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Beginner
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cycle velocity

Dear all,

I have a very simple question. If I have two vector, let's say AA(:) and BB(:), what is between the following options the faster one?

DO i=1,SIZE(AA)

       AA(i)=BB(i)

ENDDO

or 

AA(:) = BB(:)

thanks a lot

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2 Replies
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Valued Contributor III
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See this thread: https://software.intel.com/en-us/forums/intel-visual-fortran-compiler-for-windows/topic/539969

 

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Black Belt
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Assuming that diedro hasn't set up any EQUIVALENCE or POINTER overlap between these arrays, there's no reason for the generated code to differ (probably a call to an intel_fast_memcpy, in the absence of directives to the contrary).  You can't call it a "very simple question" considering that it doesn't make sense in isolation.

AA(:)=BB(:) used to be more likely to provoke an extra copy than AA=BB, but one might hope that such an embarrassment is a thing of the past.

There's a use for the opt-report.

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