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math.primes: fix "11 >bignum prime?".

db4
John Benediktsson 2015-06-15 23:02:39 -07:00
parent 4550294227
commit e3ec051527
2 changed files with 11 additions and 6 deletions
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2
basis/math/primes/primes-tests.factor
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@ -39,3 +39,5 @@ IN: math.primes.tests
[ 5 t { 14 14 14 14 14 } ] [ 5 t { 14 14 14 14 14 } ]
[ 5 15 unique-primes [ length ] [ [ prime? ] all? ] [ [ log2 ] map ] tri ] unit-test [ 5 15 unique-primes [ length ] [ [ prime? ] all? ] [ [ log2 ] map ] tri ] unit-test
{ t t } [ 11 dup >bignum [ prime? ] bi@ ] unit-test

15
basis/math/primes/primes.factor
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@ -9,12 +9,13 @@ IN: math.primes
<PRIVATE <PRIVATE
: look-in-bitmap ( n -- ? ) : look-in-bitmap ( n -- ? )
$[ 8999999 sieve ] marked-unsafe? ; inline integer>fixnum $[ 8999999 sieve ] marked-unsafe? ; inline
: (prime?) ( n -- ? ) : (prime?) ( n -- ? )
dup 8999999 <= [ look-in-bitmap ] [ miller-rabin ] if ; dup 8999999 <= [ look-in-bitmap ] [ miller-rabin ] if ;
: simple? ( n -- ? ) { [ even? ] [ 3 divisor? ] [ 5 divisor? ] } 1|| ; : simple? ( n -- ? )
{ [ even? ] [ 3 divisor? ] [ 5 divisor? ] } 1|| ;
PRIVATE> PRIVATE>
@ -37,10 +38,12 @@ PRIVATE>
: <primes-range> ( low high -- range ) : <primes-range> ( low high -- range )
[ 3 max dup even? [ 1 + ] when ] dip 2 <range> ; [ 3 max dup even? [ 1 + ] when ] dip 2 <range> ;
! In order not to reallocate large vectors, we compute the upper bound ! In order not to reallocate large vectors, we compute the upper
! of the number of primes in a given interval. We use a double inequality given ! bound of the number of primes in a given interval. We use a
! by Pierre Dusart in http://www.ams.org/mathscinet-getitem?mr=99d:11133 ! double inequality given by Pierre Dusart in
! for x > 598. Under this limit, we know that there are at most 108 primes. ! http://www.ams.org/mathscinet-getitem?mr=99d:11133 for x >
! 598. Under this limit, we know that there are at most 108
! primes.
: upper-pi ( x -- y ) : upper-pi ( x -- y )
dup log [ / ] [ 1.2762 swap / 1 + ] bi * ceiling ; dup log [ / ] [ 1.2762 swap / 1 + ] bi * ceiling ;