• Ross McIlroy's avatar
    [Ignition] [TurboFan] Generate speculation poison in code generator. · a021b6c4
    Ross McIlroy authored
    Moves generation of speculation poison to be based on the PC target vs the
    actual PC being executed. The speculation poison is generated in the prologue
    of the generated code if CompilationInfo::kGenerateSpeculationPoison is set.
    The result is stored in a known register, which can then be read using the
    SpeculationPoison machine node.
    
    Currently we need to ensure the SpeculationPoison node is scheduled right after
    the code prologue so that the poison register doesn't get clobbered. This is
    currently not verified, however it's only use is in RawMachineAssembler where
    it is manually scheduled early.
    
    The Ignition bytecode handlers are updated to use this speculation poison
    rather than one generated by comparing the target bytecode.
    
    BUG=chromium:798964
    
    Change-Id: I2a3d0cfc694e88d7a8fe893282bd5082f693d5e2
    Reviewed-on: https://chromium-review.googlesource.com/893160
    Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
    Reviewed-by: 's avatarJaroslav Sevcik <jarin@chromium.org>
    Reviewed-by: 's avatarMichael Starzinger <mstarzinger@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#51229}
    a021b6c4
macro-assembler-arm64.h 87.2 KB