This wednesday we landed the baseline compiler on Firefox nightly. After six months of work from start to finish, we are finally able to merge the fruits of our toils into the main release stream.
Baseline (no, there is no *Monkey codename for this one) is IonMonkey’s new warm-up compiler. It brings performance improvements in the short term, and opportunities for new performance improvements in the long term. It opens the door for discarding JaegerMonkey, which will enable us to make other changes that greatly reduce the memory usage of SpiderMonkey. It makes it easier and faster to implement first-tier optimizations for new language features, and to more easily enhance those into higher-tier optimizations in IonMonkey.
Our scores on the Kraken, Sunspider, and Octane benchmarks have improved by 5-10% on landing, and will continue to improve as we continue to leverage Baseline to make SpiderMonkey better.