c++-mode dreadfully slow?

c++-mode dreadfully slow?

[Miles Bader]

Has anyone noticed c++-mode being really slow recently?  Recently I've
noticed that sometimes even just scrolling to a new screen can take on
the order of 5 seconds in some C++ files.

[The file I'm looking at currently is a "medium-sized" source file, ~3K
lines, and uses no particularly weird constructs (for instance, no
templates), and has no long functions.]

-Miles

-- 
Carefully crafted initial estimates reward you not only with
reduced computational effort, but also with understanding and
increased self-esteem.         -- Numerical methods in C,
  Chapter 9. "Root Finding and Nonlinear Sets of Equations"

Re: c++-mode dreadfully slow?

[Alan Mackenzie]

Hi, Miles!

On Thu, Oct 23, 2008 at 08:36:24PM +0900, Miles Bader wrote:
> Has anyone noticed c++-mode being really slow recently?  Recently I've
> noticed that sometimes even just scrolling to a new screen can take on
> the order of 5 seconds in some C++ files.

Lets assume emacs -Q and cc-*.el have been properly compiled.

By "scrolling to a new screen", do you mean <PageUp> or <PageDown> to an
adjacent screen?  Presumably, it's not so bad the second time you scroll
into the same bit of buffer.

> [The file I'm looking at currently is a "medium-sized" source file, ~3K
> lines, and uses no particularly weird constructs (for instance, no
> templates), and has no long functions.]

That's slower than it should be.  Is it any slower than an old version?
Say, that in Emacs 22.1 or 22.2?

> -Miles

-- 
Alan Mackenzie (Nuremberg, Germany).