diff --git a/gcc/tree.c b/gcc/tree.c
index f756d05faa7..658c05f8684 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -4346,12 +4346,18 @@ int_fits_type_p (c, type)
     return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
 	       && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c))
 	    && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
-		  && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type))));
+		  && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)))
+	    /* Negative ints never fit unsigned types.  */
+	    && ! (TREE_INT_CST_HIGH (c) < 0
+		  && ! TREE_UNSIGNED (TREE_TYPE (c))));
   else
     return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST
 	       && INT_CST_LT (TYPE_MAX_VALUE (type), c))
 	    && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST
-		  && INT_CST_LT (c, TYPE_MIN_VALUE (type))));
+		  && INT_CST_LT (c, TYPE_MIN_VALUE (type)))
+	    /* Unsigned ints with top bit set never fit signed types.  */
+	    && ! (TREE_INT_CST_HIGH (c) < 0
+		  && TREE_UNSIGNED (TREE_TYPE (c))));
 }
 
 /* Return the innermost context enclosing DECL that is