• Kevin Modzelewski's avatar
    Add 'runtime ics' to improve C++ runtime speed · 191b46b3
    Kevin Modzelewski authored
    An experimental way of making the runtime faster.  Previously, the C++
    runtime was much slower than pure-Python code, since the Python code
    can use the JIT to improve performance (through inline caches and type
    speculation).  This commit adds "runtime ics", which are out-of-band
    patchpoints that we can allocate from C++.  We insert them into the
    same patchpoint system that gets used by the main JIT pipeline, so
    they get rewritten like any other patchpoint, but the lifetime and use
    gets controlled by the C++ code.
    
    The trickiest part is getting the newly-allocated instruction regions
    to work with our exception handling; to make this work we have to emit
    .eh_frame sections.  (A custom libunwind-based exception unwinder
    might not have this requirement.)
    
    Otherwise it feels like a decent approach.  Right now just using it to
    implement class slots and then only using them in the pyElements
    iterator; it's probably not the most direct or efficient way of
    implementing that particular feature, but it has the benefit of being
    general and being useful for things such as binops which are not
    directly expressible in terms of class slots.
    
    This commit adds the support without turning the feature on (next
    commit will turn it on), since there are a number of other changes
    needed.
    191b46b3
options.h 1.74 KB