From: robert_dewar@my-dejanews.com
Subject: Re: Calculating SQRT in ADA
Date: 1999/03/30
Date: 1999-03-30T00:00:00+00:00 [thread overview]
Message-ID: <7dq5b2$2dk$1@nnrp1.dejanews.com> (raw)
In-Reply-To: 36FFF83A.BE789C93@mitre.org
In article <36FFF83A.BE789C93@mitre.org>,
"Robert I. Eachus" <eachus@mitre.org> wrote:
> Nowadays it is very hard to improve on the "hardware"
> IEEE
> instructions,
I am not sure what this refers to, what "hardware" IEEE
instructions are you referring to. Certainly IEEE does not
include elementary functions except for sqrt, and this is
of course NOT hardware on most machines.
> even when they involve some software
> emulation.
"some software emulation" = done by a software library
routine for most architectures for sqrt, and there are no
other operations defined in IEEE.
Back to
> the original topic, the best way to compute square roots
> is not to use
> NR, but to use the same algorithm you learned in school
> (with calculating the exponent correctly for
> floating-point values). On most
> RISC hardware it is slightly faster than one
> floating-point divide, so
> Newton-Rhapson can't compete. (Of course, the hardware
> instruction, if
> it is really done in hardware, is faster still.)
Sure, a sqrt in hardware can be as fast as a divide, since
a very similar algorithm can be used. But I challenge your
initial statement here. Please cough up code on a specific
machine to justify the statement that you can do a sqrt in
floating-point divide time.
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next prev parent reply other threads:[~1999-03-30 0:00 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-03-24 0:00 Calculating SQRT in ADA cmcrae
1999-03-23 0:00 ` Chris Morgan
1999-03-24 0:00 ` Marin David Condic
[not found] ` <36F913E0.75F51763@lmco.com>
1999-03-24 0:00 ` Ada 83 - Sometimes still chosen Richard D Riehle
1999-03-25 0:00 ` robert_dewar
1999-03-25 0:00 ` Richard D Riehle
1999-03-25 0:00 ` Larry Kilgallen
1999-03-26 0:00 ` robert_dewar
1999-03-26 0:00 ` Tarjei Tj�stheim Jensen
1999-03-27 0:00 ` robert_dewar
1999-03-27 0:00 ` Tarjei Tj�stheim Jensen
1999-03-26 0:00 ` Tom Moran
1999-03-26 0:00 ` Richard D Riehle
1999-03-26 0:00 ` Tom Moran
1999-03-26 0:00 ` Larry Kilgallen
1999-03-29 0:00 ` Marin David Condic
1999-03-29 0:00 ` Tarjei Tj�stheim Jensen
1999-03-27 0:00 ` Matthew Heaney
1999-03-25 0:00 ` robert_dewar
1999-03-25 0:00 ` Richard D Riehle
1999-03-25 0:00 ` Marin David Condic
1999-03-26 0:00 ` robert_dewar
1999-03-24 0:00 ` Calculating SQRT in ADA John Herro
1999-03-24 0:00 ` Hans Marqvardsen
[not found] ` <36FAA3DF.42C31CF@lmco.com>
1999-03-26 0:00 ` Tom Moran
1999-03-25 0:00 ` robert_dewar
1999-03-25 0:00 ` John Herro
1999-03-24 0:00 ` Hans Marqvardsen
1999-03-25 0:00 ` David C. Hoos, Sr.
1999-03-25 0:00 ` robert_dewar
1999-03-26 0:00 ` Calculating SQRT in Ada John Herro
1999-03-26 0:00 ` David C. Hoos, Sr.
1999-03-26 0:00 ` John Herro
1999-03-25 0:00 ` Calculating SQRT in ADA robert_dewar
1999-03-25 0:00 ` David C. Hoos, Sr.
1999-03-26 0:00 ` Howard W. LUDWIG
1999-03-26 0:00 ` Ole-Hjalmar Kristensen
1999-03-27 0:00 ` robert_dewar
1999-03-29 0:00 ` Robert I. Eachus
1999-03-30 0:00 ` robert_dewar [this message]
1999-04-02 0:00 ` Robert I. Eachus
1999-04-03 0:00 ` robert_dewar
1999-03-30 0:00 ` robert_dewar
1999-04-02 0:00 ` Robert I. Eachus
1999-03-25 0:00 ` robert_dewar
1999-03-25 0:00 ` robert_dewar
1999-03-24 0:00 ` Howard W. LUDWIG
1999-03-25 0:00 ` Larry Kilgallen
1999-03-24 0:00 ` bob
1999-03-24 0:00 ` Niklas Holsti
1999-03-26 0:00 ` als0045
1999-03-26 0:00 ` als0045
1999-03-26 0:00 ` bob
1999-03-26 0:00 ` Marin David Condic
1999-03-26 0:00 ` David C. Hoos, Sr.
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