Add UNLIKELY and LIKELY macros

* src/g10lib.h (LIKELY, UNLIKELY): New.
(gcry_assert): Use LIKELY for assert check.
(fast_wipememory2_unaligned_head): Use UNLIKELY for unaligned
branching.
* cipher/bufhelp.h (buf_cpy, buf_xor, buf_xor_1, buf_xor_2dst)
(buf_xor_n_copy_2): Ditto.
--

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>

diff --git a/cipher/bufhelp.h b/cipher/bufhelp.h
index 3110a1d..b854bc0 100644 (file)
--- a/cipher/bufhelp.h
+++ b/cipher/bufhelp.h
@@ -1,5 +1,5 @@
 /* bufhelp.h  -  Some buffer manipulation helpers
- * Copyright (C) 2012 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
+ * Copyright (C) 2012-2017 Jussi Kivilinna <jussi.kivilinna@iki.fi>
  *
  * This file is part of Libgcrypt.
  *
@@ -20,6 +20,7 @@
 #define GCRYPT_BUFHELP_H
 
 
+#include "g10lib.h"
 #include "bithelp.h"
 
 
@@ -88,7 +89,7 @@ buf_cpy(void *_dst, const void *_src, size_t len)
   const unsigned int longmask = sizeof(bufhelp_int_t) - 1;
 
   /* Skip fast processing if buffers are unaligned.  */
-  if (((uintptr_t)dst | (uintptr_t)src) & longmask)
+  if (UNLIKELY(((uintptr_t)dst | (uintptr_t)src) & longmask))
     goto do_bytes;
 #endif
 
@@ -124,7 +125,7 @@ buf_xor(void *_dst, const void *_src1, const void *_src2, size_t len)
   const unsigned int longmask = sizeof(bufhelp_int_t) - 1;
 
   /* Skip fast processing if buffers are unaligned.  */
-  if (((uintptr_t)dst | (uintptr_t)src1 | (uintptr_t)src2) & longmask)
+  if (UNLIKELY(((uintptr_t)dst | (uintptr_t)src1 | (uintptr_t)src2) & longmask))
     goto do_bytes;
 #endif
 
@@ -160,7 +161,7 @@ buf_xor_1(void *_dst, const void *_src, size_t len)
   const unsigned int longmask = sizeof(bufhelp_int_t) - 1;
 
   /* Skip fast processing if buffers are unaligned.  */
-  if (((uintptr_t)dst | (uintptr_t)src) & longmask)
+  if (UNLIKELY(((uintptr_t)dst | (uintptr_t)src) & longmask))
     goto do_bytes;
 #endif
 
@@ -196,7 +197,7 @@ buf_xor_2dst(void *_dst1, void *_dst2, const void *_src, size_t len)
   const unsigned int longmask = sizeof(bufhelp_int_t) - 1;
 
   /* Skip fast processing if buffers are unaligned.  */
-  if (((uintptr_t)src | (uintptr_t)dst1 | (uintptr_t)dst2) & longmask)
+  if (UNLIKELY(((uintptr_t)src | (uintptr_t)dst1 | (uintptr_t)dst2) & longmask))
     goto do_bytes;
 #endif
 
@@ -238,8 +239,8 @@ buf_xor_n_copy_2(void *_dst_xor, const void *_src_xor, void *_srcdst_cpy,
   const unsigned int longmask = sizeof(bufhelp_int_t) - 1;
 
   /* Skip fast processing if buffers are unaligned.  */
-  if (((uintptr_t)src_cpy | (uintptr_t)src_xor | (uintptr_t)dst_xor |
-       (uintptr_t)srcdst_cpy) & longmask)
+  if (UNLIKELY(((uintptr_t)src_cpy | (uintptr_t)src_xor | (uintptr_t)dst_xor |
+       (uintptr_t)srcdst_cpy) & longmask))
     goto do_bytes;
 #endif
 

diff --git a/src/g10lib.h b/src/g10lib.h
index 8ce84b8..0309a83 100644 (file)
--- a/src/g10lib.h
+++ b/src/g10lib.h
@@ -75,6 +75,14 @@
 #define GCC_ATTR_UNUSED
 #endif
 
+#if __GNUC__ >= 3
+#define LIKELY( expr )    __builtin_expect( !!(expr), 1 )
+#define UNLIKELY( expr )  __builtin_expect( !!(expr), 0 )
+#else
+#define LIKELY( expr )    (!!(expr))
+#define UNLIKELY( expr )  (!!(expr))
+#endif
+
 /* Gettext macros.  */
 
 #define _(a)  _gcry_gettext(a)
@@ -165,15 +173,15 @@ int _gcry_log_verbosity( int level );
 
 #ifdef JNLIB_GCC_M_FUNCTION
 #define BUG() _gcry_bug( __FILE__ , __LINE__, __FUNCTION__ )
-#define gcry_assert(expr) ((expr)? (void)0 \
+#define gcry_assert(expr) (LIKELY(expr)? (void)0 \
          : _gcry_assert_failed (STR(expr), __FILE__, __LINE__, __FUNCTION__))
 #elif __STDC_VERSION__ >= 199901L
 #define BUG() _gcry_bug( __FILE__ , __LINE__, __func__ )
-#define gcry_assert(expr) ((expr)? (void)0 \
+#define gcry_assert(expr) (LIKELY(expr)? (void)0 \
          : _gcry_assert_failed (STR(expr), __FILE__, __LINE__, __func__))
 #else
 #define BUG() _gcry_bug( __FILE__ , __LINE__ )
-#define gcry_assert(expr) ((expr)? (void)0 \
+#define gcry_assert(expr) (LIKELY(expr)? (void)0 \
          : _gcry_assert_failed (STR(expr), __FILE__, __LINE__))
 #endif
 
@@ -346,7 +354,7 @@ typedef struct fast_wipememory_s
 } __attribute__((packed, aligned(1), may_alias)) fast_wipememory_t;
 #else
 #define fast_wipememory2_unaligned_head(_vptr,_vset,_vlen) do { \
-              while((size_t)(_vptr)&(sizeof(FASTWIPE_T)-1) && _vlen) \
+              while(UNLIKELY((size_t)(_vptr)&(sizeof(FASTWIPE_T)-1)) && _vlen) \
                 { *_vptr=(_vset); _vptr++; _vlen--; } \
                   } while(0)
 typedef struct fast_wipememory_s