Interface Specializers

[vyzo]

On top of ##1126

And so it begins... the compiler generates specializers for all bound methods that could benefit from it, and interface prototype creation plugs to it, with wondrous performance results for certain programs.

Here is an example:

(defclass A (x y))
(defclass (B A) (z))

(defmethod {linear A}
  (lambda (self w)
    (fx+ (fx* (A-x self) w) (A-y self))))

(defmethod {bilinear-combination B}
  (lambda (self w z)
    {self.bilinear {self.linear w} z}))

(defmethod {bilinear B}
  (lambda (self lc z)
    (fx+ lc (fx* (B-z self) z))))

(interface Combinator
  (bilinear-combination w z))

(def (run iters)
  (let (instance (Combinator (B x: 1 y: 2 z: 3)))
    (for (i (in-range iters))
      (let (result (&Combinator-bilinear-combination instance 4 5))
        (unless (= result 21)
          (error "bad result" result: result expected: 21))))))

(def (main iters)
  (let (iters (string->number iters))
    (time (run iters))))

With gxc master:

$ gxc -exe -o /tmp/ispec-bench -O src/gerbil/test/interface-specialization-bench.ss
/tmp/gxc.1708454081.817515/test__interface-specialization-bench.scm:
/tmp/ispec-bench__exe.scm:
/tmp/gxc.1708454081.817515/test__interface-specialization-bench.c:
/tmp/ispec-bench__exe.c:
/tmp/ispec-bench__exe_.c:
$ /tmp/ispec-bench 1000000
(time (let () (declare (not safe)) (test/interface-specialization-bench#run _iters79_)))
    0.215345 secs real time
    0.215332 secs cpu time (0.211338 user, 0.003994 system)
    20 collections accounting for 0.016191 secs real time (0.015828 user, 0.000356 system)
    159892208 bytes allocated
    671 minor faults
    no major faults
    562301090 cpu cycles

With the specializers:

$ ./build.sh env gxc -exe -o /tmp/ispec-bench -O gerbil/test/interface-specialization-bench.ss
/tmp/gxc.1708454105.0922964/test__interface-specialization-bench.scm:
/tmp/ispec-bench__exe.scm:
/tmp/gxc.1708454105.0922964/test__interface-specialization-bench.c:
/tmp/ispec-bench__exe.c:
/tmp/ispec-bench__exe_.c:
[*] Done
$ /tmp/ispec-bench 1000000
(time (let () (declare (not safe)) (test/interface-specialization-bench#run _iters79_)))
    0.010587 secs real time
    0.010587 secs cpu time (0.010586 user, 0.000001 system)
    no collections
    1408 bytes allocated
    no minor faults
    no major faults
    27638154 cpu cycles

20x, not bad huh?

Basically all the dynamic dispatch call cost of the MOP for self references (slots or methods) has disappeared.

[fare]

LGTM

[fare]

I'd like to see more documentation comments and type signature comments above all functions everywhere.

[vyzo]

rebased on master.

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[vyzo]

Added some more comments; we need to write docs, the code is mostly self explanatory with a good mop page in the hyperspec.