Emacs awfully slow on some files

[Deniz Dogan]

I have a file which is 1 MB long and all of the content is on a single
line. Using Emacs on this file is pretty much impossible due to the
super-sluggish behavior. It's embarrassing. Why is this? Can it be
fixed? This is with fundamental-mode, by the way. `forward-char' and
`backward-char' are pretty much the only usable commands, even "C-h f"
(describe-function) is extremely slow in this scenario.

-- 
Deniz Dogan