sh.c (trap_exit, sp_switch): New variables.

sh.c (trap_exit, sp_switch): New variables.

	* sh.c (trap_exit, sp_switch): New variables.
	(print_operand, case '@'): If trap_exit is nonzero, then use
	a trapa instead of an rte/rts to exit the current function.
	(sh_expand_prologue): Switch stacks at function entry as needed.
	(sh_expand_epilogue): Similarly at function exit.
	(function_epilogue): Clear trap_exit and sp_switch too.
	(sh_valid_machine_decl_attribute): New function.
	* sh.h (VALID_MACHINE_DECL_ATTRIBUTE): Define.
	(sp_switch): Declare.
	* sh.md (sp_switch_1, sp_switch_2): New named patterns.

From-SVN: r14148