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

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Guest

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
 
Fiddelm3742 said:
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?
Click to expand...

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
 
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.
Click to expand...

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/produ...edbackid=e497db51-4024-404c-b8a1-9b4c1fe463d9

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

Greetings
Jochen
 
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