Environment

Windows 2000 Professional

CYGWIN_NT-5.0 1.3.22(0.78/3/2)

Intel(R) Celeron(R) CPU 1.70 GHz

GNU gcc/g++ version 3.2 20020927 (prerelease)

Compilation : No optimization

Method	Data Type	Performance for size			Unit of Measurement = milliseconds/per-times
Method	Data Type	10	100	1000	Iterations	Per-times

C-string initialization
http://groups.google.com/groups?selm=bcs4nc$lsdbq$1@ID-79865.news.dfncis.de
init (char* x = y)	char*	4	4	4	5000000	1000000
init (char[] x = y)	char[]	5	232	402	5000000	1000000


string initialization (C vs. STL)
http://groups.google.com/groups?selm=bcs72j$ljpau$8@ID-79865.news.dfncis.de
malloc & free	char[]	132	162	162	500000	100000
(malloc+strcpy) & free	char[]	137	179	274
(malloc+memset) & free	char[]	161	187	217
ctor & dtor	string	30	30	30
new & delete	string	223	274	892


string length (C vs. STL)
http://groups.google.com/groups?selm=bcs72e$ljpau$7@ID-79865.news.dfncis.de
strlen	char[]	222	693	5410	5000000	1000000
string.size()	string	16	15	15	5000000	1000000


string assignment and addition (C vs. STL) - 1
http://groups.google.com/groups?selm=bcs724$ljpau$6@ID-79865.news.dfncis.de
strcpy	char[]	6	22	147	500000	100000
operator=	string	3	3	3
strcat (with cutting off)	char[]	10	26	152
operator+= (with erase)	string	100	112	184
operator+ (with erase)	string	234	234	508


string assignment and addition (C vs. STL) - 2
http://groups.google.com/groups?selm=bcs71t$ljpau$5@ID-79865.news.dfncis.de
accumulated strcat (with cutting off)	char[]	1090	1194	1277	50000	10000
accumulated operator+= (with erase)	string	10	12	20
accumulated operator+ (with erase)	string	6311	6993	7280


find method vs. find algorithm
http://groups.google.com/groups?selm=bcs71j$ljpau$4@ID-79865.news.dfncis.de
find algorithm	vector<int>	2	8	69	50000	10000
find algorithm	list<int>	2	15	142
find algorithm	set<int>	3	22	217
find method	set<int>	2	4	4
find method	map<int>	2	4	4


for-loop vs. for_each
http://groups.google.com/groups?selm=bcs715$ljpau$3@ID-79865.news.dfncis.de
for-loop	vector<uint>	13	124	1225	50000	10000
for-loop	string	14	120	1189
for-loop	list<uint>	15	133	1330
for-loop	set<uint>	13	129	1311
for_each	vector<uint>	10	92	915
for_each	string	10	93	917
for_each	list<uint>	9	78	773
for_each	set<uint>	12	104	1070


access to element
http://groups.google.com/groups?selm=bcs70m$ljpau$2@ID-79865.news.dfncis.de
operator[]	char[]	5	5	4	5000000	1000000
operator[]	vector<char>	90	90	90
operator[]	string	34	34	33
at method	vector<char>	222	222	223
at method	string	32	33	33


calling functions : templated vs. non-templated
http://groups.google.com/groups?selm=bcs70m$ljpau$2@ID-79865.news.dfncis.de
templated function	int	16			5000000	1000000
ordinary function	int	5
templated function	string	344	345	345
ordinary function	string	344	345	350

Alex Vinokur

mailto:alexvn@connect.to

http://mathforum.org/library/view/10978.html

07 Jule 2003

Environment

C-string initialization

Alex Vinokur