On Mon, 29 Jul 2024 at 09:42, Ehrnsperger, Markus <markus_ehrnsper...@yahoo.de> wrote: > > Hi, > > > I'm attaching two files: > > 1.: to_chars10.h: > > This is intended to be included in libstdc++ / gcc to achieve performance > improvements. It is an implementation of > > to_chars10(char* first, char* last, /* integer-type */ value); > > Parameters are identical to std::to_chars(char* first, char* last, /* > integer-type */ value, int base = 10 ); . It only works for base == 10. > > If it is included in libstdc++, to_chars10(...) could be renamed to > std::to_chars(char* first, char* last, /* integer-type */ value) to provide > an overload for the default base = 10
Thanks for the email. This isn't in the form of a patch that we can accept as-is, although I see that the license is compatible with libstdc++, so if you are looking to contribute it then that could be done either by assigning copyright to the FSF or under the DCO terms. See https://gcc.gnu.org/contribute.html#legal for more details. I haven't looked at the code in detail, but is it a similar approach to https://jk-jeon.github.io/posts/2022/02/jeaiii-algorithm/ ? How does it compare to the performance of that algorithm? I have an incomplete implementation of that algorithm for libstdc++ somewhere, but I haven't looked at it for a while. > > 2.: to_chars10.cpp: > > This is a test program for to_chars10 verifying the correctness of the > results, and measuring the performance. The actual performance improvement is > system dependent, so please test on your own system. > > On my system the performance improvement is about factor two, my results are: > > > Test int8_t verifying to_chars10 = std::to_chars ... OK > Test uint8_t verifying to_chars10 = std::to_chars ... OK > Test int16_t verifying to_chars10 = std::to_chars ... OK > Test uint16_t verifying to_chars10 = std::to_chars ... OK > Test int32_t verifying to_chars10 = std::to_chars ... OK > Test uint32_t verifying to_chars10 = std::to_chars ... OK > Test int64_t verifying to_chars10 = std::to_chars ... OK > Test uint64_t verifying to_chars10 = std::to_chars ... OK > > Benchmarking test case tested method ... time (lower is > better) > Benchmarking random unsigned 64 bit to_chars10 ... 0.00957 > Benchmarking random unsigned 64 bit std::to_chars ... 0.01854 > Benchmarking random signed 64 bit to_chars10 ... 0.01018 > Benchmarking random signed 64 bit std::to_chars ... 0.02297 > Benchmarking random unsigned 32 bit to_chars10 ... 0.00620 > Benchmarking random unsigned 32 bit std::to_chars ... 0.01275 > Benchmarking random signed 32 bit to_chars10 ... 0.00783 > Benchmarking random signed 32 bit std::to_chars ... 0.01606 > Benchmarking random unsigned 16 bit to_chars10 ... 0.00536 > Benchmarking random unsigned 16 bit std::to_chars ... 0.00871 > Benchmarking random signed 16 bit to_chars10 ... 0.00664 > Benchmarking random signed 16 bit std::to_chars ... 0.01154 > Benchmarking random unsigned 08 bit to_chars10 ... 0.00393 > Benchmarking random unsigned 08 bit std::to_chars ... 0.00626 > Benchmarking random signed 08 bit to_chars10 ... 0.00465 > Benchmarking random signed 08 bit std::to_chars ... 0.01089 > > > Thanks, Markus > > >
