Re: Add more supported primitives in libgccjit IR (was: Shrinking the C core)

["Alfred M. Szmidt" <ams@gnu.org>]

   So, in a statically typed language, adding two integers takes a
   single CPU cycle.  In a dynamically typed language, it can take
   many CPU cycles.  And of course, using a JIT compiler does not
   magically transform a dynamically typed language into a statically
   typed one: you still need to do these dynamic dispatches.

To add to that, in SBCL, these checks can be inlined, and optimized
out (since SBCL has more information about what it has to do with --
the compiler has access to literally everything it produces and runs,
which is not the case in Emacs).  So something like FLOOR can be
reduced to just doing what is needed (is it of the promised type? If
not error, otherwise call the specialized code for doing FLOOR), so
the code path becomes much smaller.

Like with the arith_driver example, what one would maybe like to do is
jump directly to the case one needs instead of going through multiple
checks.  And who knows how much or little that would matter.  It is
just one of bazillion differences between SBCL and Emacs.