https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98365
--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> ---
> cnt.1_7 = (unsigned char) cnt_21;
> _8 = cnt.1_7 + 1;
> cnt_16 = (char) _8;
> cnt_9 = _3 == _6 ? cnt_16 : cnt_21;
>
In tree_if_conversion, there's is_cond_scalar_reduction, i'm think to extend
the currect implementation to reduce bellow
loop-header:
cnt_21 = PHI <0, cnt_9>
...
if (cond_expr)
tmp1 = (unsigned type) cnt_21
tmp2 = tmp1 +/- rhs2
cnt_16 = (signed type) tmp2
cnt_9 = PHI <cnt_16, cnt_21>
to
cnt_9 = PHI <0, cnt_21>
tmp1 = (unsigned type)cnt_9;
ifcvt = cond_expr ? rhs2 : 0
tmp2 = tmp1 +/- ifcvt;
cnt_21 = (signed type)tmp2;
I hope vectorizer reduction can handle the upper sequence.
