Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8221220

AArch64: Add StoreStore membar explicitly for Volatile Writes in TemplateTable

    XMLWordPrintable

Details

    • b14
    • aarch64
    • generic

    Backports

      Description

        The original discussion can be found here:
        https://mail.openjdk.java.net/pipermail/aarch64-port-dev/2019-February/006875.html

        It has been known that Volatile Store needs a StoreLoad|StoreStore barrier at the end of the templateTable_aarch64 functions like fast_storefield, putfield_or_static. In Arm reference manual, according to the description of DMB instruction, the option ISH (Any-Any) for StoreLoad barrier option covers ISHST for StoreStore, so StoreLoad was/is sufficient from the view point of functionality.

        In order to make the code self-documented and would not confuse people in future, a suggestion here is to add back the intentionally missed "|StoreStore".

        This change will not bring practical impacts to functions since generated instructions are same.

        The positive part of this is: making things clarified and aligned, for example, the logic in interpreter here will be more clearly aligned with the logic in C2 implementation for a volatile write:
        dmb ish
        str<x>
        dmb ish

        Attachments

          Issue Links

            backported by

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8226665 AArch64: Add StoreStore membar explicitly for Volatile Writes in TemplateTable

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Resolved

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8248630 AArch64: Add StoreStore membar explicitly for Volatile Writes in TemplateTable

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Resolved

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8260835 AArch64: Add StoreStore membar explicitly for Volatile Writes in TemplateTable

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Resolved
            relates to

            Bug - A problem which impairs or prevents the functions of the product. JDK-8218185 aarch64: missing LoadStore barrier in TemplateTable::putfield_or_static

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Resolved

            Bug - A problem which impairs or prevents the functions of the product. JDK-8219635 aarch64: missing LoadStore barrier in TemplateTable::fast_storefield

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Resolved

            Enhancement - null JDK-8257192 Integrate AArch64 JIT port into 8u

            • P3 - Major loss of function.
            • Resolved

            Activity

              People

                qpzhang Patrick Zhang
                qpzhang Patrick Zhang
                Votes:
                0 Vote for this issue
                Watchers:
                2 Start watching this issue

                Dates

                  Created:
                  Updated:
                  Resolved: