On Wed, 19 Oct 2011, David Miller wrote: > From: Konrad Eisele <konrad@xxxxxxxxxxx> > Date: Wed, 19 Oct 2011 10:33:25 +0200 > > > It seems to me that memcpy is tightly programmed. Is saving 2 lines of gdbstub.c > > diff worth a memcpy rewrite? > > You really can't find another register to save the initial %o0 value in? > Have you even tried? This might be considered a ugly hack. But what about using %y ? According to the V8 manual, %y might be destroyed across a procedure call, and none of the functions in memcpy.S use multiply/divide instructions. It is however not mentioned as a available register in the section dealing with leaf procedures. A quick test on a SS20 did not reveal any immediate side-effects, and the return value of memcpy is now the destination pointer. --- diff --git a/arch/sparc/lib/memcpy.S b/arch/sparc/lib/memcpy.S index 34fe657..0327309 100644 --- a/arch/sparc/lib/memcpy.S +++ b/arch/sparc/lib/memcpy.S @@ -23,8 +23,8 @@ x: * One should use macros in asm/string.h for that purpose. * We return 0, so that bugs are more apparent. */ -#define SETUP_RETL -#define RETL_INSN clr %o0 +#define SETUP_RETL mov %o0, %y +#define RETL_INSN mov %y, %o0 #else -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
