[gcc r12-4408] rs6000: Fix memory leak in rs6000_density_test

[gcc r12-4408] rs6000: Fix memory leak in rs6000_density_test

[Richard Sandiford]

https://gcc.gnu.org/g:73f34f4d02d72dd61e4573402a202b35cf3cce0f

commit r12-4408-g73f34f4d02d72dd61e4573402a202b35cf3cce0f
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Thu Oct 14 16:35:42 2021 +0100

    rs6000: Fix memory leak in rs6000_density_test
    
    rs6000_density_test has an early exit test between a call
    to get_loop_body and the corresponding free.  This would
    lead to a memory leak if the early exit is taken.
    
    gcc/
            * config/rs6000/rs6000.c (rs6000_density_test): Move early
            exit test further up the function.

Diff:
---
 gcc/config/rs6000/rs6000.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index acba4d9f26c..01a95591a5d 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -5289,20 +5289,19 @@ struct rs6000_cost_data
 static void
 rs6000_density_test (rs6000_cost_data *data)
 {
-  struct loop *loop = data->loop_info;
-  basic_block *bbs = get_loop_body (loop);
-  int nbbs = loop->num_nodes;
-  loop_vec_info loop_vinfo = loop_vec_info_for_loop (data->loop_info);
-  int vec_cost = data->cost[vect_body], not_vec_cost = 0;
-  int i, density_pct;
-
   /* This density test only cares about the cost of vector version of the
      loop, so immediately return if we are passed costing for the scalar
      version (namely computing single scalar iteration cost).  */
   if (data->costing_for_scalar)
     return;
 
-  for (i = 0; i < nbbs; i++)
+  struct loop *loop = data->loop_info;
+  basic_block *bbs = get_loop_body (loop);
+  int nbbs = loop->num_nodes;
+  loop_vec_info loop_vinfo = loop_vec_info_for_loop (data->loop_info);
+  int vec_cost = data->cost[vect_body], not_vec_cost = 0;
+
+  for (int i = 0; i < nbbs; i++)
     {
       basic_block bb = bbs[i];
       gimple_stmt_iterator gsi;
@@ -5322,7 +5321,7 @@ rs6000_density_test (rs6000_cost_data *data)
     }
 
   free (bbs);
-  density_pct = (vec_cost * 100) / (vec_cost + not_vec_cost);
+  int density_pct = (vec_cost * 100) / (vec_cost + not_vec_cost);
 
   if (density_pct > rs6000_density_pct_threshold
       && vec_cost + not_vec_cost > rs6000_density_size_threshold)