[svn-r7481] Purpose:

    Bug fix

Description:
    The MPI_File_set_size() routine on ASCI Red is not able to extend files
so that they are larger than 2GB.

Solution:
    Add an extra macro which controls whether MPI_File_set_size() can handle
>2GB offsets or if our "older" way of reading a byte, then writing a byte at
the appropriate offset should be used.

Platforms tested:
    FreeBSD 4.9 (sleipnir)
    h5committest

1 files changed, 19 insertions, 1 deletions

diff --git a/configure.in b/configure.in
index 17c897b..9f4186d 100644
--- a/configure.in
+++ b/configure.in
@@ -1548,7 +1548,7 @@ int main(void)
 
 if test ${hdf5_cv_malloc_works} = "yes"; then
   AC_DEFINE(MALLOC_WORKS, 1,
-            [Define if your system has a working \`malloc' function.])
+            [Define if your system's \`malloc' function returns a valid pointer for 0-byte allocations.])
   AC_MSG_RESULT(yes)
 else
   AC_MSG_RESULT(no)
@@ -2058,6 +2058,24 @@ dnl     AC_MSG_RESULT(yes)
 dnl   else
 dnl     AC_MSG_RESULT(no)
 dnl   fi
+
+  dnl ----------------------------------------------------------------------
+  dnl Set the flag to indicate that the MPI_File_set_size() function
+  dnl works with files over 2GB, unless it's already set in the cache.
+  dnl (This flag should be set for all machines, except for ASCI Red, where
+  dnl the cache value is set in it's config file)
+  dnl
+  AC_MSG_CHECKING([if MPI_File_set_size works for files over 2GB])
+  AC_CACHE_VAL([hdf5_cv_mpi_file_set_size_big], [hdf5_cv_mpi_file_set_size_big=yes])
+  
+  if test ${hdf5_cv_mpi_file_set_size_big} = "yes"; then
+    AC_DEFINE([MPI_FILE_SET_SIZE_BIG], [1],
+              [Define if your system's \`MPI_File_set_size' function works for files over 2GB.])
+    AC_MSG_RESULT([yes])
+  else
+    AC_MSG_RESULT([no])
+  fi
+  
 fi
 
 dnl ----------------------------------------------------------------------