Changelog:

        PR tree-optimization/26360
        * tree-vectorizer.c (destroy_loop_vec_info): Remove (dead) pattern
        stmts.

testsuite/Changelog:
        PR tree-optimizations/26360
        * gcc.dg/vect/vect.exp: Compile tests prefixed with "no-tree-dce"
        with -fno-tree-dce.
        * gcc.dg/vect/no-tree-dce-pr26360.c: New test.




git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@114386 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 19 insertions, 1 deletions

diff --git a/gcc/tree-vectorizer.c b/gcc/tree-vectorizer.c
index b6538a4b46d..c0d783474de 100644
--- a/gcc/tree-vectorizer.c
+++ b/gcc/tree-vectorizer.c
@@ -1467,7 +1467,7 @@ destroy_loop_vec_info (loop_vec_info loop_vinfo)
           set_stmt_info (ann, NULL);
         }
 
-      for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
+      for (si = bsi_start (bb); !bsi_end_p (si); )
 	{
 	  tree stmt = bsi_stmt (si);
 	  stmt_ann_t ann = stmt_ann (stmt);
@@ -1475,10 +1475,28 @@ destroy_loop_vec_info (loop_vec_info loop_vinfo)
 
 	  if (stmt_info)
 	    {
+	      /* Check if this is a "pattern stmt" (introduced by the 
+		 vectorizer during the pattern recognition pass).  */
+	      bool remove_stmt_p = false;
+	      tree orig_stmt = STMT_VINFO_RELATED_STMT (stmt_info);
+	      if (orig_stmt)
+		{
+		  stmt_vec_info orig_stmt_info = vinfo_for_stmt (orig_stmt);
+		  if (orig_stmt_info
+		      && STMT_VINFO_IN_PATTERN_P (orig_stmt_info))
+		    remove_stmt_p = true; 
+		}
+			
+	      /* Free stmt_vec_info.  */
 	      VEC_free (dr_p, heap, STMT_VINFO_SAME_ALIGN_REFS (stmt_info));
 	      free (stmt_info);
 	      set_stmt_info ((tree_ann_t)ann, NULL);
+
+	      /* Remove dead "pattern stmts".  */
+	      if (remove_stmt_p)
+	        bsi_remove (&si, true);
 	    }
+	  bsi_next (&si);
 	}
     }