Visit basic blocks using the work-list based algorithm.
2011-01-24 H.J. Lu <hongjiu.lu@intel.com>
PR target/46519
* config/i386/i386.c: Include sbitmap.h and fibheap.h.
(block_info): Add scanned and prev.
(move_or_delete_vzeroupper_2): Return if the basic block
has been scanned and the upper 128bit state is unchanged
from the last scan.
(move_or_delete_vzeroupper_1): Return true if the exit
state is changed.
(move_or_delete_vzeroupper): Visit basic blocks using the
work-list based algorithm based on vt_find_locations in
var-tracking.c.
* config/i386/t-i386: Also depend on sbitmap.h and $(FIBHEAP_H).