https://gcc.gnu.org/bugzilla/show_bug.cgi?id=22401
--- Comment #5 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
This is now threaded by threadfull2:
Checking profitability of path (backwards): bb:3 (2 insns) bb:2
Control statement insns: 2
Overall: 0 insns
path: 2->3->xx REJECTED
Checking profitability of path (backwards): bb:3 (2 insns) bb:5 (latch)
Control statement insns: 2
Overall: 0 insns
Checking profitability of path (backwards):
[1] Registering jump thread: (5, 3) incoming edge; (3, 5) nocopy;
path: 5->3->5 SUCCESS
Merging blocks 2 and 3
Merging blocks 5 and 6
fix_loop_structure: fixing up loops for function
fix_loop_structure: removing loop 1
flow_loops_find: discovered new loop 2 with header 3
and we get correct profile:
void __show_backtrace (void * rw)
{
;; basic block 2, loop depth 0, count 118111600 (estimated locally), maybe
hot
;; prev block 0, next block 3, flags: (NEW, REACHABLE, VISITED)
;; pred: ENTRY [always] count:118111600 (estimated locally)
(FALLTHRU,EXECUTABLE)
if (rw_1(D) != 0B)
goto <bb 3>; [0.00%]
else
goto <bb 4>; [100.00%]
;; succ: 3 [never (guessed)] count:0 (estimated locally)
(TRUE_VALUE,EXECUTABLE)
;; 4 [always (guessed)] count:118111600 (estimated locally)
(FALSE_VALUE,EXECUTABLE)
;; basic block 3, loop depth 1, count 955630224 (estimated locally), maybe
hot
;; prev block 2, next block 4, flags: (NEW, REACHABLE, VISITED)
;; pred: 2 [never (guessed)] count:0 (estimated locally)
(TRUE_VALUE,EXECUTABLE)
;; 3 [always] count:955630224 (estimated locally)
(FALLTHRU,DFS_BACK)
goto <bb 3>; [100.00%]
;; succ: 3 [always] count:955630224 (estimated locally)
(FALLTHRU,DFS_BACK)
;; basic block 4, loop depth 0, count 118111600 (estimated locally), maybe
hot
;; prev block 3, next block 1, flags: (NEW, REACHABLE, VISITED)
;; pred: 2 [always (guessed)] count:118111600 (estimated locally)
(FALSE_VALUE,EXECUTABLE)
return;
;; succ: EXIT [always] count:118111600 (estimated locally)
(EXECUTABLE) q.c:4:1
}
