When entering an interrupt, not only the call save registers needs to
be place on stack but also the call clobbers one. More over, the
ARC700 return from interrupt instruction needs to be rtie, the same
like ARCv2 CPUs. While the ARC6xx family uses j.f [ilinkX]
instruction. Additionally, we need to save the state of the ZOL
machinery, namely the lp_count, lp_end and lp_start registers. For
architectures which are using extension registers (i.e., HS48) we need
to save/restore them as well.

gcc/
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc-protos.h (arc_output_function_epilogue): Delete
	declaration.
	(arc_compute_frame_size): Millicode is disabled when compiling
	ISR.
	(arc_return_address_register): Likewise.
	(arc_compute_function_type): Likewise.
	(arc_compute_frame_size): Likewise.
	(secondary_reload_info): Likewise.
	(arc_get_unalign): Likewise.
	(arc_can_use_return_insn): Declare.
	* config/arc/arc.c (AUX_LP_START): Define
	(AUX_LP_END): Likewise.
	(arc_frame_info): Update gmask member to 64-bit datum.
	(GMASK_LEN): Update.
	(arc_compute_function_type): Make it static, move it forward.
	(arc_must_save_register): Update, consider the extra regs.
	(arc_compute_millicode_save_restore_regs): Update to use the 64
	bit gmask.
	(arc_compute_frame_size): Likewise.
	(arc_enter_leave_p): Likewise.
	(arc_save_callee_saves): Likewise.
	(arc_restore_callee_saves): Likewise.
	(arc_save_callee_enter): Likewise.
	(arc_restore_callee_leave): Likewise.
	(arc_save_callee_milli): Likewise.
	(arc_restore_callee_milli): Likewise.
	(arc_expand_prologue): Add new interrupt handling.
	(arc_return_address_register): Make it static, move it forward.
	(arc_expand_epilogue): Add new interrupt handling.
	(arc_get_unalign): Delete.
	(arc_epilogue_uses): Make sure we do not remove the extra
	saved/restored registers when interrupt.
	(arc_can_use_return_insn): New function.
	(push_reg): Likewise.
	(pop_reg): Likewise.
	(arc_save_callee_saves): Add ZOL and FPX aux registers saving
	procedures.
	(arc_restore_callee_saves): Likewise, but restoring.
	* config/arc/arc.md (VUNSPEC_ARC_ARC600_RTIE): Define.
	(R33_REG): Likewise.
	(R34_REG): Likewise.
	(R35_REG): Likewise.
	(R36_REG): Likewise.
	(R37_REG): Likewise.
	(R38_REG): Likewise.
	(R39_REG): Likewise.
	(R45_REG): Likewise.
	(R46_REG): Likewise.
	(R47_REG): Likewise.
	(R48_REG): Likewise.
	(R49_REG): Likewise.
	(R50_REG): Likewise.
	(R51_REG): Likewise.
	(R52_REG): Likewise.
	(R53_REG): Likewise.
	(R54_REG): Likewise.
	(R55_REG): Likewise.
	(R56_REG): Likewise.
	(R58_REG): Likewise.
	(type): Add rtie attribute.
	(in_call_delay_slot): Use RETURN_ADDR_REGNUM.
	(movsi_insn): Accept moves to lp_count.
	(rtie): Update pattern.
	(simple_return): Simplify it, don't use this pattern as a return
	from an interrupt.
	(arc600_rtie): New pattern.
	(p_return_i): Clean up.
	(return): Likewise.
	* config/arc/builtins.def (rtie): Only available for non ARC6xx
	family CPUs.
	* config/arc/predicates.md (move_src_operand): Consider lp_count
	as a register.

gcc/testsuite
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* gcc.target/arc/arc.exp (check_effective_target_accregs): New
	predicate.
	* gcc.target/arc/builtin_special.c: Update test/
	* gcc.target/arc/interrupt-1.c: Likewise.
	* gcc.target/arc/interrupt-10.c: New test.
	* gcc.target/arc/interrupt-11.c: Likewise.
	* gcc.target/arc/interrupt-12.c: Likewise.

update

From-SVN: r273761