[Bug tree-optimization/105793] Missed vectorisation with conditional-select inside loop

[crazylht at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105793

--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> ---
Guess vectorizer expects something like

tmp1 = cond ? b : -b;
a_5 = a_4 + tmp1;

from ifcvt instead of current

  a_13 = b_10 + a_16;
  # DEBUG a => NULL
  _4 = b_10 < 1.0e+1;
  # DEBUG BEGIN_STMT
  a_12 = a_16 - b_10;
  # DEBUG a => NULL
  a_5 = _4 ? a_13 : a_12;