Re: GCC Status Report (2004-09-13)

[Jeffrey A Law <law@redhat.com>]

On Mon, 2004-09-13 at 17:05, Mark Mitchell wrote:

September 19


* General compile-time performance improvements [Weinberg]

Q. Presumably we can still also attack memory consumption
   issues as well.    Right?

The reason I ask is I have the first in what I expect will
be a series of patches to start reducing memory consumption
and bring more sense to our data structures.

The first patch converts our freelist of SSA_NAMEs to a bitmap;
ie, we no longer chain free nodes through the TREE_CHAIN field.
This allows us to attach information like global equivalences
and range information to the SSA_NAME rather than having that
information be stored in per-pass data structures.  This is
of interest as those per-pass data structures are allocated 
multiple times per function we compile and thus result in a
fair amount of garbage.

This first patch reduces memory in a very very tiny way (probably
due to fewer dangling pointers from SSA_NAMEs to statement nodes)
and is compile time neutral.

Anyway, I wanted to get a clarification on were we stand before
pushing those changes forward.

jeff