Swift versus C++ g++

How the programs are written matters! Always look at the source code.

If the fastest programs are flagged * possible hand-written vector instructions or "unsafe" or naked ffi, does the host language matter? You might be more interested in the less optimised programs — more seconds, less gz source code.

fannkuch-redux
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* C++ g++ #6	3.33	13.12	5,800	1535	4.64
* C++ g++ #7	14.06	14.04—14.11	2,449	1156	2.95
C++ g++ #5	7.86	30.73—30.82	5,792	987	3.67
* Swift #3	8.20	32.45—32.61	13,722	1103	12.93
Swift #8	34.68	34.68—34.74	13,484	470	12.33
C++ g++ #4	8.91	34.99—35.47	5,710	1445	12.14
C++ g++ #2	9.14	35.88—36.26	5,698	1446	11.86
C++ g++ #3	37.89	37.90—37.99	2,351	600	2.70
C++ g++	10.53	41.25—41.55	5,534	1065	3.88
n-body
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* C++ g++ #0	2.15	2.16	2,417	1933	3.66
* C++ g++ #7	4.09	4.12—4.17	5,124	1815	4.18
C++ g++ #9	5.15	5.17	2,486	1536	3.03
C++ g++ #3	5.33	5.34	2,482	1402	2.85
* Swift #3	5.45	5.44—5.48	24,928	1688	14.75
* C++ g++ #4	5.46	5.46	2,482	1434	2.83
* Swift #4	5.48	5.49	24,846	1361	13.94
* Swift #5	5.52	5.50—5.55	24,928	1372	12.83
* Swift #7	5.53	5.52	24,932	1333	13.80
Swift #6	5.82	5.81	12,956	1213	12.42
C++ g++ #2	6.02	6.02—6.10	2,490	1524	3.04
C++ g++ #5	6.33	6.35	2,478	1544	2.92
C++ g++	6.62	6.64	2,499	1666	3.15
Swift #8	6.66	6.56—6.95	12,804	1285	12.85
C++ g++ #6	6.94	6.93—6.98	2,499	1674	2.98
Swift	7.89	7.88	12,812	1210	12.10
Swift #9	287.37	287.38—288.05	24,793	1532	13.91
spectral-norm
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* C++ g++ #6	0.72	2.86	3,981	1050	3.08
* C++ g++ #5	1.33	5.28	5,820	1050	2.86
C++ g++	5.34	5.34	5,292	459	3.75
Swift #8	5.36	5.35	24,859	411	14.09
Swift #3	1.45	5.71	13,689	607	12.54
C++ g++ #7	1.53	6.07	4,071	1284	2.71
mandelbrot
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* C++ g++ #4	0.89	3.46	37,941	3554	5.04
* C++ g++	0.90	3.48	37,626	1797	3.59
* C++ g++ #6	0.98	3.87	37,908	1014	4.36
* Swift #7	1.35	5.29	57,836	1147	14.15
* Swift #6	1.48	5.80	60,985	1147	14.36
C++ g++ #0	2.36	9.31	38,281	2752	4.60
C++ g++ #7	4.87	13.30	38,048	749	3.03
C++ g++ #5	13.47	13.49	36,884	596	2.76
C++ g++ #9	3.53	13.59	37,863	732	3.03
C++ g++ #2	16.96	16.96	36,704	700	3.28
Swift #8	25.62	25.60—25.64	12,784	426	11.26
Swift	26.55	26.54	12,780	400	12.99
Swift #5	7.27	27.13	49,312	665	13.83
C++ g++ #3	27.38	27.38	5,181	421	3.69
* Swift #3		Bad Output
fasta
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* C++ g++ #9	0.78	1.56	6,214	2758	6.43
C++ g++ #2	1.85	1.85	5,108	1129	2.89
C++ g++	1.93	1.93	5,104	1064	2.98
C++ g++ #3	2.63	2.63	5,284	1311	3.33
C++ g++ #7	0.88	3.06	6,304	2711	4.58
C++ g++ #4	3.34	3.34	2,363	1291	3.03
C++ g++ #5	1.07	3.69—3.73	7,012	2345	3.90
C++ g++ #6	1.08	3.90	7,127	2326	3.72
* Swift	5.37	5.38	12,546	1533	13.34
* Swift #3	2.20	5.37	39,002	2097	14.73
* Swift #2	3.15	5.63—5.96	13,726	1952	14.91
Swift #8	18.19	18.18—18.35	12,829	828	11.99
k-nucleotide
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
C++ g++ #2	2.02	6.05—6.54	162,349	1634	7.41
C++ g++ #3	4.19	13.83—14.44	171,622	1280	5.17
C++ g++	7.04	15.17—15.69	778,510	1452	6.55
* Swift #2	14.45	54.24—57.70	273,949	1373	15.39
Swift #8	166.95	168.68—173.38	650,023	658	14.46
Swift #7	223.40	226.91—248.09	650,023	607	13.04
Swift		Empty
reverse-complement
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
* C++ g++ #2	0.76	0.76	514,101	2099	4.30
* Swift	2.05	2.48	825,635	1293	14.28
C++ g++	6.55	6.55—6.68	1,006,805	599	3.43
C++ g++ #5	37.66	37.65—37.69	792,846	704	3.40
C++ g++ #6		Bad Output
C++ g++ #3		Bad Output
binary-trees [ Contentious. Different approaches. ]
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
C++ g++ #7	1.01	3.46—3.62	175,108	896	7.50
C++ g++ #5	1.17	4.12—4.17	208,171	891	3.87
C++ g++ #9	1.76	4.66—4.82	140,571	815	4.05
C++ g++ #6	1.93	4.90—5.09	273,973	851	4.98
C++ g++ #3	2.28	5.06—5.10	273,715	951	4.79
C++ g++ #4	2.22	5.20—5.33	273,977	826	5.16
C++ g++	2.69	9.43—9.52	1,896,727	760	5.34
C++ g++ #2	22.77	22.81—23.05	274,080	514	3.52
Swift	18.21	54.03—54.29	763,523	720	13.97
Swift #4	17.62	54.69—59.64	733,094	772	13.31
Swift #5	18.90	56.44—56.88	764,391	813	14.89
Swift #3	18.26	58.41—58.87	733,180	868	18.46
Swift #2	18.24	58.41—58.84	732,828	822	14.89
* Swift #9		Empty
pidigits [ Contentious. Different libraries. ]
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
C++ g++ #4	0.72	0.72	6,496	521	3.45
* C++ g++ #5	0.73	0.73	6,300	804	3.34
* Swift #2	0.76	0.75	14,459	606	12.50
regex-redux [ Contentious. Different libraries. ]
	elapsed	Mean or 95% CI
source	secs	cpu secs	mem	gz	make
C++ g++ #6	1.14	2.25	285,639	2856	5.06
C++ g++ #3	12.37	18.03—18.68	222,614	859	12.29
Swift #2	39.33	39.34—39.45	710,697	678	13.66
Swift	23.92	40.23—40.37	922,243	721	13.56
Swift #4	18.21	41.75—42.40	1,102,254	751	13.30
C++ g++		Empty
C++ g++ #2		Empty
C++ g++ #5		Empty
C++ g++ #4		Empty
Swift	Swift version 6.0.3 (swift-6.0.3-RELEASE) Target: x86_64-unknown-linux-gnu
C++ g++	g++ (Ubuntu 14.2.0-4ubuntu2) 14.2.0