re PR tree-optimization/58958 (Wrong aliasing info for variable index)

2013-11-05  Marc Glisse  <marc.glisse@inria.fr>

	PR tree-optimization/58958
gcc/
	* tree-ssa-alias.c (ao_ref_init_from_ptr_and_size): Use
	get_addr_base_and_unit_offset instead of get_ref_base_and_extent.

gcc/testsuite/
	* gcc.dg/tree-ssa/pr58958.c: New file.

From-SVN: r204389

gcc/ChangeLog

 2013-11-05  Marc Glisse  <marc.glisse@inria.fr>
 
+	PR tree-optimization/58958
+	* tree-ssa-alias.c (ao_ref_init_from_ptr_and_size): Use
+	get_addr_base_and_unit_offset instead of get_ref_base_and_extent.
+
+2013-11-05  Marc Glisse  <marc.glisse@inria.fr>
+
 	* tree-ssa-alias.h (ranges_overlap_p): Handle negative offsets.
 	* tree-ssa-alias.c (ao_ref_init_from_ptr_and_size): Likewise.
 

gcc/testsuite/ChangeLog

 2013-11-05  Marc Glisse  <marc.glisse@inria.fr>
 
+	PR tree-optimization/58958
+	* gcc.dg/tree-ssa/pr58958.c: New file.
+
+2013-11-05  Marc Glisse  <marc.glisse@inria.fr>
+
 	* gcc.dg/tree-ssa/alias-26.c: New file.
 
 2013-11-05  Jakub Jelinek  <jakub@redhat.com>

gcc/testsuite/gcc.dg/tree-ssa/pr58958.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+double a[10];
+int f(int n){
+  a[3]=9;
+  __builtin_memset(&a[n],3,sizeof(double));
+  return a[3]==9;
+}
+
+/* { dg-final { scan-tree-dump " == 9" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/tree-ssa-alias.c

@@ -566,7 +566,7 @@ ao_ref_alias_set (ao_ref *ref)
 void
 ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size)
 {
-  HOST_WIDE_INT t1, t2, extra_offset = 0;
+  HOST_WIDE_INT t, extra_offset = 0;
   ref->ref = NULL_TREE;
   if (TREE_CODE (ptr) == SSA_NAME)
     {
@@ -585,8 +585,17 @@ ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size)
     }
 
   if (TREE_CODE (ptr) == ADDR_EXPR)
-    ref->base = get_ref_base_and_extent (TREE_OPERAND (ptr, 0),
-					 &ref->offset, &t1, &t2);
+    {
+      ref->base = get_addr_base_and_unit_offset (TREE_OPERAND (ptr, 0), &t);
+      if (ref->base)
+	ref->offset = BITS_PER_UNIT * t;
+      else
+	{
+	  size = NULL_TREE;
+	  ref->offset = 0;
+	  ref->base = get_base_address (TREE_OPERAND (ptr, 0));
+	}
+    }
   else
     {
       ref->base = build2 (MEM_REF, char_type_node,