Re: [Chicken-users] two minor tweaks to runtime.c

[Jörg F . Wittenberger]

On Sep 27 2011, Peter Bex wrote:

> On Tue, Sep 27, 2011 at 03:22:06PM +0200, Jörg F. Wittenberger wrote:
> > While I've been looking at the code I wondered if the C compiler
> > will fur sure pull that one test out of the for-loop.
> >
> > Maybe it's better no have it there at the first place.
> > IMHO the code is not more confusing to read this way and should
> > run better in case the C compiler is not smart enough.
>
> I'm firmly opposed to any such change that makes the code
> much less readable for very little gain.

Please excuse me objecting.

IMHO the code is not less readable the rewritten way.
In fact - and so far it's a matter of taste - I would find it less
confusing.  (Let alone that it's fewer instructions.)

However I'm quite old school.  If I can tell the compiler something
and not rely on the compilers cleverness, I'll do so.  (And NOT do so
iff I want to create a test case for the compiler.)

In the case at hand I applied something which would have been typical
educational example in the late 70th: pull conditionals out of
frequently executed code if you can.



Is there anybody on the list who has a test case at hand, which would
exercise cons/list operations or initialisation code?  (Mine would be
suspicious in this case.)  Looking at "alternativ" compilers (besides
gcc) would be very nice.


The chance, which - depending on taste, would make the code either more
comprehensible or less - could have an actual effect.  That would be
the final argument in my case.