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

[Fred Fish]

On Friday 16 February 2007, 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?

Good question.

Originally the problem popped up in an environment where the user was
using stabs debugging format with a pretty ancient compiler.

I distilled the problem down to a simple test case and compiled it
without debugging info, after I figured out the problem was an issue
with the prologue scanner.

Perhaps this has uncovered another bug related to how the DWARF info
is used.  It's certainly worth investigating.

However I believe the patch is still beneficial, for the cases where
the debug format is something other than DWARF or there is no debug
info.

-Fred