+# -----------------------------------------------------------------------------
+# Link-Time-Optimization
+
+if test "${enable_lto}" != "no"; then
+ opt="-flto"
+ AX_CHECK_COMPILE_FLAG(${opt}, [have_lto=yes], [have_lto=no])
+fi
+if test "${have_lto}" = "yes"; then
+ oCFLAGS="${CFLAGS}"
+ CFLAGS="${CFLAGS} -flto ${OPTIONAL_MATH_CLFAGS} ${OPTIONAL_NFACCT_CLFAGS} ${OPTIONAL_ZLIB_CLFAGS} ${OPTIONAL_UUID_CLFAGS} ${OPTIONAL_LIBCAP_CFLAGS} ${OPTIONAL_IPMIMONITORING_CFLAGS}"
+ ac_cv_c_lto_cross_compile="${enable_lto}"
+ test "${ac_cv_c_lto_cross_compile}" != "yes" && ac_cv_c_lto_cross_compile="no"
+ AC_C_LTO
+ CFLAGS="${oCFLAGS}"
+ test "${ac_cv_c_lto}" != "yes" && have_lto="no"
+fi
+test "${enable_lto}" = "yes" -a "${have_lto}" != "yes" && \
+ AC_MSG_ERROR([LTO is required but is not available.])
+AC_MSG_CHECKING([if LTO should be enabled])
+if test "${enable_lto}" != "no" -a "${have_lto}" = "yes"; then
+ enable_lto="yes"
+ CFLAGS="${CFLAGS} -flto"
+else
+ enable_lto="no"
+fi
+AC_MSG_RESULT([${enable_lto}])
+
+