From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00
	autolearn=unavailable autolearn_force=no version=3.4.4
Path: 
 Xl.tags.giganews.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!local2.nntp.dca.giganews.com!nntp.earthlink.com!news.earthlink.com.POSTED!not-for-mail
NNTP-Posting-Date: Sat, 20 Dec 2014 10:49:48 -0600
From: Dennis Lee Bieber <wlfraed@ix.netcom.com>
Newsgroups: comp.lang.ada
Subject: Re: =?ISO-8859-1?Q?GNAT=A0and_Tasklets?=
Date: Sat, 20 Dec 2014 11:49:54 -0500
Organization: IISS Elusive Unicorn
Message-ID: <4s9b9ah19vch9lshchrbi3vndv0ktan5i4@4ax.com>
References: <8277a521-7317-4839-b0b6-97f8155be1a4@googlegroups.com>
 <fegtcevrst5z$.fck8rij41mwt.dlg@40tude.net>
 <9e1d2b9f-1b97-4679-8eec-5ba75f3c357c@googlegroups.com>
 <zdj4kqj1rzxe.o579icl2x61u$.dlg@40tude.net>
 <478c81f9-5233-4ae1-a3eb-e67c4dbd0da1@googlegroups.com>
 <m70va3$t6a$1@dont-email.me> <yjrnhk0w8gjd.k6ht3uh7raiw.dlg@40tude.net>
 <gAYkw.944188$Fo3.593534@fx09.iad>
 <1r2ziulc78imb$.ad6zx5upic6s$.dlg@40tude.net>
 <td_kw.949255$FX2.779836@fx18.iad>
X-Newsreader: Forte Agent 6.00/32.1186
X-No-Archive: YES
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Usenet-Provider: http://www.giganews.com
NNTP-Posting-Host: 108.68.177.133
X-Trace: 
 sv3-k9N8hqGy+rsz6HeM4eCcnwIy16y7RYtxJUY6j7jt2pneOm56oLRwpeZK36T22XYeaPAbSK046djeDNX!ejkUpswpyEwAIY0uOp9xS219WeXFT3amuBPMK+AOluk+1X/FuO8QZFzgnNqxvW4OIw1Im1oiboM4!iQtMcKX39Y0pSfm2ndJjbiyRJ20r
X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers
X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint
 properly
X-Postfilter: 1.3.40
X-Original-Bytes: 2807
Xref: number.nntp.giganews.com comp.lang.ada:191483
Date: 2014-12-20T11:49:54-05:00
List-Id: <comp.lang.ada>

On Fri, 19 Dec 2014 11:35:05 -0700, Brad Moore <brad.moore@shaw.ca>
declaimed the following:

>
>I haven't listed all the semantics but for the questions you ask,
>each arm of the parallel block is a separate thread of execution (which 
>we have been calling a tasklet).
>
>Each tasklet starts off with its own local declaration of Total, 
>initialized to 0, which is the Identity value for the reduction.
>
>So, for the top Total, you end up with {Top_}Total := 1 + A + B;

	There is no way I would ever interpret /that/ result... I'd actually
expect an optimizing compiler to see that the result of incrementing Total
is thrown away by the next statement in the block.

>for the bottom Total, you end up with {Bottom_}Total := C + D;
>
>Then during the reduction phase, those two results get reduced using the 
>reduction operation, which in this case is "+".
>
>So the end result is Total = 1 + A + B + C + D;
>

	So your reduction phase becomes the equivalent of a summing
operation...

	par_sum(	1,
				A + B,
				C + D	)	{of course, to do this right requires deferred
								evaluation of the parameters}

What if you want the result to be a product?
-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
    wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/