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benchmark improvement

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Hash to a box, because finding and updating a box is faster than
updating a hash-table entry.
This commit is contained in:
Matthew Flatt 2012-11-13 17:05:58 -07:00
parent 5400b41bce
commit 447db085dc
1 changed files with 7 additions and 4 deletions
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11
collects/tests/racket/benchmarks/shootout/k-nucleotide.rkt
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@ -9,12 +9,15 @@
(for ([s (in-range (- (string-length dna) len) -1 -1)])
(string-copy! seq 0 dna s (+ s len))
(let ([key (string->symbol seq)])
(let ([cnt (hash-ref table key 0)])
(hash-set! table key (add1 cnt)))))
(let ([b (or (hash-ref table key #f)
(let ([b (box 0)])
(hash-set! table key b)
b))])
(set-box! b (add1 (unbox b))))))
table))
(define (write-freqs table)
(let* ([content (hash-map table cons)]
(let* ([content (hash-map table (lambda (k v) (cons k (unbox v))))]
[total (exact->inexact (apply + (map cdr content)))])
(for ([a (sort content > #:key cdr)])
(printf "~a ~a\n"
@ -23,7 +26,7 @@
(define (write-one-freq table key)
(let ([cnt (hash-ref table key 0)])
(printf "~a\t~a\n" cnt key)))
(printf "~a\t~a\n" (unbox cnt) key)))
(define dna
(let ([in (current-input-port)])