Thanks Rich!
On Feb 13, 10:01 am, Rich Hickey <richhic...@gmail.com> wrote:
> On Feb 13, 9:06 am, Vincent Foley <vfo...@gmail.com> wrote:
>
> > Should I add this to the list of issues in the Google Code tracker?
>
> No. Those hints were suspect to begin with.
>
> .get returns a byte already, and .getShort a short, so those hints
> shouldn't do anything useful.
>
> Similarly, coercing to primitive on return doesn't help much as the
> result is always boxed.
>
> The code should have been:
>
> (defn get-byte [#^ByteBuffer buf]
> (let [x (int (.get buf))]
> (bit-and x 0xff)))
>
> (defn get-short [#^ByteBuffer buf]
> (let [x (int (.getShort buf))]
> (bit-and x 0xffff))))
>
> but there weren't inline conversions from byte/short/char to int. I've
> added them in SVN 1279.
>
> get-byte
> "Elapsed time: 13.051 msecs"
> get-short
> "Elapsed time: 10.747 msecs"
>
> Thanks for the report.
>
> Rich
>
>
>
> > On Feb 12, 4:15 pm, Vincent Foley <vfo...@gmail.com> wrote:
>
> > > Hello,
>
> > > I was surprised today to see that my Starcraft replay program became
> > > slower when I updated my Clojure working copy. About a week ago,
> > > Chouser helped me adding type hints to avoid reflection in my
> > > functions. The warnings came back today.
>
> > > I started going through the different revisions of Clojure starting at
> > > r1260 and I found that the warnings (and slowness) appear starting at
> > > r1265:
>
> > > ------------------------------------------------------------------------
> > > r1265 | richhickey | 2009-02-10 12:24:20 -0500 (Tue, 10 Feb 2009) | 1
> > > line
> > > Changed paths:
> > > M /trunk/src/clj/clojure/core.clj
>
> > > added inlining on remaining coercions
> > > ------------------------------------------------------------------------
>
> > > I have created a small demo program with my functions to show the
> > > difference. Here is the program and the output with r1264 and r1265.
>
> > > (set! *warn-on-reflection* true)
>
> > > (ns slowdemo
> > > (:import [java.nio ByteBuffer]))
>
> > > (defn get-byte
> > > [#^ByteBuffer buf]
> > > (let [x (byte (.get buf))]
> > > (short (bit-and x 0xff))))
>
> > > (defn get-short
> > > [#^ByteBuffer buf]
> > > (let [x (short (.getShort buf))]
> > > (int (bit-and x 0xffff))))
>
> > > (defn buf []
> > > (ByteBuffer/wrap (into-array Byte/TYPE (map byte (range 256)))))
>
> > > (println "get-byte")
> > > (time
> > > (dotimes [i 100]
> > > (let [b (buf)]
> > > (dotimes [j 256]
> > > (get-byte b)))))
>
> > > (println "get-short")
> > > (time
> > > (dotimes [i 100]
> > > (let [b (buf)]
> > > (dotimes [j 128]
> > > (get-short b)))))
>
> > > $ time java -server -cp $HOME/src/clojure-old/clojure.jar:.
> > > clojure.main slowdemo.clj
> > > get-byte
> > > "Elapsed time: 308.339245 msecs"
> > > get-short
> > > "Elapsed time: 188.635614 msecs"
> > > real: 3.946s; user: 2.720s; sys: 1.064s; CPU: 95.89%
>
> > > $ time java -server -cp $HOME/src/clojure-old/clojure.jar:.
> > > clojure.main slowdemo.clj
> > > Reflection warning, line: 9 - call to and can't be resolved.
> > > Reflection warning, line: 14 - call to and can't be resolved.
> > > get-byte
> > > "Elapsed time: 2765.621864 msecs"
> > > get-short
> > > "Elapsed time: 1134.288161 msecs"
> > > real: 7.400s; user: 4.928s; sys: 2.196s; CPU: 96.27%
>
>
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