+/* CC0 (Public domain) - see LICENSE file for details */
#ifndef CCAN_ENDIAN_H
#define CCAN_ENDIAN_H
#include <stdint.h>
#include "config.h"
/**
- * swab_u16 - reverse bytes in a uint16_t value.
+ * BSWAP_16_CONST - reverse bytes in a constant uint16_t value.
+ * @val: constant value whose bytes to swap.
+ *
+ * Designed to be usable in constant-requiring initializers.
+ *
+ * Example:
+ * struct mystruct {
+ * char buf[BSWAP_16_CONST(0x1234)];
+ * };
+ */
+#define BSWAP_16_CONST(val) \
+ ((((uint16_t)val & 0x00ff) << 8) \
+ | (((uint16_t)val & 0xff00) >> 8))
+
+/**
+ * BSWAP_32_CONST - reverse bytes in a constant uint32_t value.
+ * @val: constant value whose bytes to swap.
+ *
+ * Designed to be usable in constant-requiring initializers.
+ *
+ * Example:
+ * struct mystruct {
+ * char buf[BSWAP_32_CONST(0xff000000)];
+ * };
+ */
+#define BSWAP_32_CONST(val) \
+ ((((uint32_t)val & 0x000000ff) << 24) \
+ | (((uint32_t)val & 0x0000ff00) << 8) \
+ | (((uint32_t)val & 0x00ff0000) >> 8) \
+ | (((uint32_t)val & 0xff000000) >> 24))
+
+/**
+ * BSWAP_64_CONST - reverse bytes in a constant uint64_t value.
+ * @val: constantvalue whose bytes to swap.
+ *
+ * Designed to be usable in constant-requiring initializers.
+ *
+ * Example:
+ * struct mystruct {
+ * char buf[BSWAP_64_CONST(0xff00000000000000ULL)];
+ * };
+ */
+#define BSWAP_64_CONST(val) \
+ ((((uint64_t)val & 0x00000000000000ffULL) << 56) \
+ | (((uint64_t)val & 0x000000000000ff00ULL) << 40) \
+ | (((uint64_t)val & 0x0000000000ff0000ULL) << 24) \
+ | (((uint64_t)val & 0x00000000ff000000ULL) << 8) \
+ | (((uint64_t)val & 0x000000ff00000000ULL) >> 8) \
+ | (((uint64_t)val & 0x0000ff0000000000ULL) >> 24) \
+ | (((uint64_t)val & 0x00ff000000000000ULL) >> 40) \
+ | (((uint64_t)val & 0xff00000000000000ULL) >> 56))
+
+#if HAVE_BYTESWAP_H
+#include <byteswap.h>
+#else
+/**
+ * bswap_16 - reverse bytes in a uint16_t value.
* @val: value whose bytes to swap.
+ *
+ * Example:
+ * // Output contains "1024 is 4 as two bytes reversed"
+ * printf("1024 is %u as two bytes reversed\n", bswap_16(1024));
*/
-static inline uint16_t swab_u16(uint16_t val)
+static inline uint16_t bswap_16(uint16_t val)
{
- return ((val & (uint16_t)0x00ffU) << 8)
- | ((val & (uint16_t)0xff00U) >> 8);
+ return BSWAP_16_CONST(val);
}
/**
- * swab_u32 - reverse bytes in a uint32_t value.
+ * bswap_32 - reverse bytes in a uint32_t value.
* @val: value whose bytes to swap.
+ *
+ * Example:
+ * // Output contains "1024 is 262144 as four bytes reversed"
+ * printf("1024 is %u as four bytes reversed\n", bswap_32(1024));
*/
-static inline uint32_t swab_u32(uint32_t val)
+static inline uint32_t bswap_32(uint32_t val)
{
- return ((val & (uint32_t)0x000000ffUL) << 24)
- | ((val & (uint32_t)0x0000ff00UL) << 8)
- | ((val & (uint32_t)0x00ff0000UL) >> 8)
- | ((val & (uint32_t)0xff000000UL) >> 24);
+ return BSWAP_32_CONST(val);
}
+#endif /* !HAVE_BYTESWAP_H */
+#if !HAVE_BSWAP_64
/**
- * swab_u64 - reverse bytes in a uint64_t value.
+ * bswap_64 - reverse bytes in a uint64_t value.
* @val: value whose bytes to swap.
