re PR rtl-optimization/55630 (FAIL: g++.dg/pr48660.C -std=c++98 (internal compiler error))

	PR rtl-optimization/55630
	* expr.c (expand_assignment): Do not call copy_blkmode_to_reg to move
	BLKmode return values to the return register.

From-SVN: r194530

gcc/ChangeLog

+2012-12-16  Eric Botcazou  <ebotcazou@adacore.com>
+
+	PR rtl-optimization/55630
+	* expr.c (expand_assignment): Do not call copy_blkmode_to_reg to move
+	BLKmode return values to the return register.
+
 2012-12-15  Alexandre Oliva <aoliva@redhat.com>
 
 	PR libmudflap/53952

gcc/expr.c

@@ -4947,7 +4947,12 @@ expand_assignment (tree to, tree from, bool nontemporal)
       rtx temp;
 
       push_temp_slots ();
-      if (REG_P (to_rtx) && TYPE_MODE (TREE_TYPE (from)) == BLKmode)
+
+      /* If the source is itself a return value, it still is in a pseudo at
+	 this point so we can move it back to the return register directly.  */
+      if (REG_P (to_rtx)
+	  && TYPE_MODE (TREE_TYPE (from)) == BLKmode
+	  && TREE_CODE (from) != CALL_EXPR)
 	temp = copy_blkmode_to_reg (GET_MODE (to_rtx), from);
       else
 	temp = expand_expr (from, NULL_RTX, GET_MODE (to_rtx), EXPAND_NORMAL);