From 9337e03824a5bdd3bbbcb8382cabefe6d6c32e1e Mon Sep 17 00:00:00 2001
From: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Date: Sat, 21 Sep 2013 13:54:38 +0300
Subject: Optimize and cleanup 32-bit and 64-bit endianess transforms

* cipher/bithelp.h (bswap32, bswap64, le_bswap32, be_bswap32)
(le_bswap64, be_bswap64): New.
* cipher/bufhelp.h (buf_get_be32, buf_get_le32, buf_put_le32)
(buf_put_be32, buf_get_be64, buf_get_le64, buf_put_be64)
(buf_put_le64): New.
* cipher/blowfish.c (do_encrypt_block, do_decrypt_block): Use new
endian conversion helpers.
(do_bf_setkey): Turn endian specific code to generic.
* cipher/camellia.c (GETU32, PUTU32): Use new endian conversion
helpers.
* cipher/cast5.c (rol): Remove, use rol from bithelp.
(F1, F2, F3): Fix to use rol from bithelp.
(do_encrypt_block, do_decrypt_block, do_cast_setkey): Use new endian
conversion helpers.
* cipher/des.c (READ_64BIT_DATA, WRITE_64BIT_DATA): Ditto.
* cipher/md4.c (transform, md4_final): Ditto.
* cipher/md5.c (transform, md5_final): Ditto.
* cipher/rmd160.c (transform, rmd160_final): Ditto.
* cipher/salsa20.c (LE_SWAP32, LE_READ_UINT32): Ditto.
* cipher/scrypt.c (READ_UINT64, LE_READ_UINT64, LE_SWAP32): Ditto.
* cipher/seed.c (GETU32, PUTU32): Ditto.
* cipher/serpent.c (byte_swap_32): Remove.
(serpent_key_prepare, serpent_encrypt_internal)
(serpent_decrypt_internal): Use new endian conversion helpers.
* cipher/sha1.c (transform, sha1_final): Ditto.
* cipher/sha256.c (transform, sha256_final): Ditto.
* cipher/sha512.c (__transform, sha512_final): Ditto.
* cipher/stribog.c (transform, stribog_final): Ditto.
* cipher/tiger.c (transform, tiger_final): Ditto.
* cipher/twofish.c (INPACK, OUTUNPACK): Ditto.
* cipher/whirlpool.c (buffer_to_block, block_to_buffer): Ditto.
* configure.ac (gcry_cv_have_builtin_bswap32): Check for compiler
provided __builtin_bswap32.
(gcry_cv_have_builtin_bswap64): Check for compiler provided
__builtin_bswap64.
--

Patch add helper functions that provide conversions to/from integers and
buffers of different endianess. Benefits are code cleanup and optimization
for architectures that have byte-swaping instructions and/or can do fast
unaligned memory accesses.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
---
 cipher/bithelp.h | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

(limited to 'cipher/bithelp.h')

diff --git a/cipher/bithelp.h b/cipher/bithelp.h
index 785701e3..734dcbb5 100644
--- a/cipher/bithelp.h
+++ b/cipher/bithelp.h
@@ -20,6 +20,8 @@
 #ifndef G10_BITHELP_H
 #define G10_BITHELP_H
 
+#include "types.h"
+
 
 /****************
  * Rotate the 32 bit unsigned integer X by N bits left/right
@@ -52,5 +54,43 @@ ror(u32 x, int n)
 #define ror(x,n) ( ((x) >> (n)) | ((x) << (32-(n))) )
 #endif
 
+/* Byte swap for 32-bit and 64-bit integers.  If available, use compiler
+   provided helpers.  */
+#ifdef HAVE_BUILTIN_BSWAP32
+# define bswap32 __builtin_bswap32
+#else
+static inline u32 bswap32(u32 x)
+{
+	return ((rol(x, 8) & 0x00ff00ffL) | (ror(x, 8) & 0xff00ff00L));
+}
+#endif
+
+#ifdef HAVE_U64_TYPEDEF
+# ifdef HAVE_BUILTIN_BSWAP64
+#  define bswap64 __builtin_bswap64
+# else
+static inline u64 bswap64(u64 x)
+{
+	return ((u64)bswap32(x) << 32) | (bswap32(x >> 32));
+}
+# endif
+#endif
+
+/* Endian dependent byte swap operations.  */
+#ifdef WORDS_BIGENDIAN
+# define le_bswap32(x) bswap32(x)
+# define be_bswap32(x) ((u32)(x))
+# ifdef HAVE_U64_TYPEDEF
+#  define le_bswap64(x) bswap64(x)
+#  define be_bswap64(x) ((u64)(x))
+# endif
+#else
+# define le_bswap32(x) ((u32)(x))
+# define be_bswap32(x) bswap32(x)
+# ifdef HAVE_U64_TYPEDEF
+#  define le_bswap64(x) ((u64)(x))
+#  define be_bswap64(x) bswap64(x)
+# endif
+#endif
 
 #endif /*G10_BITHELP_H*/
-- 
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