If we const-prop the required functions and leafs then we can directly
encode the CPUID information rather than jumping out of the JIT.
In testing almost all CPUID executions const-prop which function is
getting called. Worst case that I found was only 85% const-prop rate.
This isn't quite 100% optimal since we need to call the RCLSE and
Constprop passes after we optimize these, which would remove some
redundant moves.
Sadly there seems to be a bug in the constprop pass that starts crashing
applications if that is done.
Easily enough tested by running Half-Life 2 and it immediately hitting
SIGILL.
Even without this optimization, this is stil a significant savings since
we aren't jumping out of the JIT anymore for these optimized CPUIDs.
It is not an external component, and it makes paths needlessly long.
Ryan seemed amenable to this when we discussed on IRC earlier.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Ryan Houdek