* fold-const.c (fold_truthop): Fix bug in last change.

From-SVN: r16473

gcc/ChangeLog

+Thu Nov 13 23:33:50 1997  J"orn Rennecke <amylaar@cygnus.co.uk>
+
+	* fold-const.c (fold_truthop): Fix bug in last change.
+
 1997-11-13  Paul Eggert  <eggert@twinsun.com>
 
 	Fix some confusion with IEEE minus zero.

gcc/fold-const.c

@@ -3425,7 +3425,7 @@ fold_truthop (code, truth_type, lhs, rhs)
     {
       if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
 	{
-	  if (ll_unsignedp)
+	  if (ll_unsignedp || tree_log2 (ll_mask) + 1 < ll_bitsize)
 	    l_const = ll_mask;
 	else
 	  /* Since ll_arg is a single bit bit mask, we can sign extend
@@ -3443,7 +3443,7 @@ fold_truthop (code, truth_type, lhs, rhs)
     {
       if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
 	{
-	  if (rl_unsignedp)
+	  if (rl_unsignedp || tree_log2 (rl_mask) + 1 < rl_bitsize)
 	    r_const = rl_mask;
 	else
 	  /* This is analogous to the code for l_const above.  */