• Junliang Yan's avatar
    ppc/s390: [isolate-data] Split builtin tables into tiers · dc88bdf3
    Junliang Yan authored
    Port 06af754c
    
    Original Message:
      .. for more efficient access to builtins from generated code.
    
      Root-relative accesses tend to be faster and produce more compact
      code when the root-relative offset is small. IsolateData contains
      a few large tables (roots, external references, builtins), resulting
      in very large offsets in general.
    
      This CL starts by splitting the builtin table into tiers: tier 0
      is a minimal set of perf-critical builtins that should be cheap to
      access. The offset to tier 0 builtins is guaranteed to be small.
    
      The full builtin table also remains in IsolateData for occasions in
      which we need to lookup builtins by index.
    
      In future work, we can also split external references and roots into
      tiers.
    
      On x64, this reduces deopt exit sizes from 7 to 4 bytes and from 12
      to 9 bytes (dynamic map checks / EagerWithResume deopts).
    
    Change-Id: I021d60b20b783da170987ffcf0327b93206f7e5d
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3172917Reviewed-by: 's avatarMilad Fa <mfarazma@redhat.com>
    Commit-Queue: Junliang Yan <junyan@redhat.com>
    Cr-Commit-Position: refs/heads/main@{#76967}
    dc88bdf3
deoptimizer-ppc.cc 2.01 KB