+dnl On GNU/Linux ifunc is supported by the dynamic linker in glibc
+dnl 2.11 or later, and by binutils 2.20.1 or later.
+AC_CACHE_CHECK([for glibc ifunc support], [gold_cv_lib_glibc_ifunc],
+[save_LDFLAGS="$LDFLAGS"
+LDFLAGS="$LDFLAGS -static"
+AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#include <features.h>
+#if !defined __GLIBC__
+error
+#elif __GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 11)
+error
+#endif
+void func (void) { }
+void invoke (void);
+__asm__(".type invoke, %gnu_indirect_function");
+typedef void (*funcptr) (void);
+funcptr dispatch (void) __asm__ ("invoke");
+funcptr dispatch (void) { return &func; }]],
+[[invoke();]])
+], [
+if ${NM} conftest$EXEEXT | grep "__rela\?_iplt_start" >/dev/null 2>&1; then
+ gold_cv_lib_glibc_ifunc=both
+else
+ gold_cv_lib_glibc_ifunc=dyn
+fi], [gold_cv_lib_glibc_ifunc=no])
+LDFLAGS="$save_LDFLAGS"])
+
+AM_CONDITIONAL(IFUNC, test "$gold_cv_lib_glibc_ifunc" != "no")
+AM_CONDITIONAL(IFUNC_STATIC, test "$gold_cv_lib_glibc_ifunc" = "both")
+