Index: kernel/arch/amd64/Makefile.inc
===================================================================
--- kernel/arch/amd64/Makefile.inc	(revision b511c2003b4475be254644e2e4cc4462936e14b7)
+++ kernel/arch/amd64/Makefile.inc	(revision 5d5068606a18e27450340baa4f164a93d978c7ba)
@@ -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.
 #