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  1. JDK
  2. JDK-8179004

Add an efficient implementation of the "count trailing zeros" operation

    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 9
    • Fix Version/s: 10
    • Component/s: hotspot
    • Labels:
      None
    • Subcomponent:
    • Resolved In Build:
      b21
    • CPU:
      generic
    • OS:
      generic

      Description

      There are a number of possible uses for an efficient "count trailing zero" operation. By efficient we mean access to the underlying hardware support; supported hardware architectures generally provide an efficient implementation, e.g. a single instruction or a short instruction sequence.

      One obvious use is in the BitMap search functions, which are presently performing that operation using a for-loop to iterate over the bits in the word of interest. See JDK-6735527.

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              • Assignee:
                kbarrett Kim Barrett
                Reporter:
                kbarrett Kim Barrett
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                Dates

                • Created:
                  Updated:
                  Resolved: