Re: [RFC]: New dwarf2 reader

[Michael Snyder <msnyder@cygnus.com>]

Daniel Berlin wrote:
> 
> Still a work in progress, however, i'm only bugfixing now, as i'm
> happy with memory usage, etc.
> 
> Changes:
> 1.
> This has an improved implementation of removing duplicates. It's done
> basically the same way gcc does it, which is to actually just go all out and md5
> checksum the attributes of dies.  Conservatively, of course.
> Currently, this means that duplicate things with different offsets for their
> types, siblings, etc, don't get eliminated.
> I'll improve this in a bit (We'll ignore the sibling attribute for
> checksum purposes, and a few other minor twiddles.)
> 
> You'd think that the fact that the relative placement inside the
> section mattering would stop us from eliminating most duplicates.
> You'd be very wrong.
> 
> GCC, by deferring output a lot, tends to end up outputting things in
> the same order.
> 
> We are now down to 21 meg of memory to debug gdb, with all symbols
> fully read in.
> Down from 80.
> 
> STABS takes 22 or 24, I forget which.

Daniel, this is a very promising development.  Have you done any 
timing checks?  How long does it take to load all those symbols 
and remove duplicates, compared to the old code?