Re:A Deep Introduction to JIT Compilers: JITs are not very J...
by seanmcdirmid on Sunday July 05, 2020 @04:58PM
(#23741914)
Pretty sure assymetrix was done in the late 90s. 1998 or so, they started out doing educational software and pivoted to doing ahead of time compilation for some weird reason. Here is a link to when it failed in 1999: https://www.cbronline.com/news/sepercede_exits_java_sells_to...
Most compilers for embedded systems have always offered that option, and in what concerns enterprise JVMs, JIT compilers have had the capability to cache JIT code and PGO data between runs.
Both options that have come now to OpenJDK, OpenJ9 and Graal.
Android also learned the hard way that changing to pure AOT did not achieve the performance improvements that they expected, while compilation on device achieved C++ compile times when it was time to update all apps, hence the multi-tier interpreter/JIT/AOT with PGO introduced in Android 7.
The main problem of AOT compilation with PGO, is that first of all one needs a good dataset so that the optimizations are in line with the actual behaviour in production, still doesn't work across dynamic libraries so optimizations like devirtualization are not possible, and most of the time the tooling is quite cumbersome to use.