[PATCH] Fix memory leak in the vectorizer (PR tree-optimization/79340)

[Jakub Jelinek]

Hi!

As mentioned in the PR, on the gfortran.dg/forall_7.f90 testcase
we leak memory starting with r239542.  vect_get_slp_defs allocates
a vector of vectors, elements corresponding to NULL in slp_ops
are .create (0) vectors that don't need freeing, but the rest
is safe_spliced into other vectors.  We need to release those
vectors afterwards, before the vector containing them is released.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2017-02-03  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/79340
        * tree-vect-loop.c (vectorizable_reduction): Release
        vec_defs elements after safe_splicing them into other vectors.
        Formatting fixes.

--- gcc/tree-vect-loop.c.jj     2017-02-02 08:44:13.000000000 +0100
+++ gcc/tree-vect-loop.c        2017-02-03 13:19:00.087499820 +0100
@@ -6172,20 +6172,24 @@ vectorizable_reduction (gimple *stmt, gi
          if (slp_node)
            {
              /* Get vec defs for all the operands except the reduction index,
-               ensuring the ordering of the ops in the vector is kept.  */
+                ensuring the ordering of the ops in the vector is kept.  */
              auto_vec<tree, 3> slp_ops;
              auto_vec<vec<tree>, 3> vec_defs;
 
-             slp_ops.quick_push ((reduc_index == 0) ? NULL : ops[0]);
-             slp_ops.quick_push ((reduc_index == 1) ? NULL : ops[1]);
+             slp_ops.quick_push (reduc_index == 0 ? NULL : ops[0]);
+             slp_ops.quick_push (reduc_index == 1 ? NULL : ops[1]);
              if (op_type == ternary_op)
-               slp_ops.quick_push ((reduc_index == 2) ? NULL : ops[2]);
+               slp_ops.quick_push (reduc_index == 2 ? NULL : ops[2]);
 
              vect_get_slp_defs (slp_ops, slp_node, &vec_defs, -1);
 
-             vec_oprnds0.safe_splice (vec_defs[(reduc_index == 0) ? 1 : 0]);
+             vec_oprnds0.safe_splice (vec_defs[reduc_index == 0 ? 1 : 0]);
+             vec_defs[reduc_index == 0 ? 1 : 0].release ();
              if (op_type == ternary_op)
-               vec_oprnds1.safe_splice (vec_defs[(reduc_index == 2) ? 1 : 2]);
+               {
+                 vec_oprnds1.safe_splice (vec_defs[reduc_index == 2 ? 1 : 2]);
+                 vec_defs[reduc_index == 2 ? 1 : 2].release ();
+               }
            }
           else
            {
@@ -6194,7 +6198,7 @@ vectorizable_reduction (gimple *stmt, gi
               vec_oprnds0.quick_push (loop_vec_def0);
               if (op_type == ternary_op)
                {
-                op1 = (reduc_index == 0) ? ops[2] : ops[1];
+                op1 = reduc_index == 0 ? ops[2] : ops[1];
                  loop_vec_def1 = vect_get_vec_def_for_operand (op1, stmt);
                  vec_oprnds1.quick_push (loop_vec_def1);
                }

        Jakub