Re: [myhdl-list] intbv return types

[Jan D. <ja...@ja...>]

Christopher L. Felton wrote:
> Curiosity, what was the rational behind the mathematical operators for 
> the intbv object returning the integer values and the logic operators 
> (shifts, and, or, xor, etc) returning an intbv object?
> 
> Example
> a = intbv(1)
> b = intbv(2)
> 
> c = a + b
> type(c)
> <type 'int'>
> 
> c = a ^ b
> type(c)
> <class 'myhdl._intbv.intbv'>

If the return value is an intbv, you can slice and index it.
This probably makes sense for "bit-oriented" operations,
and perhaps less for "arithmetic" operations.
Therefore, for the latter case it might be a good idea
to avoid the overhead of intbv construction.

This is all a little bit arbitrary and speculative -
for example, I haven't done tests to check how significant
the intbv construction overhead exactly is.
We always have the option to change the return type
to intbv if there's a real need.

Jan


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