RE: [sv-bc] Type/size propagation does not stop at parens (6.6.2, V-2005)

Brad,

I believe you mean 5.5.2 (in P1364/D8p1) instead of 6.6.2.

I agree that "simple operand" here was maybe not intended to include
parenthesized expressions.

However, even if you included them, I think the statement is still true:
the parenthesized expression can be considered to be type-converted. But
it does not say that propagation stops there.

Anyway, I agree that the text is still not clear enough.

Parenthetical text is not excluded from being normative.

How do you distinguish between a "comment" and a non-"comment"?

Shalom


>-----Original Message-----
>From: owner-sv-bc@eda.org [mailto:owner-sv-bc@eda.org] On
>Behalf Of Brad Pierce
>Sent: Monday, November 07, 2005 10:28 PM
>To: sv-bc@eda.org
>Subject: [sv-bc] Type/size propagation does not stop at parens
>(6.6.2, V-2005)
>
>According to 6.6.2, regarding propagating the type and size of
>an
>expression "back down to the context-determined operands of the
>expression" --
>
>    "When propagation reaches a simple operand as defined in
>5.2 (a
>primary as defined in A.8.4), then that operand shall be
>converted to
>the propagated type and size. If the operand must be extended,
>then it
>shall be sign-extended only if the propagated type is signed."
>
>Yet every parenthesized expression is a primary
>
>      primary --> ( mintypmax_expression )
>              --> ( expression )
>
>and width propagation does not stop at parens.  For example,
>the
>following yields |0001000|1001000|, not |0000000|1000000|.
>
>   module m;
>   reg [6:0] a;
>   initial begin
>     a = (3'b111 + 3'b001);
>     $display("|%b|%b|", a, 7'b1000000 + (3'b111 + 3'b001));
>   end
>   endmodule
>
>Note also that "simple operand" is not actually defined in 5.2.
>
>Are parenthetical comments even normative?
>
>-- Brad
>