1
0
Fork 0
mirror of https://github.com/ruby/ruby.git synced 2022-11-09 12:17:21 -05:00
ruby--ruby/benchmark/bm_so_nsieve.rb
ko1 30b2cb380e * benchmark/driver.rb: fix notations.
* benchmark/bm_loop_whileloop.rb: ditto.
* benchmark/bm_loop_whileloop2.rb: ditto.
* benchmark/bm_app_uri.rb: added.
* benchmark/bm_vm1_ivar_set.rb: ditto.
* benchmark/bm_so_binary_trees.rb: added from Computer Language
  Benchmarks Game (http://shootout.alioth.debian.org/).
* benchmark/bm_so_fannkuch.rb: ditto.
* benchmark/bm_so_mandelbrot.rb: ditto.
* benchmark/bm_so_meteor_contest.rb: ditto.
* benchmark/bm_so_nbody.rb: ditto.
* benchmark/bm_so_nsieve.rb: ditto.
* benchmark/bm_so_nsieve_bits.rb: ditto.
* benchmark/bm_so_partial_sums.rb: ditto.
* benchmark/bm_so_pidigits.rb: ditto.
* benchmark/bm_so_spectralnorm.rb: ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@13548 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2007-09-28 10:18:53 +00:00

35 lines
714 B
Ruby

# The Computer Language Shootout
# http://shootout.alioth.debian.org/
#
# contributed by Glenn Parker, March 2005
# modified by Evan Phoenix, Sept 2006
def sieve(m)
flags = Flags.dup[0,m]
count = 0
pmax = m - 1
p = 2
while p <= pmax
unless flags[p].zero?
count += 1
mult = p
while mult <= pmax
flags[mult] = 0
mult += p
end
end
p += 1
end
count
end
n = 9 # (ARGV[0] || 2).to_i
Flags = ("\x1" * ( 2 ** n * 10_000)).unpack("c*")
n.downto(n-2) do |exponent|
break if exponent < 0
m = (1 << exponent) * 10_000
# m = (2 ** exponent) * 10_000
count = sieve(m)
printf "Primes up to %8d %8d\n", m, count
end