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Re: Loop unrolling
- To: Mike Stump <mrs at wrs dot com>, amylaar at cygnus dot co dot uk
- Subject: Re: Loop unrolling
- From: Richard Henderson <rth at cygnus dot com>
- Date: Thu, 11 Jun 1998 19:35:25 -0700
- Cc: egcs-patches at cygnus dot com, egcs at cygnus dot com, pfeifer at dbai dot tuwien dot ac dot at
- References: <199806111804.LAA28554@kankakee.wrs.com>
- Reply-To: Richard Henderson <rth at cygnus dot com>
On Thu, Jun 11, 1998 at 11:04:17AM -0700, Mike Stump wrote:
> > Well, how about some plain C macroid code:
>
> macros are not your friend, don't use them.
Ok, now that's just stupid. Macros in C are as to inlines in C++,
that is, indespensible.
> Having said that...
> After preprocessing, the ')' and ';' appear adjacent, hence it is a
> empty loop, hence it should not be removed.
Also a nonsense definition:
for (i = 0; i < 10; ++i) continue;
is by that definition not an empty loop. But if you distinguish
between that and just `;' you are being gratuitously obtuse.
In summary, there are lots of empty loops that occur naturally
in C, very few programs rely on such things, and for them we
provide a switch.
r~