On Monday 11 January 2010 01:27:48 Larry Finger wrote: > On 01/10/2010 04:32 PM, Michael Buesch wrote: > > On Sunday 10 January 2010 23:13:20 Rafał Miłecki wrote: > >> + buf[0] += (s8)(((s[0] & 0x3F) << 2) >> 2); > >> + buf[1] += (s8)((((s[0] >> 8) & 0x3F) << 2) >> 2); > >> + buf[2] += (s8)(((s[1] & 0x3F) << 2) >> 2); > >> + buf[3] += (s8)((((s[1] >> 8) & 0x3F) << 2) >> 2); > > > > I suggest buf[3] += (s8)((((s[1] >> 8) & 0x3F) << 2) >> 2) << 2) >> 2) << 2) >> 2) << 2) >> 2) << 2) >> 2) << 2) >> 2) << 2) >> 2) > > ;) > > No, seriously, why shift left and then shift right? Is this a translation error? > > I _guess_ it's some mistranslation of the sign extension going on. > > Or alternatively a compiler going insane on sign extension. > > > > The question is: Do we want these integers to be signextended or not? > > > > What we currently do is this: > > buf[3] += (s8)((s[1] >> 8) & 0x3F); > > > > which will always result in a positive 8bit integer, as far as I can see. > > Which smells fishy. > > We do want sign extension of the signed 6-bit quantities into an 8-bit word. The > translation is correct. Do you know of a better way to extend the signs? Well, I think you got the parenthesis and cast wrong then. I think what we want is the following: + buf[3] += (s8)(((s[1] >> 8) & 0x3F) << 2) >> 2; The code is different and the specs, too. -- Greetings, Michael. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
