xrt_byte_order.h

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// Copyright 2025, Beyley Cardellio
// SPDX-License-Identifier: BSL-1.0
/*!
 * @file
 * @brief  Endian-specific byte order defines.
 * @author Beyley Cardellio <ep1cm1n10n123@gmail.com>
 * @ingroup aux_os
 */
 
#pragma once
 
#include "xrt_compiler.h"
 
#include <stdint.h>
 
#ifdef __linux__
 
// On Linux, all these conversion functions are defined for both endians
#include <asm/byteorder.h>
 
#elif defined(XRT_BIG_ENDIAN)
 
#error "@todo: Add byte order constants and functions for this OS or big endian machines."
 
#else
 
#define __be64 uint64_t
#define __be32 uint32_t
#define __be16 uint16_t
 
#define __be16_to_cpu(x) ((((uint16_t)x & (uint16_t)0x00FFU) << 8) | (((uint16_t)x & (uint16_t)0xFF00U) >> 8))
#define __cpu_to_be16(x) __be16_to_cpu(x)
 
#define __be32_to_cpu(x)                                                                                               \
        ((((uint32_t)x & (uint32_t)0x000000FFUL) << 24) | (((uint32_t)x & (uint32_t)0x0000FF00UL) << 8) |              \
         (((uint32_t)x & (uint32_t)0x00FF0000UL) >> 8) | (((uint32_t)x & (uint32_t)0xFF000000UL) >> 24))
#define __cpu_to_be32(x) __be32_to_cpu(x)
 
#define __be64_to_cpu(x)                                                                                               \
        ((((uint64_t)x & (uint64_t)0x00000000000000FFULL) << 56) |                                                     \
         (((uint64_t)x & (uint64_t)0x000000000000FF00ULL) << 40) |                                                     \
         (((uint64_t)x & (uint64_t)0x0000000000FF0000ULL) << 24) |                                                     \
         (((uint64_t)x & (uint64_t)0x00000000FF000000ULL) << 8) |                                                      \
         (((uint64_t)x & (uint64_t)0x000000FF00000000ULL) >> 8) |                                                      \
         (((uint64_t)x & (uint64_t)0x0000FF0000000000ULL) >> 24) |                                                     \
         (((uint64_t)x & (uint64_t)0x00FF000000000000ULL) >> 40) |                                                     \
         (((uint64_t)x & (uint64_t)0xFF00000000000000ULL) >> 56)) |
#define __cpu_to_be64(x) __be64_to_cpu(x)
 
#define __le64 uint64_t
#define __le32 uint32_t
#define __le16 uint16_t
#define __u8 uint8_t
#define __s8 int8_t
#define __cpu_to_le16
#define __le16_to_cpu
#define __cpu_to_le32
#define __le32_to_cpu
#define __cpu_to_le64
#define __le64_to_cpu
 
#endif
 
/*!
 * Little endian 32-bit float wrapper struct.
 */
typedef struct
{
        __le32 val;
} __lef32;
 
/*!
 * Big endian 32-bit float wrapper struct.
 */
typedef struct
{
        __be32 val;
} __bef32;
 
static inline float
__lef32_to_cpu(__lef32 f)
{
        union {
                uint32_t raw;
                float f32;
        } safe_copy;
 
        safe_copy.raw = __le32_to_cpu(f.val);
        return safe_copy.f32;
}
 
static inline __lef32
__cpu_to_lef32(float f)
{
        union {
                uint32_t wire;
                float f32;
        } safe_copy;
 
        safe_copy.f32 = f;
        return (__lef32){.val = __cpu_to_le32(safe_copy.wire)};
}
 
static inline float
__bef32_to_cpu(__bef32 f)
{
        union {
                uint32_t raw;
                float f32;
        } safe_copy;
 
        safe_copy.raw = __be32_to_cpu(f.val);
        return safe_copy.f32;
}
 
static inline __bef32
__cpu_to_bef32(float f)
{
        union {
                uint32_t wire;
                float f32;
        } safe_copy;
 
        safe_copy.f32 = f;
        return (__bef32){.val = __cpu_to_be32(safe_copy.wire)};
}
 
/*
 *
 * Vec2
 *
 */
 
struct __levec2
{
        __lef32 x;
        __lef32 y;
};
 
static inline struct xrt_vec2
__levec2_to_cpu(struct __levec2 v)
{
        return (struct xrt_vec2){
            .x = __lef32_to_cpu(v.x),
            .y = __lef32_to_cpu(v.y),
        };
}
 
static inline struct __levec2
__cpu_to_levec2(struct xrt_vec2 v)
{
        return (struct __levec2){
            .x = __cpu_to_lef32(v.x),
            .y = __cpu_to_lef32(v.y),
        };
}
 
/*
 *
 * Vec3
 *
 */
 
struct __levec3
{
        __lef32 x;
        __lef32 y;
        __lef32 z;
};
 
static inline struct xrt_vec3
__levec3_to_cpu(struct __levec3 v)
{
        return (struct xrt_vec3){
            .x = __lef32_to_cpu(v.x),
            .y = __lef32_to_cpu(v.y),
            .z = __lef32_to_cpu(v.z),
        };
}
 
static inline struct __levec3
__cpu_to_levec3(struct xrt_vec3 v)
{
        return (struct __levec3){
            .x = __cpu_to_lef32(v.x),
            .y = __cpu_to_lef32(v.y),
            .z = __cpu_to_lef32(v.z),
        };
}