On Mon, Jan 12, 2026 at 11:09 AM Bruce Richardson <[email protected]> wrote: > > On Mon, Jan 12, 2026 at 10:40:59AM -0500, [email protected] wrote: > > From: Scott Mitchell <[email protected]> > > > > Modify RTE_PTR_ADD and RTE_PTR_SUB to use char* pointer arithmetic > > instead of uintptr_t casts. Benefits of this approach: > > - API compatibility: works for both integer and pointer inputs > > - Retains simple macros: no pragmas, no _Generic > > - Enables compiler optimizations: Clang now can unroll and vectorize > > pointer loops, and GCC still can apply these optimizations. > > > > Example use case which benefits is __rte_raw_cksum. Performance > > results from cksum_perf_autotest on Intel Xeon (Cascade Lake, > > AVX-512) built with Clang 18.1 (TSC cycles/byte): > > Block size Before After Improvement > > 100 0.40 0.24 ~40% > > 1500 0.50 0.06 ~8x > > 9000 0.49 0.06 ~8x > > > > Signed-off-by: Scott Mitchell <[email protected]> > > --- > > > The macro implementation LGTM > > Acked-by: Bruce Richardson <[email protected]> > > Couple of comments on the unit tests inline below. Most are only > suggestions, so feel free to ignore if you think they aren't worth > considering.
Thanks for the review! I will need a v6 as CI detected compiler/environment combos with errors. I'm trying to thread the needle to find a way to preserve APIs and enable clang optimizations. > Given all the typecasting in the macros, I don't like the casting to > uintptr_t when checking the return values. Maybe use (void *) on the value > being compared-with instead. > > A suggestion: can you maybe put at the top: > > #define test_initval 0x1000 > #define test_increment 100 > #define test_retval ((void *)0x1064)) > > and use those everywhere rather than the hard-coded constants? Sounds good! > Maybe define a new set of macros for small sized ints? Or else just use 100 > and 50 generally, rather than 0x1064? The test should be just as good, > right? I'll use macros for different sizes to catch potential for unexpected truncation. > Very comprehensive set of tests, thanks. No problem!
