Diego Novillo wrote:
On Mon, Nov 24, 2008 at 12:23, Mark Mitchell <[EMAIL PROTECTED]> wrote:
David Edelsohn wrote:
It currently is broken on many platforms. Why not remove it now? What is
the purpose of keeping a pass that does not work correctly and developers
cannot use?
As a user I'd like to point out that I would jump up and down in joy if
-frtl-abstract-sequences would work.
I do a lot of embedded work for a wide range of targets using GCC and
often I find myself in situations where another 20 to 30% of
code-reduction could improve the performance of my code a lot. My
targets often just have a simplistic 8k direct mapped code-cache.
For critical things I did just what -frtl-abstract-sequences did (along
with some hand optimizing) and I've seen performance improvements of 50%
and more just by getting my working set of code to fit into the cache-size.
Once the feature is removed: Will there ever be any chance that the
feature will be re-implemented?
Maybe someone with contacts could convince NXP, ARM, NEC or another
low/middle end microcontroller manufacturer to pay someone to do fix the
current code instead of removing it. These days probably noone do so,
but maybe in a year or two when we're all less paranoid about the world
economy someone could be convinced. The potential performance
improvement for small cache architectures should not be underestimated:
However, in the current state the feature is useless and should be
removed. (in the tests I've done so far it hangs the gcc even with very
simple code).
Cheers,
Nils
