Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH v2] ice: use min_t() to make code cleaner in ice_gnss | Date | Tue, 22 Mar 2022 18:12:08 +0000 |
| |
From: Alexander Lobakin > Sent: 22 March 2022 17:51 > From: David Laight <David.Laight@ACULAB.COM> > Date: Mon, 21 Mar 2022 16:02:20 +0000 > > > From: Wan Jiabing > > > Sent: 21 March 2022 14:00 > > > > > > Fix the following coccicheck warning: > > > ./drivers/net/ethernet/intel/ice/ice_gnss.c:79:26-27: WARNING opportunity for min() > > > > > > Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> > > > --- > > > Changelog: > > > v2: > > > - Use typeof(bytes_left) instead of u8. > > > --- > > > drivers/net/ethernet/intel/ice/ice_gnss.c | 3 +-- > > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > > > diff --git a/drivers/net/ethernet/intel/ice/ice_gnss.c b/drivers/net/ethernet/intel/ice/ice_gnss.c > > > index 35579cf4283f..57586a2e6dec 100644 > > > --- a/drivers/net/ethernet/intel/ice/ice_gnss.c > > > +++ b/drivers/net/ethernet/intel/ice/ice_gnss.c > > > @@ -76,8 +76,7 @@ static void ice_gnss_read(struct kthread_work *work) > > > for (i = 0; i < data_len; i += bytes_read) { > > > u16 bytes_left = data_len - i; > > > > Oh FFS why is that u16? > > Don't do arithmetic on anything smaller than 'int' > > Any reasoning? I don't say it's good or bad, just want to hear your > arguments (disasms, perf and object code measurements) etc.
Look at the object code on anything except x86. The compiler has to add instruction to mask the value (which is in a full sized register) down to 16 bits after every arithmetic operation.
David
- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
| |