Having access to the full power of the prefetch is way more interesting. There

are 3 arguments: the pointer to the memory location to prefetch, the type of
operation that will be done on the memory (read or write) and the expected
locality.

This commit was SVN r10294.

config/ompi_setup_cc.m4

@@ -174,7 +174,7 @@ AC_DEFUN([OMPI_SETUP_CC],[
         [ompi_cv_cc_supports___builtin_prefetch],
         [AC_TRY_COMPILE([],
           [int ptr;
-           __builtin_prefetch(&ptr);],
+           __builtin_prefetch(&ptr,0,0);],
           [ompi_cv_cc_supports___builtin_prefetch="yes"],
           [ompi_cv_cc_supports___builtin_prefetch="no"])])
     if test "$ompi_cv_cc_supports___builtin_prefetch" = "yes" ; then

config/ompi_setup_cxx.m4

@@ -159,7 +159,7 @@ AC_DEFUN([OMPI_SETUP_CXX],[
         [ompi_cv_cxx_supports___builtin_prefetch],
         [AC_TRY_COMPILE([],
           [int ptr;
-           __builtin_prefetch(&ptr);],
+           __builtin_prefetch(&ptr,0,0);],
           [ompi_cv_cxx_supports___builtin_prefetch="yes"],
           [ompi_cv_cxx_supports___builtin_prefetch="no"])])
     if test "$ompi_cv_cxx_supports___builtin_prefetch" = "yes" ; then

opal/include/opal/prefetch.h

@@ -31,9 +31,9 @@
 #endif
 
 #if OMPI_CXX_HAVE_BUILTIN_PREFETCH
-#define OPAL_PREFETCH(address) __builtin_prefetch(address)
+#define OPAL_PREFETCH(address,rw,locality) __builtin_prefetch(address,rw,locality)
 #else
-#define OPAL_PREFETCH(address)
+#define OPAL_PREFETCH(address,rw,locality)
 #endif
 
 #else
@@ -48,9 +48,9 @@
 #endif
 
 #if OMPI_C_HAVE_BUILTIN_PREFETCH
-#define OPAL_PREFETCH(address) __builtin_prefetch(address)
+#define OPAL_PREFETCH(address,rw,locality) __builtin_prefetch(address,rw,locality)
 #else
-#define OPAL_PREFETCH(address)
+#define OPAL_PREFETCH(address,rw,locality)
 #endif
 
 #endif