re PR middle-end/89412 (gcc ICE in simplify_subreg, at simplify-rtx.c:6273 on i686-linux-gnu)

	PR middle-end/89412
	* expr.c (expand_assignment): If result is a MEM, use change_address
	instead of simplify_gen_subreg.

	* gcc.c-torture/compile/pr89412.c: New test.

From-SVN: r269057

gcc/ChangeLog

 2019-02-20  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/89412
+	* expr.c (expand_assignment): If result is a MEM, use change_address
+	instead of simplify_gen_subreg.
+
+2019-02-20  Jakub Jelinek  <jakub@redhat.com>
 	    David Malcolm  <dmalcolm@redhat.com>
 
 	PR middle-end/89091

gcc/expr.c

@@ -5211,9 +5211,13 @@ expand_assignment (tree to, tree from, bool nontemporal)
 		}
 	      else
 		{
-		  rtx from_rtx
-		    = simplify_gen_subreg (to_mode, result,
-					   TYPE_MODE (TREE_TYPE (from)), 0);
+		  rtx from_rtx;
+		  if (MEM_P (result))
+		    from_rtx = change_address (result, to_mode, NULL_RTX);
+		  else
+		    from_rtx
+		      = simplify_gen_subreg (to_mode, result,
+					     TYPE_MODE (TREE_TYPE (from)), 0);
 		  if (from_rtx)
 		    {
 		      emit_move_insn (XEXP (to_rtx, 0),

gcc/testsuite/ChangeLog

 2019-02-20  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/89412
+	* gcc.c-torture/compile/pr89412.c: New test.
+
+2019-02-20  Jakub Jelinek  <jakub@redhat.com>
 	    David Malcolm  <dmalcolm@redhat.com>
 
 	PR middle-end/89091

gcc/testsuite/gcc.c-torture/compile/pr89412.c

+/* PR middle-end/89412 */
+
+struct S { double a, b; } d;
+int e;
+double f;
+
+void
+foo ()
+{
+  _Complex double h;
+  while (e)
+    {
+      f = h;
+      *(struct S *) &h = d;
+    }
+}