RE: CP-003


Subject: RE: CP-003
From: Bert Molenkamp (molenkam@cs.utwente.nl)
Date: Wed Feb 19 2003 - 02:30:16 PST


> Thus, I think option 2 wins over the status quo. I would support adding
corresponding
> overloads for bit/bit_vector in std.standard.
>

I agree with this.

> What I am asking in this proposal (and the similar one
> I requested of 1076.3 for "+") is that you remember an
> additional set of properties:
..
> For math operators,
> '1' becomes "000 ...1"
> '0' becomes "000 ...0"
>
> Yes, using arrays with bits does add some non-orthagonality
> to the operator overloading, but this is engineering and
> non-orthagonality is a normal part of life.

Although not relevant (at this time) would a user expect the
proposed extension for math operators?
 Signal a : signed (3 downto 0);
 Signal b : unsigned( 3 downto 0);

May be the user expects:
 a and '1' ==> a and "1111" sign extension since a is a signed
 b and '1' ==> b and "0001" since b is an unsigned
(In 1076.3 for arithmetic operations a +'1' (and b + '1')
is not supported)

Egbert Molenkamp



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