I'm currently building a language for writing games that compiles directly to JavaScript. As a part of this I wrap JS arrays inside my own Array object, and inside it's 'set' method I run 'parseInt' on the given key to ensure the index is always an int.
Due to warnings given by the closure JavaScript optimizer I use, today I changed 'parseInt( key )' to 'parseInt( key, 10 )' (the optimizer gives you a warning if you fail to do this). However I found that after adding the radix I received a major performance drop. I'm using Chrome 11.0.672.2. With some of the array intensive examples (namely this one http://playmycode.com/play/game/Sandbox/Blobs) the loss in framerate was almost 60% (from around 35fps on my machine to 15fps)! That's surprising since it's also doing lots of drawing too (although most time is spent on the number crunching). Simply removing the redux from parseInt solved this issue and brought the performance back up. In my own primitive benchmarks (running parseInt 1000's of times) I find similar, but with less of a performance drop. I'm just really stunned that simply supplying the radix can cause such a big drop in performance. Could this be solved in the future? -- v8-dev mailing list v8-dev@googlegroups.com http://groups.google.com/group/v8-dev
