* explow.c (force_reg): Call mark_reg_pointer as appropriate.
        * config/alpha/alpha.c (alpha_emit_conditional_branch): Don't
        use (op0-op1) == 0 if op0 is a pointer.
        * config/alpha/alpha.md (cmpdi): Use some_operand.
        (three comparison combine splits): Remove.

From-SVN: r78475