Optimization Problem With Data Conversion

[Raymond Lu <songyulu@xxxxxxxxxxxx>]

Our HDF5 software has been having some data conversion problem with 
GCC's optimization for a few years.   One example is to convert data 
from short to int.  You can find the program at

 ftp://ftp.hdfgroup.uiuc.edu/pub/outgoing/slu/tmp/ctest.c

When I use "gcc -O2" or "gcc -O3" to compile it, I get wrong values 
after the conversion.  When I use "gcc -O0" or "gcc -O1", the values are 
correct.

I'll greatly appreciate your help if you can have a look at it.

Ray