[RFC/PATCH] powerpc: Always use -mno-string & -mno-multiple

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

powerpc: Always use -mno-string and -mno-multiple

The string and multiple load/store instructions are causing more
damage than help on a lot of processors where they are microcoded
and are generally no good for the kernel to use. Let's make sure
we don't emit them on any powerpc variant.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

Is that actually true ? What about 601 ? 4xx ? Do we want to keep
generating those for space on embedded processors where they actually
work (if they do) ?

Index: linux-cell/arch/powerpc/Makefile
===================================================================
--- linux-cell.orig/arch/powerpc/Makefile	2007-03-22 17:02:42.000000000 +1100
+++ linux-cell/arch/powerpc/Makefile	2007-03-22 17:05:23.000000000 +1100
@@ -102,9 +102,9 @@ CFLAGS += $(call cc-option,-mno-altivec)
 # kernel considerably.
 CFLAGS += $(call cc-option,-funit-at-a-time)
 
-ifndef CONFIG_FSL_BOOKE
-CFLAGS		+= -mstring
-endif
+# Never use string and multiple load/store instructions as they are
+# often slow when they are implemented at all
+CFLAGS		+= -mno-string -mno-multiple
 
 ifeq ($(CONFIG_6xx),y)
 CFLAGS		+= -mcpu=powerpc