[libc++][format][3/7] Improves std::format performance. #101817
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This patch is the start of a series to improve the speed of std::format, std::format_to, std::format_to_n, and std::formatted_size. This is mostly achieved by changing the __output_buffer class. This new __output_buffer class also makes it easier to implement buffering for P3107R5 "Permit an efficient implementation of std::print"
The formatter specializations for _CharT* and const _CharT* typically write all elements in a loop. This format's internal functions are optimized for larger writes. Instead of writing one element at a time conversion the range to a basic_string_view and write that instead. For C string of 6 characters this is a bit slower, but for 60 characters it's faster. The improvements for back_inserter<std::list<_CharT>> are not as great as the others; it just gets as slow as basic_string_view<_CharT>. Before --------------------------------------------------------------------------------------------------------------- Benchmark Time CPU Iterations --------------------------------------------------------------------------------------------------------------- BM_sprintf/C string len = 6 4.81 ns 4.80 ns 145890280 BM_format/C string len = 6 52.6 ns 52.4 ns 13252327 BM_format_to_back_inserter<std::string>/C string len = 6 53.0 ns 52.8 ns 13262680 BM_format_to_back_inserter<std::vector<char>>/C string len = 6 69.7 ns 69.6 ns 10045636 BM_format_to_back_inserter<std::deque<char>>/C string len = 6 148 ns 148 ns 4729368 BM_format_to_back_inserter<std::list<char>>/C string len = 6 127 ns 126 ns 5538441 BM_format_to_iterator/<std::array> C string len = 6 42.9 ns 42.8 ns 16367158 BM_format_to_iterator/<std::string> C string len = 6 43.5 ns 43.4 ns 16141644 BM_format_to_iterator/<std::vector> C string len = 6 42.9 ns 42.8 ns 16366718 BM_format_to_iterator/<std::deque> C string len = 6 47.8 ns 47.7 ns 14686488 BM_format/string len = 6 55.3 ns 55.2 ns 12696889 BM_format_to_back_inserter<std::string>/string len = 6 55.4 ns 55.2 ns 12660731 BM_format_to_back_inserter<std::vector<char>>/string len = 6 70.7 ns 70.5 ns 9927313 BM_format_to_back_inserter<std::deque<char>>/string len = 6 153 ns 153 ns 4573936 BM_format_to_back_inserter<std::list<char>>/string len = 6 128 ns 128 ns 5486033 BM_format_to_iterator/<std::array> string len = 6 44.6 ns 44.5 ns 15758122 BM_format_to_iterator/<std::string> string len = 6 44.7 ns 44.6 ns 15690226 BM_format_to_iterator/<std::vector> string len = 6 44.3 ns 44.2 ns 15715898 BM_format_to_iterator/<std::deque> string len = 6 50.3 ns 50.1 ns 13958635 BM_format/string_view len = 6 54.2 ns 54.1 ns 12929525 BM_format_to_back_inserter<std::string>/string_view len = 6 54.3 ns 54.1 ns 12929219 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6 70.0 ns 69.8 ns 10022355 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6 153 ns 152 ns 4585749 BM_format_to_back_inserter<std::list<char>>/string_view len = 6 128 ns 128 ns 5489760 BM_format_to_iterator/<std::array> string_view len = 6 44.2 ns 44.1 ns 15884839 BM_format_to_iterator/<std::string> string_view len = 6 44.8 ns 44.6 ns 15664278 BM_format_to_iterator/<std::vector> string_view len = 6 44.7 ns 44.6 ns 15716983 BM_format_to_iterator/<std::deque> string_view len = 6 50.3 ns 50.2 ns 13936091 BM_sprintf/C string len = 60 4.16 ns 4.15 