Hello:

I have a little problem, i participe in the 'Large Compression Benchmark' (http://cs.fit.edu/~mmahoney/compression/text.html) and need to cache the whole enwik8 file (100MB) on memory but when i try to allocate space for it i get a compiler error, saying that maximum is 64MB (67108864). I tried to use $MEMORY 200000000,500000000 (200MB stack and 500MB heap) and the compiler switches, but no success.

I need all the file on RAM beacause i want to do a BWT, which implies a sort of the 100MB and uses 400 more MB, and doing so from hard disk is very slow. The contest has a time limit of 10 hours on a 1Ghz machine, but i need all speed at BWT/sort phase, so i can spend the time on getting better compression.

Must i touch the system, rtl etc... files and recompile compiler? Or is there another, and simpler, way?

P.D. Of course, my pc has more than 100 MB (1.25 GB)

How are you trying to allocate the memory, and for which target operating system are you compiling?

Jonas

Oppsss, sorry, I have tried to allocate using pointer, direct array var and pointer to type array

a)
var
     p : pointer of byte;
...
     GetMem(p,100000000); //100 MB
b)
var
     a : array[1..100000000] of byte; //100MB
c)
type
     a = array[1..100000000] of byte; //100MB
     pa = ^a;
var
     p : pa;
...
     GetMem(p,sizeof(a));

Also tried changing 100M of byte with 25M of cardinal but got the same error.

Operating system is WinXP SP2. AthlonXP 2000+ and 1.25 GBRam

I don't tested this with large files, but why don't you use TMemoryStream:

var
  myFile: TMemoryStream;
begin
  myFile := TMemoryStream.Create;
  myFile.LoadFromFile('c:\myfile');
  ...
end;

Leonardo M. Ramé
http://leonardorame.blogspot.com

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>On 11 Sep 2006, at 18:09, Eduardo wrote: Also tried changing 100M of byte with 25M of cardinal but got the same error. Operating system is WinXP SP2. AthlonXP 2000+ and 1.25 GBRam

What are you compiling _for_ ? The plain dos compiler has a limit of 64MB under Windows. Make sure you use the Windows (win32) compiler under windows.

fpc -iTO

will show the target. If it says "go32v2" you have the wrong (dos) compiler.

var a : array[1..100000000] of byte; //100MB Operating system is WinXP SP2. AthlonXP 2000+ and 1.25 GBRam

Both with 2.1.1 rev. 4609 and 2.0.4rc2:
{$MODE OBJFPC}
var a: array[1..100000000] of byte;
    i: integer;
begin write('('); for i:=1 to 100000000 do a[i]:=a[100000001-i]; writeln(')'); end.

Works allright. (I use "fpc -vlwni -Xs -Xi -Sg -O3rp4" by default.) WinXP-sp2, Celeron 2.4 GHz.

Yes, after make a clean directory and copy there *.pas files, now works, don't know what happened.

Sorry for your time, and thanks Jonas and Ppkk

Not need OOP for do it, i need as much speed as i can and using a plain array is faster than a stream. Also, now all compiles, perhaps for a temp files cleaning or the dos<->win32 (i don't use "windows" in uses clause, or my ide have dos as default) as Marco said.

Thanks again to all.