PATCH: Re: 971225: bootstrap fails on powerpc-unknown-linux-gnu*

[David Edelsohn]

>>>>> Franz Sirl writes:

Franz> The problems remaining AFAIK:
Franz> - spill register problems

	If you mean mentioning clobbered registers by name sometimes
evoking a fatal error from reload about spilling a forbidden register,
that is a general problem.  I thought you and I and Joern all agreed that
providing an inline assembly equivalent of a scratch register for a
register class, as used in MD files, was the appropriate solution.  Simply
converting named clobbered registers who are lone members of a register
class into a scratch of that same class seems the most direct and
least-intrusive method.  I do not know enough about that aspect of GCC to
impliment such a solution.

Franz> - the optimizer problems mentioned by Gary Thomas

	Problems?  Plural?  I believe from Gary's messages referred to a
JUMP / CSE problem with respect to duplicate_loop_exit() code.  I do not
believe the problem is in jump.c itself but I have not had a chance to
track down why CSE is breaking.  If someone would help perform the
analysis of CSE to find the location of the bug -- even without providing
a patch -- that probably would help those who can fix it narrow down the
location and develop a proper patch.  Even the initial location may be
incorrect, but someone with knowledge of CSE could then track it back to
the true source of the mistaken assumption.

David