Messages in this thread | | | From | Bartosz Golaszewski <> | Date | Mon, 2 Nov 2020 11:16:51 +0100 | Subject | Re: [RFT PATCH 5/7] gpio: exar: unduplicate address and offset computation |
| |
On Mon, Oct 26, 2020 at 3:51 PM Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > > On Mon, Oct 26, 2020 at 4:23 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote: > > > > From: Bartosz Golaszewski <bgolaszewski@baylibre.com> > > > > Provide and use helpers for calculating the register address and bit > > offset instead of hand coding it in every function. > > Can you check code generation on x86, for example? > > Sometimes compilers are eager to use idiv assembly instruction which > does simultaneously / and %. > I dunno if a) it's used for / 8 and % 8 since 8 is 2^3, b) splitting > to functions makes the above optimisation impossible. >
Is this optimization really needed though? It's not like it's a hot path if it's protected by a mutex anyway. I prefer cleaner code here.
Bartosz
| |