*vl-incexpr-1*
The literal 1 we use when eliminating increment/decrement expressions.
Context: we are converting real increment/decrement expressions,
i.e., a++, ++a, a--, or --a, into assignments such as a
= a + 1'b1 or a = a - 1'b1.
Using 1'b1 works correctly but sign/sizing deserves some justification.
If a is unsigned, then the expression a + 1'b1 or a - 1'b1 are
clearly fine. If a is signed, then a + 1'b1 or a - 1'b1 are
going to be treated as unsigned additions. But this is fine since addition and
subtraction are the same in 2's complement signed or unsigned arithmetic, and
these are the only operators we're dealing with.
Definition: *vl-incexpr-1*
(defconst *vl-incexpr-1*
(hons-copy
(make-vl-literal :val (make-vl-constint :value 1
:origwidth 1
:origsign :vl-unsigned))))