7d0b1d5695
The ray tracer is compute-bound and the three existing benches only cover alloc / megamorphic-dispatch / collections. Add three axes the epic needs to judge itself holistically: - mono-dispatch: monomorphic protocol dispatch. Its jolt/JVM ratio (~110x) is *worse* than megamorphic (~76x) — the JVM inline-caches a runtime-monomorphic call site to near-free while jolt does a full registry dispatch (devirt only fires on statically-proven receivers). Points at the call-site inline cache. - mandelbrot: pure float compute, no alloc/dispatch. The floor at ~15x — native arith already gets close to the JVM. - fib: recursion, call + integer-arith overhead. run.sh gains JVM=1, which runs each bench on JVM Clojure too and prints the jolt/JVM ratio. collections sized up now that the map is a HAMT (jolt-684u). README documents the axes and the current scorecard. Co-authored-by: Yogthos <yogthos@gmail.com>
45 lines
1.8 KiB
Clojure
45 lines
1.8 KiB
Clojure
;; mono-dispatch — protocol dispatch where every call site sees ONE record type
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;; (monomorphic). This is the regime where devirtualization (jolt-41m) and a
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;; call-site inline cache CAN fire — the megamorphic `dispatch` bench deliberately
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;; defeats them, so this is its complement: it measures how close a proven/cached
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;; monomorphic dispatch gets to a direct call. Same per-call work as `dispatch`.
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;;
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;; Portable Clojure (jolt + JVM Clojure).
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;; jolt -m mono-dispatch 20000 (JOLT_DIRECT_LINK=1 JOLT_WHOLE_PROGRAM=1)
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(ns mono-dispatch)
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(defprotocol Shape
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(area [s])
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(sides [s]))
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(defrecord Circle [r] Shape (area [_] (* (* 3.14159 r) r)) (sides [_] 0))
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;; homogeneous: every element is a Circle -> the call site is monomorphic
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(defn build-shapes [n]
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(mapv (fn [i] (->Circle (+ 1 (mod i 7)))) (range n)))
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(defn sum-area [shapes]
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(reduce (fn [acc s] (+ (+ acc (area s)) (sides s))) 0.0 shapes))
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(defn run [iters]
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(let [shapes (build-shapes 1000)]
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(loop [i 0 acc 0.0]
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(if (< i iters)
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(recur (inc i) (+ acc (sum-area shapes)))
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acc))))
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(defn -main [& args]
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(let [iters (if (seq args) (Integer/parseInt (first args)) 20000)]
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(dotimes [_ 2] (run (quot iters 4))) ; warmup
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(let [runs 3
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times (mapv (fn [_]
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(let [t0 (System/nanoTime)
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r (run iters)
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ms (/ (- (System/nanoTime) t0) 1000000.0)]
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[ms r]))
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(range runs))
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mss (mapv first times)
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mean (/ (reduce + mss) runs)]
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(println "mono-dispatch iters" iters "result" (second (first times)))
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(println "runs:" (mapv (fn [t] (/ (Math/round (* t 10.0)) 10.0)) mss))
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(println "mean:" (/ (Math/round (* mean 10.0)) 10.0) "ms"))))
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