patch: alpha haifa abort

[David Edelsohn]

>>>>> Jeffrey A Law writes:

Jeff> The "trick" is to define an intermediate pattern so that combine
Jeff> will do a 2/3 -> 1 to create the intermediate pattern.  If that
Jeff> is successful combine will then try to combine the intermediate
Jeff> pattern with the 4th insn.

	Doesn't the intermediate pattern need to be a valid instruction?
Mike and I went into this issue as well.

	I also remember some complexities due to other GCC optimizations
of the RTL generated for the shift-or way of writing the code.

David