https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113134
--- Comment #21 from JuzheZhong <juzhe.zhong at rivai dot ai> ---
Hi, Richard. I looked into ivcanon.
I found that:
/* If the loop has more than one exit, try checking all of them
for # of iterations determinable through scev. */
if (!exit)
niter = find_loop_niter (loop, &exit);
In find_loop_niter, we iterate 2 exit edges:
1. bb 5 -> bb 6 with niter = (unsigned int) N_13(D).
2. bb 3 -> bb 6 with niter = 1001.
It just skip niter = (unsigned int) N_13(D) in:
if (!integer_zerop (desc.may_be_zero))
continue;
find_loop_niter (loop, &exit) return 1001 with skipping (unsigned int)
N_13(D).
Should it return MIN (1001, (unsigned int) N_13(D)).
I prefer fix it in ivcanon since I believe it would be more elegant than fix it
in loop splitter.
I am still investigating, any guides will be really appreciated.
Thanks.
