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  1. JDK
  2. JDK-8255553

[PPC64] Introduce and use setbc and setnbc P10 instructions

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    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 16
    • Fix Version/s: 16
    • Component/s: hotspot
    • Labels:
      None
    • Subcomponent:
    • Resolved In Build:
      b25
    • CPU:
      ppc

      Description

      - setbc RT,BI: sets RT to 1 if CR(BI) is 1, otherwise 0.
      - setnbc RT,BI: sets RT to -1 if CR(BI) is 1, otherwise 0.
      Ref: PowerISA 3.1, page 129.

      These instructions are particularly interesting to improve the following pattern `(src1<src2)? -1: ((src1>src2)? 1: 0)`, which can be found in `instruct cmpL3_reg_reg_ExEx()@ppc.ad`, by removing its branches.

      Long.toString, that generate such pattern in getChars, has showed a good performance gain by using these new instructions.

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              Assignee:
              jziviani Jose Ziviani
              Reporter:
              jziviani Jose Ziviani
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