check for ARMv6 instruction set support

Originally committed as revision 7719 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -117,6 +117,7 @@ show_help(){
   echo "                           (requires enabling PMC)"
   echo "  --disable-mmx            disable MMX usage"
   echo "  --disable-armv5te        disable armv5te usage"
+  echo "  --disable-armv6          disable armv6 usage"
   echo "  --disable-iwmmxt         disable iwmmxt usage"
   echo "  --disable-altivec        disable AltiVec usage"
   echo "  --disable-audio-oss      disable OSS audio support [default=no]"
@@ -465,6 +466,7 @@ CONFIG_LIST='
 
 HAVE_LIST='
     altivec_h
+    armv6
     beosthreads
     byteswap_h
     dcbzl
@@ -574,6 +576,7 @@ mmx="default"
 cmov="no"
 cmov_is_fast="no"
 armv5te="default"
+armv6="default"
 iwmmxt="default"
 altivec="default"
 dcbzl="no"
@@ -963,6 +966,8 @@ for opt do
   ;;
   --disable-armv5te) armv5te="no"
   ;;
+  --disable-armv6) armv6="no"
+  ;;
   --disable-iwmmxt) iwmmxt="no"
   ;;
   --disable-altivec) altivec="no"
@@ -1449,6 +1454,14 @@ if test $armv5te = "default" -a $arch = "armv4l"; then
 EOF
 fi
 
+if test $armv6 = "default" -a $arch = "armv4l"; then
+    check_cc <<EOF && armv6=yes || armv6=no
+int main(void) {
+    __asm__ __volatile__ ("sadd16 r0, r0, r0");
+}
+EOF
+fi
+
 # check iwmmxt support
 if test $iwmmxt = "default" -a $arch = "armv4l"; then
     iwmmxt=no
@@ -1835,6 +1848,7 @@ if test $arch = "x86_32" -o $arch = "x86_64"; then
 fi
 if test $arch = "armv4l"; then
     echo "ARMv5TE enabled           $armv5te"
+    echo "ARMv6 enabled             $armv6"
     echo "IWMMXT enabled            $iwmmxt"
 fi
 if test $arch = "mips"; then