/*
 * Copyright 2016 Józef Kucia for CodeWeavers
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#ifndef __VKD3D_COMMON_H
#define __VKD3D_COMMON_H

#include "config.h"
#include "vkd3d_windows.h"

#include <ctype.h>
#include <limits.h>
#include <stdbool.h>

#ifdef _MSC_VER
#include <intrin.h>
#endif

#ifndef ARRAY_SIZE
# define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
#endif

#define DIV_ROUND_UP(a, b) ((a) % (b) == 0 ? (a) / (b) : (a) / (b) + 1)

#define STATIC_ASSERT(e) extern void __VKD3D_STATIC_ASSERT__(int [(e) ? 1 : -1])

#define MEMBER_SIZE(t, m) sizeof(((t *)0)->m)

static inline size_t align(size_t addr, size_t alignment)
{
    return (addr + (alignment - 1)) & ~(alignment - 1);
}

#ifdef __GNUC__
# define VKD3D_PRINTF_FUNC(fmt, args) __attribute__((format(printf, fmt, args)))
# define VKD3D_UNUSED __attribute__((unused))
#else
# define VKD3D_PRINTF_FUNC(fmt, args)
# define VKD3D_UNUSED
#endif  /* __GNUC__ */

static inline unsigned int vkd3d_popcount(unsigned int v)
{
#ifdef _MSC_VER
    return __popcnt(v);
#elif defined(HAVE_BUILTIN_POPCOUNT)
    return __builtin_popcount(v);
#else
    v -= (v >> 1) & 0x55555555;
    v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
    return (((v + (v >> 4)) & 0x0f0f0f0f) * 0x01010101) >> 24;
#endif
}

static inline bool vkd3d_bitmask_is_contiguous(unsigned int mask)
{
    unsigned int i, j;

    for (i = 0, j = 0; i < sizeof(mask) * CHAR_BIT; ++i)
    {
        if (mask & (1u << i))
            ++j;
        else if (j)
            break;
    }

    return vkd3d_popcount(mask) == j;
}

/* Undefined for x == 0. */
static inline unsigned int vkd3d_log2i(unsigned int x)
{
#ifdef _MSC_VER
    /* _BitScanReverse returns the index of the highest set bit,
     * unlike clz which is 31 - index. */
    unsigned long result;
    _BitScanReverse(&result, x);
    return (unsigned int)result;
#elif defined(HAVE_BUILTIN_CLZ)
    return __builtin_clz(x) ^ 0x1f;
#else
    static const unsigned int l[] =
    {
        ~0u, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
          4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
          5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
          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,
          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,
          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,
    };
    unsigned int i;

    return (i = x >> 16) ? (x = i >> 8) ? l[x] + 24
            : l[i] + 16 : (i = x >> 8) ? l[i] + 8 : l[x];
#endif
}

static inline int ascii_isupper(int c)
{
    return 'A' <= c && c <= 'Z';
}

static inline int ascii_tolower(int c)
{
    return ascii_isupper(c) ? c - 'A' + 'a' : c;
}

static inline int ascii_strcasecmp(const char *a, const char *b)
{
    int c_a, c_b;

    do
    {
        c_a = ascii_tolower(*a++);
        c_b = ascii_tolower(*b++);
    } while (c_a == c_b && c_a != '\0');

    return c_a - c_b;
}

#ifndef _WIN32
# if HAVE_SYNC_ADD_AND_FETCH
static inline LONG InterlockedIncrement(LONG volatile *x)
{
    return __sync_add_and_fetch(x, 1);
}
# else
#  error "InterlockedIncrement() not implemented for this platform"
# endif  /* HAVE_SYNC_ADD_AND_FETCH */

# if HAVE_SYNC_SUB_AND_FETCH
static inline LONG InterlockedDecrement(LONG volatile *x)
{
    return __sync_sub_and_fetch(x, 1);
}
# else
#  error "InterlockedDecrement() not implemented for this platform"
# endif
#endif  /* _WIN32 */

#if HAVE_SYNC_ADD_AND_FETCH
# define atomic_add_fetch(ptr, val) __sync_add_and_fetch(ptr, val)
#elif defined(_MSC_VER)
/* InterlockedAdd returns value after increment, like add_and_fetch. */
# define atomic_add_fetch(ptr, val) InterlockedAdd(ptr, val)
#else
# error "atomic_add_fetch() not implemented for this platform"
#endif  /* HAVE_SYNC_ADD_AND_FETCH */

static inline void vkd3d_parse_version(const char *version, int *major, int *minor)
{
    *major = atoi(version);

    while (isdigit(*version))
        ++version;
    if (*version == '.')
        ++version;

    *minor = atoi(version);
}

#endif  /* __VKD3D_COMMON_H */