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authork0kubun <k0kubun@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2018-07-10 13:08:40 (GMT)
committerk0kubun <k0kubun@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2018-07-10 13:08:40 (GMT)
commit433af16167aec949c6345ad41b78b17c440b4a6d (patch)
tree42b9a14817cccef4a57177329381f97a7a2ac75c /benchmark/so_nsieve.rb
parentf992f4251874a025de09ffecf0f2b8cb984f2201 (diff)
benchmark: drop all bm_ prefix for legacy driver.rb
benchmark/*.rb is only benchmarks now. We don't need prefixes. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63928 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'benchmark/so_nsieve.rb')
-rw-r--r--benchmark/so_nsieve.rb35
1 files changed, 35 insertions, 0 deletions
diff --git a/benchmark/so_nsieve.rb b/benchmark/so_nsieve.rb
new file mode 100644
index 0000000..a65cc78
--- /dev/null
+++ b/benchmark/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