PR debug/54114
PR debug/54402
PR debug/49888
* var-tracking.c (negative_power_of_two_p): New.
(global_get_addr_cache, local_get_addr_cache): New.
(get_addr_from_global_cache, get_addr_from_local_cache): New.
(vt_canonicalize_addr): Rewrite using the above.  Adjust the
heading comment.
(vt_stack_offset_p): Remove.
(vt_canon_true_dep): Always canonicalize loc's address.
(clobber_overlapping_mems): Make sure we have a MEM.
(local_get_addr_clear_given_value): New.
(val_reset): Clear local cached entries.
(compute_bb_dataflow): Create and release the local cache.
Disable duplicate MEMs clobbering.
(emit_notes_in_bb): Clobber MEMs likewise.
(vt_emit_notes): Create and release the local cache.
(vt_initialize, vt_finalize): Create and release the global
cache, respectively.
* alias.c (rtx_equal_for_memref_p): Compare operands of
ENTRY_VALUEs.

From-SVN: r195291