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author | k0kubun <k0kubun@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2018-07-10 13:05:29 +0000 |
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committer | k0kubun <k0kubun@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2018-07-10 13:05:29 +0000 |
commit | 8068d34cfe4f74784cba29e981e2d8437ff02a9f (patch) | |
tree | 85b1f81c676f3fecdf3c425a94f341f63797eec4 /benchmark/bm_so_nsieve_bits.rb | |
parent | bd12037e50a216bda5896676b678bafee5eacb49 (diff) | |
download | ruby-8068d34cfe4f74784cba29e981e2d8437ff02a9f.tar.gz |
Revert "benchmark/*.yml: convert from benchmark/bm_*.rb"
This reverts r63900.
Having single-execution benchmark as a normal Ruby script is preferred
by ko1. I'm not a big fan of having inconsistent benchmark formats, but
I can understand some benefits of it.
common.mk: remove obsolsted benchmark-each PHONY declaration, support
running Ruby scripts added by this commit.
README.md: follow ARGS change
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63926 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'benchmark/bm_so_nsieve_bits.rb')
-rw-r--r-- | benchmark/bm_so_nsieve_bits.rb | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/benchmark/bm_so_nsieve_bits.rb b/benchmark/bm_so_nsieve_bits.rb new file mode 100644 index 0000000000..6f958ee44e --- /dev/null +++ b/benchmark/bm_so_nsieve_bits.rb @@ -0,0 +1,43 @@ +#!/usr/bin/ruby +#coding: us-ascii +# +# The Great Computer Language Shootout +# http://shootout.alioth.debian.org/ +# +# nsieve-bits in Ruby +# Contributed by Glenn Parker, March 2005 + +CharExponent = 3 +BitsPerChar = 1 << CharExponent +LowMask = BitsPerChar - 1 + +def sieve(m) + items = "\xFF" * ((m / BitsPerChar) + 1) + masks = "" + BitsPerChar.times do |b| + masks << (1 << b).chr + end + + count = 0 + pmax = m - 1 + 2.step(pmax, 1) do |p| + if items[p >> CharExponent][p & LowMask] == 1 + count += 1 + p.step(pmax, p) do |mult| + a = mult >> CharExponent + b = mult & LowMask + items[a] -= masks[b] if items[a][b] != 0 + end + end + end + count +end + +n = 9 # (ARGV[0] || 2).to_i +n.step(n - 2, -1) do |exponent| + break if exponent < 0 + m = 2 ** exponent * 10_000 + count = sieve(m) + printf "Primes up to %8d %8d\n", m, count +end + |