diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index af4fae53571..603f6a45f29 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2004-03-23  Roger Sayle  <roger@eyesopen.com>
+
+	* fold-const.c (tree_expr_nonnegative_p): A&B is nonnegative when
+	A is nonnegative or B is nonnegative.  Similarly A|B is nonnegative
+	when both A and B are nonnegative.
+	(tree_expr_nonzero_p): A|B is nonzero when A is nonzero or B is
+	nonzero.
+
 2004-03-23  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* fold-const.c (fold): Remove cases for INTEGER_CST, REAL_CST,
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 948a46c939d..417d1a45c8e 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -8717,6 +8717,13 @@ tree_expr_nonnegative_p (tree t)
       return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
 	     && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
 
+    case BIT_AND_EXPR:
+      return tree_expr_nonnegative_p (TREE_OPERAND (t, 1))
+	     || tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
+    case BIT_IOR_EXPR:
+      return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
+	     && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
+
     case NOP_EXPR:
       {
 	tree inner_type = TREE_TYPE (TREE_OPERAND (t, 0));
@@ -8955,6 +8962,10 @@ tree_expr_nonzero_p (tree t)
     case NON_LVALUE_EXPR:
       return tree_expr_nonzero_p (TREE_OPERAND (t, 0));
 
+    case BIT_IOR_EXPR:
+      return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
+	     || tree_expr_nonzero_p (TREE_OPERAND (t, 0));
+
     default:
       break;
     }