6 times slower on Linux than xp

[Chen Shizhong-FCHN289]

Hi,

<<main.cpp>> <<R_Exception.hpp>>

When run above code on linux (Ubuntu 10.04, g++4.4.3), the output is:

~/PerfExcept$ date; ./a.out 100000000 20; date
Mon Jun 13 13:31:45 CST 2011

LOOP=100000000, ERR_RATE=0.2

totalTraditionErr=20001530, time=3430000, /time=5.83135

totalIntException=19997909, time=86630000, /time=0.230843

totalObjException=20002016, time=88600000, /time=0.225756
Mon Jun 13 13:34:44 CST 2011

So costs 179sec.

When run it on XP (same PC, g++4.4.1), the output is:

C:\>perfexcept 100000000 20

LOOP=100000000, ERR_RATE=0.2

totalTraditionErr=20003550, time=2593, /time=7714.44

totalIntException=19998567, time=13531, /time=1477.98

totalObjException=20005020, time=13235, /time=1511.52

And it only costs 29sec.

The cpu is Pentium dual-core address@hidden

I doubt the big performance gap is from the compiler. Is it a bug of Linux G++?

Thanks if you can help,
Chen

(1 more thing, I noticed above code occupied 2 cores on xp - each cost ~50%, but linux focus on 1 core & achieve 100% utilization on that core…)

main.cpp
Description: main.cpp

R_Exception.hpp
Description: R_Exception.hpp