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Subject: [Bug tree-optimization/27090] FRE does not look past previous type casts
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------- Comment #8 from rguenth at gcc dot gnu dot org  2006-04-20 13:54 -------
Which, for the testcase in comment #4 gives us

;; Function f (f)

Created value VH.0 for a_1
Created value VH.1 for *VH.0 vuses: (SMT.4_8)
Created value VH.2 for (unsigned int *) VH.0
Created value VH.3 for (int *) VH.2
Created value VH.4 for VH.1 + VH.1
Created value VH.5 for <retval>_7
exp_gen[0] := {  }
tmp_gen[0] := { a_1 (VH.0)  }
avail_out[0] := { a_1 (VH.0)  }
exp_gen[2] := { a_1 (VH.0) , *VH.0 (VH.1) , (unsigned int *) VH.0 (VH.2) , (int
*) VH.2 (VH.3) , VH.1 + VH.1 (VH.4)  }
tmp_gen[2] := { t_2 (VH.1) , b_3 (VH.2) , c_4 (VH.3) , D.1527_5 (VH.1) ,
D.1526_6 (VH.4) , <retval>_7 (VH.5)  }
avail_out[2] := { a_1 (VH.0) , t_2 (VH.1) , b_3 (VH.2) , c_4 (VH.3) , D.1526_6
(VH.4) , <retval>_7 (VH.5)  }
exp_gen[1] := {  }
tmp_gen[1] := {  }
avail_out[1] := {  }
Replaced *c_4 with t_2 in D.1527_5 = *c_4;
f (a)
{
  int * c;
  unsigned int * b;
  int t;
  int D.1527;
  int D.1526;

<bb 2>:
  t_2 = *a_1;
  b_3 = (unsigned int *) a_1;
  c_4 = (int *) b_3;
  D.1527_5 = t_2;
  D.1526_6 = D.1527_5 + t_2;
  return D.1526_6;

}


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27090