From: jsa@alexandria (Jon S Anthony)
Subject: Re: Ada95 to ANSI_C converter
Date: 1997/04/04
Date: 1997-04-04T00:00:00+00:00 [thread overview]
Message-ID: <JSA.97Apr3191910@alexandria> (raw)
In-Reply-To: JSA.97Apr2144544@alexandria
In article <E831sB.M4s@world.std.com> bobduff@world.std.com (Robert A Duff) writes:
> >> <<So, were these tricks still captured in generated C or were they
> >> something else? If they were still captured in the generated C, then
> >> it would seem that the use of the term "fundamentally" here is not
> >> quite accurate. I mean, the ICC work would be an existence proof to
> >> the contrary.>>
>
> I'm not sure what you're asking. My belief (from vague memories of a
> Dan Eilers post) is that they did something different for different
> targets, to support "efficient" trapping of overflows. I don't know
> whether it was different generated C code, or different libraries, or
> what. I've never actually used the thing, myself -- just vague
> memories of postings.
OK, this is certainly an answer to the question - you aren't sure how
the tricks were done. Basically I just was wondering if the "tricks"
were implemented via generated C (then assuming they really were
efficient, then the ICC impl would be something of a counter example -
at least for overflow stuff).
> Particular implementations of C might be able to. So there's something
> "fundamental" about this inefficiency, if we're talking about standard,
> portable C. ^^^^^^^^
^^^^^^^^^^
OK, check.
> This is just one issue. How do you implement the "raise" statement
> in standard C. Well, most C programmers return status codes, or
> whatever, which is, I think, fundamentally less efficient than real
> exception handling supported by a run-time system. If you're
> willing to take advantage of a particular C implementation's stack
> layout, then you might be able to gain efficiency. But in standard
> C, I don't see how to implement the typical "near-zero overhead" for
> entering the region of an exception handler.
OK, you convinced me.
> Well, I didn't really understand the question, so I'm not surprised
> Robert didn't, either.
Managed to answer it though! :-)
/Jon
--
Jon Anthony
Organon Motives, Inc.
Belmont, MA 02178
617.484.3383
jsa@organon.com
next prev parent reply other threads:[~1997-04-04 0:00 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <5hbrah$ctt$1@gail.ripco.com>
1997-03-26 0:00 ` Ada95 to ANSI_C converter Nick Roberts
1997-03-26 0:00 ` Robert Dewar
1997-03-27 0:00 ` Jennifer E. Lee
1997-03-28 0:00 ` Craig Franck
1997-03-28 0:00 ` Robert Dewar
1997-03-28 0:00 ` Steve Doiel
1997-03-28 0:00 ` Robert Dewar
1997-04-02 0:00 ` Richard Kenner
1997-04-02 0:00 ` Robert Dewar
1997-04-02 0:00 ` Robert A Duff
1997-04-04 0:00 ` Keith Thompson
1997-04-04 0:00 ` Robert Dewar
1997-04-07 0:00 ` Arthur Schwarz
1997-04-07 0:00 ` Robert Dewar
1997-04-08 0:00 ` Robert A Duff
1997-04-07 0:00 ` Peter Seebach
1997-04-07 0:00 ` Kaz Kylheku
1997-04-08 0:00 ` Keith Thompson
1997-04-02 0:00 ` Richard Kenner
1997-04-02 0:00 ` Robert Dewar
1997-04-02 0:00 ` Richard Kenner
1997-04-03 0:00 ` Fergus Henderson
1997-03-27 0:00 ` Jennifer E. Lee
1997-03-27 0:00 ` Philip Johnson
1997-04-01 0:00 ` Jennifer E. Lee
1997-04-02 0:00 ` Philip E. Johnson
1997-04-03 0:00 ` Jon S Anthony
1997-03-28 0:00 ` Robert Dewar
1997-03-28 0:00 ` Craig Franck
1997-03-28 0:00 ` Robert Dewar
1997-04-01 0:00 ` Tom Wheeley
1997-04-01 0:00 ` David Kristola
1997-04-01 0:00 ` Jennifer E. Lee
1997-03-27 0:00 ` Craig Franck
1997-03-27 0:00 ` Jennifer E. Lee
1997-04-01 0:00 ` Robert I. Eachus
1997-03-27 0:00 ` Jeff Carter
1997-03-28 0:00 ` Jon S Anthony
1997-03-28 0:00 ` Robert Dewar
1997-04-02 0:00 ` Jon S Anthony
1997-04-03 0:00 ` Robert Dewar
1997-04-04 0:00 ` Jon S Anthony [this message]
1997-04-03 0:00 ` Jon S Anthony
1997-04-03 0:00 ` Robert A Duff
1997-04-03 0:00 ` Robert Dewar
1997-04-03 0:00 ` Robert Dewar
1997-04-04 0:00 ` Jon S Anthony
1997-04-04 0:00 ` Robert Dewar
1997-04-04 0:00 ` Robert Dewar
1997-04-07 0:00 ` Jon S Anthony
1997-04-07 0:00 ` Jon S Anthony
1997-03-28 0:00 ` Jon S Anthony
1997-03-31 0:00 ` Jon S Anthony
1997-03-31 0:00 ` Robert Dewar
1997-04-01 0:00 ` Robert A Duff
1997-03-31 0:00 ` David Emery
1997-04-03 0:00 ` Jon S Anthony
1997-04-03 0:00 ` Jennifer E. Lee
1997-04-04 0:00 ` Howard W. LUDWIG
1997-04-16 0:00 Dan Lehman
1997-04-17 0:00 ` Robert Dewar
1997-04-20 0:00 ` Nick Roberts
1997-04-20 0:00 ` Robert Dewar
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