expr.c (expand_expr_real_2): Properly truncate the BIT_NOT_EXPR expansion result…

expr.c (expand_expr_real_2): Properly truncate the BIT_NOT_EXPR expansion result to bitfield precision if...

2011-07-18  Richard Guenther  <rguenther@suse.de>

	* expr.c (expand_expr_real_2): Properly truncate the BIT_NOT_EXPR
	expansion result to bitfield precision if required.

	* gcc.dg/torture/20110718-1.c: New testcase.

From-SVN: r176398

gcc/ChangeLog

+2011-07-18  Richard Guenther  <rguenther@suse.de>
+
+	* expr.c (expand_expr_real_2): Properly truncate the BIT_NOT_EXPR
+	expansion result to bitfield precision if required.
+
 2011-07-18  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* config.gcc (i[3456x]86-*-netware*): Remove.

gcc/expr.c

@@ -8037,7 +8037,15 @@ expand_expr_real_2 (sepops ops, rtx target, enum machine_mode tmode,
 			 VOIDmode, EXPAND_NORMAL);
       if (modifier == EXPAND_STACK_PARM)
 	target = 0;
-      temp = expand_unop (mode, one_cmpl_optab, op0, target, 1);
+      /* In case we have to reduce the result to bitfield precision
+	 expand this as XOR with a proper constant instead.  */
+      if (reduce_bit_field)
+	temp = expand_binop (mode, xor_optab, op0,
+			     immed_double_int_const
+			       (double_int_mask (TYPE_PRECISION (type)), mode),
+			     target, 1, OPTAB_LIB_WIDEN);
+      else
+	temp = expand_unop (mode, one_cmpl_optab, op0, target, 1);
       gcc_assert (temp);
       return temp;
 

gcc/testsuite/ChangeLog

+2011-07-18  Richard Guenther  <rguenther@suse.de>
+
+	* gcc.dg/torture/20110718-1.c: New testcase.
+
 2011-07-18  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* g++.dg/ext/bitfield2.C: Remove i?86-*-netware support.

gcc/testsuite/gcc.dg/torture/20110718-1.c

+/* { dg-do run } */
+
+extern void abort (void);
+struct X {
+#if (__SIZEOF_LONG__ != __SIZEOF_INT__) && (__SIZEOF_LONG__ == 8)
+  unsigned long i : 33;
+#else
+  unsigned long i;
+#endif
+};
+unsigned long __attribute__((noinline))
+foo (struct X *p)
+{
+  return ~p->i;
+}
+int main()
+{
+  struct X x;
+  x.i = -1;
+  if (foo (&x) != 0)
+    abort ();
+  return 0;
+}