From: bobduff@world.std.com (Robert A Duff)
Subject: Re: CRC in Ada?
Date: 1997/03/08
Date: 1997-03-08T00:00:00+00:00 [thread overview]
Message-ID: <E6qE3L.68t@world.std.com> (raw)
In-Reply-To: dewar.857749952@merv
In article <dewar.857749952@merv>, Robert Dewar <dewar@merv.cs.nyu.edu> wrote:
>I'll tell you what. Go measure the relative speed of reading a 1 meg
>file a character at a time, vs using read to read the entire 1 meg at
>a time. Do this measurement on at least six different systems. Come
>back here with the results and we will discuss them!
I think the presumption is that the program needs to look at each
character, one at a time. So to make it a fair test, you need to loop
through all the characters and do something with them. Preferably
something that will prevent optimizing away the whole loop (like add
them up and print out the result at the end). The first program should
read a character at a time, and do something. The second should read
into a giant buffer, and *then* loop through it doing (the same)
something.
- Bob
next prev parent reply other threads:[~1997-03-08 0:00 UTC|newest]
Thread overview: 143+ messages / expand[flat|nested] mbox.gz Atom feed top
1997-03-02 0:00 CRC in Ada? Dr. John B. Matthews
1997-03-03 0:00 ` Tom Moran
1997-03-03 0:00 ` David Brown
1997-03-04 0:00 ` David L Brown
1997-03-04 0:00 ` Robert Dewar
1997-03-05 0:00 ` Stephen Garriga
1997-03-05 0:00 ` Larry Kilgallen
1997-03-05 0:00 ` Robert A Duff
1997-03-05 0:00 ` Larry Kilgallen
1997-03-06 0:00 ` Robert A Duff
1997-03-06 0:00 ` Larry Kilgallen
1997-03-06 0:00 ` Robert Dewar
1997-03-06 0:00 ` Robert Dewar
1997-03-09 0:00 ` Dr. John B. Matthews
1997-03-06 0:00 ` Robert Dewar
1997-03-06 0:00 ` Fergus Henderson
1997-03-06 0:00 ` Larry Kilgallen
1997-03-06 0:00 ` Robert A Duff
1997-03-07 0:00 ` Larry Kilgallen
1997-03-07 0:00 ` Tom Moran
[not found] ` <1997Mar7.202252.1@eisner>
1997-03-08 0:00 ` Robert Dewar
1997-03-09 0:00 ` Geert Bosch
1997-03-11 0:00 ` Robert Dewar
1997-03-12 0:00 ` Mats Weber
1997-03-12 0:00 ` Robert Dewar
1997-03-10 0:00 ` Dr. John B. Matthews
1997-03-10 0:00 ` Robert Dewar
1997-03-10 0:00 ` Tom Moran
1997-03-12 0:00 ` Robert Dewar
1997-03-07 0:00 ` Robert A Duff
1997-03-10 0:00 ` Jim Balter
1997-03-07 0:00 ` Robert Dewar
1997-03-10 0:00 ` Jim Balter
1997-03-06 0:00 ` Robert Dewar
1997-03-10 0:00 ` David Brown
1997-03-12 0:00 ` Robert Dewar
1997-03-10 0:00 ` Tarjei Jensen
1997-03-10 0:00 ` Robert Dewar
1997-03-10 0:00 ` Graham Hughes
1997-03-11 0:00 ` Robert Dewar
1997-03-11 0:00 ` Graham Hughes
1997-03-12 0:00 ` Robert Dewar
1997-03-10 0:00 ` Robert Dewar
1997-03-11 0:00 ` Mark & Zurima McKinney
1997-03-12 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-12 0:00 ` Robert I. Eachus
1997-03-13 0:00 ` Jon S Anthony
1997-03-13 0:00 ` Robert Dewar
1997-03-14 0:00 ` Jim Balter
1997-03-14 0:00 ` Jon S Anthony
1997-03-15 0:00 ` Robert Dewar
1997-03-15 0:00 ` Dr. John B. Matthews
1997-03-17 0:00 ` Jon S Anthony
1997-03-06 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-07 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-07 0:00 ` Robert Dewar
1997-03-08 0:00 ` Robert A Duff [this message]
