int128_t Benchmarks :: Boost.int128

Methodology

The benchmarks below represent the time in microseconds it takes to perform 20'000'000 operations between two values of random width (e.g. 2x1 words, 1x2 words, etc.). On most platforms we use the builtin __int128 as the reference benchmark. When this is unavailable (such as on 32-bit architectures) we use boost::multiprecision::int128_t (abbreviated as boost::mp::int128_t) as it is widely used, and known to be portable. On MSVC platforms we use as reference std::_Signed128 from the header <__msvc_int128.hpp> since this is bundled with their compiler.

Linux

x86_64

Operation	`__int128`	`int128_t`	`boost::mp::int128_t`	`absl::int128`
Comparisons	2232997	1970941	5478483	1944089
Addition	244246	292081	650160	227720
Subtraction	220957	196953	1625774	315611
Multiplication	433431	321168	1595688	304069
Division	4462364	4983165	4992819	4986970
Modulo	4803576	5257406	4988844	5081814

ARM64

Operation	`__int128`	`int128_t`	`boost::mp::int128_t`	`absl::int128`
Comparisons	4115337	2169531	5914108	3725321
Addition	194461	196244	543680	195216
Subtraction	151441	97565	1161677	192729
Multiplication	334847	232518	904461	240980
Division	2403064	1848517	2493904	2431322
Modulo	2235322	2159401	2535438	2321638

S390x

Operation	`__int128`	`int128_t`	`boost::mp::int128_t`	`absl::int128`
Comparisons	5171094	5069329	7457296	5343843
Addition	625328	785936	1286888	670826
Subtraction	667538	356865	2555881	741947
Multiplication	904480	729911	1562062	786829
Division	3758577	2211087	3095993	3940264
Modulo	4218409	2330114	3684163	3849849

PPC64LE

Operation	`__int128`	`int128_t`	`boost::mp::int128_t`
Comparisons	4538094	5796198	13907323
Addition	221708	191841	1177034
Subtraction	222629	174273	1861166
Multiplication	193315	191785	878393
Division	5607581	4669820	5616217
Modulo	5623562	4750314	5641480

x86_32

This platform has no hardware type so we compare relative to boost::mp::int128_t

Operation	`int128_t`	`boost::mp::int128_t`
Comparisons	10310201	14160000
Addition	786499	7379646
Subtraction	907051	7890190
Multiplication	855780	10826565
Division	10254664	24702433
Modulo	10851123	17348307

ARM32

This platform has no hardware type so we compare relative to boost::mp::int128_t

Operation	`int128_t`	`boost::mp::int128_t`
Comparisons	6149439	6432579
Addition	457850	5669571
Subtraction	488321	7464427
Multiplication	1793874	11410321
Division	17738614	38956122
Modulo	18064819	30144743

Windows

x86_64

Operation	`std::_Signed128`	`int128_t`	`boost::mp::int128_t`
Comparisons	1879694	1894168	5198915
Addition	141120	143877	2846799
Subtraction	157649	156965	3027203
Multiplication	266740	138754	4080611
Division	1387560	1752869	6924406
Modulo	1616895	1908345	6397442

ARM64

Operation	`std::_Signed128`	`int128_t`	`boost::mp::int128_t`
Comparisons	991273	391918	2551137
Addition	34519	48953	1243326
Subtraction	34184	36278	1387708
Multiplication	126490	36781	1632232
Division	1128432	1107571	2472959
Modulo	1427629	1310481	2926904

x86_32

Operation	`std::_Signed128`	`int128_t`	`boost::mp::int128_t`
Comparisons	3832024	3823023	5568151
Addition	232554	197092	3488510
Subtraction	1198377	145823	4011233
Multiplication	2921104	428925	6219931
Division	7174578	7189000	9748526
Modulo	5528639	7028725	9205892

macOS

ARM64 (Apple Silicon)

Operation	`__int128`	`int128_t`	`boost::mp::int128_t`	`absl::int128`
Comparisons	135259	134127	340037	136845
Addition	20399	18575	169575	20429
Subtraction	20156	18983	168041	20875
Multiplication	20654	20860	69443	20651
Division	668004	659823	976248	660963
Modulo	664356	662282	1026487	665474