gcc-pr27603.patch

   1 --- gcc-4_1-branch/gcc/tree-ssa-loop-niter.c    (wersja 113819)
   2 +++ gcc-4_1-branch/gcc/tree-ssa-loop-niter.c    (wersja 113820)
   3 @@ -1562,15 +1562,20 @@
   4
   5                     utype = unsigned_type_for (type);
   6                     if (tree_int_cst_lt (step, integer_zero_node))
   7 -                     diff = fold_build2 (MINUS_EXPR, utype, init,
   8 +                     diff = fold_build2 (MINUS_EXPR, type, init,
   9                                           TYPE_MIN_VALUE (type));
  10                     else
  11 -                     diff = fold_build2 (MINUS_EXPR, utype,
  12 +                     diff = fold_build2 (MINUS_EXPR, type,
  13                                           TYPE_MAX_VALUE (type), init);
  14
  15 -                   estimation = fold_build2 (CEIL_DIV_EXPR, utype, diff,
  16 -                                             step);
  17 -                   record_estimate (loop, estimation, boolean_true_node, stmt);
  18 +                   if (integer_nonzerop (step))
  19 +                     {
  20 +                       estimation = fold_build2 (CEIL_DIV_EXPR, type, diff,
  21 +                                                 step);
  22 +                       record_estimate (loop,
  23 +                                        fold_convert (utype, estimation),
  24 +                                        boolean_true_node, stmt);
  25 +                     }
  26                   }
  27
  28                 break;