re PR rtl-optimization/56181 (ICE in verify_loop_structure, at cfgloop.c:1581 with -ftracer)
2013-02-08 Richard Biener <rguenther@suse.de>
PR middle-end/56181
* cfgloop.h (flow_loops_find): Adjust.
(bb_loop_header_p): Declare.
* cfgloop.c (bb_loop_header_p): New function split out from ...
(flow_loops_find): ... here. Adjust function signature,
support incremental loop structure update.
(verify_loop_structure): Cleanup. Verify a loop is a loop.
* cfgloopmanip.c (fix_loop_structure): Move ...
* loop-init.c (fix_loop_structure): ... here.
(apply_loop_flags): Split out from ...
(loop_optimizer_init): ... here.
(fix_loop_structure): Use apply_loop_flags. Use flow_loops_find
in incremental mode, only remove dead loops here.