tree d2086c915ebeddea5775aa66e0dc07dae41addc2
parent 96717d9fb4560ad98a737108f83c7b247ef04674
author Denys Vlasenko <vda.linux@googlemail.com> 1608664120 +0100
committer Denys Vlasenko <vda.linux@googlemail.com> 1608665070 +0100

factor: detect squares

If we have a square, the speedup can be extremely large
(in best case example below, it's ~40000 times faster):

$ time ./busybox_old factor 18446743988964486098
18446743988964486098: 2 3037000493 3037000493
real	0m4.246s
$ time ./busybox factor 18446743988964486098
18446743988964486098: 2 3037000493 3037000493
real	0m0.000s

function                                             old     new   delta
isqrt_odd                                              -      57     +57
print_w                                                -      36     +36
factorize                                            218     236     +18
print_h                                                -       7      +7
factorize_numstr                                      65      72      +7
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(add/remove: 3/0 grow/shrink: 2/0 up/down: 125/0)             Total: 125 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>