re PR rtl-optimization/49429 (dse.c change (r175063) causes execution failures)

2011-06-24  Easwaran Raman  <eraman@google.com>

      PR rtl-optimization/49429
      PR target/49454
      * expr.c (emit_block_move_hints):  Mark MEM_EXPR(x) and
      MEM_EXPR(y) addressable if emit_block_move_via_libcall is
      used to copy y into x.
      * calls.c (initialize_argument_information): Mark
      an argument addressable if it is passed by invisible reference.
      (emit_library_call_value_1): Mark  MEM_EXPR (val) addressable
      if it is passed by reference.

From-SVN: r175384

gcc/ChangeLog

+2011-06-24  Easwaran Raman  <eraman@google.com>
+
+	PR rtl-optimization/49429
+	PR target/49454
+	* expr.c (emit_block_move_hints):  Mark MEM_EXPR(x) and
+	MEM_EXPR(y) addressable if emit_block_move_via_libcall is
+	used to copy y into x.
+	* calls.c (initialize_argument_information): Mark
+	an argument addressable if it is passed by invisible reference.
+	(emit_library_call_value_1): Mark  MEM_EXPR (val) addressable
+	if it is passed by reference.
+
 2011-06-24  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR rtl-optimization/49504

gcc/calls.c

@@ -1084,6 +1084,8 @@ initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
 		  && TREE_CODE (base) != SSA_NAME
 		  && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
 	    {
+	      mark_addressable (args[i].tree_value);
+
 	      /* We can't use sibcalls if a callee-copied argument is
 		 stored in the current function's frame.  */
 	      if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
@@ -3524,7 +3526,12 @@ emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
 	    }
 
 	  if (MEM_P (val) && !must_copy)
-	    slot = val;
+	    {
+	      tree val_expr = MEM_EXPR (val);
+	      if (val_expr)
+		mark_addressable (val_expr);
+	      slot = val;
+	    }
 	  else
 	    {
 	      slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),

gcc/expr.c

@@ -1181,8 +1181,19 @@ emit_block_move_hints (rtx x, rtx y, rtx size, enum block_op_methods method,
   else if (may_use_call
 	   && ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (x))
 	   && ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (y)))
-    retval = emit_block_move_via_libcall (x, y, size,
-					  method == BLOCK_OP_TAILCALL);
+    {
+      /* Since x and y are passed to a libcall, mark the corresponding
+	 tree EXPR as addressable.  */
+      tree y_expr = MEM_EXPR (y);
+      tree x_expr = MEM_EXPR (x);
+      if (y_expr)
+	mark_addressable (y_expr);
+      if (x_expr)
+	mark_addressable (x_expr);
+      retval = emit_block_move_via_libcall (x, y, size,
+					    method == BLOCK_OP_TAILCALL);
+    }
+
   else
     emit_block_move_via_loop (x, y, size, align);