freeswitch/libs/libg722_1/config/ax_misaligned_access_fails.m4
Brian West 1220bbcff2 tweak
git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@10732 d0543943-73ff-0310-b7d9-9358b9ac24b2
2008-12-12 16:01:36 +00:00

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# AX_MISALIGNED_ACCESS_FAILS(MACHINE, [ACTION-IF-MISALIGNED-FAILS], [ACTION-IF-MISALIGNED-OK])
# -------------------------------------------------------------------------------------
#
# Check if a specified machine type cannot handle misaligned data. That is, multi-byte data
# types which are not properly aligned in memory fail. Many machines are happy to work with
# misaligned data, but slowing down a bit. Other machines just won't tolerate such data.
#
# This is a simple lookup amongst machines known to the current autotools. So far we only deal
# with the ARM and sparc.
# A lookup is used, as many of the devices which cannot handled misaligned access are embedded
# processors, for which the code normally be cross-compiled.
#
AC_DEFUN([AX_MISALIGNED_ACCESS_FAILS],
[AS_VAR_PUSHDEF([ac_MisalignedAccessFails], [ac_cv_misaligned_access_fails_$1])dnl
AC_CACHE_CHECK([if $1 fails on misaligned memory access], ac_MisalignedAccessFails,
[case $1 in
arc | arm | arm[bl]e | arme[lb] | armv[2345] | armv[345][lb] \
| bfin \
| sparc \
| xscale | xscalee[bl] \
| arm-* | armbe-* | armle-* | armeb-* | armv*-* \
| bfin-* \
| sparc-* \
| xscale-* | xscalee[bl]-* )
AS_VAR_SET(ac_MisalignedAccessFails, yes)
;;
*)
AS_VAR_SET(ac_MisalignedAccessFails, no)
;;
esac])
AS_IF([test AS_VAR_GET(ac_MisalignedAccessFails) = yes], [$2], [$3])[]dnl
AS_VAR_POPDEF([ac_MisalignedAccessFails])dnl
])# MISALIGNED_ACCESS_FAILS