re PR tree-optimization/36493 (vectorizer aliasing bug)

	PR tree-optimization/36493
	* tree-vect-transform.c (vect_create_data_ref_ptr): Remove TYPE from
	the arguments list. Use VECTYPE to create vector pointer.
	(vectorizable_store): Fail if accesses through a pointer to vectype
	do not alias the original memory reference operands.
	Call vect_create_data_ref_ptr without the removed argument.
	(vectorizable_load): Likewise.
	(vect_setup_realignment): Call vect_create_data_ref_ptr without the
	removed argument.

From-SVN: r136843

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 777743ae0ab1cba78cb154ec54e8eae0ba7468ec..6b6a931e948719dd8619e6c42aa95a145a456b43 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2008-06-16  Ira Rosen  <irar@il.ibm.com>
+
+       PR tree-optimization/36493
+       * tree-vect-transform.c (vect_create_data_ref_ptr): Remove TYPE from
+       the arguments list. Use VECTYPE to create vector pointer.
+       (vectorizable_store): Fail if accesses through a pointer to vectype
+       do not alias the original memory reference operands.
+       Call vect_create_data_ref_ptr without the removed argument.
+       (vectorizable_load): Likewise.
+       (vect_setup_realignment): Call vect_create_data_ref_ptr without the
+       removed argument.
+
 2008-06-015  Andy Hutchinson  <hutchinsonandy@aim.com>
 
        PR target/36336

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 6084985374f49a334e496a414d09162f0b44c3b6..e97e60b6ebf3f948013343e360c2c984bbe4b49e 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2008-06-16  Ira Rosen  <irar@il.ibm.com>
+
+       PR tree-optimization/36493
+       * gcc.dg/vect/pr36493.c: New testcase.
+
 2008-06-15  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
 
        PR fortran/36515

diff --git a/gcc/testsuite/gcc.dg/vect/pr36493.c b/gcc/testsuite/gcc.dg/vect/pr36493.c
new file mode 100644 (file)
index 0000000..d96e962
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr36493.c
@@ -0,0 +1,23 @@
+/* { dg-require-effective-target vect_int } */
+
+#include "tree-vect.h"
+
+int
+main (void)
+{
+  int i;
+  long x[12] __attribute__((aligned(16)));
+
+  x[0] = 1;
+  for (i = 0; i < 12; i++)
+    x[i] = i;
+
+  if (x[0] != 0)
+    abort ();
+
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect"  } } */
+/* { dg-final { cleanup-tree-dump "vect" } } */
+

diff --git a/gcc/tree-vect-transform.c b/gcc/tree-vect-transform.c
index 450af302403ce1ca8206f043a4c237c1693c15bb..4110b335d7450c274bc14d8b93505b7c66f1253d 100644 (file)
--- a/gcc/tree-vect-transform.c
+++ b/gcc/tree-vect-transform.c
@@ -49,7 +49,7 @@ along with GCC; see the file COPYING3.  If not see
 static bool vect_transform_stmt (tree, block_stmt_iterator *, bool *, slp_tree);
 static tree vect_create_destination_var (tree, tree);
 static tree vect_create_data_ref_ptr 
-  (tree, struct loop*, tree, tree *, tree *, bool, tree, bool *); 
+  (tree, struct loop*, tree, tree *, tree *, bool, bool *); 
 static tree vect_create_addr_base_for_vector_ref 
   (tree, tree *, tree, struct loop *);
 static tree vect_get_new_vect_var (tree, enum vect_var_kind, const char *);
@@ -951,7 +951,6 @@ vect_create_addr_base_for_vector_ref (tree stmt,
         by the data-ref in STMT.
    4. ONLY_INIT: indicate if vp is to be updated in the loop, or remain
         pointing to the initial address.
-   5. TYPE: if not NULL indicates the required type of the data-ref
 
    Output:
    1. Declare a new ptr to vector_type, and have it point to the base of the
@@ -981,7 +980,7 @@ vect_create_addr_base_for_vector_ref (tree stmt,
 static tree
 vect_create_data_ref_ptr (tree stmt, struct loop *at_loop,
                          tree offset, tree *initial_address, tree *ptr_incr,
-                         bool only_init, tree type, bool *inv_p)
+                         bool only_init, bool *inv_p)
 {
   tree base_name;
   stmt_vec_info stmt_info = vinfo_for_stmt (stmt);
@@ -1040,10 +1039,8 @@ vect_create_data_ref_ptr (tree stmt, struct loop *at_loop,
     }
 
