.NET JIT potential error?

Question

The following code gives different output when running the release inside Visual Studio, and running the release outside Visual Studio. I\'m using Visual Studio 2008 and targeti

Answer 1

I copied your code into a new Console App.

• Debug Build
  • Correct output with both debugger and no debugger
• Switched to Release Build
  • Again, correct output both times
• Created a new x86 configuration (I'm on running X64 Windows 2008 and was using 'Any CPU')
• Debug Build
  • Got the correct output both F5 and CTRL+F5
• Release Build
  • Correct output with Debugger attached
  • No debugger - Got the incorrect output

So it is the x86 JIT incorrectly generating the code. Have deleted my original text about reordering of loops etc. A few other answers on here have confirmed that the JIT is unwinding the loop incorrectly when on x86.

To fix the problem you can change the declaration of IntVec to a class and it works in all flavours.

Think this needs to go on MS Connect....

-1 to Microsoft!