speci.js - specialization benchmark test

Tests two-property objects with {x, y} or {y, x} and access in a tight loop When the array contains consistent elements it optimizes well, but the first run is much slower on a randomly mixed array.

Subsequent runs come up much faster as the higher-tier compilers in V8 can handle a couple of different variants -- but this might not be true of all possibilities. 256 randomized variants is linearly slower.

 % node speci.js
** x_first
run 1
72 ms

run 2
15 ms

run 3
22 ms

** y_first
run 1
73 ms

run 2
23 ms

run 3
20 ms

** mixed
run 1
2766 ms

run 2
52 ms

run 3
53 ms

** randomized
run 1
464 ms

run 2
445 ms

run 3
445 ms