root/opal/include/opal/prefetch.h

INCLUDED FROM

   1 /*
   2  * Copyright (c) 2004-2006 The Regents of the University of California.
   3  *                         All rights reserved.
   4  * $COPYRIGHT$
   5  *
   6  * Additional copyrights may follow
   7  *
   8  * $HEADER$
   9  */
  10 
  11 /** @file
  12  *
  13  * Compiler-specific prefetch functions
  14  *
  15  * A small set of prefetch / prediction interfaces for using compiler
  16  * directives to improve memory prefetching and branch prediction
  17  */
  18 
  19 #ifndef OPAL_PREFETCH_H
  20 #define OPAL_PREFETCH_H
  21 
  22 #if defined(c_plusplus) || defined(__cplusplus)
  23 /* C++ code */
  24 
  25 #if OMPI_CXX_HAVE_BUILTIN_EXPECT
  26 #define OPAL_LIKELY(expression) __builtin_expect(!!(expression), 1)
  27 #define OPAL_UNLIKELY(expression) __builtin_expect(!!(expression), 0)
  28 #else
  29 #define OPAL_LIKELY(expression) (expression)
  30 #define OPAL_UNLIKELY(expression) (expression)
  31 #endif
  32 
  33 #if OMPI_CXX_HAVE_BUILTIN_PREFETCH
  34 #define OPAL_PREFETCH(address,rw,locality) __builtin_prefetch(address,rw,locality)
  35 #else
  36 #define OPAL_PREFETCH(address,rw,locality)
  37 #endif
  38 
  39 #else
  40 /* C code */
  41 
  42 #if OPAL_C_HAVE_BUILTIN_EXPECT
  43 #define OPAL_LIKELY(expression) __builtin_expect(!!(expression), 1)
  44 #define OPAL_UNLIKELY(expression) __builtin_expect(!!(expression), 0)
  45 #else
  46 #define OPAL_LIKELY(expression) (expression)
  47 #define OPAL_UNLIKELY(expression) (expression)
  48 #endif
  49 
  50 #if OPAL_C_HAVE_BUILTIN_PREFETCH
  51 #define OPAL_PREFETCH(address,rw,locality) __builtin_prefetch(address,rw,locality)
  52 #else
  53 #define OPAL_PREFETCH(address,rw,locality)
  54 #endif
  55 
  56 #endif
  57 
  58 #endif