Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8220566

AArch64: Set default vm features for Ampere eMAG CPUs

    XMLWordPrintable

Details

    • Enhancement
    • Resolution: Fixed
    • P4
    • 13
    • 13
    • hotspot
    • None
    • b13
    • aarch64
    • linux

    Description

      This vm features tuning logic is wrapped by _cpu == CPU_AMCC, Ampere Computing owns this product.
      Verification will be done on Ampere eMAG platforms.
      Suppose no direct impacts on functions at other platforms.

      --- old/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp 2019-03-12 14:04:03.162682861 +0800
      +++ new/src/hotspot/cpu/aarch64/vm_version_aarch64.cpp 2019-03-12 14:04:02.926683992 +0800
      @@ -194,6 +194,19 @@
       
         // Enable vendor specific features
       
      + // Ampere eMAG
      + if (_cpu == CPU_AMCC && (_model == 0) && (_variant == 0x3)) {
      + if (FLAG_IS_DEFAULT(AvoidUnalignedAccesses)) {
      + FLAG_SET_DEFAULT(AvoidUnalignedAccesses, true);
      + }
      + if (FLAG_IS_DEFAULT(UseSIMDForMemoryOps)) {
      + FLAG_SET_DEFAULT(UseSIMDForMemoryOps, true);
      + }
      + if (FLAG_IS_DEFAULT(UseSIMDForArrayEquals)) {
      + FLAG_SET_DEFAULT(UseSIMDForArrayEquals, !(_revision == 1 || _revision == 2));
      + }
      + }
      +
         // ThunderX
         if (_cpu == CPU_CAVIUM && (_model == 0xA1)) {
           if (_variant == 0) _features |= CPU_DMB_ATOMICS;

      Attachments

        Activity

          People

            qpzhang Patrick Zhang
            qpzhang Patrick Zhang
            Votes:
            0 Vote for this issue
            Watchers:
            1 Start watching this issue

            Dates

              Created:
              Updated:
              Resolved: