PR rtl-opt/38582
* regrename.c (struct du_head): New structure; some elements moved
from...
(struct du_chain): ... this one.
(open_chains, closed_chains): Now of type struct du_head *.
(do_replace): Accept du_head argument, not du_chain. All callers
changed. Modified code to match new data structures.
(build_def_use): Return a list of du_head structures. Modified code
to match new data structures.
(dump_def_use_chain): Accept du_head argument, not du_chain. All
callers changed. Modified code to match new data structures.
(merge_overlapping_regs): Accept du_head argument, not du_chain. All
callers changed. Modified code to match new data structures.
(scan_rtx_reg): Change type of this_regno and this_nregs to unsigned.
Allocate a du_head structure as well as a du_chain when creating a
new chain. Modified other code to match new data structures.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@154123
138bc75d-0d04-0410-961f-
82ee72b054a4