byteorder: Add a header file defining common byteswap functions

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 40 insertions, 0 deletions

diff --git a/src/byteorder.h b/src/byteorder.h
new file mode 100644
index 00000000..0ecd68d3
--- /dev/null
+++ b/src/byteorder.h
@@ -0,0 +1,40 @@
+#ifndef __BYTEORDER_H
+#define __BYTEORDER_H
+
+#include <stdint.h> // uint32_t
+
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+
+#define cpu_to_le16(x) ((uint16_t)(x))
+#define cpu_to_le32(x) ((uint32_t)(x))
+#define cpu_to_le64(x) ((uint64_t)(x))
+#define le16_to_cpu(x) ((uint16_t)(x))
+#define le32_to_cpu(x) ((uint32_t)(x))
+#define le64_to_cpu(x) ((uint64_t)(x))
+
+#define cpu_to_be16(x) __builtin_bswap16(x)
+#define cpu_to_be32(x) __builtin_bswap32(x)
+#define cpu_to_be64(x) __builtin_bswap64(x)
+#define be16_to_cpu(x) __builtin_bswap16(x)
+#define be32_to_cpu(x) __builtin_bswap32(x)
+#define be64_to_cpu(x) __builtin_bswap64(x)
+
+#else // big endian
+
+#define cpu_to_le16(x) __builtin_bswap16(x)
+#define cpu_to_le32(x) __builtin_bswap32(x)
+#define cpu_to_le64(x) __builtin_bswap64(x)
+#define le16_to_cpu(x) __builtin_bswap16(x)
+#define le32_to_cpu(x) __builtin_bswap32(x)
+#define le64_to_cpu(x) __builtin_bswap64(x)
+
+#define cpu_to_be16(x) ((uint16_t)(x))
+#define cpu_to_be32(x) ((uint32_t)(x))
+#define cpu_to_be64(x) ((uint64_t)(x))
+#define be16_to_cpu(x) ((uint16_t)(x))
+#define be32_to_cpu(x) ((uint32_t)(x))
+#define be64_to_cpu(x) ((uint64_t)(x))
+
+#endif
+
+#endif // byteorder.h