gxi_out.txt

(time (u8vector->uint16-0 u16))
    0.000004 secs real time
    0.000005 secs cpu time (0.000004 user, 0.000001 system)
    no collections
    64 bytes allocated
    no minor faults
    no major faults
(time (std/misc/bytes#u8vector->uint u16))
    0.000004 secs real time
    0.000005 secs cpu time (0.000005 user, 0.000000 system)
    no collections
    48 bytes allocated
    no minor faults
    no major faults
(time (u8vector->uint16-1 u16))
    0.000003 secs real time
    0.000003 secs cpu time (0.000003 user, 0.000000 system)
    no collections
    64 bytes allocated
    no minor faults
    no major faults
(time (std/misc/bytes#u8vector->uint u16))
    0.000002 secs real time
    0.000003 secs cpu time (0.000003 user, 0.000000 system)
    no collections
    48 bytes allocated
    no minor faults
    no major faults
(time (u8vector->uint32-0 u32))
    0.000004 secs real time
    0.000004 secs cpu time (0.000004 user, 0.000000 system)
    no collections
    304 bytes allocated
    no minor faults
    no major faults
(time (std/misc/bytes#u8vector->uint u32))
    0.000004 secs real time
    0.000004 secs cpu time (0.000004 user, 0.000000 system)
    no collections
    48 bytes allocated
    no minor faults
    no major faults
(time (u8vector->uint32-1 u32))
    0.000004 secs real time
    0.000004 secs cpu time (0.000004 user, 0.000000 system)
    no collections
    304 bytes allocated
    no minor faults
    no major faults
(time (std/misc/bytes#u8vector->uint u32))
    0.000003 secs real time
    0.000003 secs cpu time (0.000003 user, 0.000000 system)
    no collections
    48 bytes allocated
    no minor faults
    no major faults
(time (u8vector->uint32-2 u32))
    0.000003 secs real time
    0.000003 secs cpu time (0.000003 user, 0.000000 system)
    no collections
    160 bytes allocated
    no minor faults
    no major faults
(time (std/misc/bytes#u8vector->uint u32))
    0.000003 secs real time
    0.000003 secs cpu time (0.000003 user, 0.000000 system)
    no collections
    48 bytes allocated
    no minor faults
    no major faults
(time (u8vector->uint32-3 u32))
    0.000003 secs real time
    0.000003 secs cpu time (0.000003 user, 0.000000 system)
    no collections
    160 bytes allocated
    no minor faults
    no major faults
(time (std/misc/bytes#u8vector->uint u32))
    0.000003 secs real time
    0.000002 secs cpu time (0.000002 user, 0.000000 system)
    no collections
    48 bytes allocated
    no minor faults
    no major faults
(time (u8vector->uint32-4 u32))
    0.000003 secs real time
    0.000003 secs cpu time (0.000003 user, 0.000000 system)
    no collections
    160 bytes allocated
    no minor faults
    no major faults
(time (std/misc/bytes#u8vector->uint u32))
    0.000004 secs real time
    0.000003 secs cpu time (0.000000 user, 0.000003 system)
    no collections
    48 bytes allocated
    no minor faults
    no major faults

u8_uint_benchmark.ss

;; comment for gambit
(import :std/misc/bytes)

;; uncomment for gambit
;; (define (u8vector->uint bv)
;;   (let ((l (fx- (u8vector-length bv) 1)))
;;     (let loop ((s 0) (i 0))
;;       (if (< i l)
;;         (loop (+ s (* (u8vector-ref bv i) (expt 256 (- l i)))) (+ i 1))
;;         (+ s (* (u8vector-ref bv i) (expt 256 (- l i))))))))

(define u16 (make-u8vector 2 #xFF))
(define u32 (make-u8vector 4 #xFF))
(define u64 (make-u8vector 8 #xFF))

(define (u8vector->uint16-0 bv)
  (+ (* 256 (u8vector-ref bv 0)) (u8vector-ref bv 1)))

(time (u8vector->uint16-0 u16))
(time (u8vector->uint u16))

(define (u8vector->uint16-1 bv)
  (fx+ (fx* 256 (u8vector-ref bv 0)) (u8vector-ref bv 1)))

(time (u8vector->uint16-1 u16))
(time (u8vector->uint u16))

(define (u8vector->uint32-0 bv)
  (+
   (* 256 256 256 (u8vector-ref bv 0))
   (* 256 256 (u8vector-ref bv 1))
   (* 256 (u8vector-ref bv 2))
   (u8vector-ref bv 3)))

(time (u8vector->uint32-0 u32))
(time (u8vector->uint u32))

(define (u8vector->uint32-1 bv)
  (fx+
   (fx* 256 256 256 (u8vector-ref bv 0))
   (fx* 256 256 (u8vector-ref bv 1))
   (fx* 256 (u8vector-ref bv 2))
   (u8vector-ref bv 3)))

(time (u8vector->uint32-1 u32))
(time (u8vector->uint u32))

(define (u8vector->uint32-2 bv)
  (fx+
   (fx* 16777216 (u8vector-ref bv 0))
   (fx* 65536 (u8vector-ref bv 1))
   (fx* 256 (u8vector-ref bv 2))
   (u8vector-ref bv 3)))

(time (u8vector->uint32-2 u32))
(time (u8vector->uint u32))

(define (u8vector->uint32-3 bv)
  (fx+
   (fx* (expt 256 3) (u8vector-ref bv 0))
   (fx* (expt 256 2) (u8vector-ref bv 1))
   (fx* 256 (u8vector-ref bv 2))
   (u8vector-ref bv 3)))

(time (u8vector->uint32-3 u32))
(time (u8vector->uint u32))

(define (u8vector->uint32-4 bv)
  (+
   (* (expt 256 3) (u8vector-ref bv 0))
   (* (expt 256 2) (u8vector-ref bv 1))
   (* 256 (u8vector-ref bv 2))
   (u8vector-ref bv 3)))

(time (u8vector->uint32-4 u32))
(time (u8vector->uint u32))