godot/drivers/webp/utils/endian_inl.h

101 lines
3.0 KiB
C++

// Copyright 2014 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// Endian related functions.
#ifndef WEBP_UTILS_ENDIAN_INL_H_
#define WEBP_UTILS_ENDIAN_INL_H_
#ifdef HAVE_CONFIG_H
#include "webp/config.h"
#endif
#include "../dsp/dsp.h"
#include "webp/types.h"
// some endian fix (e.g.: mips-gcc doesn't define __BIG_ENDIAN__)
#if !defined(WORDS_BIGENDIAN) && \
(defined(__BIG_ENDIAN__) || defined(_M_PPC) || \
(defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)))
#define WORDS_BIGENDIAN
#endif
#if defined(WORDS_BIGENDIAN)
#define HToLE32 BSwap32
#define HToLE16 BSwap16
#else
#define HToLE32(x) (x)
#define HToLE16(x) (x)
#endif
#if !defined(HAVE_CONFIG_H)
#if LOCAL_GCC_PREREQ(4,8) || __has_builtin(__builtin_bswap16)
#define HAVE_BUILTIN_BSWAP16
#endif
#if LOCAL_GCC_PREREQ(4,3) || __has_builtin(__builtin_bswap32)
#define HAVE_BUILTIN_BSWAP32
#endif
#if LOCAL_GCC_PREREQ(4,3) || __has_builtin(__builtin_bswap64)
#define HAVE_BUILTIN_BSWAP64
#endif
#endif // !HAVE_CONFIG_H
static WEBP_INLINE uint16_t BSwap16(uint16_t x) {
#if defined(HAVE_BUILTIN_BSWAP16)
return __builtin_bswap16(x);
#elif defined(_MSC_VER)
return _byteswap_ushort(x);
#else
// gcc will recognize a 'rorw $8, ...' here:
return (x >> 8) | ((x & 0xff) << 8);
#endif // HAVE_BUILTIN_BSWAP16
}
static WEBP_INLINE uint32_t BSwap32(uint32_t x) {
#if defined(WEBP_USE_MIPS32_R2)
uint32_t ret;
__asm__ volatile (
"wsbh %[ret], %[x] \n\t"
"rotr %[ret], %[ret], 16 \n\t"
: [ret]"=r"(ret)
: [x]"r"(x)
);
return ret;
#elif defined(HAVE_BUILTIN_BSWAP32)
return __builtin_bswap32(x);
#elif defined(__i386__) || defined(__x86_64__)
uint32_t swapped_bytes;
__asm__ volatile("bswap %0" : "=r"(swapped_bytes) : "0"(x));
return swapped_bytes;
#elif defined(_MSC_VER)
return (uint32_t)_byteswap_ulong(x);
#else
return (x >> 24) | ((x >> 8) & 0xff00) | ((x << 8) & 0xff0000) | (x << 24);
#endif // HAVE_BUILTIN_BSWAP32
}
static WEBP_INLINE uint64_t BSwap64(uint64_t x) {
#if defined(HAVE_BUILTIN_BSWAP64)
return __builtin_bswap64(x);
#elif defined(__x86_64__)
uint64_t swapped_bytes;
__asm__ volatile("bswapq %0" : "=r"(swapped_bytes) : "0"(x));
return swapped_bytes;
#elif defined(_MSC_VER)
return (uint64_t)_byteswap_uint64(x);
#else // generic code for swapping 64-bit values (suggested by bdb@)
x = ((x & 0xffffffff00000000ull) >> 32) | ((x & 0x00000000ffffffffull) << 32);
x = ((x & 0xffff0000ffff0000ull) >> 16) | ((x & 0x0000ffff0000ffffull) << 16);
x = ((x & 0xff00ff00ff00ff00ull) >> 8) | ((x & 0x00ff00ff00ff00ffull) << 8);
return x;
#endif // HAVE_BUILTIN_BSWAP64
}
#endif // WEBP_UTILS_ENDIAN_INL_H_