# Copyright 2008 Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 3, or (at your option)

# any later version.

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Boston, MA

# 02110-1301, USA.

AC_DEFUN([GR_CHECK_MEMALIGN],

[

  AC_REQUIRE([AC_CANONICAL_HOST])

  # Check for allocing memory alignment functions

  # If 'posix_memalign' is available, use it solely.

  AC_CHECK_FUNCS([posix_memalign],,[

    # Otherwise, check for valloc and the

    # (a-priori known) alignment of 'malloc'

    AC_CHECK_FUNCS([valloc])

    aligned_malloc=0

    # 'malloc' is 16-byte aligned on (at least) Darwin 8 and 9

    case "$host_os" in

      darwin8*) aligned_malloc=16 ;;

      darwin9*) aligned_malloc=16 ;;

      *) ;;

    esac

    if test $aligned_malloc = 0; then

      AC_MSG_RESULT([malloc has unknown alignment.])

    else

      AC_MSG_RESULT([malloc is $aligned_malloc-byte aligned.])

    fi

    AC_DEFINE_UNQUOTED([ALIGNED_MALLOC],[$aligned_malloc],[Define as the alignment of malloc if known; otherwise 0.])

  ])

])