X-Git-Url: https://erislabs.net/gitweb/?a=blobdiff_plain;f=tests%2Ftest-ffs.c;h=5c04d2dddd556311d0125376093ef90d8729d4f7;hb=8e0f64e4cd12f7779113bc438afd106dad3e1f1a;hp=cfc4d0ec5330f49ab5e96d0acc06696cae1d84ee;hpb=d767af3634fa49b048bf073327092be19c7c7fd1;p=gnulib.git

diff --git a/tests/test-ffs.c b/tests/test-ffs.c
index cfc4d0ec5..5c04d2ddd 100644
--- a/tests/test-ffs.c
+++ b/tests/test-ffs.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Free Software Foundation, Inc.
+ * Copyright (C) 2011-2013 Free Software Foundation, Inc.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -26,11 +26,13 @@ SIGNATURE_CHECK (ffs, int, (int));
 
 #include "macros.h"
 
+#define NBITS (sizeof (int) * CHAR_BIT)
+
 static int
 naive (int i)
 {
   unsigned int j;
-  for (j = 0; j < CHAR_BIT * sizeof i; j++)
+  for (j = 0; j < NBITS; j++)
     if (i & (1U << j))
       return j + 1;
   return 0;
@@ -39,14 +41,28 @@ naive (int i)
 int
 main (int argc, char *argv[])
 {
+  int x;
   int i;
 
-  for (i = -128; i <= 128; i++)
-    ASSERT (ffs (i) == naive (i));
-  for (i = 0; i < CHAR_BIT * sizeof i; i++)
+  for (x = -128; x <= 128; x++)
+    ASSERT (ffs (x) == naive (x));
+  for (i = 0; i < NBITS; i++)
     {
       ASSERT (ffs (1U << i) == naive (1U << i));
       ASSERT (ffs (1U << i) == i + 1);
+      ASSERT (ffs (-1U << i) == i + 1);
+    }
+  for (i = 0; i < NBITS - 1; i++)
+    {
+      ASSERT (ffs (3U << i) == i + 1);
+      ASSERT (ffs (-3U << i) == i + 1);
+    }
+  for (i = 0; i < NBITS - 2; i++)
+    {
+      ASSERT (ffs (5U << i) == i + 1);
+      ASSERT (ffs (-5U << i) == i + 1);
+      ASSERT (ffs (7U << i) == i + 1);
+      ASSERT (ffs (-7U << i) == i + 1);
     }
   return 0;
 }