#include <linux/module.h>

__u8 bitmaps[11][27] = {
		{1, 123, 2, 3, 127, 200, 100,
		 123, 23, 13, 78, 42, 123, 50,
		 123, 56, 198, 0, 58, 22, 19,
		 123, 23, 13, 78, 42, 123},
		{2, 0, 0, 0, 0, 0, 0,
		 123, 23, 13, 78, 42, 123, 50,
		 123, 56, 198, 0, 58, 22, 19,
		 23, 123, 2, 34, 123, 12},
		{4, 0, 0, 0, 0, 0, 0,
		 123, 56, 198, 0, 58, 22, 19,
		 123, 23, 13, 78, 42, 123,
		 0, 0, 0, 34, 45, 29},
		{8, 0, 0, 0, 0, 0, 0,
		 1, 123, 2, 3, 127, 200, 100,
		 123, 23, 13, 78, 42, 123, 50,
		 0, 0, 0, 0, 0, 0},
		{16, 0, 0, 0, 0, 0, 0,
		 8, 78, 0, 0, 23, 0, 213,
		 0, 12, 0, 45, 0, 109, 111,
		 231, 11, 11, 88, 77, 99},
		{32, 0, 0, 0, 0, 0, 0,
		 8, 78, 0, 0, 23, 0, 213,
		 0, 12, 0, 45, 0, 109, 111,
		 231, 11, 11, 88, 77, 99},
		{64, 0, 0, 0, 0, 0, 0,
		 8, 78, 0, 0, 23, 0, 213,
		 0, 12, 0, 45, 0, 109, 111,
		 0, 0, 0, 0, 0, 0},
		{255, 255, 255, 255, 255, 255, 255,
		 255, 255, 255, 255, 255, 255, 255,
		 255, 255, 255, 255, 255, 255, 255,
		 255, 255, 255, 255, 255, 255},
		{170, 170, 170, 170, 170, 170, 170,
		 170, 170, 170, 170, 170, 170, 170,
		 170, 170, 170, 170, 170, 170, 170,
		 170, 170, 170, 170, 170, 170},
		{255, 0, 255, 0, 255, 0, 255,
		 0, 255, 0, 255, 0, 255, 0,
		 255, 0, 255, 0, 255, 0, 255,
		 0, 255, 0, 255, 0, 255},
		 {15, 15, 15, 15, 15, 15, 15,
		 15, 15, 15, 15, 15, 15, 15,
		 15, 15, 15, 15, 15, 15, 15,
		 15, 15, 15, 15, 15, 15}
		};

uint64_t rdtsc(void) {
uint32_t lo, hi;
__asm__ __volatile__ ("rdtsc" : "=a" (lo), "=d" (hi));
return (uint64_t)hi << 32 | lo;
}

static void test_bit_search_speed(void)
{
	unsigned long flags;
	uint64_t tsc_s, tsc_diff;
	int i, j, pos;
	const void *bit_addr;

	local_irq_save(flags);
	preempt_disable();

	printk("find_next_bit_le    test_bit_le\n");

	for (i = 0; i < 11; i++) {
		bit_addr = &bitmaps[i];

		pos = 0;
		tsc_s = rdtsc();

		for (j = 0; j < 1000; j++, pos = 0)
			while (pos < 216)
				pos = find_next_bit_le(bit_addr, 216, pos) + 1;
		mb();
		tsc_diff = (rdtsc() - tsc_s)/1000;

		printk("%8llu", tsc_diff);

		pos = 0;
		tsc_s = rdtsc();

		for (j = 0; j < 1000; j++, pos = 0)
			while (pos < 216)
				test_bit_le(pos++, bit_addr);

		mb();
		tsc_diff = (rdtsc() - tsc_s)/1000;

		printk("%20llu \n", tsc_diff);
	}

	preempt_enable();
	local_irq_restore(flags);
}

static int __init start_test(void) {
	test_bit_search_speed();
	return 0;
}

static void __exit exit_test(void) {

}

module_init(start_test);
module_exit(exit_test);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Gu Zheng");