[PATCH] Fix PPC scan_prologue for code generated with -mno-update

[Daniel Jacobowitz]

On Fri, Feb 16, 2007 at 09:22:34AM +0100, Mark Kettenis wrote:
> Looks reasonable to me.  However there's one thing I don't understand.
> Presuming you're using DWARF2 debug info, why does improving the
> prologue scanner make such a big difference?

Because we still haven't hooked up the DWARF2 unwinder for PowerPC;
I believe this is because of the (now long-ago fixed) botch on CFI
register numbering for lr.  The last message I recall is:

  http://sourceware.org/ml/gdb-patches/2006-05/msg00341.html

I think all that we need is a way to check the recorded LR column
and adjust register numbering based on that.

-- 
Daniel Jacobowitz
CodeSourcery