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optimization and vectorizing problem

Michel
Beginner
‎11-28-2014 12:50 AM
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We have run into a problem after updating to 2015.1.148

The combination of /arch:SSE3 and /O2 causes that in a vectorized loop where an array is filled the returned data is not updated after a 2nd call.

lowering the optimization to 1 or changing /arch to SSE4.1 or higher solves the problem.

the optrpt then also shows that vectorization is also done under the <Remainder> when things are ok.

We solved it by using /QaxAVX /arch:SSE4.1 which means we dropped support for older processors.

 

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Steven_L_Intel1
Employee
‎11-28-2014 05:15 PM
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Can you provide us with a small but complete example that demonstrates the problem?

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Michel
Beginner
‎12-05-2014 02:50 AM
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It happens deep in a function so I need to make a testcase with prefilled arrays. This takes some time.

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