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checksums.superfast: reuse code and make a bit faster.

db4
John Benediktsson 2013-11-23 18:49:59 -08:00
parent df47ff8289
commit 405e543f92
1 changed files with 13 additions and 16 deletions
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basis/checksums/superfast/superfast.factor
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@ -1,10 +1,9 @@
! Copyright (C) 2013 John Benediktsson. ! Copyright (C) 2013 John Benediktsson.
! See http://factorcode.org/license.txt for BSD license. ! See http://factorcode.org/license.txt for BSD license.
USING: accessors alien alien.data byte-arrays checksums USING: accessors alien alien.c-types alien.data byte-arrays
combinators fry grouping io.binary kernel math math.bitwise checksums combinators fry grouping io.binary kernel math
math.ranges sequences sequences.private ; math.bitwise math.ranges sequences sequences.private ;
QUALIFIED-WITH: alien.c-types c
IN: checksums.superfast IN: checksums.superfast
@ -15,23 +14,21 @@ C: <superfast> superfast
: 32-bit ( n -- n' ) 32 on-bits mask ; inline : 32-bit ( n -- n' ) 32 on-bits mask ; inline
: main-loop ( seq hash -- seq hash' ) : (main-loop) ( hash m n -- hash' )
over byte-array? little-endian? and [
[ 0 over length 4 - 4 <range> ] dip
[
pick
[ <displaced-alien> c:short deref ]
[ [ 2 + ] dip <displaced-alien> c:short deref ] 2bi
[ + ] [ 11 shift dupd bitxor ] bi* [ + ] [ 11 shift dupd bitxor ] bi*
[ 16 shift ] [ bitxor ] bi* 32-bit [ 16 shift ] [ bitxor ] bi* 32-bit
[ -11 shift ] [ + ] bi [ -11 shift ] [ + ] bi ; inline
: main-loop ( seq hash -- seq hash' )
over byte-array? little-endian? and [
[ 0 over length 4 - 4 <range> ] dip [
pick <displaced-alien> int deref
[ 16 on-bits mask ] [ -16 shift ] bi
(main-loop)
] reduce ] reduce
] [ ] [
[ dup length 4 mod dupd head-slice* 4 <groups> ] dip [ [ dup length 4 mod dupd head-slice* 4 <groups> ] dip [
2 cut-slice 2 cut-slice [ le> ] bi@ (main-loop)
[ le> + ] [ le> 11 shift dupd bitxor ] bi*
[ 16 shift ] [ bitxor ] bi* 32-bit
[ -11 shift ] [ + ] bi
] reduce ] reduce
] if ; inline ] if ; inline