bin/71623: [PATCH] cleanup of the usr.sbin/pcvt code
keramida at freebsd.org
Mon Sep 13 02:20:20 PDT 2004
The following reply was made to PR bin/71623; it has been noted by GNATS.
From: Giorgos Keramidas <keramida at freebsd.org>
To: Dan Lukes <dan at obluda.cz>
Cc: bug-followup at freebsd.org
Subject: Re: bin/71623: [PATCH] cleanup of the usr.sbin/pcvt code
Date: Mon, 13 Sep 2004 12:10:54 +0300
On 2004-09-13 08:48, Dan Lukes <dan at obluda.cz> wrote:
> Giorgos Keramidas wrote:
> >>>>! if (kbdc < 32) printf(" %s", ckeytab[(short int)kbdc].csymbol);
> >>>Does the value really have to be a (short int) here? Wouldn't an (int) be
> >>Because kbdc is type of char. Short int should be sufficient for char.
> > Apparently there's no special reason why this value should be
> > `short' and not `int', so keeping the existing practice of using an
> > `int' for holding a `char' value is what my suggestion was about.
> When sizes aren't equal then compiler must emit an conversion code.
> Well, I'm understand now that nobody here cares about a few bytes of
> memory or tenths CPU ticks. Some of my programmesr skills came from
> ancient days, so every byte and ticks seems to be valuable for me. But
> no problem for me to adapt to todays programers practices ... ;-)
> If existing practice want int here we should use int.
I'm far from the best person to ask for a definition of today's "canonical
programming practice", but I'm trying to learn too. After reading parts of
the FreeBSD source tree I've learned a tremendous amount of things and I
still do learn every day. Influences by others are obvious too in the way
I think and work though. One of the most influencial persons whose work
I've admired is Donald E. Knuth, who has said:
"We should forget about small efficiencies, say about 97% of the time:
premature optimization is the root of all evil." -- Donald Knuth
This is why I think that this sort of micro-optimizations are not worth a
lot of trouble or time.
Of course, this doesn't mean that I don't want you to keep improving the
source of FreeBSD. I'm just vehemently opposed to optimizations done to
tweak a machine-cycle here, a byte there, a single word of memory there,
etc. by sacrifizing clarity, style and cleanness of the source or, for
instance, by introducing dependencies to the way a specific compiler works.
But I'm probably beginning to sound like an insufferable pedant. Off to a
bit of hacking :)
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