LSL NSieve Benchmark

<lsl> // // The Great Computer Language Shootout // http://shootout.alioth.debian.org/ // // contributed by Isaac Gouy // modified by Babbage Linden //

string setByteArray(integer numbytes) {

   string result = "";
   integer i;
   for(i = 0; i < numbytes; ++i)
   {
       result += "1";
   }
   result += "1";
   return result;

}

string replace(string s, integer index, string char) {

   string result = "";
   if(index >= 1)
   { 
       result += llGetSubString(s, 0, index - 1);
   }
   result += char;
   if(index < (llStringLength(s) - 1))
   {
       result += llGetSubString(s, index + 1, -1);
   }
   return result;

}

integer get(string s, integer index) {

   return llGetSubString(s, index, index) == "1";

}

string set(string s, integer index) {

   return replace(s, index, "1");

}

string unset(string s, integer index) {

   return replace(s, index, "0");

}

test() {

   integer m = 128;
   string bytes = setByteArray(m);
   integer count = 0;

   integer i;
   for (i=2; i <= m; i++)
   {
        if(get(bytes, i))
        {
           integer k;
           for(k=i+i; k <= m; k+=i)
           {
               bytes = unset(bytes, k);
           }
           count++;
        }
   }
   llSay(0, "Primes up to " + (string)m + " " + (string)count);

}

time() {

   llResetTime();
   llSay(0, "Starting tests...");
   test();
   llSay(0, "Finished tests in " + (string)llGetTime() + "s");

}

default {

   state_entry()
   {
       time();
   }
   
   touch_start(integer num)
   {
       time();
   }

} </lsl>

LSL2 Optimized

This version was optimized for the LSL2 VM, it might run faster under Mono then the unoptimized version. In LSLEditor, it runs about 20% faster.

<lsl>// // The Great Computer Language Shootout // http://shootout.alioth.debian.org/ // // contributed by Isaac Gouy // modified by Babbage Linden // optimized for LSL2 by Strife Onizuka, Apr 14 2008 //

test() {

   integer m = 128;

   string bytes = "11";
   integer i = 2;
   for(; i <= m; i = i << 1)
   {
       bytes += bytes;
   }
   bytes = llGetSubString(bytes , 0, m);
   integer count = 0;

   for (i = 2; i <= m; ++i)
   {
       if(llGetSubString(bytes, i, i) == "1")
       {
           integer k = i;
           while((k += i) <= m)
           {
               bytes = llInsertString(llDeleteSubString(bytes, k, k), k, "0");
           }
           ++count;
       }
   }
   llSay(0, "Primes up to " + (string)m + " " + (string)count);

}

time() {

   llResetTime();
   llSay(0, "Starting tests...");
   test();
   llSay(0, "Finished tests in " + (string)llGetTime() + "s");

}

default {

   state_entry()
   {
       time();
   }
   
   touch_start(integer num)
   {
       time();
   }

} </lsl>