Re: [PATCH] Speed up bfd_elf_match_symbols_in_sections

["H. J. Lu" <hjl at lucon dot org>]

On Thu, Feb 01, 2007 at 09:12:17PM +0100, Jakub Jelinek wrote:
> On Fri, Jan 19, 2007 at 09:58:24AM -0800, H. J. Lu wrote:
> > > BTW, unless you plan to reuse elf_tdata (bfd)->symbuf in some other
> > > place, bfd_elf_match_symbols_in_sections only ever looks at
> > > st_info, st_other, st_shndx st_name of the internal symbols.
> > > So to save memory, you can very well also just save that data and
> > > nothing else (nor the undef symbols and save more than 50% of memory on
> > > this).
> > 
> > I can't reproduce
> > 
> > https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=223181
> > 
> > with the current binutils in CVS. I believe the Linux binutils
> > 2.17.50.0.9 is also OK.  We can certainly improve it further.  But
> > I don't believe it is a major problem.
> 
> Here is what I had in mind.
> 
> On the mozilla libgtklayout.so testcase (elf_i386) I measured following
> speedups:
> 
> 2007-02-01  Jakub Jelinek  <jakub@redhat.com>
> 
> 	* elf-bfd.h (struct elf_obj_tdata): Change symbuf type to void *.
> 	* elf.c (struct elf_symbuf_symbol, struct elf_symbuf_head): New types.
> 	(struct elf_symbol): Change first member into union.
> 	(elf_sort_elf_symbol): Compare pointers to internal syms rather than
> 	internal syms.  Only compare st_shndx fields.
> 	(elf_create_symbuf): New function.
> 	(bfd_elf_match_symbols_in_sections): Use it.  If symbufs are available
> 	for bfds, use a binary search, otherwise don't qsort symbols
> 	unnecessarily only to select which symbols are for the particular
> 	shndx.
> 

It looks good to me.

Thanks.

H.J.