diff -ur acpica-unix-20121114/generate/unix/Makefile.config acpica-unix-20121114.patched/generate/unix/Makefile.config
--- acpica-unix-20121114/generate/unix/Makefile.config	2012-11-14 17:22:38.000000000 +0100
+++ acpica-unix-20121114.patched/generate/unix/Makefile.config	2012-11-15 21:19:36.683902859 +0100
@@ -104,6 +104,7 @@
 # automatically included in -Wall.
 #
 CFLAGS += \
+    -O \
     $(BITSFLAG) \
     -D$(HOST) \
     -D_GNU_SOURCE \