/*
 * Copyright 2016 WebAssembly Community Group participants
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef WABT_CONFIG_H_
#define WABT_CONFIG_H_

/* TODO(binji): nice way to define these with WABT_ prefix? */

/* Whether <alloca.h> is available */
#cmakedefine01 HAVE_ALLOCA_H

/* Whether <unistd.h> is available */
#cmakedefine01 HAVE_UNISTD_H

/* Whether snprintf is defined by stdio.h */
#cmakedefine01 HAVE_SNPRINTF

/* Whether sysconf is defined by unistd.h */
#cmakedefine01 HAVE_SYSCONF

/* Whether ssize_t is defined by stddef.h */
#cmakedefine01 HAVE_SSIZE_T

/* Whether strcasecmp is defined by strings.h */
#cmakedefine01 HAVE_STRCASECMP

/* Whether ENABLE_VIRTUAL_TERMINAL_PROCESSING is defined by windows.h */
#cmakedefine01 HAVE_WIN32_VT100

#cmakedefine01 COMPILER_IS_CLANG
#cmakedefine01 COMPILER_IS_GNU
#cmakedefine01 COMPILER_IS_MSVC

#cmakedefine01 WITH_EXCEPTIONS

#define SIZEOF_SIZE_T @SIZEOF_SIZE_T@
#define SIZEOF_INT @SIZEOF_INT@
#define SIZEOF_LONG @SIZEOF_LONG@
#define SIZEOF_LONG_LONG @SIZEOF_LONG_LONG@

#if HAVE_ALLOCA_H
#include <alloca.h>
#elif COMPILER_IS_MSVC
#include <malloc.h>
#define alloca _alloca
#elif defined(__MINGW32__)
#include <malloc.h>
#elif defined(__FreeBSD__)
#include <stdlib.h>
#else
#error no alloca
#endif

#if COMPILER_IS_CLANG || COMPILER_IS_GNU

#define WABT_UNUSED __attribute__ ((unused))
#define WABT_WARN_UNUSED __attribute__ ((warn_unused_result))
#define WABT_INLINE inline
#define WABT_UNLIKELY(x) __builtin_expect(!!(x), 0)
#define WABT_LIKELY(x) __builtin_expect(!!(x), 1)

#if __MINGW32__
// mingw defaults to printf format specifier being ms_printf (which doesn't
// understand 'llu', etc.) We always want gnu_printf, and force mingw to always
// use mingw_printf, mingw_vprintf, etc.
#define WABT_PRINTF_FORMAT(format_arg, first_arg) \
  __attribute__((format(gnu_printf, (format_arg), (first_arg))))
#else
#define WABT_PRINTF_FORMAT(format_arg, first_arg) \
  __attribute__((format(printf, (format_arg), (first_arg))))
#endif

#ifdef __cplusplus
#if __cplusplus >= 201103L
#define WABT_STATIC_ASSERT(x) static_assert((x), #x)
#else
#define WABT_STATIC_ASSERT__(x, c) \
  static int static_assert_##c[(x ? 0 : -1)] WABT_UNUSED
#define WABT_STATIC_ASSERT_(x, c) WABT_STATIC_ASSERT__(x, c)
#define WABT_STATIC_ASSERT(x) WABT_STATIC_ASSERT_(x, __COUNTER__)
#endif
#else
#define WABT_STATIC_ASSERT(x) _Static_assert((x), #x)
#endif

#if SIZEOF_INT == 4
#define wabt_clz_u32(x) __builtin_clz(x)
#define wabt_ctz_u32(x) __builtin_ctz(x)
#define wabt_popcount_u32(x) __builtin_popcount(x)
#elif SIZEOF_LONG == 4
#define wabt_clz_u32(x) __builtin_clzl(x)
#define wabt_ctz_u32(x) __builtin_ctzl(x)
#define wabt_popcount_u32(x) __builtin_popcountl(x)
#else
#error "don't know how to define 32-bit builtins"
#endif

#if SIZEOF_LONG == 8
#define wabt_clz_u64(x) __builtin_clzl(x)
#define wabt_ctz_u64(x) __builtin_ctzl(x)
#define wabt_popcount_u64(x) __builtin_popcountl(x)
#elif SIZEOF_LONG_LONG == 8
#define wabt_clz_u64(x) __builtin_clzll(x)
#define wabt_ctz_u64(x) __builtin_ctzll(x)
#define wabt_popcount_u64(x) __builtin_popcountll(x)
#else
#error "don't know how to define 64-bit builtins"
#endif

#define WABT_UNREACHABLE __builtin_unreachable()

#elif COMPILER_IS_MSVC

#include <cstring>
#include <intrin.h>

#define WABT_UNUSED
#define WABT_WARN_UNUSED _Check_return_
#define WABT_INLINE __inline
#define WABT_STATIC_ASSERT(x) _STATIC_ASSERT(x)
#define WABT_UNLIKELY(x) (x)
#define WABT_LIKELY(x) (x)
#define WABT_PRINTF_FORMAT(format_arg, first_arg)

#define WABT_UNREACHABLE __assume(0)