1997-03-10 0:00 ` Jim Balter
1997-03-11 0:00 ` Robert Dewar
1997-03-11 0:00 ` Jim Balter
1997-03-11 0:00 ` Robert Dewar
1997-03-12 0:00 ` Jim Balter
1997-03-14 0:00 ` Richard A. O'Keefe
1997-03-14 0:00 ` Jim Balter
1997-03-06 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-06 0:00 ` Graham Hughes
1997-03-06 0:00 ` Robert Dewar
1997-03-06 0:00 ` Larry Kilgallen
1997-03-09 0:00 ` Robert Dewar
1997-03-07 0:00 ` David Brown
1997-03-07 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-07 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-07 0:00 ` Robert Dewar
1997-03-08 0:00 ` Fergus Henderson
1997-03-10 0:00 ` Jim Balter
1997-03-11 0:00 ` Robert Dewar
1997-03-11 0:00 ` Jim Balter
1997-03-11 0:00 ` Robert Dewar
1997-03-12 0:00 ` Jim Balter
1997-03-11 0:00 ` Jim Balter
1997-03-12 0:00 ` Robert Dewar
1997-03-12 0:00 ` Jim Balter
1997-03-14 0:00 ` Samuel Mize
1997-03-10 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-10 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-10 0:00 ` Robert Dewar
1997-03-10 0:00 ` Jim Balter
1997-03-11 0:00 ` Robert Dewar
1997-03-11 0:00 ` Jim Balter
1997-03-11 0:00 ` Robert Dewar
1997-03-12 0:00 ` Jim Balter
1997-03-11 0:00 ` Fergus Henderson
1997-03-11 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-12 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-12 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-03-12 0:00 ` Jim Balter
1997-03-04 0:00 ` Stephen Garriga
1997-03-04 0:00 ` Matthew Heaney
1997-03-04 0:00 ` Tom Moran
1997-03-04 0:00 ` Stephen Garriga
1997-03-04 0:00 ` Robert Dewar
1997-03-05 0:00 ` Stephen Garriga
1997-03-15 0:00 ` Michael & Amy Hartsough
1997-03-16 0:00 ` Robert Dewar
1997-03-16 0:00 ` Michael & Amy Hartsough
1997-03-16 0:00 ` Robert Dewar
1997-03-18 0:00 ` Michael & Amy Hartsough
1997-03-19 0:00 ` Robert Dewar
1997-03-20 0:00 ` Michael & Amy Hartsough
1997-03-22 0:00 ` Mark & Zurima McKinney
1997-03-22 0:00 ` Robert Dewar
1997-03-22 0:00 ` Robert Dewar
1997-03-24 0:00 ` Sequential IO on OpenVMS (was: CRC in Ada?) Ken Garlington
1997-03-24 0:00 ` Larry Kilgallen
1997-03-21 0:00 ` CRC in Ada? Tom Moran
1997-03-23 0:00 ` Robert Dewar
1997-03-23 0:00 ` Tom Moran
1997-03-24 0:00 ` Portable Code (was: CRC in Ada?) Larry Kilgallen
1997-03-24 0:00 ` CRC in Ada? Robert A Duff
1997-03-24 0:00 ` Robert Dewar
1997-03-24 0:00 ` Robert A Duff
1997-03-24 0:00 ` Larry Kilgallen
1997-03-24 0:00 ` Robert A Duff
1997-03-25 0:00 ` Robert I. Eachus
1997-04-01 0:00 ` David Emery
1997-03-07 0:00 ` John Apa
1997-03-04 0:00 ` Jon S Anthony
1997-03-05 0:00 ` Robert Dewar
1997-03-05 0:00 ` Laurent Pautet
1997-03-05 0:00 ` David C. Hoos, Sr.
1997-03-06 0:00 ` Jon S Anthony
2013-11-14 17:39 ` david
2013-11-14 18:55 ` Adam Beneschan
2013-11-14 19:35 ` tmoran
2013-11-14 20:09 ` Dmitry A. Kazakov
2013-11-14 20:40 ` John B. Matthews
-- strict thread matches above, loose matches on Subject: below --
1997-03-13 0:00 tmoran
1997-03-13 0:00 ` Robert Dewar
1997-03-14 0:00 ` Joakim Olsson
1997-03-14 0:00 ` Tom Moran
1997-03-15 0:00 ` Tom Moran
1997-03-14 0:00 ` Richard A. O'Keefe
1997-03-14 0:00 ` Jon S Anthony
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