Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8269821

Remove is-queue-active check in inner loop of write_ref_array_pre_work

    XMLWordPrintable

Details

    • gc
    • b05

    Description

      G1BarrierSet::write_ref_array_pre_work roughly looks as follows:

      if marking active -> exit

      for all references in array:
        if array[i] != NULL
          enqueue(array[i])

      enqueue every time checks again whether marking is active. In reality, the generated assembly code seems to load Thread::current() and does the check for every loop iteration which is really unnecessary.

      Also some other code can be hoisted out of the loop which results in more compact generated code.

      Attachments

        Issue Links

          Activity

            People

              tschatzl Thomas Schatzl
              tschatzl Thomas Schatzl
              Votes:
              0 Vote for this issue
              Watchers:
              4 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: