Hi, A stable map is one from which a transition has never been observed, i.e. it's the leaf of the transition tree and objects with that map can be assumed to be "stable". Perhaps "is_leaf" or "never_transitioned_away_from" could be alternative names but it's a subtle concept to name and naming is hard anyway :)
In the code you linked, I'm not 100% familiar with the reasoning but I assume that the compiler assumes that inferred stable maps are a "safe bet" as far as speculation is concerned, since they're a reliable end state, and can be assumed to be a correct inference even if the data is unreliable. That's mostly just a guess from the context though. - Leszek On Tue, 31 Dec 2019, 05:46 , <janngodsp...@gmail.com> wrote: > What is the difference between a stable and unstable map? > > Context: I'm trying to understand this line of code > https://cs.chromium.org/chromium/src/v8/src/compiler/js-native-context-specialization.cc?l=3227&rcl=4c53f9a51444393133ff303952f1296603d44ab7 > but can't seem to find any documentation about stable maps. Comments and > diffs are sparse on the subject as well. > > -- > -- > v8-dev mailing list > v8-dev@googlegroups.com > http://groups.google.com/group/v8-dev > --- > You received this message because you are subscribed to the Google Groups > "v8-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-dev+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/v8-dev/d8383180-787c-4bac-8ac3-d9295d400b2c%40googlegroups.com > <https://groups.google.com/d/msgid/v8-dev/d8383180-787c-4bac-8ac3-d9295d400b2c%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- -- v8-dev mailing list v8-dev@googlegroups.com http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-dev+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/v8-dev/CAGRskv9r8GDZrOgeiYya5Gk%2Bbz5Pq_EBPNb%2BfWiP%3DT827UBw5A%40mail.gmail.com.
