From: anon@att.net
Subject: Re: Efficiency of code generated by Ada compilers
Date: Tue, 10 Aug 2010 22:50:40 +0000 (UTC)
Date: 2010-08-10T22:50:40+00:00 [thread overview]
Message-ID: <i3sl3v$1ogj$1@news.ett.com.ua> (raw)
In-Reply-To: op.vg77swroxmjfy8@garhos
In <op.vg77swroxmjfy8@garhos>, =?iso-8859-15?Q?Yannick_Duch=EAne_=28Hibou57=29?= writes:
>Le Tue, 10 Aug 2010 16:03:13 +0200, Elias Salom=E3o Helou Neto =
>
><eshneto@gmail.com> a =E9crit:
>> It is a pity that this post became a technical discussion on array
>> indexing.
>Could I, if you please, talk to Phil without your prior acknowledgment =
>
>please ? ;)
>
>While I understand why you reacted (not the way you do... closed =
>
>parenthesis)
>
>> A simple question that could be asked in a single line is:
>> can Ada access arrays without range checking?
>Sorry, due to a recent trouble with my news reader, I've the original po=
>st.
>
>However, on this sentence basis, I would say: if you do not want range =
>
>check, then just disable it in the compiler option. But be warned you wi=
>ll =
>
>then be unable to catch runtime error. While there is a way to safely dr=
>op =
>
>this compiler option: validation with SPARK checker (just tell if you ne=
>ed =
>
>to learn about it).
>
>If your matter is just about range checking, the answer is as simple as =
> =
>
>that.
>
>If you use GNAT, you may insert "-gnatp" in the command line arguments.
>http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gnat_ugn_unw/Run_002dTime-Checks=
>..html
>
>If you use GNAT from the GPS environment, you may open the "Project" men=
>u, =
>
>then the "Edit project properties" submenu. Then choose the "Switches" =
>
>tab, then the "Ada" tab and check the "Suppress all check" check box or =
> =
>
>uncheck the "Overflow check" check box.
>
>Providing I did not fail to understand what you meant.
>
>-- =
>
>There is even better than a pragma Assert: a SPARK --# check.
>--# check C and WhoKnowWhat and YouKnowWho;
>--# assert Ada;
>-- i.e. forget about previous premises which leads to conclusion
>-- and start with new conclusion as premise.
While the main expression are equal. The code generation by Ada compilers
versus C or C++ is less efficient do to a number of factors.
1. Elaboration: Ada compilers can generate run-time elaboration
routines that must be executed before starting
the main users program. C/C++ compilers do not
perform any run-time elaboration, which cause
the execution and code generation to be more
efficient but cause the less program to be less
reliable.
2. Run-Time Checks: The Ada compiler generates inline run-time checks
which the C/C++ compiler do not. Using the pragma
"suppress" statement can eliminate most checks. The
absent of these checks makes C/C++ less reliable.
Using the following removes all checks the statement
does have other precise options as well.
pragma Suppress ( All_Checks ) ;
-- removes all checks on the program or that package.
pragma Suppress ( All_Checks, ON => <name 1>,
...
ON => <name n> ) ;
-- removes all checks on that set of names only.
-- Names may be an object such as an array or routine
-- Also, the "ON =>" symbols are optional
3. GCC backend: Ada as well as any other language besides C or C++
must translate the core language into the C/C++ like
tree structure. Which forces the core languages to be
limited to C/C++ code generation.
