Long time ago, I've did some experiments with luajit and branching (well more like the CPU). It was based on this article: http://igoro.com/archive/fast-and-slo

Long time ago, I've did some experiments with luajit and branching (well more like the CPU). It was based on this article: http://igoro.com/archive/fast-and-slow-if-statements-branch-prediction-in-modern-processors/ http://igoro.com/archive/fast-and-slow-if-statements-branch-... https://raw.githubusercontent.com/malkia/ufo/master/samples/bench/badif.lua https://raw.githubusercontent.com/malkia/ufo/master/samples/... local ffi = require("ffi") local band = bit.band local function test(n, m) local count = 0; for i=1, n do if band(i, m)==0 then count = count + 1 end end return count end local function timeit(m) local t = os.clock() test(0xFFFFFFF,m) local t = os.clock() - t print(string.format("%08X",m),t) end timeit(0x80000000) timeit(0xffffffff) timeit(1) timeit(3) timeit(2) timeit(4) timeit(8) timeit(16) --[[ -- This is on OSX 10.7.2 MBP 2008 Jan build ./luajit samples/badif.lua 80000000 14.067395 FFFFFFFF 20.252955 00000001 13.497108 00000003 17.337942 00000002 14.142266 00000004 14.221376 00000008 14.42377 00000010 14.708237 --]] Results now - 2015 (again Macbook OSX, much better than before and also luajit 2.0.4): 80000000 0.247822 FFFFFFFF 1.253168 00000001 0.664586 00000003 0.974336 00000002 0.676823 00000004 0.679609 00000008 0.675207 00000010 0.673961 without jit, just interpretter (pretty much the same results): $ src/luajit -joff ~/badif.lua 80000000 3.329909 FFFFFFFF 3.553143 00000001 3.440378 00000003 3.484646 00000002 3.424834 00000004 3.424539 00000008 3.616981 00000010 3.598598