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Diffstat (limited to 'benchmark/so_nsieve_bits.yml')
-rw-r--r-- | benchmark/so_nsieve_bits.yml | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/benchmark/so_nsieve_bits.yml b/benchmark/so_nsieve_bits.yml new file mode 100644 index 0000000000..08b47f53bb --- /dev/null +++ b/benchmark/so_nsieve_bits.yml @@ -0,0 +1,46 @@ +prelude: | + #!/usr/bin/ruby + #coding: us-ascii +benchmark: + so_nsieve_bits: | + # + # 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 +loop_count: 1 |