busybox.git/coreutils/factor.c, branch master Unnamed repository; edit this file 'description' to name the repository. Update applet size estimates 2023-07-10T15:25:21+00:00 Denys Vlasenko vda.linux@googlemail.com 2023-07-10T15:25:21+00:00 5353df91cba7b397b9407701681708d0a1518df6 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> 
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
factor: we can pack 21, not 20, 3-bit elements into packed wheel words 2023-04-23T12:02:20+00:00 Denys Vlasenko vda.linux@googlemail.com 2023-04-23T11:42:19+00:00 382e1634972f7aab883259dd22cf721d1c205055 function old new delta packed_wheel 192 184 -8 factor_main 171 163 -8 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-16) Total: -16 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> 
function                                             old     new   delta
packed_wheel                                         192     184      -8
factor_main                                          171     163      -8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-16)             Total: -16 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
factor: fix comment 2020-12-23T01:03:04+00:00 Denys Vlasenko vda.linux@googlemail.com 2020-12-23T01:03:04+00:00 6297d66eda43ca8439cb55a198b512346ce9459c Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> 
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
factor: detect squares 2020-12-22T19:24:30+00:00 Denys Vlasenko vda.linux@googlemail.com 2020-12-22T19:08:40+00:00 6452c300366cf0e322227ad39991ec2fdfd6beed 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 ------------------------------------------------------------------------------ (add/remove: 3/0 grow/shrink: 2/0 up/down: 125/0) Total: 125 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> 
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
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 2/0 up/down: 125/0)             Total: 125 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
factor: fix typo in undef 2020-12-21T06:45:08+00:00 Denys Vlasenko vda.linux@googlemail.com 2020-12-21T06:45:08+00:00 901d2c3862e0aaf96fc38ab32bdf1aa3f7f509d2 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> 
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
factor: code shrink 2020-12-21T06:22:55+00:00 Denys Vlasenko vda.linux@googlemail.com 2020-12-21T06:22:26+00:00 3e544d6ec778fd1f9c4e425e279660fa6f66c3ac function old new delta factor_main 176 171 -5 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> 
function                                             old     new   delta
factor_main                                          176     171      -5

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
factor: 30% faster trial division (better sieve) 2020-12-20T20:37:29+00:00 Denys Vlasenko vda.linux@googlemail.com 2020-12-20T20:37:29+00:00 f079f913711091c87557a4c7854385c408e4ab7c function old new delta packed_wheel - 192 +192 factor_main 108 176 +68 factorize 284 218 -66 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 1/1 up/down: 260/-66) Total: 194 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> 
function                                             old     new   delta
packed_wheel                                           -     192    +192
factor_main                                          108     176     +68
factorize                                            284     218     -66
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/1 up/down: 260/-66)           Total: 194 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
config: update size information 2018-12-28T02:20:17+00:00 Denys Vlasenko vda.linux@googlemail.com 2018-12-28T02:20:17+00:00 b097a84d62dcfcf201a695b54bcfafae70cac8a6 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> 
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
config: deindent all help texts 2017-07-21T07:50:55+00:00 Denys Vlasenko vda.linux@googlemail.com 2017-07-21T07:50:55+00:00 72089cf6b4a77214ec4fd21d5ee5bf56958781cb Those two spaces after tab have no effect, and always a nuisance when editing. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> 
Those two spaces after tab have no effect, and always a nuisance when editing.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Update menuconfig items with approximate applet sizes 2017-07-18T20:01:24+00:00 Denys Vlasenko vda.linux@googlemail.com 2017-07-18T20:01:24+00:00 4eed2c6c5092ed95b8ee6d994106c54a9fc6ed3e Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> 
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>