[Bug tree-optimization/86363] [9 Regression] wrong code with __builtin_memset() at -O1

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86363

Bernd Edlinger <bernd.edlinger at hotmail dot de> changed:

           What    |Removed                     |Added
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                 CC|                            |bernd.edlinger at hotmail dot 
de

--- Comment #1 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
looks correct until pr86363.c.032t.ealias:
  _1 = BIT_FIELD_REF <v_15(D), 32, 0>;
  # PT = null { D.1901 }
  _2 = &VIEW_CONVERT_EXPR<charD.7[16]>(uD.1901)[_1];
  # .MEM_11 = VDEF <.MEM_10(D)>
  # USE = nonlocal null
  # CLB = nonlocal null 
  memsetD.870 (_2, 0, 1);
  # VUSE <.MEM_11>
  _12 = BIT_FIELD_REF <uD.1901, 8, 0>;
  _4 = (unsigned intD.9) _12;
  _5 = (unsigned intD.9) _12;
  _6 = (unsigned intD.9) _12;
  _7 = (unsigned intD.9) _12;
  _3 = {_4, _5, _6, _7};
  # VUSE <.MEM_11>
  g.0_8 = gD.1899;
  _9 = _3 ^ g.0_8; 
  # .MEM_13 = VDEF <.MEM_11>
  gD.1899 = _9;



problem starts in pr86363.c.033t.fre1:
Replaced BIT_FIELD_REF <u, 8, 0> with 0 in all uses of _12 = BIT_FIELD_REF <u,
8, 0>;
...
  _1 = BIT_FIELD_REF <v_15(D), 32, 0>;
  # PT = null { D.1901 }
  _2 = &VIEW_CONVERT_EXPR<charD.7[16]>(uD.1901)[_1];
  # .MEM_11 = VDEF <.MEM_10(D)>
  # USE = nonlocal null
  # CLB = nonlocal null
  memsetD.870 (_2, 0, 1);
  # VUSE <.MEM_11>
  g.0_8 = gD.1899;
  # VUSE <.MEM_11>
  return g.0_8;