Date: Wed, 1 Feb 95 19:53:55 PST
From: paktor@hal.com (David Paktor)
Subject: Item #227: "Split" and "Join" words for Core


P1275 Open Firmware Working Group Proposal -- Proposal #:227 Ver 1

Title:		"Split" and "Join" words for Core

Author:		David L. Paktor

Date:		Wed 01 Feb 95

Ed/Tech:	Editorial

Synopsis:	Clarify the phrasing of the descriptions of  bljoin  bwjoin
		     lbsplit  lwsplit  wbsplit  and  wljoin  in the Core.

Doc & Version:	1275.0 D12

Problem:        The descriptions of  bljoin  bwjoin  lbsplit  lwsplit  wbsplit
		    and  wljoin , if taken literally, would be inaccurate.
		    An earlier proposal addressing this was phrased awkwardly
		    and might have gotten tangled.

Proposal:  Change the text on the following page:lines as shown:

    pg:ln#	Word Described
		Changed Text

     131:12	bljoin
		The eight least significant bits of each operand are combined
		    to form a quadlet.  Other operand bits must be zero.

     135:03	bwjoin
		The eight least significant bits of each operand are combined
		    to form a doublet.  Other operand bits must be zero.

     168:23	lbsplit
		The bits of greater significance than the eight least
		    significant bits of each of the four resulting values
		    will be zero.

     171:29	lwsplit
		The bits of greater significance than the sixteen least
		    significant bits of each of the two resulting values
		    will be zero.

     207:17	wbsplit
		The bits of greater significance than the eight least
		    significant bits of each of the two resulting values
		    will be zero.

     208:03	wljoin
		The sixteen least significant bits of each operand are combined
		    to form a quadlet.  Other operand bits must be zero.


Discussion:  I would have liked to say "are ignored" in the xxJoin words,
	instead of "must be zero", but, in fact, many existing implementa-
	tions do not ignore these bits.  I would prefer to place the burden
	of trimming out the "other operand bits" on the implementation,
	rather than on the application.  Certainly, to do so would not break
	any existing applications...


David

[ P1275 Item #227 -- Received: Wed Feb  1 19:56:31 PST 1995 ]