asm clobbers, !SMALL_REGISTER_CLASSES patch.

[David Edelsohn]

>>>>> Jeffrey A Law writes:

Jeff> I wonder if it makes more sense to have asm clobbers specify a
Jeff> register class instead of explicit registers as an option.  That
Jeff> would at least give us the option of doing the clobber both ways
Jeff> depending on how the target port handled the register in question.

	Exactly!  This is the problem most people are encountering and the
solution that I have been trying to recommend all along.  If the register
is alone in a class, then the class is preferred -- assuming that the port
did not need to specify SMALL_REGISTER_CLASSES for other reasons.

	Once one can specify a register class for a clobber (essentially
creating a clobber match-scratch, it should not be difficult for GCC to
recognize this and convert a register specified by name as a clobber into
the equivalent class containing only one register.

David