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authorko1 <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2007-09-28 10:18:53 +0000
committerko1 <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2007-09-28 10:18:53 +0000
commit30b2cb380e0a8f777a2fc2d736c2ccddf3362fcd (patch)
tree715a72c59e797ee8ca71ce8870db38bf68ed3fd1 /benchmark/bm_so_nsieve.rb
parent335fe1ee7bf51534c5f2abd0f359e86721307335 (diff)
* 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
Diffstat (limited to 'benchmark/bm_so_nsieve.rb')
-rw-r--r--benchmark/bm_so_nsieve.rb35
1 files changed, 35 insertions, 0 deletions
diff --git a/benchmark/bm_so_nsieve.rb b/benchmark/bm_so_nsieve.rb
new file mode 100644
index 0000000..59aead5
--- /dev/null
+++ b/benchmark/bm_so_nsieve.rb
@@ -0,0 +1,35 @@
+# 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