Giani,

Thank you for the problem report.  I will try to see if I can reproduce this problem. In the mean time, if you could provide an example, or instructions on how to reproduce this issue please let me know?

Thanks,
mark

Thank you for the update giani.  And thanks to Georg for root causing and solving the problem.  I'm providing the link here to the details in case other people run into this issue, and list Georg's response below.

"the problem you reported is neither a compiler nor debugger issue. The result is intended.

Rationale: You used IVDEP pragma which makes the compiler ignore assumed dependencies. This usually has benefits in cases were those assumed dependencies never hold during runtime. The compiler can apply more aggressive optimizations. In your case, however, assumed dependencies hold, which are accesses to array "hist". There can be multiple loop iterations writing to the same element of that array. With the IVDEP pragma you had indicated the compiler that multiple accesses can not happen, which is wrong.

If you use this pragma (also applies to SIMD pragma) you have to always verify your code. You apparently did so and proved not to use that pragma for your algorithm."