Index: kernel/arch/amd64/Makefile.inc
===================================================================
--- kernel/arch/amd64/Makefile.inc	(revision 740018f4c7ff02f7a03a4b5ac90b15a05cdaa3d1)
+++ kernel/arch/amd64/Makefile.inc	(revision a347a110d7ea83c8d45c6874cb10eb949d5d595c)
@@ -41,5 +41,5 @@
 # is fixed.
 #
-# If GCC generates a code for tail call, instead of generating ..
+# When GCC generates a code for tail call, instead of generating ..
 #
 #   jmp *fnc
@@ -48,4 +48,6 @@
 #
 #   jmp *$fnc
+#
+# See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48385 for reference.
 #