Here are results of comparative performance tests carried out
using the same compiler (gcc 3.2)
in different environments (CYGWIN, MINGW, DJGPP)
on Windows 2000 Professional.
The following C-functions were tested :
* strcpy
* memcpy
* memmove
* memset
The summary results are below.
################################################## ###############
str-functions vs. mem-functions (C-language)
============================================
C/C++ Performance Tests
=======================
Using C/C++ Program Perfometer
http://sourceforge.net/projects/cpp-perfometer http://alexvn.freeservers.com/s1/perfometer.html
Environment
-----------
Windows 2000 Professional
* CYGWIN_NT-5.0 1.3.22(0.78/3/2)
* MINGW 2.0.0.-2
* DJGPP 2.03
Intel(R) Celeron(R) CPU 1.70 GHz
GNU g++/gpp 3.2
Compilation : No optimization
================ Performance tests : BEGIN ================
#================================================= =========
# Comparison : str-functions vs. mem-functions (C)
#----------------------------------------------------------
# Resource Name : user time used (via rusage)
# Resource Cost Unit : milliseconds (unsigned long long)
# Resource State Unit : timeval
#================================================= =========
Summary test results
CYGWIN_NT-5.0 1.3.22(0.78/3/2)
gcc/g++ version 3.2 20020927 (prerelease)
============================
----------------------------------------
| | | User time used for |
| N | Function | string size |
| | |-----------------------|
| | | 10 | 100 | 1000 |
|--------------------------------------|
| 1 | strcpy | 46 | 165 | 1088 |
| 2 | memcpy | 166 | 223 | 1069 |
| 3 | memmove | 215 | 274 | 1124 |
| 4 | memset | 133 | 213 | 540 |
----------------------------------------
Note C1. memcpy is slower than strcpy
for relatively short strings
Note C2. memmove is slower than memcpy
Raw Log :
http://groups.google.com/groups?selm....uni-berlin.de
Summary test results
MINGW 2.0.0-2
gcc/g++ version 3.2 (mingw special 20020817-1)
============================
----------------------------------------
| | | User time used for |
| N | Function | string size |
| | |-----------------------|
| | | 10 | 100 | 1000 |
|--------------------------------------|
| 1 | strcpy | 50 | 250 | 1982 |
| 2 | memcpy | 51 | 180 | 1150 |
| 3 | memmove | 50 | 180 | 1161 |
| 4 | memset | 110 | 160 | 607 |
----------------------------------------
Note M1. Actually memcpy is faster than strcpy
Note M2. memmove & memcpy have the same performance
Raw Log :
http://groups.google.com/groups?selm....uni-berlin.de
Summary test results
DJGPP 2.03
gcc/gpp version 3.2.1
============================
----------------------------------------
| | | User time used for |
| N | Function | string size |
| | |-----------------------|
| | | 10 | 100 | 1000 |
|--------------------------------------|
| 1 | strcpy | 63 | 567 | 5329 |
| 2 | memcpy | 173 | 329 | 1492 |
| 3 | memmove | 274 | 384 | 1098 |
| 4 | memset | 191 | 292 | 695 |
----------------------------------------
Note D1. For very short strings
memcpy is slower than strcpy,
for other strings
memcpy is faster than strcpy,
Note D2. strcpy seems to work too slow
(relative to CYGWIN, MINGW)
Raw Log :
http://groups.google.com/groups?selm....uni-berlin.de
================ Performance tests : END ==================
==============================================
Alex Vinokur
mailto:al****@connect.to
http://mathforum.org/library/view/10978.html
==============================================
