https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97627
--- Comment #10 from bin cheng <amker at gcc dot gnu.org> ---
hmm,
For below basic block:
128 ;; basic block 4, loop depth 2, maybe hot
129 ;; prev block 3, next block 9, flags: (NEW, VISITED)
130 ;; pred: 3 (FALLTHRU,EXECUTABLE)
131 ;; 7 (FALLTHRU,DFS_BACK,EXECUTABLE)
132 # RANGE [0, 2147483647] NONZERO 2147483647
133 # c_5 = PHI <0(3), c_17(7)>
134 # .MEM_8 = PHI <.MEM_7(3), .MEM_9(7)>
135 if (_2 < c_5)
136 goto <bb 8>; [INV]
137 else
138 goto <bb 9>; [INV]
139 ;; succ: 8 (TRUE_VALUE,EXECUTABLE)
140 ;; 9 (FALSE_VALUE,EXECUTABLE)
Code in :
4276
4277 basic_block *body = get_loop_body (loop);
4278 exits = get_loop_exit_edges (loop, body);
4279 likely_exit = single_likely_exit (loop, exits);
4280 FOR_EACH_VEC_ELT (exits, i, ex)
4281 {
4282 if (ex == likely_exit)
4283 {
4284 gimple *stmt = last_stmt (ex->src);
4285 if (stmt != NULL)
4286 {
gets three exit edges, one of which is <bb4 -> bb1>, as a result, 0 niter is
computed for this exit in function number_of_iterations_exit_assumptions. This
seems strange, is it a fake edge added for some reason?
Thanks
