From: "Robert I. Eachus" <eachus@mitre.org>
Subject: Re: Why Ada is not the Commercial Lang of Choice
Date: 1997/06/18
Date: 1997-06-18T00:00:00+00:00 [thread overview]
Message-ID: <33A7FBFF.29D2@mitre.org> (raw)
Paul Van Bellinghen writes:
>
> Claim:
> It is much easier in C, for example, to output a data word to
> an I/O device that is memory mapped.
>
> Supporting Evidence:
> 1 One need only define a pointer
> 2 and assign it the memory mapped address
> 3 then store the desired data value to the contents of the pointer.
>
> Example:
> #define mem_map_addr B0100040
> unsigned int *p;
>
> p = (unsigned int *) mem_map_addr;
>
> *p = 0x00344556;
>
> Claim:
> It is harder to do it in Ada because i write it out in more words.
Wait a second here. The eqivalent Ada is:
Mem_Map: Integer;
for Mem_Map'Address use 16#B0100040#;
begin
Mem_Map := 16#00344556#;
...which is a little shorter in terms of characters, words, and
lines. I could go into the bugs in both the Ada and the C--I'd want
pragma Volitile(Mem_Map); in both Ada and C. Most compilers will get it
"right" but why take the risk. Also, it might be necessary to call
System.Storage_Elements.To_Address, but I can't imagine any compiler for
a machine where 16#B01000040# is a meaningful address not allowing
literals for addresses.
--
Robert I. Eachus
with Standard_Disclaimer;
use Standard_Disclaimer;
next reply other threads:[~1997-06-18 0:00 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
1997-06-18 0:00 Robert I. Eachus [this message]
1997-06-18 0:00 ` Why Ada is not the Commercial Lang of Choice Dale Stanbrough
1997-06-19 0:00 ` Steve Jones - JON
1997-06-19 0:00 ` Peter Hermann
1997-06-19 0:00 ` Anonymous
1997-07-17 0:00 ` Shmuel (Seymour J.) Metz
1997-06-19 0:00 ` Robert A Duff
1997-06-21 0:00 ` Paul Van Bellinghen
1997-06-20 0:00 ` Robert Dewar
1997-06-23 0:00 ` John G. Volan
1997-07-03 0:00 ` Shmuel (Seymour J.) Metz
1997-07-03 0:00 ` Robert Dewar
1997-07-06 0:00 ` Yasmiin S. Davis
1997-07-06 0:00 ` Robert Dewar
1997-07-07 0:00 ` Shmuel (Seymour J.) Metz
1997-07-04 0:00 ` Paul Van Bellinghen
1997-07-13 0:00 ` Ken Mays
1997-07-13 0:00 ` Robert Munck
1997-07-14 0:00 ` Ken Mays
1997-06-20 0:00 ` Don Harrison
1997-06-20 0:00 ` Roy Grimm
1997-06-20 0:00 ` Donovan Baarda
1997-06-20 0:00 ` Larry Kilgallen
1997-06-20 0:00 ` Nick Leaton
1997-06-23 0:00 ` Don Harrison
1997-06-24 0:00 ` Bertrand Meyer
1997-06-24 0:00 ` Nick Leaton
1997-07-22 0:00 ` Dr. Vladimir Il'ich Fomin
1997-06-23 0:00 ` Joachim Durchholz
1997-06-23 0:00 ` Robert Dewar
1997-06-24 0:00 ` Don Harrison
1997-06-24 0:00 ` Robert Dewar
1997-06-20 0:00 ` Robert Dewar
1997-06-20 0:00 ` Robert Dewar
1997-06-21 0:00 ` Keith Thompson
1997-06-21 0:00 ` Robert Dewar
1997-06-24 0:00 ` Ken Garlington
1997-06-24 0:00 ` Robert Dewar
1997-06-28 0:00 ` Robert I. Eachus
1997-06-28 0:00 ` Robert Dewar
-- strict thread matches above, loose matches on Subject: below --
1997-06-13 0:00 Paul Van Bellinghen
1997-06-17 0:00 ` Dale Stanbrough
1997-06-17 0:00 ` Robert Munck
1997-06-18 0:00 ` Ken Garlington
1997-06-19 0:00 ` Ole-Hjalmar Kristensen FOU.TD/DELAB
1997-06-19 0:00 ` Ken Garlington
1997-06-17 0:00 ` Robert Dewar
1997-06-20 0:00 ` nma123
1997-06-24 0:00 ` Adam Beneschan
1997-06-18 0:00 ` Nick Roberts
1997-06-18 0:00 ` Peter Hermann
1997-06-20 0:00 ` Robert Dewar
1997-06-25 0:00 ` Van Snyder
1997-06-26 0:00 ` Robert Dewar
1997-06-30 0:00 ` Ralph Paul
1997-07-02 0:00 ` Joerg Rodemann
1997-07-02 0:00 ` Ralph Paul
1997-07-02 0:00 ` Joerg Rodemann
1997-06-19 0:00 ` Steve Doiel
1997-06-19 0:00 ` Anonymous
1997-07-22 0:00 ` Shmuel (Seymour J.) Metz
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