[Bug tree-optimization/114056] ifcvt may introduce use of uninitialized variables

[rguenth at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114056

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2024-02-22
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  A better example would be one that's actually vectorized.  Note
with -O2 -ftree-loop-if-convert we get the following from the pass,
using j_14(D) uninitialized (it's not recommended to enable
-ftree-loop-if-convert but we never removed the ability to enable it outside of
vectorization
but we probably should).

  <bb 2> [local count: 118111600]:
  c.4_1 = c;
  b.5_2 = b;
  e.6_25 = e;
  _26 = (int) e.6_25;
  f_lsm.16_27 = f;
  d.9_8 = d;
  _28 = c.4_1 != 0;
  _35 = j_14(D) != 0;
  _33 = (int) _35;
  _16 = b.5_2 != 0;
  _20 = _16 & _28;

  <bb 3> [local count: 1073741824]:
  # f_lsm.16_22 = PHI <f_lsm.16_27(2), _7(8)>
  iftmp.7_10 = _20 ? _33 : 0;
  _5 = iftmp.7_10 < _26;
  _15 = (int) _5;
  _7 = _15 & f_lsm.16_22;
  if (d.9_8 == 0)
    goto <bb 7>; [11.00%]
  else
    goto <bb 8>; [89.00%]

  <bb 8> [local count: 955630224]:
  goto <bb 3>; [100.00%]

  <bb 7> [local count: 118111600]:
  # _24 = PHI <_7(3)>
  f = _24;