__inline unsigned long wabt_clz_u32(unsigned long mask) {
  unsigned long index;
  _BitScanReverse(&index, mask);
  return sizeof(unsigned long) * 8 - (index + 1);
}

__inline unsigned long wabt_clz_u64(unsigned __int64 mask) {
#if _M_X64
  unsigned long index;
  _BitScanReverse64(&index, mask);
  return sizeof(unsigned __int64) * 8 - (index + 1);
#elif _M_IX86
  unsigned long index;
  unsigned long high_mask;
  memcpy(&high_mask, (unsigned char*)&mask + sizeof(unsigned long),
         sizeof(unsigned long));
  if (_BitScanReverse(&index, high_mask)) {
    return sizeof(unsigned long) * 8 - (index + 1);
  }

  unsigned long low_mask;
  memcpy(&low_mask, &mask, sizeof(unsigned long));
  _BitScanReverse(&index, low_mask);
  return sizeof(unsigned __int64) * 8 - (index + 1);
#else
#error unexpected architecture
#endif
}

__inline unsigned long wabt_ctz_u32(unsigned long mask) {
    unsigned long index;
    _BitScanForward(&index, mask);
    return index;
}

__inline unsigned long wabt_ctz_u64(unsigned __int64 mask) {
#if _M_X64
    unsigned long index;
    _BitScanForward64(&index, mask);
    return index;
#elif _M_IX86
    unsigned long low_mask = (unsigned long)mask;
    if (low_mask) {
        return wabt_ctz_u32(low_mask);
    }
    unsigned long high_mask;
    memcpy(&high_mask, (unsigned char*)&mask + sizeof(unsigned long),
           sizeof(unsigned long));
    return sizeof(unsigned long) * 8 + wabt_ctz_u32(high_mask);
#else
#error unexpected architecture
#endif
}


#define wabt_popcount_u32 __popcnt
#if _M_X64
#elif _M_IX86
__inline unsigned __int64 __popcnt64(unsigned __int64 value) {
    unsigned long high_value;
    unsigned long low_value;
    memcpy(&high_value, (unsigned char*)&value + sizeof(unsigned long),
           sizeof(unsigned long));
    memcpy(&low_value, &value, sizeof(unsigned long));
    return wabt_popcount_u32(high_value) + wabt_popcount_u32(low_value);
}
#else
#error unexpected architecture
#endif
#define wabt_popcount_u64 __popcnt64

#else

#error unknown compiler

#endif


#if COMPILER_IS_MSVC

/* print format specifier for size_t */
#if SIZEOF_SIZE_T == 4
#define PRIzd "d"
#define PRIzx "x"
#elif SIZEOF_SIZE_T == 8
#define PRIzd "I64d"
#define PRIzx "I64x"
#else
#error "weird sizeof size_t"
#endif

#elif COMPILER_IS_CLANG || COMPILER_IS_GNU

/* print format specifier for size_t */
#define PRIzd "zd"
#define PRIzx "zx"

#else

#error unknown compiler

#endif


#if HAVE_SNPRINTF
#define wabt_snprintf snprintf
#elif COMPILER_IS_MSVC
/* can't just use _snprintf because it doesn't always null terminate */
#include <cstdarg>
int wabt_snprintf(char* str, size_t size, const char* format, ...);
#else
#error no snprintf
#endif

#if COMPILER_IS_MSVC
/* can't just use vsnprintf because it doesn't always null terminate */
int wabt_vsnprintf(char* str, size_t size, const char* format, va_list ap);
#else
#define wabt_vsnprintf vsnprintf
#endif

#if !HAVE_SSIZE_T
typedef int ssize_t;
#endif

#if !HAVE_STRCASECMP
#if COMPILER_IS_MSVC
#define strcasecmp _stricmp
#else
#error no strcasecmp
#endif
#endif

#if COMPILER_IS_MSVC && defined(_M_X64)
// MSVC on x64 generates uint64 -> float conversions but doesn't do
// round-to-nearest-ties-to-even, which is required by WebAssembly.
#include <emmintrin.h>
__inline double wabt_convert_uint64_to_double(unsigned __int64 x) {
  __m128d result = _mm_setzero_pd();
  if (x & 0x8000000000000000ULL) {
    result = _mm_cvtsi64_sd(result, (x >> 1) | (x & 1));
    result = _mm_add_sd(result, result);
  } else {
    result = _mm_cvtsi64_sd(result, x);
  }
  return _mm_cvtsd_f64(result);
}

__inline float wabt_convert_uint64_to_float(unsigned __int64 x) {
  __m128 result = _mm_setzero_ps();
  if (x & 0x8000000000000000ULL) {
    result = _mm_cvtsi64_ss(result, (x >> 1) | (x & 1));
    result = _mm_add_ss(result, result);
  } else {
    result = _mm_cvtsi64_ss(result, x);
  }
  return _mm_cvtss_f32(result);
}

#else
#define wabt_convert_uint64_to_double(x) static_cast<double>(x)
#define wabt_convert_uint64_to_float(x) static_cast<float>(x)
#endif

#endif /* WABT_CONFIG_H_ */