tree-ssa-alias.c (ao_ref_init_from_ptr_and_size): Look for an ADDR_EXPR in the defining statement.

2013-10-25  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* tree-ssa-alias.c (ao_ref_init_from_ptr_and_size): Look for an
	ADDR_EXPR in the defining statement.

gcc/testsuite/
	* gcc.dg/tree-ssa/alias-23.c: New file.

From-SVN: r204065

gcc/ChangeLog

+2013-10-25  Marc Glisse  <marc.glisse@inria.fr>
+
+	* tree-ssa-alias.c (ao_ref_init_from_ptr_and_size): Look for an
+	ADDR_EXPR in the defining statement.
+
 2013-10-25  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/58626

gcc/testsuite/ChangeLog

+2013-10-25  Marc Glisse  <marc.glisse@inria.fr>
+
+	* gcc.dg/tree-ssa/alias-23.c: New file.
+
 2013-10-25  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/58626

gcc/testsuite/gcc.dg/tree-ssa/alias-23.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+typedef struct A { int i; double d; } A;
+
+void f1 (const char *c)
+{
+  A *s = (A*) __builtin_malloc (sizeof (A));
+  double *p = &s->d;
+  s->i = 42;
+  __builtin_memcpy (p, c, sizeof (double));
+  int j = s->i;
+  if (j != 42) __builtin_abort();
+}
+
+/* { dg-final { scan-tree-dump-not "abort" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
+

gcc/tree-ssa-alias.c

@@ -568,6 +568,14 @@ ao_ref_init_from_ptr_and_size (ao_ref *ref, tree ptr, tree size)
 {
   HOST_WIDE_INT t1, t2;
   ref->ref = NULL_TREE;
+  if (TREE_CODE (ptr) == SSA_NAME)
+    {
+      gimple stmt = SSA_NAME_DEF_STMT (ptr);
+      if (gimple_assign_single_p (stmt)
+	  && gimple_assign_rhs_code (stmt) == ADDR_EXPR)
+	ptr = gimple_assign_rhs1 (stmt);
+    }
+
   if (TREE_CODE (ptr) == ADDR_EXPR)
     ref->base = get_ref_base_and_extent (TREE_OPERAND (ptr, 0),
 					 &ref->offset, &t1, &t2);