• danno's avatar
    [turbofan] Add general support for sp-based frame access · 51669873
    danno authored
    Some highlights of this CL:
    * Refactor the mutable state out of Frame into FrameAccessState,
      which is maintained and updated during code generation to
      record whether sp- or fp-based frame access is currently active
      and how deep the stack on top of the frame is.
    * The operand resultion in linkage.cc now uses FrameAccessState
      to determine how to generate frame-accessing operands.
    * Update all platforms to accurately track additionally pushed
      stack slots (e.g. arguments for calls) in the FrameAccessState.
    * Add a flag, --turbo_sp_frame_access, which forces all frame
      access to be sp-based whenever possible. This will likely never
      be used in production, but for testing it's useful in verifying
      that the stack-tracking of each platform maintained in the
      FrameAccessState is correct.
    * Use sp-based frame access for gap resolving before tail
      calls. This will allow for slightly more efficient restoration
      of the frame pointer in the tail call in a later CL.
    * Remove most ad hoc groping into CallDescriptors to
      determine if a frame is needed, instead consistently use
      predicates like needs_frame(), IsCFunctionCall() and
      IsJSFunctionCall().
    
    BUG=v8:4076
    LOG=n
    
    Review URL: https://codereview.chromium.org/1460183002
    
    Cr-Commit-Position: refs/heads/master@{#32234}
    51669873
linkage.cc 19.8 KB