2a\u9ad8\u6548\u7248\u3002<\/p>\n<p>\u4e8c\u3001\u4f18\u52bf<\/p>\n<p>1\uff09lua\u662f\u4e00\u4e2a\u514d\u8d39\u3001\u5c0f\u5de7\u3001\u7b80\u5355\u3001\u5f3a\u5927\u3001\u9ad8\u6548\u3001\u8f7b\u91cf\u7ea7\u7684\u5d4c\u5165\u5f0f\u7684\u811a\u672c\u8bed\u8a00,lua\u5f53\u524d\u7684\u53d1\u884c\u7248\u672c5.3.1\u53ea\u6709276k\u3002<\/p>\n<p>2\uff09\u5b83\u662f\u7528C\u8bed\u8a00\u5f00\u53d1\u7684\u9879\u76ee\uff0c\u6240\u4ee5\u53ef\u4ee5\u5728\u5927\u90e8\u5206\u7684\u64cd\u4f5c\u7cfb\u7edf\u4e0a\u8fd0\u884c<\/p>\n<p>3\uff09lua\u662f\u76ee\u524d\u901f\u5ea6\u6700\u5feb\u7684\u811a\u672c\u8bed\u8a00\uff0c\u65e2\u53ef\u4ee5\u63d0\u5347\u8bed\u8a00\u7684\u7075\u6d3b\u6027\u8fd8\u53ef\u4ee5\u6700\u5927\u9650\u5ea6\u7684\u4fdd\u7559\u901f\u5ea6<\/p>\n<p>4\uff09\u5176\u8bed\u6cd5\u975e\u5e38\u7b80\u5355\uff0c\u6ca1\u6709\u7279\u4f8b<\/p>\n<p>5\uff09lua\u8fd8\u53ef\u4ee5\u4f5c\u4e3aC\u7684API\u6765\u4f7f\u7528<\/p>\n<p>\u4e09\u3001\u4e0d\u8db3\u548c\u4e0d\u540c<\/p>\n<p>1\uff09lua\u6ca1\u6709\u5f3a\u5927\u7684\u5e93\uff0c\u6240\u4ee5\u5f88\u591a\u529f\u80fd\u5b9e\u73b0\u8d77\u6765\u6ca1\u6709python\u3001perl\u3001ruby\u7b49\u811a\u672c\u8bed\u8a00\u7b80\u6d01<\/p>\n<p>2\uff09lua\u7684\u5f02\u5e38\u5904\u7406\u529f\u80fd\u9971\u53d7\u4e89\u8bae\uff0c\u867d\u7136\u5176\u63d0\u4f9b\u4e86pcall\u548cxpcall\u7684\u5f02\u5e38\u5904\u7406\u51fd\u6570<\/p>\n<p>3\uff09lua\u539f\u751f\u8bed\u8a00\u4e2d\u6ca1\u6709\u63d0\u4f9b\u5bf9unicode\u7f16\u7801\u7684\u652f\u6301\uff0c\u867d\u7136\u53ef\u4ee5\u901a\u8fc7\u4e00\u4e9b\u6298\u4e2d\u7684\u529e\u6cd5\u5b9e\u73b0 http:\/\/www.cppblog.com\/darkdestiny\/archive\/2009\/04\/25\/81055.html<\/p>\n<p>4\uff09\u6ca1\u6709\u63d0\u4f9b\u5728C++\u4e2d\u5e94\u7528\u5f88\u5e7f\u6cdb\u7684a?b:c\u7684\u4e09\u5143\u8fd0\u7b97\u7b26\u64cd\u4f5c<\/p>\n<p>5\uff09\u6ca1\u6709switch&#8230;case&#8230;\u8bed\u6cd5\uff0c\u53ea\u80fd\u901a\u8fc7if..elseif..elseif..else..end\u7684\u65b9\u5f0f\u6298\u4e2d\u5b9e\u73b0<\/p>\n<p>6)\u5728\u5faa\u73af\u65f6\u6ca1\u6709\u63d0\u4f9bcontinue\u8bed\u6cd5<\/p>\n<p>7\uff09\u6ca1\u6709C++\u4e2d\u5e94\u7528\u5e7f\u6cdb\u7684a++\u548ca+=1\u7b49\u64cd\u4f5c<\/p>\n<p>8\uff09lua\u7684\u7d22\u5f15\u662f\u4ece1\u5f00\u59cb\u7684\uff0c\u800c\u4e0d\u662f\u6211\u4eec\u719f\u6089\u76840\uff08string\uff0ctable\uff09<\/p>\n<p>9\uff09\u5f53\u4f60\u7ed9\u4e00\u4e2a\u5143\u7d20\u8d4b\u503c\u4e3anil\u65f6\u76f8\u5f53\u4e8e\u8fd9\u4e2a\u5143\u7d20\u4e0d\u5b58\u5728<\/p>\n<p>10\uff09lua\u7684\u6570\u503c\u7c7b\u578b\u53ea\u6709number\u662f\u6ca1\u6709int\uff0cfloat\uff0cdouble\u7b49\u4e4b\u5206\u7684<\/p>\n<p>11\uff09lua\u4e2d\u6ca1\u6709\u7c7b\u7684\u6982\u5ff5\uff0c\u5176\u7c7b\u662f\u901a\u8fc7table\u7684\u5f62\u5f0f\u6765\u5b9e\u73b0\u7684<\/p>\n<p>12\uff09lua\u4e2d\u53ea\u6709nil\u548cfalse\u662f\u8868\u793a\u5047\u7684\uff0c\u96f6\u5728lua\u4e2d\u662f\u4e3a\u771f\u7684<\/p>\n<p>13\uff09\u5f88\u591a\u7a0b\u5e8f\u9700\u8981\uff08\uff09\u6807\u793a\u624d\u80fd\u8fd0\u884c\uff0c\u6bd4\u5982a={[&#8220;b&#8221;]=5},print(a.b)\u662f\u53ef\u8fd0\u884c\u7684\uff0c\u4f46\u662f {[&#8220;b&#8221;]=5}.b\u5c31\u4f1a\u62a5\u9519\uff0c\u9700\u8981\uff08{[&#8220;b&#8221;]=5}\uff09.b\u624d\u53ef\u4ee5<\/p>\n<p>\u56db\u3001\u7efc\u8ff0<\/p>\n<p>\u7efc\u4e0a\uff0clua\u662f\u4e00\u4e2a\u7b80\u5355\uff0c\u9ad8\u6548\u6240\u4ee5\u5728\u6e38\u620f\u903b\u8f91\u5f00\u53d1\u548c\u670d\u52a1\u5668\u5f00\u53d1\u4e2d\uff08ngx_lua\uff09\u5f97\u5230\u5e7f\u6cdb\u7684\u5e94\u7528\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/blog.csdn.net\/qq_35624156\/article\/details\/77455689\">luajit\u5b98\u65b9\u6027\u80fd\u4f18\u5316\u6307\u5357\u548c\u6ce8\u89e3<\/a><\/p>\n<p>&nbsp;<\/p>\n<p>luajit\u662f\u76ee\u524d\u6700\u5feb\u7684\u811a\u672c\u8bed\u8a00\u4e4b\u4e00\uff0c\u4e0d\u8fc7\u6df1\u5165\u4f7f\u7528\u5c31\u5f88\u5feb\u4f1a\u53d1\u73b0\uff0c\u8981\u628a\u8fd9\u4e2a\u8bed\u8a00\u7528\u5230\u50cf\u5ba3\u79f0\u90a3\u6837\u9ad8\u6027\u80fd\uff0c\u5e76\u4e0d\u662f\u90a3\u4e48\u5bb9\u6613\u3002\u5b9e\u9645\u4f7f\u7528\u7684\u65f6\u5019\u5f80\u5f80\u4f1a\u53d1\u73b0\uff0c\u521a\u5f00\u59cb\u5199\u7684\u4e00\u4e9b\u5c0ftest