PR target/42235

	PR target/42235
	* postreload.c (reload_cse_move2add): Return bool, true if anything.
	changed.  All callers changed.
	(move2add_use_add2_insn): Likewise.
	(move2add_use_add3_insn): Likewise.
	(reload_cse_regs): If reload_cse_move2add changed anything, rerun
	reload_combine.
	(RELOAD_COMBINE_MAX_USES): Bump to 16.
	(last_jump_ruid): New static variable.
	(struct reg_use): New members CONTAINING_MEM and RUID.
	(reg_state): New members ALL_OFFSETS_MATCH and REAL_STORE_RUID.
	(reload_combine_split_one_ruid, reload_combine_split_ruids,
	reload_combine_purge_insn_uses, reload_combine_closest_single_use
	reload_combine_purge_reg_uses_after_ruid,
	reload_combine_recognize_const_pattern): New static functions.
	(reload_combine_recognize_pattern): Verify that ALL_OFFSETS_MATCH
	is true for our reg and that we have available index regs.
	(reload_combine_note_use): New args RUID and CONTAINING_MEM.  All
	callers changed.  Use them to initialize fields in struct reg_use.
	(reload_combine): Initialize last_jump_ruid.  Be careful when to
	take PREV_INSN of the scanned insn.  Update REAL_STORE_RUID fields.
	Call reload_combine_recognize_const_pattern.
	(reload_combine_note_store): Update REAL_STORE_RUID field.

	* gcc.target/arm/pr42235.c: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@162270 138bc75d-0d04-0410-961f-82ee72b054a4