re PR rtl-optimization/52543 (lower-subreg.c: code bloat of 300%-400% for multi-word...

re PR rtl-optimization/52543 (lower-subreg.c: code bloat of 300%-400% for multi-word memory splits)

	PR rtl-optimization/52543
	* config/avr/avr.c (avr_mode_dependent_address_p): Return true for
	all non-generic address spaces.
	(TARGET_SECONDARY_RELOAD): New hook define to...
	(avr_secondary_reload): ...this new static function.
	* config/avr/avr.md (reload_in<mode>): New insns.
	Undo r185605 (mostly):
	* config/avr/avr-protos.h (avr_load_lpm): Remove.
	* config/avr/avr.c (avr_load_libgcc_p): Don't restrict to __flash loads.
	(avr_out_lpm): Also handle loads > 1 byte.
	(avr_load_lpm): Remove.
	(avr_find_unused_d_reg): New static function.
	(avr_out_lpm_no_lpmx): New static function.
	(adjust_insn_length): Remove ADJUST_LEN_LOAD_LPM.
	* config/avr/avr.md (unspec): Remove UNSPEC_LPM.
	(load_<mode>_libgcc): Use MEM instead of UNSPEC_LPM.
	(load_<mode>, load_<mode>_clobber): Remove.
	(mov<mode>): For multi-byte move from non-generic
	16-bit address spaces: Expand to *mov<mode> again.
	(load<mode>_libgcc): New expander.
	(split-lpmx): Remove split.

From-SVN: r191820