On Sat, Dec 17, 2011 at 9:58 AM, Nai Xia <nai.xia@xxxxxxxxx> wrote: > Hi Andi, > > Seems I used a stale email address of you from a related git commit log, > so this is a resend, sorry. > > ======= > Hi, > > I notice that all x86 assembly code for string operations containing > "scasb, lodsb", etc does not have "cld" at the beginning. > Is this 100% safe? > Or in other words, how could we be sure that > there is no "std" generated by compiler somewhere just before > the string operations? > > > Thanks, > > Nai > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ The i386 ELF ABI states "The direction flag must be set to the ‘‘forward’’ (that is, zero) direction before entry and upon exit from a function." Therefore it can be assumed to be clear, unless explicitly set. -- Brian Gerst -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href