PR debug/43051
	PR debug/43092
	* cselib.c (cselib_preserve_constants,
	cfa_base_preserved_val): New static variables.
	(preserve_only_constants): New function.
	(cselib_reset_table): If cfa_base_preserved_val is non-NULL, don't
	clear its REG_VALUES.  If cselib_preserve_constants, don't 
	empty the whole hash table, but preserve there VALUEs with constants,
	cfa_base_preserved_val and cfa_base_preserved_val plus constant.
	(cselib_preserve_cfa_base_value): New function.
	(cselib_invalidate_regno): Don't invalidate cfa_base_preserved_val.
	(cselib_init): Change argument to int bitfield.  Set
	cselib_preserve_constants to whether CSELIB_PRESERVE_CONSTANTS
	is in it.
	(cselib_finish): Clear cselib_preserve_constants and
	cfa_base_preserved_val.
	* cselib.h (enum cselib_record_what): New enum.
	(cselib_init): Change argument to int.
	(cselib_preserve_cfa_base_value): New prototype.
	* postreload.c (reload_cse_regs_1): Adjust cselib_init caller.
	* dse.c (dse_step1): Likewise.
	* cfgcleanup.c (thread_jump): Likewise.
	* sched-deps.c (sched_analyze): Likewise.
	* gcse.c (local_cprop_pass): Likewise.
	* simplify-rtx.c (simplify_replace_fn_rtx): Add argument to callback.
	If FN is non-NULL, call the callback always and whenever it returns
	non-NULL just return that.  Only do rtx_equal_p if FN is NULL.
	* rtl.h (simplify_replace_fn_rtx): Add argument to callback.
	* combine.c (propagate_for_debug_subst): Add old_rtx argument,
	compare from with old_rtx and if it isn't rtx_equal_p, return NULL.
	* Makefile.in (var-tracking.o): Depend on $(RECOG_H).
	* var-tracking.c: Include recog.h.
	(bb_stack_adjust_offset): Remove.
	(vt_stack_adjustments): Don't call it, instead just gather the
	adjustments using insn_stack_adjust_offset_pre_post on each bb insn.
	(adjust_stack_reference): Remove.
	(compute_cfa_pointer): New function.
	(hard_frame_pointer_adjustment, cfa_base_rtx): New static variables.
	(struct adjust_mem_data): New type.
	(adjust_mems, adjust_mem_uses, adjust_mem_stores, adjust_insn): New
	functions.
	(get_address_mode): New function.
	(replace_expr_with_values): Use it.
	(use_type): Don't do cselib_lookup for VAR_LOC_UNKNOWN_P.
	Use get_address_mode.  For cfa_base_rtx return MO_CLOBBER.
	(adjust_sets): Remove.
	(add_uses): Don't add extra MO_VAL_USE for cfa_base_rtx plus constant.
	Use get_address_mode.
	(get_adjusted_src): Remove.
	(add_stores): Don't call it.  Never reuse expr SET.  Don't add extra
	MO_VAL_USE for cfa_base_rtx plus constant.  Use get_address_mode.
	(add_with_sets): Don't call adjust_sets.
	(fp_setter, vt_init_cfa_base): New functions.
	(vt_initialize): Change return type to bool.  Move most of pool etc.
	initialization to the beginning of the function from end.  Pass
	CSELIB_RECORD_MEMORY | CSELIB_PRESERVE_CONSTANTS to cselib_init.
	If !frame_pointer_needed, call vt_stack_adjustment before mos
	vector is filled, call vt_init_cfa_base if argp/framep has been
	eliminated to sp.  If frame_pointer_needed and argp/framep has
	been eliminated to hard frame pointer, set
	hard_frame_pointer_adjustment and call vt_init_cfa_base after
	encountering fp setter in the prologue.  For MO_ADJUST, call
	log_op_type before pusing the op into mos vector, not afterwards.
	Call adjust_insn before cselib_process_insn/add_with_sets,
	call cancel_changes (0) afterwards.
	(variable_tracking_main_1): Adjust for vt_initialize calling
	vt_stack_adjustments and returning whether it succeeded or not.

	* gcc.dg/guality/pr43051-1.c: New test.

From-SVN: r157476