# Copyright (C) 2001-2009, Parrot Foundation.

=head1 NAME

examples/benchmarks/primes.pasm - Calculate prime numbers < 5000

=head1 SYNOPSIS

% time ./parrot examples/benchmarks/primes.pasm

=head1 DESCRIPTION

Calculates all the prime numbers up to 5000 and prints out the number
of primes, the last one found, and the time taken.

=cut

.pcc_sub :main main:

# P1 holds the number we're currently checking for primality
new     P1, 'Integer'
set     P1, 1

# P2 holds the highest number we want to check for primality
new     P2, 'Integer'
set     P2, 5000

new     P6, 'Integer'
set     P6, 0
new     P7, 'Integer'

print   "N primes up to "
print   P2
print   " is: "
time    N10

# P1 counts up to P2
# P3 counts from 2 up to P4 (P1/2)
new     P3, 'Integer'

REDO:
set     P3, 2
div     P4, P1, 2
# Check if P3 is a factor of P1
LOOP:
.loadlib 'math_ops' # cmod is a dynop
cmod    P5, P1, P3
if      P5, OK

# We've found a factor, so it can't be a prime and
    # we can skip right out of this loop and to the next number
    branch  NEXT
OK:
    inc     P3
    le      P3, P4, LOOP
    # We haven't found a factor so it must be a prime
    inc     P6
    assign  P7, P1
    # print I1
    # print "\n"    # to get them all

    # Move on to the next number
NEXT:
    inc     P1
    le      P1, P2, REDO
    time    N11
    say     P6
    print   "last is: "
    say     P7
    sub     N11, N10
    print   "Elapsed time: "
    say     N11
    end

=head1 SEE ALSO

F<examples/benchmarks/primes.c>,
F<examples/benchmarks/primes_i.pasm>,
F<examples/benchmarks/primes.pl>,
F<examples/benchmarks/primes.rb>,
F<examples/benchmarks/primes2_p.pasm>,
F<examples/benchmarks/primes2.c>,
F<examples/benchmarks/primes2.pir>,
F<examples/benchmarks/primes2.py>.

=cut

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