[Bug middle-end/38756] 107t.ivopts introduces pointer truncation

[bigotp at acm dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38756

--- Comment #3 from Peter A. Bigot <bigotp at acm dot org> 2012-06-21 12:04:34 
UTC ---
commit af66de00843896ad5d2980952994b31cadbf8421
Author: Peter A. Bigot <pabi...@users.sourceforge.net>
Date:   Thu Jun 21 06:35:44 2012 -0500

    Anticipatory patch for PR middle-end/38756

    Do not truncate to size_type when adding the step factor to a pointer.

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index 0693c21..f8372fd 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -6199,6 +6199,11 @@ rewrite_use_nonlinear_expr (struct ivopts_data *data,
       step = cand->iv->step;
       ctype = TREE_TYPE (step);
       utype = TREE_TYPE (cand->var_after);
+      if (TYPE_PRECISION (ctype) < TYPE_PRECISION (utype))
+       {
+         ctype = generic_type_for (utype);
+         step = fold_convert (ctype, unshare_expr (step));
+       }
       if (TREE_CODE (step) == NEGATE_EXPR)
        {
          incr_code = MINUS_EXPR;