Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8168318

PPC64: Use cmpldi instead of li/cmpld

    XMLWordPrintable

    Details

    • Subcomponent:
    • Resolved In Build:
      b146
    • CPU:
      ppc
    • OS:
      linux

      Backports

        Description

        On profiling some specific Neo4j workloads, some cases where a sequence of load (li) and compare (cmpld) can be
        replaced by a single cmpldi instructions were identified. On replacing that sequence by a single instruction it's
        possible to reduce the path length so the program is shorter, and therefore is faster.

        Additionally, the 2 instruction sequence requires an additional register that with enough register pressure a
        spill would be needed to accommodate that approach.

        It's related to the discussion started here:
        http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2016-October/024664.html

          Attachments

            Issue Links

              Activity

                People

                Assignee:
                gromero Gustavo Romero
                Reporter:
                gromero Gustavo Romero
                Votes:
                0 Vote for this issue
                Watchers:
                3 Start watching this issue

                  Dates

                  Due:
                  Created:
                  Updated:
                  Resolved: