Re: [boost] [math] Enable move semantics for polynomials

Subject: Re: [boost] [math] Enable move semantics for polynomials
From: Lakshay Garg (lakshayg373_at_[hidden])
Date: 2017-08-14 05:44:59

>
> Hello all
>>
>> The polynomial class in boost.math does not support move sematics. I tried
>> to implement them and found that they immediately lead to significant
>> improvements in performance (benchmarking using google-benchmark).
>>
>
Here are some benchmarking results:

​Run on (1 X 2394.45 MHz CPU )                       Run on (1 X 2394.45
MHz CPU )
2017-08-14 05:20:24                                 2017-08-14 05:21:31
-------------------------------------  ------------------------------------
Benchmark            Time  Iterations  Benchmark            Time Iterations
-------------------------------------  ------------------------------------
[[ move construction ]]                [[ copy construction ]]
constr/1             2 ns   343554733  constr/1            31 ns   22353034
constr/8             2 ns   343350386  constr/8            52 ns   10000000
constr/64            3 ns   344426801  constr/64          114 ns    6089098
constr/512           2 ns   207412914  constr/512         122 ns    5712918
constr/4096          2 ns   338440949  constr/4096       2076 ns     467209

[[ unmodified from boost version ]]
mult/1              92 ns    10456937  mult/1             111 ns    6406373
mult/8             202 ns     3296293  mult/8             126 ns    5272682
mult/64           1845 ns      377277  mult/64           2069 ns     375123
mult/512        111874 ns        7214  mult/512        159189 ns       4393
mult/4096     12454282 ns          56  mult/4096     12539754 ns         56

[[ addition using move semantics ]]    [[ boost addition w/ const lvalue
ref ]]
add/1               63 ns     8470126  add/1              256 ns    2726596
add/8               64 ns    10869408  add/8              318 ns    2203414
add/64             247 ns     3707535  add/64             617 ns    1105630
add/512           1352 ns      512563  add/512           1330 ns     526513
add/4096          8146 ns       81454  add/4096         15984 ns      49450

[[ unmodified from boost version ]]
inplaceAdd/1         8 ns   105715477  inplaceAdd/1        11 ns   64811794
inplaceAdd/8        16 ns    42666675  inplaceAdd/8        12 ns   44115677
inplaceAdd/64       33 ns    17414051  inplaceAdd/64       34 ns   20628203
inplaceAdd/512     181 ns     4483653  inplaceAdd/512     246 ns    4431873
inplaceAdd/4096   2737 ns      255393  inplaceAdd/4096   2766 ns     254879

[[ total heap usage ]]
308,365,390 bytes allocated            1,940,239,990 bytes allocated
​