I remade program to avoid optimizing out calulations and reduce GCing #lang racket (define (test1 x y z) (if x (+ y z) (- y z))) (define (test2 x) (if x (λ (y z) (+ y z)) (λ (y z) (- y z)))) (define (run1 data) (foldl (λ (x y) (test1 #t x y)) 0 data)) (define (run2 data) (foldl (λ (x y) ((test2 #t) x y)) 0 data)) (define data (for/list ([x 140000]) x)) (define acc 0) (time (set! acc (+ acc (run1 data)))) (time (set! acc (+ acc (run1 data)))) (time (set! acc (+ acc (run1 data)))) (time (set! acc (+ acc (run2 data)))) (time (set! acc (+ acc (run2 data)))) (time (set! acc (+ acc (run2 data)))) (time (set! acc (+ acc (run1 data)))) (time (set! acc (+ acc (run1 data)))) (time (set! acc (+ acc (run1 data)))) Now I have cpu time: 15 real time: 16 gc time: 0 cpu time: 79 real time: 78 gc time: 63 cpu time: 15 real time: 16 gc time: 0 cpu time: 16 real time: 15 gc time: 0 cpu time: 0 real time: 0 gc time: 0 cpu time: 0 real time: 0 gc time: 0 cpu time: 16 real time: 16 gc time: 0 cpu time: 16 real time: 15 gc time: 0 cpu time: 15 real time: 16 gc time: 0 or sometimes cpu time: 15 real time: 15 gc time: 0 cpu time: 78 real time: 78 gc time: 63 cpu time: 16 real time: 16 gc time: 0 cpu time: 16 real time: 16 gc time: 0 cpu time: 15 real time: 15 gc time: 0 cpu time: 16 real time: 16 gc time: 0 cpu time: 0 real time: 0 gc time: 0 cpu time: 0 real time: 0 gc time: 0 cpu time: 16 real time: 16 gc time: 0
and even cpu time: 0 real time: 0 gc time: 0 cpu time: 63 real time: 63 gc time: 47 cpu time: 15 real time: 15 gc time: 0 cpu time: 16 real time: 16 gc time: 0 cpu time: 16 real time: 16 gc time: 0 cpu time: 0 real time: 0 gc time: 0 cpu time: 15 real time: 15 gc time: 0 cpu time: 16 real time: 16 gc time: 0 cpu time: 15 real time: 15 gc time: 0 Where are these zeros from (especially on first run)? If I increse data to 200000, then zeroes disappeared (or become too seldom). Tested in DrRacket 6.0.1 winXP x86 Mon, 16 Jun 2014 13:52:02 +0400 от Roman Klochkov <kalimeh...@mail.ru>: >I have "debugging & profiling" on. > >Disable debugging. Now have all zeroes :-) > cpu time: 0 real time: 0 gc time: 0 > >I will check with optimization. If find something strange, I'll write. > > >Mon, 16 Jun 2014 08:58:16 +0100 от Matthew Flatt <mfl...@cs.utah.edu>: >>Hm... I'm not able to get anything like the results you're reporting. >>When I run the enclosed program via `racket` on the command line, I get >> >> cpu time: 3 real time: 3 gc time: 0 >> cpu time: 3 real time: 3 gc time: 0 >> cpu time: 2 real time: 2 gc time: 0 >> cpu time: 3 real time: 3 gc time: 0 >> cpu time: 5 real time: 5 gc time: 3 >> cpu time: 2 real time: 2 gc time: 0 >> cpu time: 2 real time: 2 gc time: 0 >> cpu time: 2 real time: 2 gc time: 0 >> cpu time: 4 real time: 4 gc time: 1 >> >>Running in DrRacket gives messier results, such as >> >> cpu time: 17 real time: 10 gc time: 0 >> cpu time: 19 real time: 22 gc time: 0 >> cpu time: 7 real time: 7 gc time: 0 >> cpu time: 15 real time: 8 gc time: 0 >> cpu time: 14 real time: 10 gc time: 0 >> cpu time: 10 real time: 10 gc time: 0 >> cpu time: 7 real time: 6 gc time: 0 >> cpu time: 7 real time: 7 gc time: 0 >> cpu time: 23 real time: 29 gc time: 15 >> >>or >> >> cpu time: 6 real time: 6 gc time: 0 >> cpu time: 5 real time: 4 gc time: 0 >> cpu time: 58 real time: 57 gc time: 49 >> cpu time: 6 real time: 5 gc time: 0 >> cpu time: 5 real time: 4 gc time: 0 >> cpu time: 6 real time: 6 gc time: 0 >> cpu time: 5 real time: 5 gc time: 0 >> cpu time: 5 real time: 4 gc time: 0 >> cpu time: 15 real time: 16 gc time: 9 >> >>I'm using v6.0.1.12 on Mac OS X 64-bit on a MacBook Pro. Version 6.0.1 >>on the same machine seems to produce the same sorts of results. >> >>Any idea what might be different? >> >>At Mon, 16 Jun 2014 11:44:41 +0400, Roman Klochkov wrote: >>> (define data (for/list ([x 100000]) x)) >>> >>> (time (begin0 (void) (run2 data))) >>> (time (begin0 (void) (run1 data))) >>> >>> 3 times run1, then 3 times run2, then again 3 times run1. >>> >>> Results are stable. >>> >>> Mon, 16 Jun 2014 08:28:10 +0100 от Matthew Flatt < mfl...@cs.utah.edu >: >>> >I'd expect them to run nearly the same due to inlining and constant >>> >propagation. If I save your program to "ex.rkt" and use >>> > >>> > raco make ex.rkt >>> > raco decompile ex.rkt >>> > >>> >the the output looks almost the same for both functions. >>> > >>> >There's a lot of allocation in these programs, of course, and that's >>> >going to make benchmarking relatively tricky. How are you timing the >>> >functions, and does it matter whether you `run1` or `run2` first? >>> > >>> >At Mon, 16 Jun 2014 11:16:25 +0400, Roman Klochkov wrote: >>> >> Strange. >>> >> >>> >> #lang racket >>> >> (define (test1 x y) >>> >> (if x >>> >> (+ y 1) >>> >> (- y 1))) >>> >> (define (test2 x) >>> >> (if x >>> >> (λ (y) (+ y 1)) >>> >> (λ (y) (- y 1)))) >>> >> (define (run1 data) >>> >> (map (λ (x) (test1 #t x)) data)) >>> >> (define (run2 data) >>> >> (map (λ (x) ((test2 #t) x)) data)) I expect, that run2 should be >>> >> faster, >>> >> because (test2 #t) returns const (lambda (y) (+ y 1)) and shouldn't be >>> checked >>> >> on every iteration. >>> >> >>> >> But in reality (time ...) gives 219 for run1 and 212 for run2. run2 is >>> >> 1.5 >>> >> times slower! >>> >> >>> >> Why so? >>> >> >>> >> >>> >> -- >>> >> Roman Klochkov____________________ >>> >> Racket Users list: >>> >> http://lists.racket-lang.org/users >>> >>> >>> -- >>> Roman Klochkov >>> ____________________ >>> Racket Users list: >>> http://lists.racket-lang.org/users > > >-- >Roman Klochkov -- Roman Klochkov
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