On Sat, Jan 8, 2022 at 10:53 PM Liam Beguin <liambeguin@xxxxxxxxx> wrote: > > The approximation caused by integer divisions can be costly on smaller > scale values since the decimal part is significant compared to the > integer part. Switch to an IIO_VAL_INT_PLUS_NANO scale type in such > cases to maintain accuracy. ... > + tmp = 1 << *val2; Unfortunately, potential UB is still here. I think you missed a subtle detail in the implementation of BIT()/BIT_ULL(). Let's put it here: #define BIT(nr) (UL(1) << (nr)) where #define UL(x) (_UL(x)) #define _UL(x) (_AC(x, UL)) For non-assembler case #define __AC(X,Y) (X##Y) #define _AC(X,Y) __AC(X,Y) Now you may easily see the difference. ... > + rem2 = *val % (int)tmp; > + *val = *val / (int)tmp; > + > + *val2 = rem / (int)tmp; Hmm... You divide s64 by 10^9, which means that the maximum value can be ~10^10 / 2 (because 2^64-1 ~= 10^19), but this _might_ be bigger than 'int' can hold. Can you confirm that tmp can't be so big? -- With Best Regards, Andy Shevchenko
