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  1. JDK
  2. JDK-8154826

AArch64: take better advantage of base + shifted offset addressing mode

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 9
    • Fix Version/s: 9
    • Component/s: hotspot
    • Labels:
      None
    • Subcomponent:
    • Resolved In Build:
      b120
    • CPU:
      aarch64

      Description

      The aarch64 port implicitly transforms:
      (AddP base (AddP base address (LShiftL index con)) offset)
      into:
      (AddP base (AddP base offset) (LShiftL index con))
      in the ad file to embed the shift (and possibly and i2l conversion) into the addressing mode of a memory operation. Exposing that transformation in the ideal graph allows:

      - (AddP base offset) to be scheduled (for instance outside a loop)
      - multiple identical (AddP base offset) can be commoned
      - (LShiftL index con) can be cloned during matching so that each memory access has its own

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              • Assignee:
                roland Roland Westrelin
                Reporter:
                roland Roland Westrelin
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                Dates

                • Created:
                  Updated:
                  Resolved: