Current JS engine (Jaegermonkey + Type Interference)
Benchmark December 1st December 31st jslinux 5298.0 ms 5476.5 ms regression of 180 ms V8 6811.7 7113.4 improvement in score of 300
One of the regressions I found was the following one:
eaac85c4c05f – Bug 704387: Generate SSA information for scripts containing switch and try blocks
regression of 130ms on jslinux
This increases the compilation time of scripts, with the possibility of creating faster code. In case of jslinux the gained run time doesn’t outweight the extra compilation time and therefor runs slower. Bhackett informed me that the increased compilation time will get lowered with help of bug 706914.