https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103270
--- Comment #5 from luoxhu at gcc dot gnu.org ---
;; Loop 0
;; header 0, latch 1
;; depth 0, outer -1
;; nodes: 0 1 2 3 4 5 6 11 7 8 10 9
;;
;; Loop 1
;; header 8, latch 7
;; depth 1, outer 0
;; nodes: 8 7 6 10 5 4 11 3
;;
;; Loop 2
;; header 6, latch 5
;; depth 2, outer 1
;; nodes: 6 5 4 11 3
;;
;; Loop 3
;; header 4, latch 3
;; depth 3, outer 2
;; nodes: 4 3
;; 2 succs { 8 }
;; 3 succs { 4 }
;; 4 succs { 3 5 }
;; 5 succs { 6 }
;; 6 succs { 11 7 }
;; 11 succs { 4 }
;; 7 succs { 8 }
;; 8 succs { 10 9 }
;; 10 succs { 6 }
;; 9 succs { 1 }
The CFG is:
2
|
8<----
| \ |
10 9 |
| |
6----7
6<----
| |
11 |
| |
4<- |
| \| |
5 3 |
| |
------
When iterating loop 3 in predict_extra_loop_exits, exit edge is 4->5, it finds
edge 3->4 for statement "if (d_8 == 0)", and set all e->src->preds with
"predict_paths_leading_to_edge (e1, PRED_LOOP_EXTRA_EXIT, NOT_TAKEN);".
(gdb) pbb 3
;; basic block 3, loop depth 3
;; pred: 4
_1 = *i_19(D);
_2 = a_4 & c_6;
_3 = _1 + _2;
*i_19(D) = _3;
;; succ: 4
(gdb) pbb 4
;; basic block 4, loop depth 3
;; pred: 11
;; 3
# c_6 = PHI <c_7(11), b_5(3)>
# d_8 = PHI <0(11), 1(3)>
if (d_8 == 0)
goto <bb 3>; [INV]
else
goto <bb 5>; [INV]
;; succ: 3
;; 5
(gdb) p e->src->preds
$16 = 0x7ffff4fba140 = {<edge 0x7ffff4d05b20 (4 -> 3)>}
