Path: utzoo!attcan!uunet!cs.utexas.edu!samsung!think!snorkelwacker!bloom-beacon!primerd!ENI!ENS!J.COOK
From: J.COOK@ENS.Prime.COM
Newsgroups: comp.sys.mac.programmer
Subject: Re: Need large array on Think C.
Message-ID: <1232500002@ENS.Prime.COM>
Date: 30 May 90 09:56:00 GMT
References: <26645@<265986A9>
Lines: 39
Nf-ID: #R:<265986A9:-2664500:ENS:1232500002:000:1331
Nf-From: ENS.Prime.COM!J.COOK    May 30 09:56:00 1990


========> forwarded message from eco8941@ecostat.aau.dk

There is not more problems in C than in other languages, you
can get all the spped you want by using register variables.
something like this should work:

typedef char mytype[100][300];

mytype *globalarray;

main()
{
   globalarray = malloc( (unsigned long) sizeof(mytype) );
   /*            ^^^^^^ use your favourite allocation routine here */
   .
   .
}

usearray()
{
   register mytype *myarray;

   myarray[25][50] = 'a';    /* no overhead, direct in register */
}

I haven't checked if I could make globalarray of register storage class,
but that would remove the little overhead introduced in usearray().


========================================================================
| Povl H. Pedersen      |  InterNet address: ECO8941@ecostat.aau.dk    |
| Student               |----------------------------------------------|
| Dept. of Economics    | Spare time Mac Programmer                    |
| Aarhus Universitet    | Own Hardware: Mac SE, 4MB + 49MB SCSI HD     |
| DENMARK               | Interests: Macintosh, C,  boardgames         |
|======================================================================|
[ Why I don't keep things in the right order ?    I understand Chaos ! ]
========================================================================