Re: [Fwd: evaluation order question]

From: Shalom.Bresticker@motorola.com
Date: Mon Jan 20 2003 - 19:38:31 PST

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    I don't understand that distinction.
    I don't see why the same reasoning could not apply to both blocking and
    nonblocking assignments.

    I will look to see if I can find something about it in my mail archives.

    Shalom

    On Mon, 20 Jan 2003, Karen Pieper wrote:

    > The reason that I would assume for blocking assignments is that a blocking
    > assignment
    > a[i] = #10 b;
    > can be rewritten as:
    > t = b;
    > #10
    > a[i] = t;
    > For non-blocking assignments, the statement is saying that the value being
    > assigned to is known at the time that the rhs is evaluated so that the
    > update of the
    > variable can be scheduled.
    >
    > K
    >
    >
    > At 05:11 PM 1/20/03 +0200, Shalom Bresticker wrote:
    > >I sent this question a while back, but did not get back any answers.
    > >
    > >I also have an additional question.
    > >
    > >When there IS an intra-assignment timing control, why is the
    > >variable_lvalue evaluated "at the time specified by the ... timing
    > >control" for blocking assignments (9.2.1), but "at the same time as the
    > >expression on the right-hand side" for nonblocking assignments (9.2.2)?
    > >
    > >Thanks
    > >Shalom
    > >
    > >--
    > >Shalom Bresticker Shalom.Bresticker@motorola.com
    > >Design & Reuse Methodology Tel: +972 9 9522268
    > >Motorola Semiconductor Israel, Ltd. Fax: +972 9 9522890
    > >POB 2208, Herzlia 46120, ISRAEL Cell: +972 50 441478
    > >
    > >"The devil is in the details."
    > >
    > >
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    > >Date: Mon, 25 Nov 2002 09:15:39 +0200
    > >From: Shalom Bresticker<Shalom.Bresticker@motorola.com>
    > >To: <etf@boyd.com>
    > >Subject: evaluation order question
    > >X-Mozilla-Status2: 00000000
    > >X-Status:
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    > >
    > >9.2.2 para. 3 on nonblocking assignments says,
    > >
    > >"If reg_lvalue requires an evaluation, it shall be evaluated at the same
    > >time as the expression on the right-hand side. The order of evaluation
    > >of the reg_lvalue and the expression on the right-hand side is undefined
    > >if timing control is not specified."
    > >
    > >9.2.1 on blocking assignments says,
    > >"If reg_lvalue requires an evaluation, it shall be evaluated at the time
    > >specified by the intra-assignment timing control. "
    > >
    > >Questions:
    > >1. If there is no timing control, then for nba's, why is order of rhs
    > >vs. lhs undefined ?
    > >
    > >2. What happens in blocking assignments when there is no timing control?
    > >
    > >3. Why is there no parallel statement in 9.2.1?
    > >
    > >--
    > >Shalom Bresticker Shalom.Bresticker@motorola.com
    > >Design & Reuse Methodology Tel: +972 9 9522268
    > >Motorola Semiconductor Israel, Ltd. Fax: +972 9 9522890
    > >POB 2208, Herzlia 46120, ISRAEL Cell: +972 50 441478
    > >
    > >"The devil is in the details."
    >
    >

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