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  1. JDK
  2. JDK-8266707

Consider aligning dneg/fneg specs with IEEE 754-2019 NaN handling

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    Details

    • Type: Enhancement
    • Status: New
    • Priority: P4
    • Resolution: Unresolved
    • Affects Version/s: 17
    • Fix Version/s: None
    • Component/s: specification
    • Labels:
      None
    • Subcomponent:
      vm

      Description

      The IEEE 754-2019 standard tightened the specification its negate operation so that is it a sign bit operation rather than an arithmetic operation. Operationally, that means that IEEE 754-2019 negate is also required to flip the sign bit of the input if the input is a NaN, even though the sign of a NaN doesn't have a meaning per se. See sections 5.5.1 and 6.3 of that standard.

      The dneg/fneg JVM instructions do not have a similar requirement and are allowed to return any NaN for a NaN input.

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            Assignee:
            Unassigned Unassigned
            Reporter:
            darcy Joe Darcy
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              Created:
              Updated: