Re: [9fans] caveat... optimizer? the `zero and forget' thread on HN

[Bakul Shah <bakul@bitblocks.com>]

On Mon, 29 Oct 2012 19:10:55 EDT erik quanstrom <quanstro@quanstro.net>  wrote:
> On Mon Oct 29 18:37:11 EDT 2012, bakul@bitblocks.com wrote:
> > On Mon, 29 Oct 2012 09:35:00 EDT erik quanstrom <quanstro@quanstro.net>  wr
> ote:
> > > On Mon Oct 29 05:47:10 EDT 2012, dexen.devries@gmail.com wrote:
> > > > http://news.ycombinator.com/item?id=4711346
> > > >
> > > > 9fans says, ``no room in the compiler world for amateurs''. what's your
>  tak
> > > e
> > > > on the above fubar?
> > >
> > > any sort of "advanced" code-moving optimization is confusing.  but the
> > > way c/c++ are used in linux, bsd & osx, there is a noticable benefit to
> > > optimizing calls away.  it takes smarts to optimize away those recursive
> > > wrapper macros.  so they're in a bit of a pickle.
> >
> > It has nothing to do with "how" C/C++ are used in linux, bsd &
> > osx -- you forgot windows!  The C standard allows a lot of
> > leeway in optimization.  Consider this:
>
> my point was that the attitude that every optimization allowed is required is
>  not
> helpful and is in the end counter productive.

No disagreement there on "requiring" optimization. But my
point was that a programmer should understand the standard
rather than complain when he gets "surprised" due to his lack
of knowledge.

> actually, to be a bit cute about it, i should announce the first
> international obfuscated c compiler contest.  the goal of the contest
> is to write a c99-compliant compiler that breaks every program in /sys/src/cm
> d.
> the winner will be chosen based on highest percentage of programs broken,
> with the tie going to the most devious tricks for remaining standards complia
> nt
> while missing the spirit completely.

/sys/src/cmd follows plan9 c, not c99, right? But pick a
similar set of programs.  If this happens, I claim it would be
because programs assume something not guaranteed by the
compiler.

> > > it goes without saying, i think a compiler that largely does what you
> > > ask it to optimizes the scarce resource: developer time.
> >
> > That is a separate issue.
>
> actually, i think it *is* the issue.

Best way to save developer time is to program in a HLL and not
worry about bit fiddling. C is not a HLL.