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Differences between DVF 5.0A and CVF 6.5A

Intel_C_Intel
Employee
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I have a large program divided into three source code files that I compiled from the command line in 5.0A using "DF/alignment/compile_only *.for" and then "DF/link *.obj." The program runs fine. However, when I use the same options with 6.5A the program does not run correctly. Is there a difference in the default optimization level between the two compilers? Any other possible suggestions? The program performs a lot of vector and matrix operations.
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Steven_L_Intel1
Employee
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There are three generations of optimizer improvements, and more than three years of other changes, between the versions. The default optimization level didn't change, but if you have an incorrect program, more advanced optimizations may make them visible. We also made improvements to the math library

You don't say what "does not run correctly" means. Some things to try that may be interesting are: /assume:fltconsistency, /assume:dummy_aliases You could also try lower optimization levels to see if they make a difference, and if so, which source files need to be compiled with the lower level to make the problems go away.

If you want us to look at it, after you've done some analysis on your own, send us a ZIP file of the sources, build and test instructions, to vf-support@compaq.com

Steve
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