I've just upgraded a native C++ project from VS2005-SP1 to VS2008-SP1
The first thing I tested was a very basic functionality test of the application and the first thing I noticed is that the main number-crunching algorithm performs three times slower in the VS2008 binary.
I tested again the VS2005 binary to make sure there isn't any other difference and it still performed as it did before.
Did anyone stumble into this?
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Kent Fredric
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shoosh
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Are you running optimized or debug? – David Norman Dec 12 '08 at 02:59
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running release ofcourse – shoosh Dec 12 '08 at 03:10
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Did you accidentally compile with different options? For example, did you compile for 64-bit Windows rather than 32-bit Windows? – Kevin Dec 12 '08 at 03:15
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Strangest. Thing. Ever.
It seems that the project upgrade wizard of vs2008 simply doesn't copy the 'Optimization="2"' property so the new project is left with no optimization in release.
The fix was to go to the properties dialog, change optimization to 1 and then back to 2. compile again and everything works it should.
I couldn't find any official reference for this only this obscure reference in an MSDN forum.
shoosh
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It's nice to know the optimizer is kicking that much butt, at least. – Drew Hoskins May 07 '09 at 00:20