From: kunst AT prl DOT philips DOT nl
Subject: Re: gcc swapping
To: 90700465 AT vax1 DOT dcu DOT ie
Date: Wed, 10 Nov 1993 13:19:34 +0100 (MET)
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu (DJGPP users list)


Boris Fennema writes:

> 1. the code generated by DJGPP runs slowly (slower than the TC 3.0 
> generated code) on my 40 MB RAM using HIMEM.SYS, possibly due to
> swapping to disc.

With 40 Mb RAM swapping to disk should not be required 
for small programs (if you can run them with TC as well).

The speed of djgpp compiled programs may be lower than TC when the
program is very disk intensive, e.g. when using a large (disk) database.
However, you get a large gain for math intensive applications.

> is there any systematic way of tuning my the system or is my 
> system simply too small.

Try the following settings in your CONFIG.SYS and AUTOEXEC.BAT files:
(Assuming DOS 5.0/6.0)

----------------------------- config.sys ---------------------------------
DEVICE=C:\DOS\HIMEM.SYS
DEVICE=C:\DOS\EMM386.EXE RAM FRAME=NONE
DOS=HIGH,UMB
FILES=20
BUFFERS=20
------------------------------ autoexec.bat ------------------------------
LH C:\DOS\SMARTDRV.EXE 2048 2048 /Q
--------------------------------------------------------------------------

With 40 Mb RAM you could even increase the value of 2048 (kb).

> 
> 2. can I run the profiler? I do not seem to be able to generate a 
> mon.out/gmon.out file.

Can't help you on this one; I have the same problem...

> 
> 3. using streams, (<IOstream.h>), reading the last line does 
> not set the eof flag. There is a comment in IOstream.h concerning this. 
> Is this a bug or are differences in implementation between UNIX/DOS ?
> 

Idem. I (still) use C.


Pieter Kunst (kunst AT prl DOT philips DOT nl)