Fix PR/46200

From-SVN: r166280

1 files changed, 19 insertions, 2 deletions

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index 88fc015..ab2e67a 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -4027,6 +4027,8 @@ get_computation_cost_at (struct ivopts_data *data,
   STRIP_NOPS (cbase);
   ctype = TREE_TYPE (cbase);
 
+  stmt_is_after_inc = stmt_after_increment (data->current_loop, cand, at);
+
   /* use = ubase + ratio * (var - cbase).  If either cbase is a constant
      or ratio == 1, it is better to handle this like
 
@@ -4045,8 +4047,24 @@ get_computation_cost_at (struct ivopts_data *data,
     }
   else if (ratio == 1)
     {
+      tree real_cbase = cbase;
+
+      /* Check to see if any adjustment is needed.  */
+      if (cstepi == 0 && stmt_is_after_inc)
+        {
+          aff_tree real_cbase_aff;
+          aff_tree cstep_aff;
+
+          tree_to_aff_combination (cbase, TREE_TYPE (real_cbase),
+                                   &real_cbase_aff);
+          tree_to_aff_combination (cstep, TREE_TYPE (cstep), &cstep_aff);
+
+          aff_combination_add (&real_cbase_aff, &cstep_aff);
+          real_cbase = aff_combination_to_tree (&real_cbase_aff);
+        }
+
       cost = difference_cost (data,
-			      ubase, cbase,
+			      ubase, real_cbase,
 			      &symbol_present, &var_present, &offset,
 			      depends_on);
       cost.cost /= avg_loop_niter (data->current_loop);
@@ -4088,7 +4106,6 @@ get_computation_cost_at (struct ivopts_data *data,
 
   /* If we are after the increment, the value of the candidate is higher by
      one iteration.  */
-  stmt_is_after_inc = stmt_after_increment (data->current_loop, cand, at);
   if (stmt_is_after_inc)
     offset -= ratio * cstepi;