case\u6027\u80fd\u975e\u5e38\u597d\uff0c\u7ecf\u5e38\u6beb\u79d2\u7ea7\u5c31\u7b97\u5b8c\uff0c\u53ef\u662f\u4ee3\u7801\u590d\u6742\u5ea6\u4e00\u4e0a\u53bb\u4e86\uff0c\u52a8\u8f84\u51e0\u5341\u4e0a\u767e\u6beb\u79d2\u7684\u60c5\u51b5\u5c31\u4f1a\u51fa\u73b0\uff0c\u6027\u80fd\u8868\u73b0\u975e\u5e38\u98d8\u5ffd\u3002<\/p>\n<p>\u4e3a\u6b64luajit\u7684mailling list\u4e5f\u662f\u6709\u4e0d\u5c11\u4eba\u54a8\u8be2\uff0c\u4f5c\u8005mike pall\u7684\u4e00\u7bc7\u6bd4\u8f83\u5b8c\u6574\u7684\u56de\u7b54\u88ab\u653e\u5728\u4e86\u5b98\u65b9wiki\u4e0a\uff1a<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/wiki.luajit.org\/Numerical-Computing-Performance-Guide\" rel=\"nofollow\">http:\/\/wiki.luajit.org\/Numerical-Computing-Performance-Guide<\/a><\/p>\n<p>&nbsp;<\/p>\n<p>\u4e0d\u8fc7\u539f\u6587\u8bf4\u4e86\u5f88\u591a\u600e\u4e48\u505a\uff0c\u5374\u57fa\u672c\u6ca1\u6709\u89e3\u91ca\u4e3a\u4ec0\u4e48\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u6240\u4ee5\u8fd9\u7bc7\u6587\u7ae0\u4e0d\u662f\u7b80\u5355\u7684\u7ffb\u8bd1\u5b98\u65b9\u8fd9\u4e2a\u4f18\u5316\u6307\u5357\uff0c\u6700\u4e3b\u8981\u8fd8\u662f\u8ba9\u5927\u5bb6\u4e86\u89e3luajit\u80cc\u540e\u7684\u4e00\u4e9b\u539f\u7406\uff0c\u56e0\u4e3a\u539f\u6587\u4e2d\u53ea\u6709\u544a\u8bc9\u4f60\u600e\u4e48\u505a\uff0c\u5374\u6ca1\u8bf4\u6e05\u695a\u4e3a\u4ec0\u4e48\uff0c\u5bfc\u81f4\u505a\u4e86\u8fd9\u4e9b\u4f18\u5316\uff0c\u5230\u5e95\u5f71\u54cd\u591a\u5927\uff0c\u539f\u56e0\u662f\u5565\uff0c\u5341\u5206\u6a21\u7cca\u3002\u4e86\u89e3\u80cc\u540e\u7684\u539f\u56e0\u5f80\u5f80\u5bf9\u6211\u4eec\u6709\u5f88\u5927\u7684\u5e2e\u52a9\u3002<\/p>\n<p>\u53e6\u5916\uff0c\u539f\u751flua\u3001luajit\u7684jit\u6a21\u5f0f\uff08pc\u548c\u5b89\u5353\u53ef\u7528\uff09\u3001luajit\u7684interpreter\u6a21\u5f0f\uff08ios\u4e0b\u53ea\u80fd\u8fd0\u884c\u8fd9\u4e2a\uff09\uff0c\u4ed6\u4eec\u6267\u884clua\u7684\u539f\u7406\u662f\u6709\u5f88\u5927\u7684\u4e0d\u540c\u7684\uff0c\u4e5f\u5bfc\u81f4\u4e00\u4e9blua\u4f18\u5316\u6280\u5de7\u5e76\u4e0d\u89c1\u5f97\u662f\u901a\u7528\u7684\u3002\u800c\u8fd9\u7bc7\u6587\u7ae0\u4e3b\u8981\u9488\u5bf9luajit\u7684jit\u6a21\u5f0f\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>1.Reduce number of unbiased\/unpredictable branches.<\/p>\n<p>\u51cf\u5c11\u4e0d\u53ef\u9884\u6d4b\u7684\u5206\u652f\u4ee3\u7801<\/p>\n<p>\u5206\u652f\u4ee3\u7801\u5c31\u662f\u6839\u636e\u6761\u4ef6\u4f1a\u8df3\u8f6c\u7684\u4ee3\u7801\uff08\u6700\u5178\u578b\u5c31\u662fif..else\uff09\uff0c\u90a3\u4ec0\u4e48\u662f\u4e0d\u53ef\u9884\u6d4b\u7684\u5206\u652f\u4ee3\u7801\uff1f\u7b80\u5355\u8bf4\uff1a<\/p>\n<p>if \u6761\u4ef61 then<\/p>\n<p>elseif \u6761\u4ef62 then<\/p>\n<p>\u5047\u5982\u6761\u4ef61\u6216\u8005\u6761\u4ef62\u5176\u4e2d\u4e00\u65b9\u8fbe\u6210\u7684\u6982\u7387\u975e\u5e38\u9ad8\uff08&gt;95%\uff09\uff0c\u90a3\u6211\u4eec\u8ba4\u4e3a\u8fd9\u662f\u53ef\u9884\u6d4b\u7684\u5206\u652f\u4ee3\u7801\u3002<\/p>\n<p>\u8fd9\u662f\u88abmike pall\u653e\u5230\u7b2c\u4e00\u4f4d\u7684\u6027\u80fd\u4f18\u5316\u70b9\uff08\u4e8b\u5b9e\u4e0a\u786e\u5b9e\u5e94\u8be5\u5982\u6b64\uff09\uff0c\u7a76\u5176\u539f\u56e0\u662fluajit\u4f7f\u7528\u4e86trace compiler\u7684\u7279\u6027\uff0c\u4e3a\u4e86\u751f\u6210\u7684\u673a\u5668\u7801\u5c3d\u53ef\u80fd\u9ad8\u6548\uff0c\u5b83\u4f1a\u6839\u636e\u4ee3\u7801\u7684\u8fd0\u884c\u60c5\u51b5\u8fdb\u884c\u4e00\u4e9b\u5047\u8bbe\uff0c\u6bd4\u5982\u4e0a\u9762\u7684\u4f8b\u5b50\u5982\u679cluajit\u53d1\u73b0\uff0c\u6761\u4ef62\u7684\u8fbe\u6210\u6982\u7387\u975e\u5e38\u9ad8\uff0c\u90a3\u4e48luajit\u4f1a\u751f\u6210\u6309\u6761\u4ef62\u8fbe\u6210\u6267\u884c\u6700\u5feb\u7684\u4ee3\u7801\u3002<\/p>\n<p>\u6709\u4e00\u70b9\u53ef\u80fd\u5927\u5bb6\u4f1a\u95ee\uff0cluajit\u771f\u7684\u80fd\u77e5\u9053\u8fd0\u884c\u8fc7\u7a0b\u4e2d\u7684\u4e00\u4e9b\u60c5\u51b5\uff1f<\/p>\n<p>\u662f\u7684<\/p>\n<p>\u8fd9\u4e5f\u662ftrace