see http://www.mail-archive.com/devel@lists.laptop.org/msg10626.html
--- a/arch/i386/Makefile	2008-09-09 12:15:51.000000000 +0200
+++ b/arch/i386/Makefile	2008-09-09 12:16:26.000000000 +0200
@@ -34,7 +34,9 @@ CHECKFLAGS	+= -D__i386__
 CFLAGS += -pipe -msoft-float -mregparm=3 -freg-struct-return
 
 # prevent gcc from keeping the stack 16 byte aligned
-CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2)
+CFLAGS += $(call cc-option,-mpreferred-stack-boundary=2,)
+CFLAGS += $(call cc-option,-fno-tree-scev-cprop,)
+
 
 # CPU-specific tuning. Anything which can be shared with UML should go here.
 include $(srctree)/arch/i386/Makefile.cpu