* config/m68hc11/m68hc11-protos.h (ix_reg): Declare.
* config/m68hc11/m68hc11.md ("addsi3"): Use general_operand for sources.
(splits): Remove unused add splits.
("*addhi3_68hc12"): Tune constraints.
("addhi_sp"): Try to use X instead of Y in all cases and if the
constant fits in 8-bits and D is dead use abx/aby instructions.
("*addhi3"): Remove extern declaration of ix_reg.
("*subsi3"): Optimize and provide new split.
("subhi3"): Cleanup.
("*subhi3_sp"): Avoid saving X if we know it is dead.
(arith splits): For 68hc12 save the address register on the stack
and do the arithmetic operation with a pop.
From-SVN: r50880