compiler\u7684\u7279\u5f81\uff1a\u5148\u8fd0\u884c\u5b57\u8282\u7801\uff0c\u9488\u5bf9\u70ed\u70b9\u4ee3\u7801\u505aprofile\uff0c\u4e86\u89e3\u4e86\u53ef\u4ee5\u4f18\u5316\u7684\u70b9\u540e\u518d\u4f18\u5316\u51fa\u6700\u9ad8\u6548\u7684\u673a\u5668\u7801\u3002\u8fd9\u5c31\u662fluajit\u76ee\u524d\u7684\u505a\u6cd5\u3002<\/p>\n<p>\u4e3a\u4ec0\u4e48\u8981\u8fd9\u6837\u5462\uff1f\u7ed9\u4e00\u4e2a\u6bd4\u8f83\u597d\u7406\u89e3\u7684\u4f8b\u5b50\uff1aluajit\u662f\u52a8\u6001\u7c7b\u578b\u8bed\u8a00\uff0c\u9762\u5bf9\u4e00\u4e2aa+b\uff0c\u4f60\u6839\u672c\u4e0d\u77e5\u9053a\u548cb\u662f\u4ec0\u4e48\u7c7b\u578b\uff0c\u5982\u679ca+b\u53ea\u662f\u4e24\u4e2a\u6574\u6570\u76f8\u52a0\uff0c\u90a3\u4e48\u7f16\u8bd1\u673a\u5668\u7801\u505a\u6c42\u548c\u901f\u5ea6\u81ea\u7136\u662f\u98de\u5feb\u7684\u3002\u53ef\u662f\u5982\u679c\u4f60\u65e0\u6cd5\u786e\u8ba4\u8fd9\u70b9\uff0c\u7ed3\u679c\u4f60\u53ea\u80fd\u5047\u5b9a\u5b83\u662f\u4efb\u610f\u7c7b\u578b\uff0c\u5148\u53bb\u52a8\u6001\u68c0\u67e5\u7c7b\u578b\uff08\u770b\u770b\u5230\u5e95\u662f\u4e24\u4e2a\u8868\uff0c\u8fd8\u662f\u4e24\u4e2a\u6570\u503c\uff0c\u751a\u81f3\u662f\u5176\u4ed6\u60c5\u51b5\uff09\uff0c\u518d\u8df3\u6839\u636e\u7c7b\u578b\u505a\u76f8\u5e94\u7684\u5904\u7406\uff0c\u60f3\u60f3\u90fd\u77e5\u9053\u6bd4\u4e24\u4e2a\u6574\u6570\u76f8\u52a0\u6162\u4e86\u51e0\u5341\u500d\u3002<\/p>\n<p>\u6240\u4ee5luajit\u4e3a\u4e86\u6781\u9650\u7ea7\u7684\u6027\u80fd\uff0c\u5c31\u4f1a\u5927\u80c6\u8fdb\u884c\u5047\u8bbe\uff0c\u5982\u679c\u53d1\u73b0a+b\u5c31\u662f\u4e24\u4e2a\u6570\u503c\u76f8\u52a0\uff0c\u5c31\u7f16\u8bd1\u51fa\u6570\u503c\u6c42\u548c\u7684\u673a\u5668\u7801\u3002<\/p>\n<p>\u4f46\u662f\u5982\u679c\u67d0\u4e00\u65f6\u523ba+b\u4e0d\u662f\u6570\u503c\u76f8\u52a0\uff0c\u800c\u662f\u53d8\u6210\u4e86\u4e24\u4e2a\u8868\u76f8\u52a0\u5462\uff1f\u8fd9\u673a\u5668\u7801\u5c82\u4e0d\u662f\u5c31\u5bfc\u81f4\u9519\u8bef\u4e86\uff1f\u56e0\u6b64\u6bcf\u6b21luajit\u505a\u4e86\u5047\u8bbe\u65f6\uff0c\u90fd\u4f1a\u52a0\u4e0a\u4e00\u6bb5\u5b88\u62a4\u4ee3\u7801\uff08guard\uff09\uff0c\u68c0\u67e5\u5047\u8bbe\u662f\u4e0d\u662f\u5bf9\u7684\uff0c\u5982\u679c\u4e0d\u5bf9\uff0c\u5c31\u4f1a\u8df3\u8f6c\u51fa\u53bb\uff0c\u518d\u6839\u636e\u60c5\u51b5\uff0c\u6765\u51b3\u5b9a\u8981\u4e0d\u8981\u518d\u7f16\u8bd1\u4e00\u6bb5\u65b0\u7684\u673a\u5668\u7801\uff0c\u6765\u9002\u914d\u65b0\u7684\u60c5\u51b5\u3002<\/p>\n<p>\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48\u4f60\u7684\u5206\u652f\u4ee3\u7801\u4e00\u5b9a\u8981\u53ef\u9884\u6d4b\uff0c\u56e0\u4e3a\u5982\u679c\u7ecf\u5e38\u4e0d\u7b26\u5408luajit\u5047\u8bbe\u7684\u4e1c\u897f\uff0c\u5c31\u4f1a\u7ecf\u5e38\u4ece\u7f16\u8bd1\u597d\u7684\u673a\u5668\u7801\u4e2d\u8df3\u51fa\u6765\uff0c\u751a\u81f3\u4f1a\u56e0\u4e3a\u597d\u51e0\u6b21\u5047\u8bbe\u5931\u8d25\u800c\u8fde\u8df3\u597d\u51e0\u6b21\u3002\u6240\u4ee5\uff0cluajit\u662f\u4e00\u4e2a\u5bf9\u5206\u652f\u60c5\u51b5\u6781\u5ea6\u654f\u611f\u7684\u8bed\u8a00\u3002<\/p>\n<p>\u8fd9\u662fluajit\u7684\u7b2c\u4e00\u6027\u80fd\u5927\u5751\uff0c\u4f5c\u8005\u5efa\u8bae\u53ef\u4ee5\u501f\u52a9math.min\/max\u6216\u8005bitop\u6765\u7ed5\u8fc7if else\u8fd9\u6837\u7684\u5206\u652f\u4ee3\u7801\u3002\u4e0d\u8fc7\u5b9e\u9645\u60c5\u51b5\u5f80\u5f80\u66f4\u590d\u6742\uff0c\u6240\u6709\u6d89\u53ca\u5230\u8df3\u8f6c\u4ee3\u7801\u7684\u5730\u65b9\uff0c\u90fd\u662f\u6f5c\u5728\u7684\u6027\u80fd\u5751\u3002<\/p>\n<p>\u53e6\u5916\uff0c\u5728interpreter\u6a21\u5f0f\u4e0b\uff08ios\u7684\u60c5\u51b5\uff09\uff0cluajit\u5c31\u53d8\u6210\u4e86\u8001\u8001\u5b9e\u5b9e\u52a8\u6001\u68c0\u67e5\u52a8\u6001\u8df3\u8f6c\u7684\u6267\u884c\u6a21\u5f0f\uff0c\u5bf9\u5206\u652f\u9884\u6d4b\u53cd\u800c\u5e76\u4e0d\u654f\u611f\uff0c\u5e76\u4e0d\u9700\u8981\u8fc7\u5206\u6ce8\u91cd\u8fd9\u65b9\u9762\u7684\u4f18\u5316\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>2.Use FFI data structures.<\/p>\n<p>\u5982\u679c\u53ef\u4ee5\uff0c\u5c06\u4f60\u7684\u6570\u636e\u7ed3\u6784\u7528ffi\u5b9e\u73b0\uff0c\u800c\u4e0d\u662f\u7528lua table\u5b9e\u73b0<\/p>\n<p>luajit\u7684ffi\u662f\u4e00\u4e2a\u5e38\u88ab\u5927\u5bb6\u5ffd\u7565\u7684\u529f\u80fd\uff0c\u6216\u8005\u53ea\u88ab\u5f53\u505a\u4e00\u4e2a\u66f4\u597d\u7528\u7684c\u5bfc\u51fa\u5e93\uff0c\u4f46\u4e8b\u5b9e\u4e0a\u8fd9\u662f\u4e00\u4e2a\u8d85\u7ea7\u6027\u80fd\u5229\u5668\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u6bd4\u5982\u8981\u5b9e\u73b0unity\u4e2d\u7684Vector3\uff0c\u5206\u522b\u7528lua table\u548c\u7528ffi\u5b9e\u73b0\uff0c\u6211\u4eec\u6d4b\u8bd5\u4e0b\u6765\uff0c\u5185\u5b58\u5360\u7528\u662f10:1\uff0c\u8fd0\u7b97x+y+z\u7684\u8017\u65f6\u4e5f\u662f\u5927\u69828:1\uff0c\u4f18\u5316\u6548\u7387\u60ca\u4eba\u3002<\/p>\n<p>\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n<p>local