[PATCH] powerpc: Always use -mno-string
Benjamin Herrenschmidt
benh at kernel.crashing.org
Thu Mar 22 17:23:44 EST 2007
The string load/store instructions are causing more damage than
help on a lot of processors where they are microcoded and are
generally not 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 at kernel.crashing.org>
---
Ok, let's keep load/store multiple, they are only used on 32 bits
and are actually useful. string instructions are not though.
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 17:19:28.000000000 +1100
@@ -102,9 +102,9 @@ CFLAGS += $(call cc-option,-mno-altivec)
# kernel considerably.
CFLAGS += $(call cc-option,-funit-at-a-time)
-ifndef CONFIG_FSL_BOOKE
-CFLAGS += -mstring
-endif
+# Never use string load/store instructions as they are
+# often slow when they are implemented at all
+CFLAGS += -mno-string
ifeq ($(CONFIG_6xx),y)
CFLAGS += -mcpu=powerpc
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