   /** (1) Create the new vector-pointer variable:  **/
-  if (type)  
-    vect_ptr_type = build_pointer_type (type);
-  else
-    vect_ptr_type = build_pointer_type (vectype);
+  vect_ptr_type = build_pointer_type (vectype);
+
   vect_ptr = vect_get_new_vect_var (vect_ptr_type, vect_pointer_var,
                                     get_name (base_name));
   add_referenced_var (vect_ptr);
@@ -4756,6 +4753,24 @@ vectorizable_store (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt,
       return false;
     }
 
+  /* If accesses through a pointer to vectype do not alias the original
+     memory reference we have a problem.  */
+  if (get_alias_set (vectype) != get_alias_set (TREE_TYPE (scalar_dest))
+      && !alias_set_subset_of (get_alias_set (vectype), 
+                               get_alias_set (TREE_TYPE (scalar_dest))))
+    {
+      if (vect_print_dump_info (REPORT_DETAILS))
+        fprintf (vect_dump, "vector type does not alias scalar type");
+      return false;
+    }
+
+  if (!useless_type_conversion_p (TREE_TYPE (op), TREE_TYPE (scalar_dest)))
+    {      
+      if (vect_print_dump_info (REPORT_DETAILS))
+        fprintf (vect_dump, "operands of different types");
+      return false;
+    }
+
   vec_mode = TYPE_MODE (vectype);
   /* FORNOW. In some cases can vectorize even if data-type not supported
      (e.g. - array initialization with 0).  */
@@ -4930,9 +4945,10 @@ vectorizable_store (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt,
                  next_stmt = DR_GROUP_NEXT_DR (vinfo_for_stmt (next_stmt));
                }
            }
+
          dataref_ptr = vect_create_data_ref_ptr (first_stmt, NULL, NULL_TREE, 
-                                                 &dummy, &ptr_incr, false,
-                                                 TREE_TYPE (vec_oprnd), &inv_p);
+                                                 &dummy, &ptr_incr, false, 
+                                                 &inv_p);
          gcc_assert (!inv_p);
        }
       else 
@@ -5170,7 +5186,7 @@ vect_setup_realignment (tree stmt, block_stmt_iterator *bsi,
       pe = loop_preheader_edge (loop_for_initial_load);
       vec_dest = vect_create_destination_var (scalar_dest, vectype);
       ptr = vect_create_data_ref_ptr (stmt, loop_for_initial_load, NULL_TREE,
-                               &init_addr, &inc, true, NULL_TREE, &inv_p);
+                                     &init_addr, &inc, true, &inv_p);
       data_ref = build1 (ALIGN_INDIRECT_REF, vectype, ptr);
       new_stmt = build_gimple_modify_stmt (vec_dest, data_ref);
       new_temp = make_ssa_name (vec_dest, new_stmt);
@@ -5619,6 +5635,17 @@ vectorizable_load (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt,
       return false;
     }
 
+  /* If accesses through a pointer to vectype do not alias the original
+     memory reference we have a problem.  */
+  if (get_alias_set (vectype) != get_alias_set (scalar_type)
+      && !alias_set_subset_of (get_alias_set (vectype),
+                               get_alias_set (scalar_type)))
+    {
+      if (vect_print_dump_info (REPORT_DETAILS))
+        fprintf (vect_dump, "vector type does not alias scalar type");
+      return false;
+    }
+
   /* Check if the load is a part of an interleaving chain.  */
   if (STMT_VINFO_STRIDED_ACCESS (stmt_info))
     {
@@ -5811,7 +5838,7 @@ vectorizable_load (tree stmt, block_stmt_iterator *bsi, tree *vec_stmt,
         dataref_ptr = vect_create_data_ref_ptr (first_stmt,
                                                at_loop, offset, 
                                                &dummy, &ptr_incr, false, 
-                                               NULL_TREE, &inv_p);
+                                               &inv_p);
       else
         dataref_ptr = 
                bump_vector_ptr (dataref_ptr, ptr_incr, bsi, stmt, NULL_TREE);