[Bug tree-optimization/26587] [4.1/4.2 Regression] strict aliasing incorrectly pre-loads an array element with loops

[rguenth at gcc dot gnu dot org]

------- Comment #8 from rguenth at gcc dot gnu dot org  2006-03-07 10:43 -------
With -O2 -fno-ivopts -fno-tree-vrp -fno-tree-salias -fno-strict-aliasing we
correctly get

<L11>:;

  # BF_current_23 = PHI <BF_current_21(5), BF_current_24(7)>;
  # ptr_3 = PHI <&BF_current.P[0](5), ptr_9(7)>;
  # L_2 = PHI <0(5), L_14(7)>;
<L7>:;
  ptr_9 = ptr_3 + 8B;
  #   VUSE <BF_current_23>;
  D.1541_10 = BF_current.P[0];
  L_11 = L_2 ^ D.1541_10;
  tmp4_12 = L_11 >> 24;
  #   VUSE <BF_current_23>;
  D.1542_13 = BF_current.P[17];
  L_14 = tmp4_12 ^ D.1542_13;
  D.1543_15 = ptr_9 - 8B;
  #   BF_current_24 = V_MAY_DEF <BF_current_23>;
  *D.1543_15 = L_14;
  if (ptr_9 < &BF_current.P[18]) goto <L12>; else goto <L4>;


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26587