strings.c

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#include "libc.h"
#define LELY_LIBC_STRINGS_INLINE extern inline
#include <lely/libc/strings.h>

#if !LELY_HAVE_STRINGS_H

#include <ctype.h>

#if !(defined(__GNUC__) || __has_builtin(__builtin_ffs))

#include <stdint.h>

// clang-format off
static const int ffs_tab[] = {
        0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
        5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
        6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
        6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
        7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
        7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
        7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
        7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
        8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
        8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
        8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
        8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
        8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
        8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
        8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
        8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8
};
// clang-format on

int
ffs(int i)
{
        unsigned int x = i & -i;
        // clang-format off
        unsigned int n = x > UINT32_C(0x00ffffff)
                        ? 24 : (x > UINT16_C(0xffffu)
                        ? 16 : (x > UINT8_C(0xff) ? 8 : 0));
        // clang-format on
        return n + ffs_tab[(x >> n) & UINT8_C(0xff)];
}

#endif

int
strcasecmp(const char *s1, const char *s2)
{
        if (s1 == s2)
                return 0;

        int result;
        // clang-format off
        while ((result = tolower((unsigned char)*s1)
                        - tolower((unsigned char)*s2++)) == 0 && *s1++)
                // clang-format on
                ;
        return result;
}

int
strncasecmp(const char *s1, const char *s2, size_t n)
{
        if (s1 == s2 || !n)
                return 0;

        int result;
        // clang-format off
        while ((result = tolower((unsigned char)*s1)
                        - tolower((unsigned char)*s2++)) == 0 && --n && *s1++)
                // clang-format on
                ;
        return result;
}

#endif // !LELY_HAVE_STRINGS_H