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Re: forcing tail/sibling call optimization
On Mon, Nov 27, 2000 at 05:25:45PM +0100, Jeffrey A Law wrote:
>
> In message <oupn1el760c.fsf@pigdrop.muc.suse.de>you write:
> > Problem I see with that is diagnostics again: e.g. someone depends on a
> > particular call being a tail call and not allocating new storage.
> Therein lies the first problem -- programmer dependence on specific
> optimizations in the compiler. That's a fundamental mistake.
Well, I think Fergus' whole point of the extension was to use gcc
as a backend for language compilers that have this requirement.
>
> If you _must_ have tail calls optimized to gotos, then write them that way
> or use a language which guarantees tail calls will turn into gotos. If
> tail call optimizations are merely convenience, then write them as calls :-)
That would require putting the whole program into a single function, which
given the current gcc optimizer's runtimes is surely to end with a very
slow compile process for anything >-O0.
-Andi