[GOOGLE] Handle integer overflow in unroller code size limit computation

[Teresa Johnson]

Regression tested, ok for google/4_8?

Thanks,
Teresa

2014-01-15  Teresa Johnson  <tejohn...@google.com>

        * loop-unroll.c (code_size_limit_factor): Handle int overflow.

Index: loop-unroll.c
===================================================================
--- loop-unroll.c       (revision 206601)
+++ loop-unroll.c       (working copy)
@@ -315,6 +315,7 @@ code_size_limit_factor(struct loop *loop)
   struct niter_desc *desc = get_simple_loop_desc (loop);
   gcov_type sum_to_header_ratio;
   int hotness_ratio_threshold;
+  gcov_type limit;
   int limit_factor;
   gcov_working_set_t *ws;

@@ -361,8 +362,12 @@ code_size_limit_factor(struct loop *loop)
          factor to zero as the loop's hotness reduces.  */
       if (sum_to_header_ratio > hotness_ratio_threshold)
         {
-          limit_factor = sum_to_header_ratio / hotness_ratio_threshold;
-          gcc_assert (limit_factor >= 1);
+          limit = sum_to_header_ratio / hotness_ratio_threshold;
+          gcc_assert (limit >= 1);
+          if (limit > INT_MAX)
+            limit_factor = INT_MAX;
+          else
+            limit_factor = (int) limit;
         }
       else
         limit_factor = 1;


-- 
Teresa Johnson | Software Engineer | tejohn...@google.com | 408-460-2413