> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Tyler Retzlaff > Sent: Saturday, March 13, 2021 2:10 AM > > On Fri, Mar 12, 2021 at 10:13:30PM +0100, Morten Brørup wrote: > > > > > > > > Please also update the similar math functions in rte_common.h, so the > > > return type is consistent across these functions: > > > > - rte_bsf32() > > > > - rte_bsf32_safe() > > > > - rte_fls_u32() > > > > - rte_bsf64() > > > > - rte_fls_u64() > > > > - rte_log2_u32() > > > > - rte_log2_u64() > > > > > > agreed, happy to review the whole set and deal with it all at once. > > > > Ups. I should have omitted rte_bsf32_safe() from the list. It returns a > Boolean. > > if we can agree that we can use C11 as a base we could just do away with > all this dumb 32-bit vs 64-bit static selection at the call site (at > least for rte_bsf32() and rte_bsf64() and probably others). > > i could just introduce the following macro and deprecate the current > inline functions. > > #define rte_bsf(v) \ > (uint32_t)_Generic((v), \ > uint8_t: __builtin_ctz, \ > uint16_t: __builtin_ctz, \ > uint32_t: __builtin_ctz, \ > default: __builtin_ctzll)(v) > > uint8_t a = ...; > uint16_t b = ...; > uint32_t c = ...; > uint64_t d = ...; > > the following would jw as intended, though given the range of the value > that may be returned we could narrow the cast to uint8_t so we don't > have to sprinkle casts in places where usage like uint8_t x = rte_bsf(v); > exists. > > rte_bsf(a); > rte_bsf(b); > rte_bsf(c); > rte_bsf(d); > > anyway, if people care let me know otherwise i'm just going to review > and fix what is already there.
That would certainly be a nice improvement. But going down that road should include reviewing and fixing all DPDK libraries with 32/64 versions of the same functions, e.g. rte_bitops.h - which probably requires a significant effort. So just limit the task to fixing what is already there.
