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  1. JDK
  2. JDK-8213199

GC abstraction for Assembler::needs_explicit_null_check()

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Details

    • Enhancement
    • Resolution: Fixed
    • P4
    • 12
    • 12
    • hotspot
    • gc
    • b20
    • generic
    • generic

    Description

      GCs (like Shenandoah) may emit additional loads or stores. In the case of Shenandoah, we emit forward pointer loads from offset -8. Those accesses don't match the pattern currently checked in Assembler::needs_explicit_null_check() which means that explicit null checks would be emitted for forwarding pointer loads. But we don't want that because we know that the base object cannot be NULL (everything else would be an error).

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          duplicates

          Enhancement - null JDK-8213195 GC abstraction for Assembler::needs_explicit_null_check()

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

          Bug - A problem which impairs or prevents the functions of the product. JDK-8213711 Zero build broken after JDK-8213199 (GC abstraction for Assembler::needs_explicit_null_check())

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

          Enhancement - null JDK-8225779 Remove unused CollectedHeap::cell_header_size()

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

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              rkennke Roman Kennke
              rkennke Roman Kennke
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                Created:
                Updated:
                Resolved: