* cselib.h (cselib_add_permanent_equiv): Declare.
(canonical_cselib_val): New.
* cselib.c (new_elt_loc_list): Rework to support value
equivalences.  Adjust all callers.
(preserve_only_constants): Retain value equivalences.
(references_value_p): Retain preserved values.
(rtx_equal_for_cselib_1): Handle value equivalences.
(cselib_invalidate_regno): Use canonical value.
(cselib_add_permanent_equiv): New.
* alias.c (find_base_term): Reset locs lists while recursing.
* var-tracking.c (val_bind): New.  Don't add equivalences
present in cselib table, compared with code moved from...
(val_store): ... here.
(val_resolve): Use val_bind.
(VAL_EXPR_HAS_REVERSE): Drop.
(add_uses): Do not create MOps for addresses.  Do not mark
non-REG non-MEM expressions as requiring resolution.
(reverse_op): Record reverse as a cselib equivalence.
(add_stores): Use it.  Do not create MOps for addresses.
Do not require resolution for non-REG non-MEM expressions.
Simplify support for reverse operations.
(compute_bb_dataflow): Drop reverse support.
(emit_notes_in_bb): Likewise.
(create_entry_value): Rename to...
(record_entry_value): ... this.  Use cselib equivalences.
(vt_add_function_parameter): Adjust.

From-SVN: r182760