3 ms·

Apparently linear search now beats hashmap if you have less than TWO HUNDRED elements. Crazy!

• afdbcreid 2mo ago
  But when you compare native integers, not something more complicated, right?
  • zbentley 2mo ago
    Depends. Are you searching for the complicated thing by identity, or in a system that caches identities and/or interns objects of the type you’re handling? All Of those can result in searches being word-based and thus vectorizable/cache-sympathetic more often.
• spockz 2mo ago
  So now the result of `new HashMap<>()` should be backed by an array for the first 200 elements or so? Potentially the size depending on the L1 size etc.
  • inigyou 2mo ago
    Not in Java, because a linear search map in Java means traversing over 100 (on average) pointers.
    • spockz 2mo ago
      Right, but not once these records/structs/value types arrive anymore I gather. Does this also mean we need to worry about word aligning our fields?? What about strings?
• SkiFire13 2mo ago
  For which key types, hashmap implementation, and hasher? Depending on these factors hashmaps performance can vary a lot.