C/C++ Console App running 10 times slower in VS2005 from VS2003

[Fiddelm3742]

Well, I dont exactly know if there was a change in how Console Application
projects are run/compiled from VS2003 to 2005 or what, but I have an
application (mostly C) that used to run in about 2 minutes and now runs in
hours. The output of the program seems the same, but the time it takes it
run is ridiculous. Yes, I get the general warnings when I compile to use the
now more secure functions fopen_s instead of fopen, etc. but no errors
really. I'm not quite sure as to why the program now takes sooooo much
longer to run than previously Any suggestions? When I opened the project I
let VS2005 convert it from VS2003 type. Should I not have done that? Any
suggestions?
Thanks
Matt
--
www.Fiddelke.org

[Tom Widmer [VC++ MVP]]

Fiddelm3742 wrote:

Well, I dont exactly know if there was a change in how Console Application
projects are run/compiled from VS2003 to 2005 or what, but I have an
application (mostly C) that used to run in about 2 minutes and now runs in
hours. The output of the program seems the same, but the time it takes it
run is ridiculous. Yes, I get the general warnings when I compile to use the
now more secure functions fopen_s instead of fopen, etc. but no errors
really. I'm not quite sure as to why the program now takes sooooo much
longer to run than previously Any suggestions? When I opened the project I
let VS2005 convert it from VS2003 type. Should I not have done that? Any
suggestions?

You're running the Release build, right? And it is compiled with
optimizations enabled? Excepting a few CRT functions (those that use
thread local storage) and the memory allocator, on the whole, VC++8
produces faster code than VC++7.1, so it is likely a problem with your
compiler settings. It might also conceivably be a bug in the code that
was masked under VS2003, though this is less likely I think.

Tom

[Jochen Kalmbach [MVP]]

Hi Tom!

You're running the Release build, right? And it is compiled with
optimizations enabled? Excepting a few CRT functions (those that use
thread local storage) and the memory allocator, on the whole, VC++8
produces faster code than VC++7.1, so it is likely a problem with your
compiler settings. It might also conceivably be a bug in the code that
was masked under VS2003, though this is less likely I think.

You a small note: The compiler intrinsic are now enabled by default
which are far slower than the CRT implementation, see:
http://lab.msdn.microsoft.com/produc...1-9b4c1fe463d9

The strcmp is about 5-6 times slower...

Greetings
Jochen