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ucb-bar / chisel2-deprecated

chisel.eecs.berkeley.edu
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Peeking INPUT before Poking #623

Closed shunshou closed 8 years ago

shunshou commented 8 years ago

What's the expected behavior when you peek an input before poking it? Before, peeking would just return 0x000... (I think? It's been a while since I peeked before poked... lol), but now, I get a java.util.NoSuchElementException: key not found error.

I assume it's b/c this line of peek:

else if (data.isTopLevelIO && data.dir == INPUT) _pokeMap(data)

expects _pokeMap(data) to contain something when it doesn't if you haven't poked the node yet.

I'm not objecting to having the tester error out, but a more descriptive error message would be nice...

donggyukim commented 8 years ago

I didn't expect this situation. Would it be ok to return 0?

shunshou commented 8 years ago

I'm personally ok with it returning 0, but maybe others will object? Since that assumes input nodes have a default value of 0 without it being explicitly specified? Alternatively, rather than saying key not found, you could also have it error out with input not assigned or something...

donggyukim commented 8 years ago

Let's return 0 in this case since nobody complains it.

ucbjrl commented 8 years ago

I would argue for issuing a more explicit warning, and at least, randomizing the returned value (as we do for "uninitialized" values in general).