On 2012-06-26 10:09, Ian Abbott wrote:
On 2012-06-26 01:17, H Hartley Sweeten wrote:@@ -129,7 +124,22 @@ static int das16cs_ai_rinsn(struct comedi_device *dev, outw(devpriv->status1, dev->iobase + 4); devpriv->status2 &= ~0xff00; - devpriv->status2 |= range_bits[range]; + switch (range) { + case 0: + devpriv->status2 |= 0x800; + break; + case 1: + devpriv->status2 |= 0x000; + break; + case 2: + devpriv->status2 |= 0x100; + break; + case 3: + devpriv->status2 |= 0x200; + break; + default: + return -EINVAL; + }Is that really an improvement? The 'range' variable value will be in range anyway (the comedi core checks beforehand in comedi_check_chanlist()), and looking up the constant to OR with devpriv->status2 is probably less object code (and certainly less source code).
I meant looking up the constant in the static array of course. It doesn't really matter if you want to do it this way though, and the `static int range_bits[]` you removed should have been `static const int range_bits[]` anyway.
-- -=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=- -=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=- _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