ffi = require(&#8220;ffi&#8221;)<\/p>\n<p>ffi.cdef[[<\/p>\n<p>typedef struct { float x, y, z; } vector3c;<\/p>\n<p>]]<\/p>\n<p>local count = 100000<\/p>\n<p>&nbsp;<\/p>\n<p>local function test1() &#8212; lua table\u7684\u4ee3\u7801<\/p>\n<p>local vecs = {}<\/p>\n<p>for i = 1, count do<\/p>\n<p>vecs[i] = {x=1, y = 2, z = 3}<\/p>\n<p>end<\/p>\n<p>local total = 0<\/p>\n<p>&#8212; gc\u540e\u8bb0\u5f55\u4e0b\u9762for\u5faa\u73af\u8fd0\u884c\u65f6\u7684\u65f6\u95f4\u548c\u5185\u5b58\u5360\u7528\uff0c\u8fd9\u91cc\u7701\u7565<\/p>\n<p>for i = 1, count do<\/p>\n<p>total =\u00a0total +\u00a0vecs[i].x +\u00a0vecs[i].y +\u00a0vecs[i].z<\/p>\n<p>end<\/p>\n<p>end<\/p>\n<p>local function test2() &#8212; ffi\u7684\u4ee3\u7801<\/p>\n<p>local vecs = ffi.new(&#8220;vector3c[?]&#8221;,\u00a0count)<\/p>\n<p>for i = 1, count do<\/p>\n<p>vecs[i] = {x=1, y = 2, z = 3}<\/p>\n<p>end<\/p>\n<p>local total = 0<\/p>\n<p>&#8212;\u00a0gc\u540e\u8bb0\u5f55\u4e0b\u9762for\u5faa\u73af\u8fd0\u884c\u65f6\u7684\u65f6\u95f4\u548c\u5185\u5b58\u5360\u7528\uff0c\u8fd9\u91cc\u7701\u7565<\/p>\n<p>for i = 1, count do<\/p>\n<p>total =\u00a0total +\u00a0vecs[i].x +\u00a0vecs[i].y +\u00a0vecs[i].z<\/p>\n<p>end<\/p>\n<p>end<\/p>\n<p>\u4e3a\u4f55\u6709\u8fd9\u4e48\u5927\u7684\u5dee\u8ddd\uff1f\u56e0\u4e3alua table\u672c\u8d28\u662f\u4e00\u4e2ahash table\uff0c\u5728hash table\u8bbf\u95ee\u5b57\u6bb5\u56fa\u7136\u662f\u7f13\u6162\u7684\u5e76\u4e14\u8981\u5b58\u50a8\u5927\u91cf\u989d\u5916\u7684\u4e1c\u897f\u3002\u800cffi\u53ef\u4ee5\u505a\u5230\u53ea\u5206\u914dxyz\u4e09\u4e2afloat\u7684\u7a7a\u95f4\u5c31\u80fd\u8868\u793a\u4e00\u4e2aVector3\uff0c\u81ea\u7136\u5185\u5b58\u5360\u7528\u8981\u4f4e\u5f97\u591a\uff0c\u800c\u4e14jit\u4f1a\u5229\u7528ffi\u7684\u4fe1\u606f\uff0c\u5b9e\u73b0\u8bbf\u95eexyz\u7684\u65f6\u5019\u76f4\u63a5\u8bfb\u5185\u5b58\uff0c\u800c\u4e0d\u662f\u50cfhash table\u90a3\u6837\u8d70\u4e00\u6b21key hash\uff0c\u6027\u80fd\u4e5f\u9ad8\u5f97\u591a\u3002<\/p>\n<p>\u4e0d\u5e78\u7684\u662fffi\u53ea\u5728\u6709jit\u6a21\u5f0f\u7684\u65f6\u5019\u624d\u80fd\u6709\u5f88\u597d\u7684\u8fd0\u884c\u901f\u5ea6\uff0c\u73b0\u5728\u505a\u624b\u6e38\u57fa\u672c\u90fd\u8981\u505aios\uff0c\u800cios\u4e0b\u7531\u4e8e\u53ea\u80fd\u8fd0\u884c\u89e3\u91ca\u6a21\u5f0f\uff0cffi\u7684\u6027\u80fd\u5f88\u5dee\uff08\u6bd4\u7eaftable\u53cd\u800c\u66f4\u6162\uff09\uff0c\u4ec5\u4ec5\u5185\u5b58\u4f18\u52bf\u5f97\u5230\u4fdd\u7559\uff0c\u6240\u4ee5\u5982\u679c\u8981\u8003\u8651ios\u8fd9\u6837\u7684\u5e73\u53f0\uff0c\u8fd9\u4e2a\u4f18\u5316\u70b9\u57fa\u672c\u53ef\u4ee5\u5ffd\u7565\uff0c\u6216\u8005\u53ea\u5728\u5b89\u5353\u4e0b\u9488\u5bf9\u5c11\u6570\u6838\u5fc3\u4ee3\u7801\u8fdb\u884c\u4f18\u5316\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>3.Call C functions only via the FFI.<\/p>\n<p>\u5c3d\u53ef\u80fd\u7528ffi\u6765\u8c03\u7528c\u51fd\u6570\u3002<\/p>\n<p>\u540c\u6837\u7684\uff0cffi\u4e5f\u53ef\u4ee5\u7528\u4e8e\u8c03\u7528\u5df2\u7ecfextern c\u7684c\u51fd\u6570\u3002\u5927\u5bb6\u8868\u9762\u4e0a\u90fd\u4ee5\u4e3a\u8fd9\u6837\u505a\u53ea\u662f\u7701\u6389\u4e86\u7528tolua\u4e4b\u7c7b\u7684\u5de5\u5177\u505a\u5bfc\u51fa\u7684\u9ebb\u70e6\uff0c\u4f46ffi\u66f4\u5927\u7684\u597d\u5904\uff0c\u662f\u5728\u4e8e\u6027\u80fd\u4e0a\u8d28\u7684\u63d0\u5347\u3002<\/p>\n<p>\u8fd9\u662f\u56e0\u4e3a\uff0c\u4f7f\u7528ffi\u5bfc\u51fac\u51fd\u6570\uff0c\u4f60\u9700\u8981\u63d0\u4f9bc\u51fd\u6570\u7684\u539f\u578b\uff0c\u6709\u4e86c\u51fd\u6570\u7684\u539f\u578b\u4fe1\u606f\uff0cluajit\u53ef\u4ee5\u77e5\u9053\u6bcf\u4e2a\u53c2\u6570\u7684\u51c6\u786e\u7c7b\u578b\uff0c\u8fd4\u56de\u503c\u7684\u51c6\u786e\u7c7b\u578b\u3002\u4e86\u89e3\u7f16\u8bd1\u5668\u77e5\u8bc6\u7684\u540c\u5b66\u90fd\u77e5\u9053\u51fd\u6570\u8c03\u7528\u548c\u8fd4\u56de\u4e00\u822c\u90fd\u662f\u7528\u6808\u6765\u5b9e\u73b0\u7684\uff0c\u800c\u8981\u505a\u5230\u8fd9\u70b9\u5fc5\u987b\u8981\u77e5\u9053\u6574\u4e2a\u53c2\u6570\u5217\u8868\u548c\u8fd4\u56de\u503c\u7c7b\u578b\uff0c\u624d\u80fd\u751f\u6210\u51fa\u51fa\u6808\u5165\u6808\u7684\u4ee3\u7801\u3002\u56e0\u6b64luajit\u5728\u62e5\u6709\u8fd9\u4e9b\u4