$ perl testLocal.pl
Benchmark: running localWhile, localWhileQR, whileLocal, each for at least 3 CPU seconds...
localWhile:  4 wallclock secs ( 3.02 usr +  0.00 sys =  0.02 CPU) @ 28894.20/s (n=87116)
localWhileQR:  4 wallclock secs ( 3.17 usr +  0.01 sys =  3.18 CPU) @ 45765.70/s (n=145718)
whileLocal:  4 wallclock secs ( 3.09 usr +  0.00 sys =  3.09 CPU) @ 20884.62/s (n=64617)

                Rate   whileLocal   localWhile localWhileQR
whileLocal   20885/s           --         -28%         -54%
localWhile   28894/s          38%           --         -37%
localWhileQR 45766/s         119%          58%           --