From e0a0bc708a92825de3e12111cd0ce54c33720a72 Mon Sep 17 00:00:00 2001 From: Bruno Haible Date: Mon, 2 May 2005 11:42:21 +0000 Subject: [PATCH] Add comments. --- lib/byteswap_.h | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/lib/byteswap_.h b/lib/byteswap_.h index dede8a109d..3fee78f237 100644 --- a/lib/byteswap_.h +++ b/lib/byteswap_.h @@ -18,19 +18,27 @@ #ifndef _BYTESWAP_H +/* Given an unsigned 16-bit argument X, return the value corresponding to + X with reversed byte order. */ #define bswap_16(x) ((((x) & 0x00FF) << 8) | \ - (((x) & 0xFF00) >> 8)) + (((x) & 0xFF00) >> 8)) + +/* Given an unsigned 32-bit argument X, return the value corresponding to + X with reversed byte order. */ #define bswap_32(x) ((((x) & 0x000000FF) << 24) | \ - (((x) & 0x0000FF00) << 8) | \ - (((x) & 0x00FF0000) << 8) | \ - (((x) & 0xFF000000) >> 24)) + (((x) & 0x0000FF00) << 8) | \ + (((x) & 0x00FF0000) << 8) | \ + (((x) & 0xFF000000) >> 24)) + +/* Given an unsigned 64-bit argument X, return the value corresponding to + X with reversed byte order. */ #define bswap_64(x) ((((x) & 0x00000000000000FFULL) << 56) | \ - (((x) & 0x000000000000FF00ULL) << 40) | \ - (((x) & 0x0000000000FF0000ULL) << 24) | \ - (((x) & 0x00000000FF000000ULL) << 8) | \ + (((x) & 0x000000000000FF00ULL) << 40) | \ + (((x) & 0x0000000000FF0000ULL) << 24) | \ + (((x) & 0x00000000FF000000ULL) << 8) | \ (((x) & 0x000000FF00000000ULL) >> 8) | \ - (((x) & 0x0000FF0000000000ULL) >> 24) | \ - (((x) & 0x00FF000000000000ULL) >> 40) | \ - (((x) & 0xFF00000000000000ULL) >> 56)) + (((x) & 0x0000FF0000000000ULL) >> 24) | \ + (((x) & 0x00FF000000000000ULL) >> 40) | \ + (((x) & 0xFF00000000000000ULL) >> 56)) #endif -- 2.30.2