[CLAD] Auto-indexing

[Bert_Hannon]

Dear all,

In one of the CLAD sample exams the question is as follows:

Auto-indexing at loop boundary is a feature that allows: (more than one answer may apply)

 a. Arrays to be automatically traversed from one iteration to the next

 b. Array functions to automatically index array elements

 c. Functions that use arrays to automatically index them

 d. Arrays to be automatically accumulated at loop boundaries

I thought B and D are correct, however according to the sample exam the correct answers are A and D. The justification given is "Auto-indexing is a feature for loops interacting with arrays. Array functions themselves do not have iterative auto-indexing features.". I thought A relates to shift registers?

Thank you in advance

[crossrulz]

I would have just put D.  I fully agree that A is not a correct answer (relating to shift registers or feedback nodes).

[JÞB]

While a bit missleading in wording A is correct Auto indexing input tunnels traverses the row index of an array such that row i is on the wire inside the loop.  Shift registers and feedback nodes cannot auto index.  Those nodes pass data between loop iterations 

[crossrulz]

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@JÞB wrote:

While a bit missleading in wording A is correct Auto indexing input tunnels traverses the row index of an array such that row i is on the wire inside the loop.  Shift registers and feedback nodes cannot auto index.  Those nodes pass data between loop iterations 

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I have to disagree with you Jeff.  The sentence says traverse arrays from one iteration to the next.  The arrays are not being passed on to the next iteration.  The rows are being indexed, not moved on to the next iteration.

[johnsold]

I am with Jeff on this one.  When I read that answer the first time, I interpreted "traverse" as the dictionary definition: "Travel across or through..."  Through seems to suggest autoindexing.

I agree also that the wording is somewhat ambiguous.

Lynn

[Bert_Hannon]

Hm it seems that the question indeed isn't that easy. My reasoning was that the information written to the tunnel isn't available in the next iteration so A can not be correct.

What do you guys think about answer B?

[johnsold]

Array functions refers to things like Array Subset. Autoindexing has nothing to do with those.  B is clearly not correct.

Lynn

[JÞB]

Like I said.... Poor wording.  Zaki et al are going to do better.