From: dewar@gnat.com (Robert Dewar)
To: dewar@gnat.com, fjh@cs.mu.oz.au
Cc: gcc@gcc.gnu.org
Subject: Re: forcing tail/sibling call optimization
Date: Sun, 26 Nov 2000 08:14:00 -0000 [thread overview]
Message-ID: <20001126161445.8878634D82@nile.gnat.com> (raw)
The formal definition seems quite reasonable here, but I must say
I dislike the syntax, and it is unnecessarily provocative, since
this really is not semantically a goto at all (e.g. the formal
denmotational semantics would have nothing to do with the semantics
of goto). Why not something like "tail return" or perhaps better
simply a compiler directive.
The real point here is that the semantics is identical to return. What
the declaration (in whatever form it exists) is doing is to say that
the semanjtics of execution will be undefined if there are any subsequent
references to local variables of the caller. That's *all* that needs to
be said semantically.
In Ada, one would provide this capability by simply having a pragma
e.g. pragma Tail_Return; which has no effect on the semantics of the
program if it is correct.
next reply other threads:[~2000-11-26 8:14 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2000-11-26 8:14 Robert Dewar [this message]
2000-11-26 13:43 ` Fergus Henderson
2000-11-27 7:58 ` Jeffrey A Law
2000-11-27 8:05 ` David Edelsohn
2000-11-27 8:07 ` Andi Kleen
2000-11-27 8:25 ` Jeffrey A Law
2000-11-27 8:39 ` Andi Kleen
2000-11-27 9:48 ` Jeffrey A Law
2000-11-27 11:21 ` Lars Brinkhoff
2000-11-27 10:54 ` Mark Mitchell
2000-11-27 8:38 ` Bernd Schmidt
2000-11-27 11:26 ` Eric W. Biederman
2000-11-27 10:48 ` Mark Mitchell
2000-11-27 12:46 ` Harvey J. Stein
2000-11-27 13:02 ` Travis Moulton
2000-11-27 10:47 ` Mark Mitchell
2000-11-28 19:21 ` Fergus Henderson
2000-11-29 2:09 ` Mark Mitchell
2000-11-30 23:59 ` Fergus Henderson
2000-12-01 15:51 ` Joe Buck
2001-01-03 12:24 ` Fergus Henderson
2001-01-03 13:09 ` Richard Henderson
2001-01-03 14:59 ` Fergus Henderson
2001-01-03 15:32 ` Richard Henderson
2001-01-03 15:53 ` Fergus Henderson
2001-01-03 16:11 ` Richard Henderson
2001-01-03 16:36 ` Fergus Henderson
2002-09-14 23:35 ` Fergus Henderson
2002-09-16 9:26 ` Richard Henderson
2000-11-27 23:39 ` Fergus Henderson
-- strict thread matches above, loose matches on Subject: below --
2000-11-29 4:58 Robert Dewar
2000-11-27 15:33 Mike Stump
2000-11-27 10:04 Robert Dewar
2000-11-27 9:39 Geert Bosch
2000-11-27 12:06 ` Jeffrey A Law
2000-11-27 9:08 Robert Dewar
2000-11-27 9:14 ` Bernd Schmidt
2000-11-27 10:09 ` Michael Matz
2000-11-27 8:44 Robert Dewar
2000-11-27 9:44 ` Jeffrey A Law
2000-11-27 10:22 ` Mark Probst
2000-11-27 14:42 ` Harvey J. Stein
2000-11-27 16:07 ` Mark Probst
2000-11-27 14:30 ` Harvey J. Stein
2000-11-26 18:09 Robert Dewar
2000-11-26 15:46 Robert Dewar
2000-11-26 16:21 ` Joseph S. Myers
2000-11-26 18:08 ` Fergus Henderson
2000-11-26 21:50 ` Jeffrey A Law
2000-11-26 15:27 Robert Dewar
2000-11-26 17:56 ` Fergus Henderson
2000-11-26 10:59 Timothy J. Wood
2000-11-26 9:12 Geert Bosch
2000-11-26 8:21 Robert Dewar
2000-11-26 13:51 ` Fergus Henderson
2000-11-26 5:00 Robert Dewar
2000-11-26 7:44 ` Fergus Henderson
2000-11-26 8:18 ` Bernd Schmidt
2000-11-26 9:55 ` Andi Kleen
2000-11-26 11:34 ` Per Bothner
2000-11-26 11:55 ` Mark Probst
2000-11-26 17:40 ` Fergus Henderson
2000-11-26 3:56 Fergus Henderson
2000-11-26 5:22 ` Mark Probst
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