fe1\u606f\u4e4b\u540e\u5c31\u53ef\u4ee5\u751f\u6210\u673a\u5668\u7801\uff0c\u8ddfc\u7f16\u8bd1\u5668\u4e00\u6837\u505a\u5230\u65e0\u7f1d\u7684\u8c03\u7528\uff0c\u800c\u4e0d\u9700\u8981\u50cf\u6807\u51c6\u7684lua\u4e0ec\u4ea4\u4e92\u90a3\u6837\u9700\u8981\u8c03\u7528pushint\u7b49\u7b49\u51fd\u6570\u6765\u4f20\u53c2\u4e86\u3002<\/p>\n<p>\u5982\u679c\u4e0d\u901a\u8fc7ffi\u8c03\u7528c\u5bfc\u51fa\u51fd\u6570\uff0c\u90a3\u4e48\u56e0\u4e3aluajit\u7f3a\u4e4f\u8fd9\u4e2a\u51fd\u6570\u7684\u4fe1\u606f\uff0c\u65e0\u6cd5\u751f\u6210\u7528\u4e8e\u8c03\u7528c\u51fd\u6570\u7684jit\u4ee3\u7801\uff0c\u81ea\u7136\u4f1a\u964d\u4f4e\u6027\u80fd\u3002\u800c\u4e14\u57282.1.0\u7248\u672c\u4e4b\u524d\uff0c\u8fd9\u4f1a\u76f4\u63a5\u5bfc\u81f4jit\u5931\u8d25\uff0c\u6574\u6bb5\u76f8\u5173\u7684\u4ee3\u7801\u90fd\u65e0\u6cd5jit\u5316\uff0c\u6027\u80fd\u4f1a\u6536\u5230\u6781\u5927\u7684\u5f71\u54cd\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>4.Use plain &#8216;for i=start,stop,step do &#8230; end&#8217; loops.<\/p>\n<p>\u5b9e\u73b0\u5faa\u73af\u65f6\uff0c\u6700\u597d\u4f7f\u7528\u7b80\u5355\u7684for i = start, stop, step do\u8fd9\u6837\u7684\u5199\u6cd5\uff0c\u6216\u8005\u4f7f\u7528ipairs\uff0c\u800c\u5c3d\u91cf\u907f\u514d\u4f7f\u7528for k,v in pairs(x) do<\/p>\n<p>\u9996\u5148\uff0c\u76f4\u5230\u76ee\u524d\u6700\u65b0\u7684luajit2.1.0beta2\uff0cfor k,v in pairs(t) do end\u662f\u4e0d\u652f\u6301jit\u7684\uff08\u5373\u65e0\u6cd5\u751f\u6210\u673a\u5668\u7801\u8fd0\u884c\uff09\u3002\u81f3\u4e8e\u8fd9\u4e2a\u5751\u7684\u5b58\u5728\u4e3b\u8981\u8fd8\u662f\u56e0\u4e3a\u6309kv\u904d\u5386table\u7684\u6c47\u7f16\u6bd4\u8f83\u96be\u5199\uff0c\u4f46\u81f3\u5c11\u53ef\u4ee5\u77e5\u9053\uff0c\u76ee\u524d\u5982\u679c\u60f3\u9ad8\u6548\u904d\u5386\u6570\u7ec4\u6216\u8005\u505afor\u5faa\u73af\uff0c\u76f4\u63a5\u4f7f\u7528\u6570\u503c\u505a\u7d22\u5f15\u662f\u6700\u4f73\u7684\u65b9\u6cd5\u3002<\/p>\n<p>\u5176\u6b21\uff0c\u8fd9\u6837\u7684\u5199\u6cd5\u66f4\u5229\u4e8e\u505a\u5faa\u73af\u5c55\u5f00\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>5.Find the right balance for unrolling.<\/p>\n<p>\u5faa\u73af\u5c55\u5f00\uff0c\u6709\u5229\u6709\u5f0a\uff0c\u9700\u8981\u81ea\u5df1\u53bb\u5e73\u8861<\/p>\n<p>\u5728\u65e9\u671f\u7684c++\u65f6\u4ee3\uff0c\u624b\u5de5\u5c06\u5faa\u73af\u4ee3\u7801\u5c55\u5f00\u6210\u987a\u5e8f\u4ee3\u7801\u662f\u4e00\u79cd\u5e38\u89c1\u7684\u4f18\u5316\u65b9\u6cd5\uff0c\u4f46\u662f\u540e\u6765\u7f16\u8bd1\u5668\u90fd\u96c6\u6210\u4e86\u4e00\u5b9a\u7684\u5faa\u73af\u5c55\u5f00\u4f18\u5316\u80fd\u529b\uff0c\u4ee3\u66ff\u624b\u5de5\u505a\u8fd9\u79cd\u4e8b\u60c5\u3002\u800cluajit\u672c\u8eab\u4e5f\u5e26\u6709\u8fd9\u5757\u7684\u4f18\u5316\uff08\u53ef\u4ee5\u53c2\u8003\u5176\u5b9e\u73b0\u51fd\u6570lj_opt_loop\uff09\uff0c\u53ef\u4ee5\u5bf9\u5faa\u73af\u8fdb\u884c\u5c55\u5f00\u3002<\/p>\n<p>\u4e0d\u8fc7\u8fd9\u4e2a\u5c55\u5f00\u662f\u5728\u8fd0\u884c\u65f6\u505a\u7684\uff0c\u6240\u4ee5\u4e5f\u6709\u5229\u6709\u5f0a\u3002\u4f5c\u8005\u4e3e\u4f8b\uff0c\u5982\u679c\u5728\u4e00\u4e2a\u4e24\u5c42\u5faa\u73af\u4e2d\uff0c\u5185\u5faa\u73af\u7684\u5faa\u73af\u6b21\u6570\u4e0d\u591f10\u6b21\uff0c\u8fd9\u4e2a\u90e8\u5206\u4f1a\u88ab\u5c1d\u8bd5\u5c55\u5f00\uff0c\u4f46\u662f\u7531\u4e8e\u5d4c\u5957\u5728\u5916\u90e8\u7684\u5927\u5faa\u73af\uff0c\u5916\u90e8\u5927\u5faa\u73af\u53ef\u80fd\u4f1a\u5bfc\u81f4\u5185\u90e8\u5faa\u73af\u591a\u6b21\u8fdb\u5165\uff0c\u591a\u6b21\u5c55\u5f00\uff0c\u5bfc\u81f4\u5c55\u5f00\u6b21\u6570\u8fc7\u5927\uff0c\u6700\u7ec8jit\u4f1a\u53d6\u6d88\u5c55\u5f00\u3002<\/p>\n<p>\u81f3\u4e8e\u8fd9\u65b9\u9762\u7684\u6027\u80fd\u672a\u505a\u6df1\u5165\u6d4b\u8bd5\uff0c\u4f5c\u8005\u4e5f\u53ea\u662f\u7ed9\u51fa\u4e86\u4e00\u4e9b\u6bd4\u8f83\u611f\u6027\u7684\u4f18\u5316\u5efa\u8bae\uff08\u6700\u540e\u6765\u4e86\u4e00\u53e5\uff0cYou may have to experiment a bit\uff09\uff0c\u6709\u4e86\u89e3\u7684\u540c\u5b66\u6b22\u8fce\u4ea4\u6d41\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>6.Define and call only &#8216;local&#8217; (!) functions within a module.<\/p>\n<p>7.Cache often-used functions from other modules in upvalues.