Mail Archives: djgpp/1998/05/20/15:33:59
From: | mdruiter AT cs DOT vu DOT nl (Ruiter de M)
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Newsgroups: | comp.os.msdos.djgpp
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Subject: | Re: DJGPP vs. mingwin32 I/O performances
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Date: | 20 May 1998 12:49:32 GMT
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Organization: | Fac. Wiskunde & Informatica, VU, Amsterdam
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Lines: | 34
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Message-ID: | <6jujgs$bhe$1@star.cs.vu.nl>
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References: | <3561B91D DOT 702A AT epfl DOT ch>
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NNTP-Posting-Host: | galjas.cs.vu.nl
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To: | djgpp AT delorie DOT com
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DJ-Gateway: | from newsgroup comp.os.msdos.djgpp
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Lionel Portmann (Lionel DOT Portmann AT epfl DOT ch) wrote:
> I wish to use gcc on a PC in order to do some I/O intensive work
> (parsing big ASCII files). The program will only produce displays in a
> console.
I bet GNU tools already exist for your specific task.
> I tried both ports of gcc v2.8.1 for PC, DJGPP and MINGWIN32.
> I compiled the very same source code with both environnement,
> and found that the mingwin32 executable was a least 1.5 times slower
> than djgpp one. I read in a FAQ that djgpp has to switch between
> protected mode and real mode every time it has to do I/O access,
> so I expected mingwin32 to be faster than djgpp.
I think DJGPP doesn't suffer very much from the switch, because most
I/O is buffered. That means big blocks are read/written at once,
causing just one switch per block. I don't know mingwin32, but I guess
it buffers I/O too. Maybe less efficiently? :-)
> I have to add that at compilation time, mingwin32 gave me more warnings
> than djgpp, which might indicate that the settings are not equivalent.
Have you tried the `-Wall' switch to gcc? Or maybe even `-W', which
warns about everything :) . Try `info gcc invoking warn' on the
command line.
> On the other hand, -O3 switch was ON in both versions.
`-On' is used by most (all?) C-compilers. It is a very common switch.
--
Groeten, Michel. http://www.cs.vu.nl/~mdruiter
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