diff -Nuar arpwatch-2.1a15.org/aclocal.m4 arpwatch-2.1a15.sw/aclocal.m4
--- arpwatch-2.1a15.org/aclocal.m4	2022-02-24 22:23:30.840000000 +0000
+++ arpwatch-2.1a15.sw/aclocal.m4	2022-02-24 22:25:13.280000000 +0000
@@ -567,7 +567,7 @@
     AC_CACHE_VAL(ac_cv_lbl_unaligned_fail,
 	[case "$target_cpu" in
 
-	alpha|hp*|mips|sparc)
+	sw_64|alpha|hp*|mips|sparc)
 		ac_cv_lbl_unaligned_fail=yes
 		;;
 
diff -Nuar arpwatch-2.1a15.org/config.guess arpwatch-2.1a15.sw/config.guess
--- arpwatch-2.1a15.org/config.guess	2022-02-24 22:23:30.840000000 +0000
+++ arpwatch-2.1a15.sw/config.guess	2022-02-24 22:24:52.010000000 +0000
@@ -875,6 +875,14 @@
 	UNAME_MACHINE=aarch64_be
 	echo ${UNAME_MACHINE}-unknown-linux-gnu
 	exit ;;
+    sw_64:Linux:*:*)
+	case `sed -n '/^cpu model/s/^.*: \(.*\)/\1/p' < /proc/cpuinfo` in
+	  sw)   UNAME_MACHINE=sw_64 ;;
+	esac
+	objdump --private-headers /bin/sh | grep -q ld.so.1
+	if test "$?" = 0 ; then LIBC="libc1" ; else LIBC="" ; fi
+	echo ${UNAME_MACHINE}-sunway-linux-gnu${LIBC}
+	exit ;;
     alpha:Linux:*:*)
 	case `sed -n '/^cpu model/s/^.*: \(.*\)/\1/p' < /proc/cpuinfo` in
 	  EV5)   UNAME_MACHINE=alphaev5 ;;
diff -Nuar arpwatch-2.1a15.org/config.sub arpwatch-2.1a15.sw/config.sub
--- arpwatch-2.1a15.org/config.sub	2022-02-24 22:23:30.840000000 +0000
+++ arpwatch-2.1a15.sw/config.sub	2022-02-24 22:24:11.300000000 +0000
@@ -256,6 +256,7 @@
 	1750a | 580 \
 	| a29k \
 	| aarch64 | aarch64_be \
+	| sw_64 \
 	| alpha | alphaev[4-8] | alphaev56 | alphaev6[78] | alphapca5[67] \
 	| alpha64 | alpha64ev[4-8] | alpha64ev56 | alpha64ev6[78] | alpha64pca5[67] \
 	| am33_2.0 \
@@ -368,6 +369,7 @@
 	580-* \
 	| a29k-* \
 	| aarch64-* | aarch64_be-* \
+	| sw_64-* \
 	| alpha-* | alphaev[4-8]-* | alphaev56-* | alphaev6[78]-* \
 	| alpha64-* | alpha64ev[4-8]-* | alpha64ev56-* | alpha64ev6[78]-* \
 	| alphapca5[67]-* | alpha64pca5[67]-* | arc-* \