<\/p>\n<p>\u8fd9\u4e24\u70b9\u90fd\u53ef\u4ee5\u62ff\u5230\u4e00\u8d77\u8bf4\uff0c\u5373\u8c03\u7528\u4efb\u4f55\u51fd\u6570\u7684\u65f6\u5019\uff0c\u4fdd\u8bc1\u8fd9\u4e2a\u51fd\u6570\u662flocal function\uff0c\u6027\u80fd\u4f1a\u66f4\u597d\uff0c\u6bd4\u5982\uff1a<\/p>\n<p>local ms = math.sin<\/p>\n<p>function test()<\/p>\n<p>math.sin(1)<\/p>\n<p>ms(1)<\/p>\n<p>end<\/p>\n<p>\u8fd9\u4e24\u884c\u8c03\u7528math.sin\u6709\u4ec0\u4e48\u533a\u522b\u5462\uff1f<\/p>\n<p>\u4e8b\u5b9e\u4e0amath\u662f\u4e00\u4e2a\u8868\uff0cmath.sin\u672c\u8eab\u5c31\u505a\u4e86\u4e00\u6b21\u8868\u67e5\u627e\uff0ckey\u662fsin\uff0c\u8fd9\u91cc\u6d88\u8017\u4e86\u4e00\u6b21\u3002\u800cmath\u53c8\u662f\u4e00\u4e2a\u5168\u5c40\u53d8\u91cf\uff0c\u90a3\u8fd8\u8981\u5728\u5168\u5c40\u8868\u4e2d\u505a\u4e00\u6b21\u67e5\u627e\uff08_G[math]\uff09<\/p>\n<p>\u800clocal ms\u7f13\u5b58\u8fc7\u4e4b\u540e\uff0cmath.sin\u67e5\u627e\u5c31\u53ef\u4ee5\u7701\u6389\u4e86\uff0c\u53e6\u5916\uff0c\u5bf9\u4e8efunction\u4e0a\u4e00\u5c42\u7684\u53d8\u91cf\uff0clua\u4f1a\u6709\u4e00\u4e2aupvalue\u5bf9\u8c61\u8fdb\u884c\u5b58\u50a8\uff0c\u5728\u627ems\u8fd9\u4e2a\u53d8\u91cf\u7684\u65f6\u5019\u5c31\u53ea\u9700\u8981\u5728upvalue\u5bf9\u8c61\u5185\u627e\uff0c\u67e5\u627e\u8303\u56f4\u66f4\u5c0f\u66f4\u5feb\u6377<\/p>\n<p>\u5f53\u7136\uff0cjit\u5316\u540e\u7684\u4ee3\u7801\u6709\u53ef\u80fd\u4f1a\u8fdb\u4e00\u6b65\u4f18\u5316\u8fd9\u4e2a\u8fc7\u7a0b\uff0c\u4f46\u662f\u66f4\u597d\u7684\u529e\u6cd5\u4f9d\u7136\u662f\u81ea\u884clocal\u7f13\u5b58<\/p>\n<p>\u603b\u4e4b\uff0c\u5982\u679c\u67d0\u4e2a\u51fd\u6570\u53ea\u5728\u672c\u6587\u4ef6\u5185\u7528\u5230\uff0c\u5c31\u5c06\u5176local\uff0c\u5982\u679c\u662f\u4e00\u4e2a\u5168\u5c40\u51fd\u6570\uff0c\u7528\u4e4b\u524d\u7528local\u7f13\u5b58\u4e00\u4e0b\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>8.Avoid inventing your own dispatch mechanisms.<\/p>\n<p>\u907f\u514d\u4f7f\u7528\u4f60\u81ea\u5df1\u5b9e\u73b0\u7684\u5206\u53d1\u8c03\u7528\u673a\u5236\uff0c\u800c\u5c3d\u91cf\u4f7f\u7528\u5167\u5efa\u7684\u4f8b\u5982metatable\u8fd9\u6837\u7684\u673a\u5236<\/p>\n<p>\u7f16\u7a0b\u7684\u65f6\u5019\u4e3a\u4e86\u7ed3\u6784\u4f18\u96c5\uff0c\u5e38\u5e38\u4f1a\u5f15\u5165\u50cf\u6d88\u606f\u5206\u53d1\u8fd9\u6837\u7684\u673a\u5236\uff0c\u7136\u540e\u5728\u6d88\u606f\u6765\u7684\u65f6\u5019\u6839\u636e\u6211\u4eec\u7ed9\u6d88\u606f\u5b9a\u4e49\u7684\u679a\u4e3e\u6765\u8c03\u7528\u5bf9\u5e94\u7684\u5b9e\u73b0\uff0c\u8fc7\u53bb\u6211\u4eec\u4e5f\u4e60\u60ef\u5199\u6210\uff1a<\/p>\n<p>if opcode == OP_1 then<\/p>\n<p>elesif opcode == OP_2 then<\/p>\n<p>&#8230;<\/p>\n<p>\u4f46\u5728luajit\u4e0b\uff0c\u66f4\u5efa\u8bae\u5c06\u4e0a\u9762\u5b9e\u73b0\u6210table\u6216\u8005metatable<\/p>\n<p>local callbacks = {}<\/p>\n<p>callbacks[OP_1] = function() &#8230; end<\/p>\n<p>callbacks[OP_2] = function() &#8230; end<\/p>\n<p>\u8fd9\u662f\u56e0\u4e3a\u8868\u67e5\u627e\u548cmetatable\u67e5\u627e\u90fd\u662f\u53ef\u4ee5\u53c2\u4e0ejit\u4f18\u5316\u7684\uff0c\u800c\u81ea\u884c\u5b9e\u73b0\u7684\u6d88\u606f\u5206\u53d1\u673a\u5236\uff0c\u5f80\u5f80\u4f1a\u7528\u5230\u5206\u652f\u4ee3\u7801\u6216\u8005\u5176\u4ed6\u66f4\u590d\u6742\u7684\u4ee3\u7801\u7ed3\u6784\uff0c\u6027\u80fd\u4e0a\u53cd\u800c\u4e0d\u5982\u7eaf\u7cb9\u7684\u8868\u67e5\u627e+jit\u4f18\u5316\u6765\u5f97\u5feb<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>9.Do not try to second-guess the JIT compiler.<\/p>\n<p>\u65e0\u9700\u8fc7\u591a\u53bb\u5e2ejit\u7f16\u8bd1\u5668\u505a\u624b\u5de5\u4f18\u5316\u3002<\/p>\n<p>\u4f5c\u8005\u4e3e\u4e86\u4e00\u4e2a\u4f8b\u5b50<\/p>\n<p>z = x[a+b] + y[a+b]\uff0c\u8fd9\u5728luajit\u662f\u6027\u80fdok\u7684\u5199\u6cd5\uff0c\u4e0d\u9700\u8981\u5148local c = a+b\u7136\u540ez = x[c] + y[c]<\/p>\n<p>\u540e\u9762\u7684\u5199\u6cd5\u5176\u5b9e\u672c\u8eab\u6ca1\u4ec0\u4e48\u95ee\u9898\uff0c\u4f46\u662fluajit\u7684\u53e6\u4e00\u4e2a\u5751\uff0c\u5373\u4e3a\u4e86\u63d0\u5347\u8fd0\u7b97\u6548\u7387\uff0clocal\u53d8\u91cf\u4f1a\u5c3d\u53ef\u80fd\u7528cpu\u5bc4\u5b58\u5668\u5b58\u50a8\uff0c\u8fd9\u6837\u6bd4\u9891\u7e41\u8bfb\u5185\u5b58\u8981\u5feb\u5f97\u591a\uff08\u73b0\u4ee3cpu\u8fd9\u53ef\u4ee5\u8fbe\u5230\u51e0\u767e\u500d\u7684\u5dee\u8ddd\uff09\uff0c\u4f46luajit\u5728\u8fd9\u65b9\u9762\u4e0d\u5b8c\u5584\uff0c\u4e00\u65e6local\u53d8\u91cf\u592a\u591a\uff0c\u53ef\u80fd\u4f1a\u627e\u4e0d\u5230\u8db3\u591f\u7684\u5bc4\u5b58\u5668\u5206\u914d\uff08\u8fd9\u4e2a\u95ee\u9898\u5728armv7\u4e0a\u975e\u5e38\u660e\u663e\uff0c\u5728\u8c03\u7528\u5c42\u6b21\u6df1\u7684\u65f6\u5019\uff0c\u51e0\u4e2a\u53d8\u91cf\u5c31\u4f1a\u70b8\u6389\uff09\uff0c\u7136\u540ejit\u4f1a\u76f4\u63a5\u653e\u5f03\u7f16\u8bd1\u3002\u8fd9\u91cc\u8981\u8bf4\u660e\u4e00\u70b9\u662f\uff0c\u5f88\u591alocal\u53d8\u91cf\u53ef\u80fd\u53ea\u662f\u58f0\u660e\u4e86\u653e\u5728\u90a3\u91cc\u6ca1\u6709\u7528\uff0c\u4f46\u662fluajit\u7684\u7f16\u8bd1\u5668\u4e0d\u4e00\u5b9a\u80fd\u591f\u51c6\u786e\u786e\u5b9a\u8fd9\u4e2a\u53d8\u91cf\u662f\u5426\u53ef\u4ee5\u4e0d\u518d\u5b58\u50a8\uff0c\u6240\u4ee5\u9002\u5f53\u63a7\u5236\u4e00\u4e2a\u51fd\u6570\u4f5c\u7528\u57df\u5185\u7684local\u53d8\u91cf\u7684\u6570\u91cf\u662f\u5fc5\u987b\u7684\u3002<\/p>\n<p>\u5f53\u7136\uff0c\u4e0d\u5f97\u4e0d\u8bf4\u8fd9\u6837\u5199\u4ee3\u7801\u8fd8\u8981\u731cluajit\u7684\u884c\u4e3a\u786e\u5b9e\u6bd4\u8f83\u75db\u82e6\uff0c\u4e00\u822c\u6765\u8bf4\u8fdb\u884cprofile\u7136\u540e\u5bf9\u6027\u80fd\u70ed\u70b9\u4ee3\u7801\u505a\u9488\u5bf9\u6d4b\u8bd5\u548c\u4f18\u5316\u57fa\u672c\u5df2\u7ecf\u53ef\u4ee5\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>10.Be careful with aliasing, esp. when using multiple arrays.<\/p>\n<p>\u53d8\u91cf\u7684\u522b\u540d\u53ef\u80fd\u4f1a\u963b\u6b62jit\u4f18\u5316\u6389\u5b50\u8868\u8fbe\u5f0f\uff0c\u5c24\u5176\u662f\u5728\u4f7f\u7528\u591a\u4e2a\u6570\u7ec4\u7684\u65f6\u5019\u3002<\/p>\n<p>\u4f5c\u8005\u4e3e\u4e86\u4e00\u4e2a\u4f8b\u5b50<\/p>\n<p>x[i] = a[i] + c[i]; y[i] = a[i] + d[i]<\/p>\n<p>\u6211\u4eec\u53ef\u80fd\u4f1a\u8ba4\u4e3a\u4e24a[i]\u662f\u540c\u4e00\u4e2a\u4e1c\u897f\uff0c\u7f16\u8bd1\u5668\u53ef\u4ee5\u4f18\u5316\u6210<\/p>\n<p>local t = a[i];\u00a0x[i] = t + c[i]; y[i] = t + d[i]<\/p>\n<p>\u5b9e\u5219\u4e0d\u7136\uff0c\u56e0\u4e3a\u53ef\u80fd\u4f1a\u51fa\u73b0\uff0cx\u548ca\u5c31\u662f\u540c\u4e00\u4e2a\u8868\uff0c\u8fd9\u6837\uff0cx[i] = a[i] + c[i]\u5c31\u6539\u53d8\u4e86a[i]\u7684\u503c\uff0c\u90a3\u4e48y[i] = a[i] + d[i]\u5c31\u4e0d\u80fd\u518d\u4f7f\u7528\u4e4b\u524d\u7684a[i]\u7684\u503c\u4e86<\/p>\n<p>\u8fd9\u91cc\u8ddf\u4f18\u5316\u70b99\u63cf\u8ff0\u7684\u60c5\u5f62\u7684\u672c\u8d28\u533a\u522b\u662f\uff0c\u4f18\u5316\u70b99\u91cc\u5934z\/a\/b\u90fd\u662f\u503c\u7c7b\u578b\uff0c\u800c\u8fd9\u91ccx\/a\u90fd\u662f\u5f15\u7528\u7c7b\u578b\uff0c\u5f15\u7528\u7c7b\u578b\u5c31\u6709\u5f15\u7528\u540c\u4e00\u4e2a\u4e1c\u897f\u7684\u53ef\u80fd\uff08\u53d8\u91cf\u522b\u540d\uff09\uff0c\u56e0\u6b64\u7f16\u8bd1\u5668\u4f1a\u653e\u5f03\u8fd9\u6837\u7684\u4f18\u5316\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>11.Reduce the number of live temporary variables.<\/p>\n<p>\u51cf\u5c11\u5b58\u6d3b\u7740\u7684\u4e34\u65f6\u53d8\u91cf\u7684\u6570\u91cf<\/p>\n<p>\u539f\u56e0\u57289\u4e2d\u5df2\u7ecf\u8bf4\u660e\uff0c\u5373\u8fc7\u591a\u7684\u5b58\u6d3b\u7740\u7684\u4e34\u65f6\u53d8\u91cf\u53ef\u80fd\u4f1a\u8017\u5c3d\u5bc4\u5b58\u5668\u5bfc\u81f4jit\u7f16\u8bd1\u5668\u65e0\u6cd5\u5229\u7528\u5bc4\u5b58\u5668\u505a\u4f18\u5316\u3002\u8fd9\u91cc\u6ce8\u610flive temporary variables\u662f\u6307\u5b58\u6d3b\u7684\u4e34\u65f6\u53d8\u91cf\uff0c\u5047\u5982\u4f60\u63d0\u524d\u7ed3\u675f\u4e86\u4e34\u65f6\u53d8\u91cf\u7684\u751f\u547d\u5468\u671f\uff0c\u7f16\u8bd1\u5668\u8fd8\u662f\u4f1a\u77e5\u9053\u8fd9\u4e00\u70b9\u7684\u3002\u6bd4\u5982\uff1a<\/p>\n<p>function foo()<\/p>\n<p>do<\/p>\n<p>local a = &#8220;haha&#8221;<\/p>\n<p>end<\/p>\n<p>print(a)<\/p>\n<p>end<\/p>\n<p>\u8fd9\u91ccprint\u662f\u4f1aprint\u51fanil\uff0c\u56e0\u4e3aa\u79bb\u5f00\u4e86do &#8230; end\u5c31\u7ed3\u675f\u4e86\u751f\u547d\u5468\u671f\uff0c\u901a\u8fc7\u8fd9\u79cd\u65b9\u5f0f\u53ef\u4ee5\u907f\u514d\u8fc7\u591a\u4e34\u65f6\u53d8\u91cf\u540c\u65f6\u5b58\u6d3b\u3002<\/p>\n<p>\u6b64\u5916\uff0c\u6709\u4e00\u4e2a\u5f88\u5e38\u89c1\u7684\u9677\u9631\uff0c\u4f8b\u5982\u6211\u4eec\u5b9e\u73b0\u4e86\u4e00\u4e2aVector3\u7684\u7c7b\u578b\u7528\u4e8e\u8868\u8fbe\u7acb\u4f53\u7a7a\u95f4\u4e2d\u7684\u77e2\u91cf\uff0c\u5e38\u5e38\u4f1a\u91cd\u8f7d\u4ed6\u7684\u4e00\u4e9b\u5143\u51fd\u6570\uff0c\u6bd4\u5982__add<\/p>\n<p>Vector3.