Add performance measurements to README

test/lua/perf/nsieve.lua

@@ -0,0 +1,35 @@
+-- The Computer Language Shootout
+-- http://shootout.alioth.debian.org/
+-- contributed by Isaac Gouy
+-- modified by Mike Pall
+
+
+local function nsieve(m,isPrime)
+   for i=2,m do
+      isPrime[i] = true
+   end
+   local count = 0
+
+   for i=2,m do
+      if isPrime[i] then
+         for k=i+i, m, i do
+            if isPrime[k] then isPrime[k] = false end
+         end
+         count = count + 1
+      end
+   end
+   return count
+end
+
+
+local n = tonumber(arg and arg[1]) or 1
+local flags = {}
+
+local m = (2^n)*10000
+print( string.format("Primes up to %8d %8d", m, nsieve(m,flags)))
+
+m = (2^(n-1))*10000
+print( string.format("Primes up to %8d %8d", m, nsieve(m,flags)))
+
+m = (2^(n-2))*10000
+print( string.format("Primes up to %8d %8d", m, nsieve(m,flags)))