Use typed arrays.

bloomfilter.js

@@ -6,9 +6,18 @@
   function BloomFilter(m, k) {
     this.m = m;
     this.k = k;
-    var buckets = this.buckets = [],
+    var buckets,
         n = Math.ceil(m / k),
         i = -1;
+    try {
+      var buffer = new ArrayBuffer(4 * n),
+          kbuffer = new ArrayBuffer(4 * k);
+      buckets = this.buckets = new Uint32Array(buffer);
+      this._locations = new Uint32Array(kbuffer);
+    } catch (e) {
+      buckets = this.buckets = [];
+      this._locations = [];
+    }
     while (++i < n) buckets[i] = 0;
   }
 
@@ -16,7 +25,7 @@
   BloomFilter.prototype.locations = function(v) {
     var k = this.k,
         m = this.m,
-        r = [],
+        r = this._locations,
         a = fnv_1a(v),
         b = fnv_1a_b(a),
         i = -1;