Hi,

On Mon, 26 Sep 2005, Hollis Blanchard wrote:

quoted

--- linux.orig/include/asm-ppc/io.h	2005-09-23 16:20:24.000000000 +0200
+++ linux/include/asm-ppc/io.h	2005-09-23 16:20:26.000000000 +0200

@@ -294,10 +294,10 @@ extern __inline__ void name(unsigned int
 __do_out_asm(outb, "stbx")
 #ifdef CONFIG_APUS
 __do_in_asm(inb, "lbzx")
-__do_in_asm(inw, "lhz%U1%X1")
-__do_in_asm(inl, "lwz%U1%X1")
-__do_out_asm(outl,"stw%U0%X0")
-__do_out_asm(outw, "sth%U0%X0")
+__do_in_asm(inw, "lhzx")
+__do_in_asm(inl, "lwzx")
+__do_out_asm(outl,"stwx")
+__do_out_asm(outw, "sthx")
 #elif defined (CONFIG_8260_PCI9)
 /* in asm cannot be defined if PCI9 workaround is used */
 #define inb(port)		in_8((port)+___IO_BASE)

I don't see where this is explained in the GCC docs, but as I understand it
those %U %X things are allowing somebody to use the "update" and "index"
variants of the instruction. Why doesn't this work for you?

Because it requires the matching arguments, which are defined by 
__do_{in,out}_asm, otherwise an invalid instruction is generated.

bye, Roman