+ *
+ * Example:
+ * // Output contains "1024 is 1125899906842624 as eight bytes reversed"
+ * printf("1024 is %llu as eight bytes reversed\n",
+ * (unsigned long long)bswap_64(1024));
*/
-static inline uint64_t swab_u64(uint64_t val)
+static inline uint64_t bswap_64(uint64_t val)
{
- return ((val & (uint64_t)0x00000000000000ffULL) << 56)
- | ((val & (uint64_t)0x000000000000ff00ULL) << 40)
- | ((val & (uint64_t)0x0000000000ff0000ULL) << 24)
- | ((val & (uint64_t)0x00000000ff000000ULL) << 8)
- | ((val & (uint64_t)0x000000ff00000000ULL) >> 8)
- | ((val & (uint64_t)0x0000ff0000000000ULL) >> 24)
- | ((val & (uint64_t)0x00ff000000000000ULL) >> 40)
- | ((val & (uint64_t)0xff00000000000000ULL) >> 56);
+ return BSWAP_64_CONST(val);
}
+#endif
/* Sanity check the defines. We don't handle weird endianness. */
#if !HAVE_LITTLE_ENDIAN && !HAVE_BIG_ENDIAN
#error "Can't compile for both big and little endian."
#endif
+#if HAVE_LITTLE_ENDIAN
+/**
+ * CPU_TO_LE64_CONST - convert a constant uint64_t value to little-endian
+ * @native: constant to convert
+ */
+#define CPU_TO_LE64_CONST(native) (native)
+
+/**
+ * CPU_TO_LE32_CONST - convert a constant uint32_t value to little-endian
+ * @native: constant to convert
+ */
+#define CPU_TO_LE32_CONST(native) (native)
+
+/**
+ * CPU_TO_LE16_CONST - convert a constant uint16_t value to little-endian
+ * @native: constant to convert
+ */
+#define CPU_TO_LE16_CONST(native) (native)
+
+/**
+ * LE64_TO_CPU_CONST - convert a little-endian uint64_t constant
+ * @le_val: little-endian constant to convert
+ */
+#define LE64_TO_CPU_CONST(le_val) (le_val)
+
+/**
+ * LE32_TO_CPU_CONST - convert a little-endian uint32_t constant
+ * @le_val: little-endian constant to convert
+ */
+#define LE32_TO_CPU_CONST(le_val) (le_val)
+
+/**
+ * LE16_TO_CPU_CONST - convert a little-endian uint16_t constant
+ * @le_val: little-endian constant to convert
+ */
+#define LE16_TO_CPU_CONST(le_val) (le_val)
+
+#else /* ... HAVE_BIG_ENDIAN */
+#define CPU_TO_LE64_CONST(native) BSWAP_64_CONST(native)
+#define CPU_TO_LE32_CONST(native) BSWAP_32_CONST(native)
+#define CPU_TO_LE16_CONST(native) BSWAP_16_CONST(native)
+#define LE64_TO_CPU_CONST(le_val) BSWAP_64_CONST(le_val)
+#define LE32_TO_CPU_CONST(le_val) BSWAP_32_CONST(le_val)
+#define LE16_TO_CPU_CONST(le_val) BSWAP_16_CONST(le_val)
+#endif /* HAVE_BIG_ENDIAN */
+
+#if HAVE_BIG_ENDIAN
+/**
+ * CPU_TO_BE64_CONST - convert a constant uint64_t value to big-endian
+ * @native: constant to convert
+ */
+#define CPU_TO_BE64_CONST(native) (native)
+
+/**
+ * CPU_TO_BE32_CONST - convert a constant uint32_t value to big-endian
+ * @native: constant to convert
+ */
+#define CPU_TO_BE32_CONST(native) (native)
+
+/**
+ * CPU_TO_BE16_CONST - convert a constant uint16_t value to big-endian
+ * @native: constant to convert
+ */
+#define CPU_TO_BE16_CONST(native) (native)
+
+/**
+ * BE64_TO_CPU_CONST - convert a big-endian uint64_t constant
+ * @le_val: big-endian constant to convert
+ */
+#define BE64_TO_CPU_CONST(le_val) (le_val)
+
+/**
