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
	PR target/52461
	* config/avr/avr-protos.h (avr_load_lpm): New prototype.
	* config/avr/avr.c (avr_mode_dependent_address_p): New function.
	(TARGET_MODE_DEPENDENT_ADDRESS_P): New define.
	(avr_load_libgcc_p): Restrict to __flash loads.
	(avr_out_lpm): Only handle 1-byte loads from __flash.
	(avr_load_lpm): New function.
	(avr_find_unused_d_reg): Remove.
	(avr_out_lpm_no_lpmx): Remove.
	(adjust_insn_length): Handle ADJUST_LEN_LOAD_LPM.
	* config/avr/avr.md (unspec): Add UNSPEC_LPM.
	(load_<mode>_libgcc): Use UNSPEC_LPM instead of MEM.
	(load_<mode>, load_<mode>_clobber): New insns.
	(mov<mode>): For multi-byte move from non-generic
	16-bit address spaces: Expand to load_<mode> resp.
	load_<mode>_clobber.
	(load<mode>_libgcc): Remove expander.
	(split-lpmx): Remove split.

From-SVN: r185605