This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Slowdowns in code generated by GCC>=3.3
On Tuesday 26 October 2004 22:09, Pablo Mejia wrote:
> Steven> Now, the problem is that gcse and crossjumping may move
> Steven> code in the block with the factored computed jump, so when
> Steven> we later try to undo the factoring, we think it is too
> Steven> expensive to do that. We end up with lots and lots of
> Steven> jumps to a single computed jump that is very difficult to
> Steven> predict.
>
> I just lurk on this list, so feel free to ignore this comment...
>
> Perhaps it would be possible to mark the block with the factored
> computed jump in some way.
It is cumbersome to maintain such a marking. I tried it at
first but it's hard to not lose the mark, and it's harder to
change all passes to be aware of such a block.
Gr.
Steven