Editing SpiderMonkey (section)

===TraceMonkey===
TraceMonkey<ref>{{cite web |url=https://wiki.mozilla.org/JavaScript:TraceMonkey |title=JavaScript:TraceMonkey, MozillaWiki |access-date=2020-07-22}}</ref> was the first JIT compiler written for the JavaScript language. Initially introduced as an option in a beta release and introduced in Brendan Eich's blog on August 23, 2008,<ref>{{cite web |url=https://brendaneich.com/2008/08/tracemonkey-javascript-lightspeed/ |title=TraceMonkey: JavaScript Lightspeed, Brendan Eich's Blog |access-date=2020-07-22}}</ref> the compiler became part of the mainline release as part of SpiderMonkey in [[Firefox 3.5]], providing "performance improvements ranging between 20 and 40 times faster" than the baseline interpreter in [[Firefox 3]].<ref>{{cite web |url=https://arstechnica.com/news.ars/post/20080822-firefox-to-get-massive-javascript-performance-boost.html |title=Firefox to get massive JavaScript performance boost |last=Paul |first=Ryan |date=22 August 2008 |publisher=Ars Technica |access-date=21 March 2013 |archive-url=https://web.archive.org/web/20120506204854/http://arstechnica.com/open-source/news/2008/08/firefox-to-get-massive-javascript-performance-boost.ars |archive-date=6 May 2012 |url-status=live |df=dmy-all}}</ref>

Instead of compiling whole functions, TraceMonkey was a [[tracing JIT]], which operates by recording [[control flow]] and [[data type]]s during interpreter execution. This data then informed the construction of [[trace tree]]s, highly specialized paths of [[native code]].

Improvements to JägerMonkey eventually made TraceMonkey obsolete, especially with the development of the SpiderMonkey [[type inference]] engine. TraceMonkey is absent from SpiderMonkey from Firefox 11 onward.<ref>{{cite web |url=http://blog.mozilla.com/nnethercote/2011/11/01/spidermonkey-is-on-a-diet/ |title=SpiderMonkey is on a diet &#124; Nicholas Nethercote |last=Nethercote |first=Nicholas |date=1 November 2011 |publisher=Blog.mozilla.com |access-date=21 March 2013 |archive-url=https://web.archive.org/web/20120328124431/http://blog.mozilla.com/nnethercote/2011/11/01/spidermonkey-is-on-a-diet/ |archive-date=28 March 2012 |url-status=live |df=dmy-all}}</ref>