bug#9209: bidi slowdown

[Eli Zaretskii]

Please keep 9209@debbugs.gnu.org on the CC list, so that this
discussion gets recorded in the bug tracker.

> Date: Sun, 31 Jul 2011 00:00:26 -0400
> From: emacs user <user.emacs@gmail.com>
> 
> I checked and it's perfectly OK near the beginning of the buffer, and
> very slow near the end.

OK.  Next, please tell which cursor keys are slow to respond.  Are C-f
and C-b slow?  Are left and right arrow significantly slower than C-f
and C-b?  What about C-n/C-p resp up- and down-arrows?  Finally, what
about PageUp/PageDown and C-v/M-v?

Please also try setting the variable bidi-paragraph-direction to
left-to-right, and see if that solves the problem.

Thanks.