inital checkin of spandsp from http://www.soft-switch.org/downloads/snapshots/spandsp/spandsp-20080829.tar.gz

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@9425 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/spandsp/config/ax_misaligned_access_fails.m4

@@ -0,0 +1,33 @@
+# 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