From: bobduff@world.std.com (Robert A Duff)
Subject: Re: Most efficient way to check for null string?
Date: 1997/06/21
Date: 1997-06-21T00:00:00+00:00 [thread overview]
Message-ID: <EC3ttx.I1o@world.std.com> (raw)
In-Reply-To: EC3C0x.E68.0.-s@inmet.camb.inmet.com
In article <EC3C0x.E68.0.-s@inmet.camb.inmet.com>,
Tucker Taft <stt@houdini.camb.inmet.com> wrote:
>...If you really want to
>shave cycles, the following will likely be the most efficient:
>
> if Str'Last < Str'First then ...
Bletch. That's the least readable of all, but Tucker's right that it
might be more efficient. Tucker didn't say why. It's because Ada
(foolishly, IMHO) allows Str's range to be something like
1_000 .. -1_000_000. Which means that calculating the 'Length involves
a conditional jump in the general case.
- Bob
next prev parent reply other threads:[~1997-06-21 0:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
1997-06-20 0:00 Most efficient way to check for null string? Dale Stanbrough
1997-06-20 0:00 ` Tucker Taft
1997-06-21 0:00 ` Robert A Duff [this message]
1997-06-21 0:00 ` Robert Dewar
1997-06-23 0:00 ` Richard Kenner
1997-06-23 0:00 ` Tucker Taft
1997-06-20 0:00 ` Robert A Duff
1997-06-20 0:00 ` Robert Dewar
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