next prev parent reply other threads:[~2010-08-10 22:50 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-06 20:21 Efficiency of code generated by Ada compilers Elias Salomão Helou Neto
2010-08-06 20:24 ` (see below)
2010-08-06 23:14 ` Shark8
2010-08-07 7:53 ` Dmitry A. Kazakov
2010-08-10 13:52 ` Elias Salomão Helou Neto
2010-08-10 14:24 ` Shark8
2010-08-10 14:28 ` Shark8
2010-08-10 15:01 ` Robert A Duff
2010-08-10 15:14 ` Yannick Duchêne (Hibou57)
2010-08-10 18:32 ` Robert A Duff
2010-08-10 15:10 ` Georg Bauhaus
2010-08-10 15:32 ` Dmitry A. Kazakov
2010-08-10 22:26 ` Randy Brukardt
2010-08-20 7:22 ` Yannick Duchêne (Hibou57)
2010-08-08 14:03 ` Gene
2010-08-08 15:49 ` Robert A Duff
2010-08-08 17:13 ` Charles H. Sampson
2010-08-08 18:11 ` Dmitry A. Kazakov
2010-08-08 20:51 ` Robert A Duff
2010-08-08 22:10 ` (see below)
2010-08-08 22:22 ` Robert A Duff
2010-08-09 4:46 ` Yannick Duchêne (Hibou57)
2010-08-09 5:52 ` J-P. Rosen
2010-08-09 13:28 ` Robert A Duff
2010-08-09 18:42 ` Jeffrey Carter
2010-08-09 19:05 ` Robert A Duff
2010-08-10 10:00 ` Jacob Sparre Andersen
2010-08-10 12:39 ` Robert A Duff
2010-08-09 19:33 ` Yannick Duchêne (Hibou57)
2010-08-09 21:42 ` Robert A Duff
2010-08-10 12:26 ` Phil Clayton
2010-08-10 12:57 ` Yannick Duchêne (Hibou57)
2010-08-10 14:03 ` Elias Salomão Helou Neto
2010-08-10 14:27 ` Yannick Duchêne (Hibou57)
2010-08-10 22:50 ` anon [this message]
2010-08-10 23:28 ` Yannick Duchêne (Hibou57)
2010-08-10 23:38 ` Yannick Duchêne (Hibou57)
2010-08-11 7:06 ` Niklas Holsti
2010-08-11 11:58 ` anon
2010-08-11 12:37 ` Georg Bauhaus
2010-08-11 13:13 ` Robert A Duff
2010-08-11 23:49 ` Randy Brukardt
2010-08-10 14:31 ` Shark8
2010-08-11 7:14 ` Charles H. Sampson
2010-08-11 6:42 ` Charles H. Sampson
2010-08-08 22:35 ` tmoran
2010-08-09 13:53 ` Robert A Duff
2010-08-09 17:59 ` tmoran
2010-08-09 19:36 ` Yannick Duchêne (Hibou57)
2010-08-09 21:38 ` Robert A Duff
2010-08-11 7:42 ` Charles H. Sampson
2010-08-11 13:38 ` Robert A Duff
2010-08-12 7:48 ` Charles H. Sampson
2010-08-12 8:08 ` Ludovic Brenta
2010-08-12 17:10 ` Charles H. Sampson
2010-08-12 18:06 ` Jeffrey Carter
2010-08-11 18:49 ` Simon Wright
2010-08-12 7:54 ` Charles H. Sampson
2010-08-12 8:36 ` Dmitry A. Kazakov
2010-08-12 11:04 ` Brian Drummond
2010-08-12 19:23 ` Simon Wright
2010-08-12 20:21 ` (see below)
2010-08-13 15:08 ` Elias Salomão Helou Neto
2010-08-13 15:10 ` Elias Salomão Helou Neto
2010-08-13 18:01 ` Georg Bauhaus
2010-08-13 19:52 ` Robert A Duff
2010-08-14 9:44 ` Georg Bauhaus
2010-08-13 20:22 ` Robert A Duff
2010-08-14 1:34 ` Randy Brukardt
2010-08-14 7:18 ` anon
2010-08-13 21:57 ` Jeffrey Carter
2010-08-13 22:37 ` Yannick Duchêne (Hibou57)
2010-08-13 22:43 ` Yannick Duchêne (Hibou57)
2010-08-13 23:29 ` tmoran
2010-08-14 0:02 ` Yannick Duchêne (Hibou57)
2010-08-14 0:16 ` (see below)
2010-08-14 10:47 ` Brian Drummond
2010-08-14 13:58 ` Yannick Duchêne (Hibou57)
2010-08-15 0:23 ` Brian Drummond
2010-08-14 14:51 ` (see below)
2010-08-15 0:58 ` Brian Drummond
2010-08-15 1:58 ` (see below)
2010-08-15 10:31 ` Brian Drummond
2010-08-13 15:37 ` Dmitry A. Kazakov
2010-08-16 13:29 ` Elias Salomão Helou Neto
2010-08-16 14:09 ` Dmitry A. Kazakov
2010-08-18 14:00 ` Elias Salomão Helou Neto
2010-08-18 16:38 ` Dmitry A. Kazakov
2010-08-19 18:52 ` Elias Salomão Helou Neto
2010-08-19 19:48 ` Dmitry A. Kazakov
2010-08-13 16:58 ` (see below)
2010-08-14 16:13 ` Charles H. Sampson
2010-08-16 13:45 ` Elias Salomão Helou Neto
2010-08-15 12:32 ` Florian Weimer
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