__add\u00a0=\u00a0function(va,\u00a0vb)<\/p>\n<p>return\u00a0Vector3.New(va.x\u00a0+\u00a0vb.x,\u00a0va.y\u00a0+\u00a0vb.y,\u00a0va.z\u00a0+\u00a0vb.z)<\/p>\n<p>end<\/p>\n<p>\u7136\u540e\u6211\u4eec\u5c31\u4f1a\u5728\u4ee3\u7801\u4e2d\u5927\u8086\u5730\u4f7f\u7528a + b + c\u6765\u5bf9\u4e00\u5806\u7684Vector3\u505a\u6c42\u548c\u8fd0\u7b97\u3002<\/p>\n<p>\u8fd9\u5176\u5b9e\u5bf9luajit\u662f\u6709\u5f88\u5927\u7684\u9690\u60a3\u7684\uff0c\u56e0\u4e3a\u6bcf\u4e2a+\u90fd\u4ea7\u751f\u4e86\u4e00\u4e2a\u65b0\u7684Vector3\uff0c\u8fd9\u5c06\u4f1a\u4ea7\u751f\u5927\u91cf\u7684\u4e34\u65f6\u53d8\u91cf\uff0c\u4e14\u4e0d\u8003\u8651\u8fd9\u91cc\u7684gc\u538b\u529b\uff0c\u5149\u662f\u4e3a\u8fd9\u4e9b\u53d8\u91cf\u5206\u914d\u5bc4\u5b58\u5668\u5c31\u5df2\u7ecf\u5341\u5206\u5bb9\u6613\u51fa\u95ee\u9898\u3002<\/p>\n<p>\u6240\u4ee5\u8fd9\u91cc\u6700\u597d\u5728\u6027\u80fd\u548c\u6613\u7528\u6027\u4e0a\u8fdb\u884c\u6743\u8861\uff0c\u6bcf\u6b21\u6c42\u548c\u5982\u679c\u662f\u5c06\u7ed3\u679c\u5199\u4f1a\u5230\u539f\u6765\u7684\u8868\u4e2d\uff0c\u90a3\u4e48\u538b\u529b\u4f1a\u5c0f\u5f88\u591a\uff0c\u5f53\u7136\u4ee3\u7801\u7684\u6613\u7528\u6027\u548c\u53ef\u8bfb\u6027\u4e0a\u5c31\u53ef\u80fd\u8981\u727a\u7272\u4e00\u4e9b\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>12.Do not intersperse expensive or uncompiled operations.<\/p>\n<p>\u51cf\u5c11\u4f7f\u7528\u9ad8\u6d88\u8017\u6216\u8005\u4e0d\u652f\u6301jit\u7684\u64cd\u4f5c<\/p>\n<p>\u8fd9\u91cc\u8981\u63d0\u5230\u4e00\u4e2aluajit\u6587\u6863\u4e2d\u7684\u5c5e\u4e8e\uff1aNYI\uff08not yet implement\uff09\uff0c\u610f\u601d\u5c31\u662f\uff0c\u4f5c\u8005\u8fd8\u6ca1\u6709\u628a\u8fd9\u4e2a\u529f\u80fd\u505a\u5b8c\u3002\u3002<\/p>\n<p>luajit\u5feb\u662f\u5feb\u5728\u80fd\u628a\u4ee3\u7801\u7f16\u8bd1\u4e3a\u673a\u5668\u7801\u6267\u884c\uff0c\u4f46\u662f\u5e76\u975e\u6240\u6709\u4ee3\u7801\u90fd\u53ef\u4ee5jit\u5316\uff0c\u9664\u4e86\u524d\u9762\u63d0\u5230\u7684for in pairs\u5916\uff0c\u8fd8\u6709\u5f88\u591a\u8fd9\u6837\u7684\u4e1c\u897f\uff0c\u6700\u5e38\u89c1\u7684\u6709\uff1a<\/p>\n<p>for k, v in pairs(x)\uff1a\u4e3b\u8981\u662fpairs\u662f\u65e0jit\u5b9e\u73b0\u7684\uff0c\u5c3d\u53ef\u80fd\u7528ipairs\u66ff\u4ee3\u3002<\/p>\n<p>print()\uff1a\u8fd9\u4e2a\u662f\u975ejit\u5316\u7684\uff0c\u4f5c\u8005\u5efa\u8bae\u7528io.write\u3002<\/p>\n<p>\u5b57\u7b26\u4e32\u8fde\u63a5\u7b26\uff1a\u6253\u65e5\u5fd7\u5f88\u5bb9\u6613\u4f1a\u5199log(&#8220;haha &#8220;..x)\u8fd9\u6837\u7684\u65b9\u5f0f\uff0c\u7136\u540e\u901a\u8fc7\u5c4f\u853dlog\u7684\u5b9e\u73b0\u6765\u907f\u514d\u6d88\u8017\u3002\u4e8b\u5b9e\u4e0a\u771f\u7684\u53ef\u4ee5\u5c4f\u853d\u6389\u5417\uff1f\u7136\u5e76\u5375\u3002\u56e0\u4e3a&#8221;haha&#8221;..x\u8fd9\u4e2a\u5b57\u7b26\u4e32\u94fe\u63a5\u4f9d\u7136\u4f1a\u88ab\u6267\u884c\u3002\u57282.0.x\u7684\u65f6\u5019\u8fd9\u4e2a\u4ee3\u7801\u8fd8\u4e0d\u652f\u6301jit\uff0c2.1.x\u867d\u7136\u7ec8\u4e8e\u652f\u6301\u4e86\uff0c\u4f46\u662f\u591a\u4f59\u7684\u8fde\u63a5\u5b57\u7b26\u4e32\u8fd0\u7b97\u4ee5\u53ca\u5185\u5b58\u5206\u914d\u4f9d\u7136\u53d1\u751f\u4e86\uff0c\u6240\u4ee5\u60f3\u8981\u5c4f\u853d\uff0c\u53ef\u4ee5\u7528log(&#8220;haha %s&#8221;, x)\u8fd9\u6837\u7684\u5199\u6cd5\u3002<\/p>\n<p>table.insert\uff1a\u76ee\u524d\u53ea\u6709\u4ece\u5c3e\u90e8\u63d2\u5165\u624d\u662fjit\u5b9e\u73b0\u7684\uff0c\u5982\u679c\u4ece\u5176\u4ed6\u5730\u65b9\u63d2\u5165\uff0c\u4f1a\u8df3\u8f6c\u5230c\u5b9e\u73b0\u3002<\/p>\n<\/div>\n<\/div>\n<\/article>\n","protected":false},"excerpt":{"rendered":"<p>\u539f\u6587\u5730\u5740 &nbsp; \u7ffb\u8bd1\u8349\u7433\u60c5\u00a0\u6700\u540e<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[],"tags":[118],"class_list":["post-4155","post","type-post","status-publish","format-standard","hentry","tag-02-"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/4155","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/comments?post=4155"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/4155\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=4155"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=4155"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=4155"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}