• Manos Koukoutos's avatar
    [turbofan] Introduce LoadImmutable, use it in wasm compiler · f6ee9ed0
    Manos Koukoutos authored
    LoadImmutable represents a load from a position in memory that is known
    to be immutable, e.g. an immutable IsolateRoot or an immutable field of
    a WasmInstanceObject. Because the returned value cannot change through
    the execution of a function, LoadImmutable is a pure operator and does
    not have effect or control edges.
    This will allow more aggressive optimizations of loads of fields of
    the Isolate and Instance that are known to be immutable.
    Requires that the memory in question has been initialized at function
    start even through inlining.
    
    Note: We may reconsider this approach once we have escape analysis for
    wasm, and replace it with immutable load/initialize operators that live
    inside the effect chain and are less restriced.
    
    Bug: v8:11510
    Change-Id: I5e8e4f27d7008f39f01175ffa95a9c531ba63e66
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2775568Reviewed-by: 's avatarAndreas Haas <ahaas@chromium.org>
    Reviewed-by: 's avatarGeorg Neis <neis@chromium.org>
    Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#73594}
    f6ee9ed0
instruction-selector-x64.cc 137 KB