On Sat, 24 Nov 2018 at 10:56, Ard Biesheuvel <ard.biesheu...@linaro.org> wrote: > > On Sat, 24 Nov 2018 at 07:42, sunrui <sunru...@huawei.com> wrote: > > > > > > On Thu, 22 Nov 2018 at 02:50, sunrui <sunru...@huawei.com> wrote: > > > > > > > > > > > > On Sun, 18 Nov 2018 at 23:30, Rui Sun <sunru...@huawei.com> wrote: > > > > > > > > > > > > > > add 64 bytes loop to acceleration calculation > > > > > > > > > > > > > > > > > > > Can you share some performance numbers please? > > > > > > > > > > > > Also, we don't need 64 byte, 32 byte and 16 byte code paths: just make > > > the 8 byte one a loop as well, and drop the 32 byte and 16 byte ones. > > > > > > > > > > > > -- > > > > > > > > > > > > Consider of some processor has instruction N-way parallel function, with > > > the increase of the data buf’s size, 64B loop will performance better > > > than 16B loop. > > > > > > > > > > > > On the other hand, in the same environment I tested the 8B loop, which is > > > worse than the 16-byte loop. > > > > > > > > > > > > The test result is shown in the fellow excel(crc test result.xlsx) > > > sheet1(64B loop) and sheet2(8B loop) > > > > > > > > >Maybe I phrased that wrong: if we add the 64-byte loop, there is no need > > >for a 32-byte block, a 16 byte block and a 8 byte block, since they all > > >use the same crc32x instruction. After the 64-byte loop, just loop in the > > >8-byte sequence until the remaining data is less than 8 bytes. > > > > > > > > > > > I think we should not use 8-byte loop after 64-byte loop. Although the > > number of code lines is reduced, but it will run more subs and b.cond > > instruction. I test it and shown the result in the fellow excel. > > > > OK > > > Why I used three temp variables to do the ldp below is because our > > processor have two load/store unit, if we use the registers which are > > independent, it can processed in parallel. > > > > Yes, but you are adding three instructions to a tight loop, which will > be noticeable on in-order cores. > > Just use something like > > ldp x3, x4, [x0] > ldp x5, x6, [x0, #16] > ldp x7, x8, [x0, #32] > ldp x9, x10, [x0, #48] > add x0, x0, #64 > > Those are completely independent as well > > > By the way, In most cases, crc short XOR 0xffffffff before and after the > > calculation, if we add 'mvn w0, w0' at the beginning and before the return > > will bring some benefits. What do you think about it? > > The C code will take care of that. >
I tested your code on Cortex-A57, and it performs worse in tcrypt: Before: testing speed of async crc32c (crc32c-generic) tcrypt: test 0 ( 16 byte blocks, 16 bytes per update, 1 updates): 35416299 opers/sec, 566660784 bytes/sec tcrypt: test 1 ( 64 byte blocks, 16 bytes per update, 4 updates): 5342888 opers/sec, 341944832 bytes/sec tcrypt: test 2 ( 64 byte blocks, 64 bytes per update, 1 updates): 30056634 opers/sec, 1923624576 bytes/sec tcrypt: test 3 ( 256 byte blocks, 16 bytes per update, 16 updates): 1543567 opers/sec, 395153152 bytes/sec tcrypt: test 4 ( 256 byte blocks, 64 bytes per update, 4 updates): 4865198 opers/sec, 1245490688 bytes/sec tcrypt: test 5 ( 256 byte blocks, 256 bytes per update, 1 updates): 12709474 opers/sec, 3253625344 bytes/sec tcrypt: test 6 ( 1024 byte blocks, 16 bytes per update, 64 updates): 401746 opers/sec, 411387904 bytes/sec tcrypt: test 7 ( 1024 byte blocks, 256 bytes per update, 4 updates): 2576764 opers/sec, 2638606336 bytes/sec tcrypt: test 8 ( 1024 byte blocks, 1024 bytes per update, 1 updates): 4464109 opers/sec, 4571247616 bytes/sec tcrypt: test 9 ( 2048 byte blocks, 16 bytes per update, 128 updates): 202236 opers/sec, 414179328 bytes/sec tcrypt: test 10 ( 2048 byte blocks, 256 bytes per update, 8 updates): 1344017 opers/sec, 2752546816 bytes/sec tcrypt: test 11 ( 2048 byte blocks, 1024 bytes per update, 2 updates): 2000544 opers/sec, 4097114112 bytes/sec tcrypt: test 12 ( 2048 byte blocks, 2048 bytes per update, 1 updates): 2395890 opers/sec, 4906782720 bytes/sec tcrypt: test 13 ( 4096 byte blocks, 16 bytes per update, 256 updates): 101569 opers/sec, 416026624 bytes/sec tcrypt: test 14 ( 4096 byte blocks, 256 bytes per update, 16 updates): 687876 opers/sec, 2817540096 bytes/sec tcrypt: test 15 ( 4096 byte blocks, 1024 bytes per update, 4 updates): 1029042 opers/sec, 4214956032 bytes/sec tcrypt: test 16 ( 4096 byte blocks, 4096 bytes per update, 1 updates): 1206227 opers/sec, 4940705792 bytes/sec tcrypt: test 17 ( 8192 byte blocks, 16 bytes per update, 512 updates): 50842 opers/sec, 416497664 bytes/sec tcrypt: test 18 ( 8192 byte blocks, 256 bytes per update, 32 updates): 347779 opers/sec, 2849005568 bytes/sec tcrypt: test 19 ( 8192 byte blocks, 1024 bytes per update, 8 updates): 525054 opers/sec, 4301242368 bytes/sec tcrypt: test 20 ( 8192 byte blocks, 4096 bytes per update, 2 updates): 600919 opers/sec, 4922728448 bytes/sec tcrypt: test 21 ( 8192 byte blocks, 8192 bytes per update, 1 updates): 606954 opers/sec, 4972167168 bytes/sec With your patch applied: testing speed of async crc32c (crc32c-generic) tcrypt: test 0 ( 16 byte blocks, 16 bytes per update, 1 updates): 29524327 opers/sec, 472389232 bytes/sec tcrypt: test 1 ( 64 byte blocks, 16 bytes per update, 4 updates): 4299236 opers/sec, 275151104 bytes/sec tcrypt: test 2 ( 64 byte blocks, 64 bytes per update, 1 updates): 25492193 opers/sec, 1631500352 bytes/sec tcrypt: test 3 ( 256 byte blocks, 16 bytes per update, 16 updates): 1076108 opers/sec, 275483648 bytes/sec tcrypt: test 4 ( 256 byte blocks, 64 bytes per update, 4 updates): 4201545 opers/sec, 1075595520 bytes/sec tcrypt: test 5 ( 256 byte blocks, 256 bytes per update, 1 updates): 12872662 opers/sec, 3295401472 bytes/sec tcrypt: test 6 ( 1024 byte blocks, 16 bytes per update, 64 updates): 283351 opers/sec, 290151424 bytes/sec tcrypt: test 7 ( 1024 byte blocks, 256 bytes per update, 4 updates): 2548369 opers/sec, 2609529856 bytes/sec tcrypt: test 8 ( 1024 byte blocks, 1024 bytes per update, 1 updates): 4315953 opers/sec, 4419535872 bytes/sec tcrypt: test 9 ( 2048 byte blocks, 16 bytes per update, 128 updates): 148377 opers/sec, 303876096 bytes/sec tcrypt: test 10 ( 2048 byte blocks, 256 bytes per update, 8 updates): 1321415 opers/sec, 2706257920 bytes/sec tcrypt: test 11 ( 2048 byte blocks, 1024 bytes per update, 2 updates): 1915036 opers/sec, 3921993728 bytes/sec tcrypt: test 12 ( 2048 byte blocks, 2048 bytes per update, 1 updates): 2349295 opers/sec, 4811356160 bytes/sec tcrypt: test 13 ( 4096 byte blocks, 16 bytes per update, 256 updates): 74167 opers/sec, 303788032 bytes/sec tcrypt: test 14 ( 4096 byte blocks, 256 bytes per update, 16 updates): 675385 opers/sec, 2766376960 bytes/sec tcrypt: test 15 ( 4096 byte blocks, 1024 bytes per update, 4 updates): 981948 opers/sec, 4022059008 bytes/sec tcrypt: test 16 ( 4096 byte blocks, 4096 bytes per update, 1 updates): 1178119 opers/sec, 4825575424 bytes/sec tcrypt: test 17 ( 8192 byte blocks, 16 bytes per update, 512 updates): 38580 opers/sec, 316047360 bytes/sec tcrypt: test 18 ( 8192 byte blocks, 256 bytes per update, 32 updates): 340715 opers/sec, 2791137280 bytes/sec tcrypt: test 19 ( 8192 byte blocks, 1024 bytes per update, 8 updates): 498960 opers/sec, 4087480320 bytes/sec tcrypt: test 20 ( 8192 byte blocks, 4096 bytes per update, 2 updates): 594188 opers/sec, 4867588096 bytes/sec tcrypt: test 21 ( 8192 byte blocks, 8192 bytes per update, 1 updates): 599264 opers/sec, 4909170688 bytes/sec Note that these are all integral multiples of 16 bytes, so the coverage is not great. Could you share your test script please?
