/*
 * Copyright 2025, Haiku, Inc. All rights reserved.
 * Copyright 2008, Axel Dörfler, axeld@pinc-software.de.
 * Distributed under the terms of the MIT license.
 */


#include <stdint.h>
#include <string.h>


#define LACKS_ZERO_BYTE(value) \
        (((value - 0x01010101) & ~value & 0x80808080) == 0)

int
strncmp(char const *a, char const *b, size_t count)
{
        if ((((addr_t)a) & 3) == 0 && (((addr_t)b) & 3) == 0) {
                uint32_t *a32 = (uint32_t *)a;
                uint32_t *b32 = (uint32_t *)b;

                while (count >= 4 && *a32 == *b32 && LACKS_ZERO_BYTE((*a32))) {
                        a32++;
                        b32++;
                        count -= 4;
                }
                a = (const char *)a32;
                b = (const char *)b32;
        }

        while (count > 0 && *a == *b && *a != 0) {
                a++;
                b++;
                count--;
        }

        if (count == 0)
                return 0;

        return (unsigned char)*a - (unsigned char)*b;
}