diff -Naur groff-1.22.4.org/configure groff-1.22.4.sw/configure
--- groff-1.22.4.org/configure	2022-02-14 01:50:40.730000000 +0000
+++ groff-1.22.4.sw/configure	2022-02-14 01:52:50.330000000 +0000
@@ -7038,6 +7038,12 @@
   # (according to the test results of Bruno Haible's ieeefp/fenv_default.m4
   # and the GCC 4.1.2 manual).
   case "$host_cpu" in
+    sw_64*)
+      if test -n "$GCC"; then
+        # GCC has the option -mieee.
+        CPPFLAGS="$CPPFLAGS -mieee"
+      fi
+      ;;
     alpha*)
       # On Alpha systems, a compiler option provides the behaviour.
       # See the ieee(3) manual page, also available at
@@ -11032,6 +11038,10 @@
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
          ;;
 
+       sw_64* )
+         gl_cv_host_cpu_c_abi=sw_64
+         ;;
+
        alphaev[4-8] | alphaev56 | alphapca5[67] | alphaev6[78] )
          gl_cv_host_cpu_c_abi=alpha
          ;;
diff -Naur groff-1.22.4.org/gnulib_m4/fpieee.m4 groff-1.22.4.sw/gnulib_m4/fpieee.m4
--- groff-1.22.4.org/gnulib_m4/fpieee.m4	2022-02-14 01:50:40.920000000 +0000
+++ groff-1.22.4.sw/gnulib_m4/fpieee.m4	2022-02-14 02:02:42.650000000 +0000
@@ -30,6 +30,12 @@
   # (according to the test results of Bruno Haible's ieeefp/fenv_default.m4
   # and the GCC 4.1.2 manual).
   case "$host_cpu" in
+    sw_64*)
+      if test -n "$GCC"; then
+        # GCC has the option -mieee.
+        CPPFLAGS="$CPPFLAGS -mieee"
+      fi
+      ;;
     alpha*)
       # On Alpha systems, a compiler option provides the behaviour.
       # See the ieee(3) manual page, also available at
diff -Naur groff-1.22.4.org/gnulib_m4/host-cpu-c-abi.m4 groff-1.22.4.sw/gnulib_m4/host-cpu-c-abi.m4
--- groff-1.22.4.org/gnulib_m4/host-cpu-c-abi.m4	2022-02-14 01:50:40.910000000 +0000
+++ groff-1.22.4.sw/gnulib_m4/host-cpu-c-abi.m4	2022-02-14 02:02:15.450000000 +0000
@@ -91,6 +91,12 @@
          ;;
 
 changequote(,)dnl
+       sw_64* )
+changequote([,])dnl
+         gl_cv_host_cpu_c_abi=sw_64
+         ;;
+
+changequote(,)dnl
        alphaev[4-8] | alphaev56 | alphapca5[67] | alphaev6[78] )
 changequote([,])dnl
          gl_cv_host_cpu_c_abi=alpha
@@ -355,6 +361,9 @@
 #ifndef __x86_64__
 #undef __x86_64__
 #endif
+#ifndef __sw_64__
+#undef __sw_64__
+#endif
 #ifndef __alpha__
 #undef __alpha__
 #endif
diff -Naur groff-1.22.4.org/src/include/config.hin groff-1.22.4.sw/src/include/config.hin
--- groff-1.22.4.org/src/include/config.hin	2022-02-14 01:50:40.860000000 +0000
+++ groff-1.22.4.sw/src/include/config.hin	2022-02-14 02:03:30.230000000 +0000
@@ -10,6 +10,9 @@
 #ifndef __x86_64__
 #undef __x86_64__
 #endif
+#ifndef __sw_64__
+#undef __sw_64__
+#endif
 #ifndef __alpha__
 #undef __alpha__
 #endif