From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: ADA on the super
Date: 1998/04/21
Date: 1998-04-21T00:00:00+00:00 [thread overview]
Message-ID: <dewar.893163240@merv> (raw)
In-Reply-To: m3son7o2zz.fsf@fred.muc.de
Andi said
<<It is surprising that Gnat doesn't do this. At least the C frontend of gcc
does a very similar optimization:
>>
No, the optimization you cite is at a radically different semantic level.
There is nothing like dynamic slices and concatenations in C. If you
write Ada code that corresponds to the C code you gave, which is easy
to do, you will of course get identical code.
But there is no C code that is even vaguely like the quoted Ada code.
To get a feel for the issues involved, look at the exp_pakd unit in GNAT,
and also study some -gnatdg output, to understand the general semantic
level of the tree expansions involved here.
Remember that we are talking about very general capabilities here, which
just happen to be used in this particular case to do a rotate.
next prev parent reply other threads:[~1998-04-21 0:00 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
1998-04-17 0:00 ADA on the super Alex Stuebinger
1998-04-18 0:00 ` Robert Dewar
1998-04-18 0:00 ` stuebi
1998-04-19 0:00 ` Greg Lindahl
1998-04-19 0:00 ` Robert Dewar
1998-04-20 0:00 ` Michael F Brenner
1998-04-20 0:00 ` Toon Moene
1998-04-21 0:00 ` Larry Kilgallen
1998-04-21 0:00 ` Toon Moene
1998-04-20 0:00 ` Robert Dewar
1998-04-21 0:00 ` Andi Kleen
1998-04-21 0:00 ` Robert Dewar [this message]
1998-04-21 0:00 ` Ada on the super (packed arrays) Michael F Brenner
1998-04-22 0:00 ` Andi Kleen
1998-04-21 0:00 ` ADA on the super Larry Kilgallen
1998-04-20 0:00 ` K. Mathias
1998-04-20 0:00 ` Acronyms was: " Eugene Miya
[not found] <6hibr7$kf5$1@bambi.zdv.Uni-Mainz.DE>
1998-04-21 0:00 ` Ada " Richard Toy
1998-04-21 0:00 ` Juergen Pfeifer
1998-04-22 0:00 ` Alex Stuebinger
1998-04-22 0:00 ` Jerry van Dijk
1998-04-22 0:00 ` John M. Mills
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