14 lines
800 B
Markdown
14 lines
800 B
Markdown
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Some race conditions can be resolved by every thread calculating the result in a private variable and combining all the results in the end.
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This is often faster, because it involves less waiting.
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## Knowledge
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To use the reduction, you have to add the reduction clause ``reduction(operator : var)`` to your compiler directive.
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You can use reductions for a handful of operations. Most of the arithmetic operators and some of the logic and bitwise ones plus min and max.
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For a complete list check the [quick reference](http://www.openmp.org/wp-content/uploads/OpenMP3.1-CCard.pdf).
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Reduction only need to synchronize as often as there are threads instead of how many operations are actually done.
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## Task
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Instead of using a critical section as before, try your hand at a reduction variable instead.
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