From f9c36381e1c5de5fcd6e46491ebd2f98a5e5c2ca Mon Sep 17 00:00:00 2001
From: Bruno Haible <bruno@clisp.org>
Date: Sat, 16 Jul 2011 02:36:07 +0200
Subject: [PATCH] ffs: More tests.

* tests/test-ffs.c (NBITS): New macro.
(main): Add more tests.
* tests/test-ffsl.c (NBITS): New macro.
(main): Add more tests.
* tests/test-ffsll.c (NBITS): New macro.
(main): Add more tests.
---
 ChangeLog          | 10 ++++++++++
 tests/test-ffs.c   | 24 ++++++++++++++++++++----
 tests/test-ffsl.c  | 22 +++++++++++++++++++---
 tests/test-ffsll.c | 26 +++++++++++++++++++++-----
 4 files changed, 70 insertions(+), 12 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 8104469a60..9ee9bea80b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2011-07-15  Bruno Haible  <bruno@clisp.org>
+
+	ffs: More tests.
+	* tests/test-ffs.c (NBITS): New macro.
+	(main): Add more tests.
+	* tests/test-ffsl.c (NBITS): New macro.
+	(main): Add more tests.
+	* tests/test-ffsll.c (NBITS): New macro.
+	(main): Add more tests.
+
 2011-07-15  Eric Blake  <eblake@redhat.com>
 
 	ffsl, ffsll: new modules
diff --git a/tests/test-ffs.c b/tests/test-ffs.c
index cfc4d0ec53..fb37f202ee 100644
--- a/tests/test-ffs.c
+++ b/tests/test-ffs.c
@@ -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;
 }
diff --git a/tests/test-ffsl.c b/tests/test-ffsl.c
index 2da2f5c8ce..9c134c7bc1 100644
--- a/tests/test-ffsl.c
+++ b/tests/test-ffsl.c
@@ -26,11 +26,13 @@ SIGNATURE_CHECK (ffsl, int, (long int));
 
 #include "macros.h"
 
+#define NBITS (sizeof (long int) * CHAR_BIT)
+
 static int
 naive (long int i)
 {
   unsigned long int j;
-  for (j = 0; j < CHAR_BIT * sizeof i; j++)
+  for (j = 0; j < NBITS; j++)
     if (i & (1UL << j))
       return j + 1;
   return 0;
@@ -39,14 +41,28 @@ naive (long int i)
 int
 main (int argc, char *argv[])
 {
-  long int i;
+  long int x;
+  int i;
 
   for (i = -128; i <= 128; i++)
     ASSERT (ffsl (i) == naive (i));
-  for (i = 0; i < CHAR_BIT * sizeof i; i++)
+  for (i = 0; i < NBITS; i++)
     {
       ASSERT (ffsl (1UL << i) == naive (1UL << i));
       ASSERT (ffsl (1UL << i) == i + 1);
+      ASSERT (ffsl (-1UL << i) == i + 1);
+    }
+  for (i = 0; i < NBITS - 1; i++)
+    {
+      ASSERT (ffsl (3UL << i) == i + 1);
+      ASSERT (ffsl (-3UL << i) == i + 1);
+    }
+  for (i = 0; i < NBITS - 2; i++)
+    {
+      ASSERT (ffsl (5UL << i) == i + 1);
+      ASSERT (ffsl (-5UL << i) == i + 1);
+      ASSERT (ffsl (7UL << i) == i + 1);
+      ASSERT (ffsl (-7UL << i) == i + 1);
     }
   return 0;
 }
diff --git a/tests/test-ffsll.c b/tests/test-ffsll.c
index c0fd426c94..37ce88e09e 100644
--- a/tests/test-ffsll.c
+++ b/tests/test-ffsll.c
@@ -26,11 +26,13 @@ SIGNATURE_CHECK (ffsll, int, (long long int));
 
 #include "macros.h"
 
+#define NBITS (sizeof (long long int) * CHAR_BIT)
+
 static int
 naive (long long int i)
 {
   unsigned long long int j;
-  for (j = 0; j < CHAR_BIT * sizeof i; j++)
+  for (j = 0; j < NBITS; j++)
     if (i & (1ULL << j))
       return j + 1;
   return 0;
@@ -39,14 +41,28 @@ naive (long long int i)
 int
 main (int argc, char *argv[])
 {
-  long long int i;
+  long long int x;
+  int i;
 
-  for (i = -128; i <= 128; i++)
-    ASSERT (ffsll (i) == naive (i));
-  for (i = 0; i < CHAR_BIT * sizeof i; i++)
+  for (x = -128; x <= 128; x++)
+    ASSERT (ffsll (x) == naive (x));
+  for (i = 0; i < NBITS; i++)
     {
       ASSERT (ffsll (1ULL << i) == naive (1ULL << i));
       ASSERT (ffsll (1ULL << i) == i + 1);
+      ASSERT (ffsll (-1ULL << i) == i + 1);
+    }
+  for (i = 0; i < NBITS - 1; i++)
+    {
+      ASSERT (ffsll (3ULL << i) == i + 1);
+      ASSERT (ffsll (-3ULL << i) == i + 1);
+    }
+  for (i = 0; i < NBITS - 2; i++)
+    {
+      ASSERT (ffsll (5ULL << i) == i + 1);
+      ASSERT (ffsll (-5ULL << i) == i + 1);
+      ASSERT (ffsll (7ULL << i) == i + 1);
+      ASSERT (ffsll (-7ULL << i) == i + 1);
     }
   return 0;
 }
-- 
2.30.2