/*
- * 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
#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;
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;
}