+ * BE32_TO_CPU_CONST - convert a big-endian uint32_t constant
+ * @le_val: big-endian constant to convert
+ */
+#define BE32_TO_CPU_CONST(le_val) (le_val)
+
+/**
+ * BE16_TO_CPU_CONST - convert a big-endian uint16_t constant
+ * @le_val: big-endian constant to convert
+ */
+#define BE16_TO_CPU_CONST(le_val) (le_val)
+
+#else /* ... HAVE_LITTLE_ENDIAN */
+#define CPU_TO_BE64_CONST(native) BSWAP_64_CONST(native)
+#define CPU_TO_BE32_CONST(native) BSWAP_32_CONST(native)
+#define CPU_TO_BE16_CONST(native) BSWAP_16_CONST(native)
+#define BE64_TO_CPU_CONST(le_val) BSWAP_64_CONST(le_val)
+#define BE32_TO_CPU_CONST(le_val) BSWAP_32_CONST(le_val)
+#define BE16_TO_CPU_CONST(le_val) BSWAP_16_CONST(le_val)
+#endif /* HAVE_LITTE_ENDIAN */
+
+
/**
* cpu_to_le64 - convert a uint64_t value to little-endian
* @native: value to convert
*/
static inline uint64_t cpu_to_le64(uint64_t native)
{
-#if HAVE_LITTLE_ENDIAN
- return native;
-#else
- return swab_u64(native);
-#endif
+ return CPU_TO_LE64_CONST(native);
}
/**
*/
static inline uint32_t cpu_to_le32(uint32_t native)
{
-#if HAVE_LITTLE_ENDIAN
- return native;
-#else
- return swab_u32(native);
-#endif
+ return CPU_TO_LE32_CONST(native);
}
/**
*/
static inline uint16_t cpu_to_le16(uint16_t native)
{
-#if HAVE_LITTLE_ENDIAN
- return native;
-#else
- return swab_u16(native);
-#endif
+ return CPU_TO_LE16_CONST(native);
}
/**
*/
static inline uint64_t le64_to_cpu(uint64_t le_val)
{
-#if HAVE_LITTLE_ENDIAN
- return le_val;
-#else
- return swab_u64(le_val);
-#endif
+ return LE64_TO_CPU_CONST(le_val);
}
/**
*/
static inline uint32_t le32_to_cpu(uint32_t le_val)
{
-#if HAVE_LITTLE_ENDIAN
- return le_val;
-#else
- return swab_u32(le_val);
-#endif
+ return LE32_TO_CPU_CONST(le_val);
}
/**
*/
static inline uint16_t le16_to_cpu(uint16_t le_val)
{
-#if HAVE_LITTLE_ENDIAN
- return le_val;
-#else
- return swab_u16(le_val);
-#endif
+ return LE16_TO_CPU_CONST(le_val);
}
/**
*/
static inline uint64_t cpu_to_be64(uint64_t native)
{
-#if HAVE_LITTLE_ENDIAN
- return swab_u64(native);
-#else
- return native;
-#endif
+ return CPU_TO_BE64_CONST(native);
}
/**
*/
static inline uint32_t cpu_to_be32(uint32_t native)
{
-#if HAVE_LITTLE_ENDIAN
- return swab_u32(native);
-#else
- return native;
-#endif
+ return CPU_TO_BE32_CONST(native);
}
/**
*/
static inline uint16_t cpu_to_be16(uint16_t native)
{
-#if HAVE_LITTLE_ENDIAN
- return swab_u16(native);
-#else
- return native;
-#endif
+ return CPU_TO_BE16_CONST(native);
}
/**
*/
static inline uint64_t be64_to_cpu(uint64_t be_val)
{
-#if HAVE_LITTLE_ENDIAN
- return swab_u64(be_val);
-#else
- return be_val;
-#endif
+ return BE64_TO_CPU_CONST(be_val);
}
/**
*/
static inline uint32_t be32_to_cpu(uint32_t be_val)
{
-#if HAVE_LITTLE_ENDIAN
- return swab_u32(be_val);
-#else
- return be_val;
-#endif
+ return BE32_TO_CPU_CONST(be_val);
}
/**
*/
static inline uint16_t be16_to_cpu(uint16_t be_val)
{
-#if HAVE_LITTLE_ENDIAN
- return swab_u16(be_val);
-#else
- return be_val;
-#endif
+ return BE16_TO_CPU_CONST(be_val);
}
#endif /* CCAN_ENDIAN_H */