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From: Stefan Monnier <monnier@IRO.UMontreal.CA>
To: tomas@tuxteam.de
Cc: David Kastrup <dak@gnu.org>, emacs-devel@gnu.org
Subject: Re: [PATCH] use tail pointer for LOOP
Date: Thu, 17 Jun 2010 16:48:43 -0400	[thread overview]
Message-ID: <jwvpqzpcrqe.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <20100617051021.GA26623@tomas> (tomas@tuxteam.de's message of "Thu, 17 Jun 2010 07:10:21 +0200")

>         Reverse: (1.006534 3 0.682734)
>    Tail pointer: (1.305476 4 0.9159619999999986)

> Still, reversing seems to be worth it (by some 30 percent). Unless we
> find some way to streamline the tail pointer better.

That's really not surprising: count the number of function calls and
you'll see that the nreverse way is likely to win every time, simply
because it suffers about half as much from the interpretation overhead.


        Stefan



  parent reply	other threads:[~2010-06-17 20:48 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-29 21:56 O(N^2) behavior in LOOP Daniel Colascione
2010-05-29 22:06 ` Daniel Colascione
2010-05-29 22:14   ` Lennart Borgman
2010-05-29 22:35   ` Geoff Gole
2010-05-29 23:58     ` [PATCH] use tail pointer for LOOP (Was: Re: O(N^2) behavior in LOOP) Daniel Colascione
2010-05-30  0:45       ` Ken Raeburn
2010-05-30  0:49         ` Daniel Colascione
2010-06-16 17:44           ` tomas
2010-06-16 18:10             ` [PATCH] use tail pointer for LOOP David Kastrup
2010-06-17  5:10               ` tomas
2010-06-17  7:18                 ` Thien-Thi Nguyen
2010-06-17  9:22                   ` tomas
2010-06-17 10:03                     ` Thien-Thi Nguyen
2010-06-17 14:05                       ` tomas
2010-06-17 15:16                         ` Thien-Thi Nguyen
2010-06-17 10:12                     ` Thien-Thi Nguyen
2010-06-17 20:48                 ` Stefan Monnier [this message]
2010-06-18  7:07                   ` David Kastrup
2010-06-18 13:40                     ` Stefan Monnier
2010-05-30 17:05       ` Štěpán Němec
2010-05-30 17:09         ` Daniel Colascione

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