[PATCH] Fix various issues in vect_analyze_data_refs (PR middle-end/59150)

[Jakub Jelinek]

Hi!

This patch fixes a double free on simd-lane access if
get_vectype_for_scalar_type fails (the new dr is already in datarefs[i]
and if we free_data_ref it, it will be free_data_ref'ed again at the end of
the failed vectorization), fixes handling of clobbers (plugs a memory leak
due to missed free_data_ref and more importantly, if we goto again, dr
would be kept at the old dr and thus we'd basically remove all the remaining
drs in a loop) and plugs a memory leak with simd_lane_access.

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

PS, just looking at the patch now again, in the light of PR59594
the reordering of datarefs before goto again looks also wrong, we IMHO have
to perform a vector ordered remove in that case, ok to handle it as a
follow-up?

2014-02-06  Jakub Jelinek  <ja...@redhat.com>

        PR middle-end/59150
        * tree-vect-data-refs.c (vect_analyze_data_refs): For clobbers, call
        free_data_ref on the dr first, and before goto again also set dr
        to the next dr.  For simd_lane_access, free old datarefs[i] before
        overwriting it.  For get_vectype_for_scalar_type failure, don't
        free_data_ref if simd_lane_access.

--- gcc/tree-vect-data-refs.c.jj        2014-02-05 15:28:10.000000000 +0100
+++ gcc/tree-vect-data-refs.c   2014-02-05 18:30:53.323659288 +0100
@@ -3297,12 +3297,13 @@ again:
          clobber stmts during vectorization.  */
       if (gimple_clobber_p (stmt))
        {
+         free_data_ref (dr);
          if (i == datarefs.length () - 1)
            {
              datarefs.pop ();
              break;
            }
-         datarefs[i] = datarefs.pop ();
+         datarefs[i] = dr = datarefs.pop ();
          goto again;
        }
 
@@ -3643,13 +3644,14 @@ again:
       if (simd_lane_access)
        {
          STMT_VINFO_SIMD_LANE_ACCESS_P (stmt_info) = true;
+         free_data_ref (datarefs[i]);
          datarefs[i] = dr;
        }
 
       /* Set vectype for STMT.  */
       scalar_type = TREE_TYPE (DR_REF (dr));
-      STMT_VINFO_VECTYPE (stmt_info) =
-                get_vectype_for_scalar_type (scalar_type);
+      STMT_VINFO_VECTYPE (stmt_info)
+       = get_vectype_for_scalar_type (scalar_type);
       if (!STMT_VINFO_VECTYPE (stmt_info))
         {
           if (dump_enabled_p ())
@@ -3669,7 +3671,8 @@ again:
          if (gather || simd_lane_access)
            {
              STMT_VINFO_DATA_REF (stmt_info) = NULL;
-             free_data_ref (dr);
+             if (gather)
+               free_data_ref (dr);
            }
          return false;
         }

        Jakub