On Thu, Oct 17, 2024 at 08:18:59PM +0200, Peter Zijlstra wrote: > On Wed, Oct 16, 2024 at 12:44:18PM -0700, Dave Hansen wrote: > > > Would anybody hate if we broke this up a bit, like: > > > > const typeof(var) _val = val; > > const int paoconst = __builtin_constant_p(val); > > const int paoinc = paoconst && ((_val) == 1); > > const int paodec = paoconst && ((_val) == (typeof(var))-1); > > > > and then did > > > > if (paoinc) > > percpu_unary_op(size, qual, "inc", var); > > ... > > I think that is an overall improvement. Proceed! :-) Wouldn't typeof(var) be a regression? The val can be wider (in term of bits) than var and cutting it like this might bring different result depending on the signedness. TL;DR: Whatever is done, please add more (corner) test cases to the percpu_test.c. -- With Best Regards, Andy Shevchenko
