[PATCH] Properly release pattern stmts

[Richard Biener]

This makes sure pattern stmts do not appear to be in the IL,
first by setting their BB to NULL again (the vectorizer sets this
for convenience I guess) and second by releasing SSA names we
temporarily allocated.

Esp. the non-NULL BB may confuse passes walking over
non-released SSA names.

Bootstrapped and tested on x86_64-unknown-linux-gnu, ok?

Thanks,
Richard.

2014-02-17  Richard Biener  <rguent...@suse.de>

        * tree-vect-stmts.c (free_stmt_vec_info): Clear BB and
        release SSA defs of pattern stmts.

Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c       (revision 207757)
+++ gcc/tree-vect-stmts.c       (working copy)
@@ -7389,13 +7389,25 @@ free_stmt_vec_info (gimple stmt)
       if (patt_info)
        {
          gimple_seq seq = STMT_VINFO_PATTERN_DEF_SEQ (patt_info);
+         gimple patt_stmt = STMT_VINFO_STMT (patt_info);
+         gimple_set_bb (patt_stmt, NULL);
+         tree lhs = gimple_get_lhs (patt_stmt);
+         if (TREE_CODE (lhs) == SSA_NAME)
+           release_ssa_name (lhs);
          if (seq)
            {
              gimple_stmt_iterator si;
              for (si = gsi_start (seq); !gsi_end_p (si); gsi_next (&si))
-               free_stmt_vec_info (gsi_stmt (si));
+               {
+                 gimple seq_stmt = gsi_stmt (si);
+                 gimple_set_bb (seq_stmt, NULL);
+                 lhs = gimple_get_lhs (patt_stmt);
+                 if (TREE_CODE (lhs) == SSA_NAME)
+                   release_ssa_name (lhs);
+                 free_stmt_vec_info (seq_stmt);
+               }
            }
-         free_stmt_vec_info (STMT_VINFO_RELATED_STMT (stmt_info));
+         free_stmt_vec_info (patt_stmt);
        }
     }