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Benchmarking different dispatch types
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| Date: | -- (:) |
| From: | Edgar Friendly <thelema314@g...> |
| Subject: | Re: [Caml-list] Benchmarking different dispatch types |
Nathaniel Gray wrote:
>
> Here's the output (on a PPC G4 1.25 GHz):
>
> ========
> Latencies for 40000 iterations of function, method, closure, obj. closure:
> function: 0 WALL ( 0.00 usr + -0.00 sys = 0.00 CPU) @
> 305343511.45/s (n=40000)
> (warning: too few iterations for a reliable count)
> method: 0 WALL ( 0.00 usr + -0.00 sys = 0.00 CPU) @
> 27081922.82/s (n=40000)
> (warning: too few iterations for a reliable count)
> closure: 0 WALL ( 0.00 usr + 0.00 sys = 0.00 CPU) @
> 30280090.84/s (n=40000)
> (warning: too few iterations for a reliable count)
> obj. closure: 0 WALL ( 0.00 usr + 0.00 sys = 0.00 CPU) @
> 26058631.92/s (n=40000)
> (warning: too few iterations for a reliable count)
> Rate method obj. closure closure function
> method 25974026/s -- -5% -16% -90%
> obj. closure 27210884/s 5% -- -12%
> -89%
> closure 31007752/s 19% 14% -- -88%
> function 254777070/s 881% 836% 722% --
>
> Interesting, but are they meaningful? The warnings from Benchmark are
> troubling, but I didn't have any immediate ideas on how to get rid of
> them. Any suggestions?
>
> Thanks,
> -n8
>
> [1] http://ocaml-benchmark.sourceforge.net
>
well, running only 40,000 iterations is way too low because timing
errors are going to get in the way of an accurate answer. On my
computer, I bumped the iterations up to max_int, and still the function
call was still taking less than one CPU second of time (which I guess is
the requirement for the warning to disappear).
Here's my numbers from an Athlon XP-M 2000+ (1.53GHz), compiled with
ocaml 3.09.3, cmd. line:
$ ocamlfind ocamlopt -package "benchmark" -inline 0 unix.cmxa
benchmark.cmxa dispatch.ml
Latencies for 1073741823 iterations of function, method, closure, obj.
closure:
function: 0 WALL (-0.02 usr + -0.00 sys = -0.02 CPU)
(warning: too few iterations for a reliable count)
method: 15 WALL (11.34 usr + 0.49 sys = 11.83 CPU) @ 90764313.02/s
(n=1073741823)
closure: 4 WALL ( 2.60 usr + -0.60 sys = 2.00 CPU) @ 536870911.50/s
(n=1073741823)
obj. closure: 8 WALL ( 4.31 usr + 0.03 sys = 4.34 CPU) @
247405950.00/s (n=1073741823)
Rate function method obj. closure
closure
function -5.36871e+10/s -- -59250% -21800%
-10100%
method 90764313/s -100% -- -63%
-83%
obj. closure 247405950/s -100% 173% --
-54%
closure 536870911/s -101% 491% 117%
--
Either function calls are just that stupidly efficient, or there's some
optimization still going on. I'm guessing the second.
E.