All of the "performance improvements" I've seen (only few TBF) were either not real improvements at all (think of, "I read once that in JS inverting the for() o

All of the "performance improvements" I've seen (only few TBF) were either not real improvements at all (think of, "I read once that in JS inverting the for() order is faster", without any benchmark) or true but very marginal improvements while making the code impossible to maintain (think a blob of 10 lines of bit shifting/impossible regexp).