mirror of
https://gitlab.nic.cz/labs/bird.git
synced 2024-12-23 02:01:55 +00:00
150 lines
2.8 KiB
C
150 lines
2.8 KiB
C
/*
|
|
* BIRD Library -- Generic Bit Operations Tests
|
|
*
|
|
* (c) 2015 CZ.NIC z.s.p.o.
|
|
*
|
|
* Can be freely distributed and used under the terms of the GNU GPL.
|
|
*/
|
|
|
|
#include "test/birdtest.h"
|
|
#include "test/bt-utils.h" /* naive_pow() */
|
|
|
|
#include "lib/bitops.h"
|
|
|
|
#define MAX_NUM 1000
|
|
#define CHECK_BIT(var,pos) ((var) & (u32)(1<<(pos)))
|
|
|
|
static int
|
|
t_mkmask(void)
|
|
{
|
|
int i;
|
|
u32 compute, expect;
|
|
|
|
bt_assert(u32_mkmask(0) == 0x00000000);
|
|
for (i = 1; i <= 32; i++)
|
|
{
|
|
compute = u32_mkmask(i);
|
|
expect = (u32) (0xffffffff << (32-i));
|
|
bt_assert_msg(compute == expect, "u32_mkmask(%d) = 0x%08X, expected 0x%08X", i, compute, expect);
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
u32_masklen_expected(u32 mask)
|
|
{
|
|
int j, expect = 0;
|
|
|
|
int valid = 0;
|
|
for (j = 0; j <= 32; j++)
|
|
if (mask == (j ? (0xffffffff << (32-j)) : 0)) /* Shifting 32-bit value by 32 bits is undefined behavior */
|
|
valid = 1;
|
|
|
|
if (!valid && mask != 0)
|
|
expect = 255;
|
|
else
|
|
for (j = 0; j <= 31; j++)
|
|
if (CHECK_BIT(mask, (31-j)))
|
|
expect = j+1;
|
|
else
|
|
break;
|
|
return expect;
|
|
}
|
|
|
|
static void
|
|
check_mask(u32 mask)
|
|
{
|
|
int expected, masklen;
|
|
|
|
expected = u32_masklen_expected(mask);
|
|
masklen = u32_masklen(mask);
|
|
int ok = (expected == masklen);
|
|
bt_debug("u32_masklen(Ox%08x) = %d, expected %d %s\n", mask, masklen, expected, ok ? "OK" : "FAIL!");
|
|
bt_assert(ok);
|
|
}
|
|
|
|
static int
|
|
t_masklen(void)
|
|
{
|
|
u32 i;
|
|
|
|
check_mask(0x82828282);
|
|
check_mask(0x00000000);
|
|
|
|
for (i = 0; i <= 32; i++)
|
|
check_mask(((u32) (i ? (0xffffffff << (32-i)) : 0)) & 0xffffffff); /* Shifting 32-bit value by 32 bits is undefined behavior */
|
|
|
|
for (i = 0; i <= MAX_NUM; i++)
|
|
check_mask(bt_random());
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
check_log2(u32 n)
|
|
{
|
|
u32 log = u32_log2(n);
|
|
u32 low = bt_naive_pow(2, log);
|
|
u32 high = bt_naive_pow(2, log+1);
|
|
|
|
bt_assert_msg(n >= low && n < high,
|
|
"u32_log2(%u) = %u, %u should be in the range <%u, %u)",
|
|
n, log, n, low, high);
|
|
}
|
|
|
|
static int
|
|
t_log2(void)
|
|
{
|
|
u32 i;
|
|
|
|
for (i = 0; i < 31; i++)
|
|
bt_assert(u32_log2(bt_naive_pow(2, i+1)) == i+1);
|
|
|
|
for (i = 1; i < MAX_NUM; i++)
|
|
check_log2(i);
|
|
|
|
for (i = 1; i < MAX_NUM; i++)
|
|
check_log2(((u32) bt_random()) % 0x0fffffff);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
check_bitflip(u32 n)
|
|
{
|
|
u32 rot = u32_bitflip(n);
|
|
for (int i = 0; i < 16; i++)
|
|
{
|
|
bt_assert(!((n >> i) & 1) == !((rot << i) & 0x80000000));
|
|
bt_assert(!((rot >> i) & 1) == !((n << i) & 0x80000000));
|
|
}
|
|
}
|
|
|
|
static int
|
|
t_bitflip(void)
|
|
{
|
|
u32 i;
|
|
|
|
for (i = 0; i < MAX_NUM; i++)
|
|
{
|
|
check_bitflip(i);
|
|
check_bitflip((u32) bt_random());
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
main(int argc, char *argv[])
|
|
{
|
|
bt_init(argc, argv);
|
|
|
|
bt_test_suite(t_mkmask, "u32_mkmask()");
|
|
bt_test_suite(t_masklen, "u32_masklen()");
|
|
bt_test_suite(t_log2, "u32_log2()");
|
|
bt_test_suite(t_bitflip, "u32_bitflip()");
|
|
|
|
return bt_exit_value();
|
|
}
|