[Bug bootstrap/26998] bootstrap failure building libdecnumber, ICE in compare_values, tree-vrp.c:432

["rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #11 from rguenth at gcc dot gnu dot org  2006-06-08 09:47 -------
This one:

  /* Apply the operation to each end of the range and see what we end
     up with.  */
  if (code == NEGATE_EXPR
      && !TYPE_UNSIGNED (TREE_TYPE (expr)))
    {
      /* NEGATE_EXPR flips the range around.  */
      min = (vr0.max == TYPE_MAX_VALUE (TREE_TYPE (expr)) && !flag_wrapv)
             ? TYPE_MIN_VALUE (TREE_TYPE (expr))
             : fold_unary_to_constant (code, TREE_TYPE (expr), vr0.max);

      max = (vr0.min == TYPE_MIN_VALUE (TREE_TYPE (expr)) && !flag_wrapv)
             ? TYPE_MAX_VALUE (TREE_TYPE (expr))
             : fold_unary_to_constant (code, TREE_TYPE (expr), vr0.min);

    }

is wrong for

(gdb) print vr0
$3 = {type = VR_ANTI_RANGE, min = 0xb7d2b3a8, max = 0xb7d2b3a8, 
  equiv = 0x896c298}
(gdb) call debug_generic_expr (vr0.min)
-2147483648
(gdb) call debug_generic_expr (vr0.max)
-2147483648

It needs to read:

      min = (vr0.max == TYPE_MIN_VALUE (TREE_TYPE (expr)) && !flag_wrapv)
             ? TYPE_MAX_VALUE (TREE_TYPE (expr))
             : fold_unary_to_constant (code, TREE_TYPE (expr), vr0.max);

values other than TYPE_MIN_VALUE are not special with inversion.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |rguenth at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2006-06-08 09:13:37         |2006-06-08 09:47:25
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26998