[Bug tree-optimization/109048] [13 regression] redundant mask compare generated by vectorizer.

[crazylht at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109048

--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> ---
Lots of logic operation for mask in ifcvt

  <bb 17> [local count: 531502205]:
  # i_18 = PHI <i_47(26), 0(42)>
  # ivtmp_15 = PHI <ivtmp_43(26), 256(42)>
  # DEBUG i => NULL
  # DEBUG BEGIN_STMT
  _38 = (long unsigned int) i_18;
  _37 = _38 * 4;
  _36 = af_24(D) + _37;
  x_20 = *_36;
  # DEBUG x => NULL
  # DEBUG BEGIN_STMT
  # DEBUG D#1 => NULL
  # DEBUG z => NULL
  # DEBUG BEGIN_STMT
  _50 = x_20 >= 0.0;
  _52 = x_20 < iftmp.0_34;
  _53 = _50 & _52;
  _55 = x_20 >= iftmp.0_34;
  _56 = _50 & _55;
  _74 = x_20 < 0.0;
  _ifc__73 = _74 ? 2.0e+0 : prephitmp_41;
  _ifc__75 = _53 ? prephitmp_41 : _ifc__73;
  prephitmp_17 = _56 ? iftmp.1_16 : _ifc__75;
  # DEBUG t1 => D#2
  # DEBUG BEGIN_STMT
  # DEBUG neg_t1 => -D#2
  # DEBUG BEGIN_STMT
  # DEBUG t2 => prephitmp_17
  # DEBUG BEGIN_STMT
  _12 = res_28(D) + _37;
  _26 = *_12;
  _27 = _26 + x_20;
  _45 = prephitmp_17 + _27;
  *_12 = _45;
  # DEBUG BEGIN_STMT
  i_47 = i_18 + 1;
  # DEBUG i => i_47
  # DEBUG BEGIN_STMT
  ivtmp_43 = ivtmp_15 - 1;