ns 168764227 BM_format/C string len = 60 169 ns 169 ns 4144060 BM_format_to_back_inserter<std::string>/C string len = 60 167 ns 167 ns 4203915 BM_format_to_back_inserter<std::vector<char>>/C string len = 60 177 ns 176 ns 3965619 BM_format_to_back_inserter<std::deque<char>>/C string len = 60 383 ns 382 ns 1832531 BM_format_to_back_inserter<std::list<char>>/C string len = 60 1270 ns 1267 ns 552686 BM_format_to_iterator/<std::array> C string len = 60 141 ns 140 ns 4988441 BM_format_to_iterator/<std::string> C string len = 60 141 ns 141 ns 4956101 BM_format_to_iterator/<std::vector> C string len = 60 141 ns 141 ns 4963443 BM_format_to_iterator/<std::deque> C string len = 60 144 ns 143 ns 4893139 BM_format/string len = 60 73.4 ns 73.2 ns 9548455 BM_format_to_back_inserter<std::string>/string len = 60 73.2 ns 73.0 ns 9524524 BM_format_to_back_inserter<std::vector<char>>/string len = 60 81.6 ns 81.4 ns 8584033 BM_format_to_back_inserter<std::deque<char>>/string len = 60 279 ns 279 ns 2515146 BM_format_to_back_inserter<std::list<char>>/string len = 60 1177 ns 1174 ns 597172 BM_format_to_iterator/<std::array> string len = 60 44.5 ns 44.4 ns 15753131 BM_format_to_iterator/<std::string> string len = 60 44.7 ns 44.6 ns 15692630 BM_format_to_iterator/<std::vector> string len = 60 44.8 ns 44.7 ns 15664689 BM_format_to_iterator/<std::deque> string len = 60 50.6 ns 50.5 ns 13838617 BM_format/string_view len = 60 72.8 ns 72.6 ns 9674007 BM_format_to_back_inserter<std::string>/string_view len = 60 72.7 ns 72.6 ns 9638209 BM_format_to_back_inserter<std::vector<char>>/string_view len = 60 82.6 ns 82.4 ns 8496602 BM_format_to_back_inserter<std::deque<char>>/string_view len = 60 280 ns 280 ns 2508982 BM_format_to_back_inserter<std::list<char>>/string_view len = 60 1176 ns 1173 ns 597714 BM_format_to_iterator/<std::array> string_view len = 60 44.2 ns 44.1 ns 15896934 BM_format_to_iterator/<std::string> string_view len = 60 44.7 ns 44.6 ns 15695427 BM_format_to_iterator/<std::vector> string_view len = 60 44.7 ns 44.6 ns 15680899 BM_format_to_iterator/<std::deque> string_view len = 60 50.3 ns 50.1 ns 13962755 BM_sprintf/C string len = 6000 114 ns 114 ns 6170153 BM_format/C string len = 6000 11792 ns 11763 ns 59619 BM_format_to_back_inserter<std::string>/C string len = 6000 11778 ns 11746 ns 59572 BM_format_to_back_inserter<std::vector<char>>/C string len = 6000 11715 ns 11686 ns 60053 BM_format_to_back_inserter<std::deque<char>>/C string len = 6000 25464 ns 25403 ns 27538 BM_format_to_back_inserter<std::list<char>>/C string len = 6000 126044 ns 125726 ns 5572 BM_format_to_iterator/<std::array> C string len = 6000 10792 ns 10766 ns 64943 BM_format_to_iterator/<std::string> C string len = 6000 10791 ns 10761 ns 64918 BM_format_to_iterator/<std::vector> C string len = 6000 10775 ns 10750 ns 65149 BM_format_to_iterator/<std::deque> C string len = 6000 11242 ns 11215 ns 62542 BM_format/string len = 6000 919 ns 917 ns 763961 BM_format_to_back_inserter<std::string>/string len = 6000 920 ns 917 ns 763094 BM_format_to_back_inserter<std::vector<char>>/string len = 6000 888 ns 886 ns 793468 BM_format_to_back_inserter<std::deque<char>>/string len = 6000 14999 ns 14963 ns 46758 BM_format_to_back_inserter<std::list<char>>/string len = 6000 114504 ns 114213 ns 6130 BM_format_to_iterator/<std::array> string len = 6000 120 ns 120 ns 5823426 BM_format_to_iterator/<std::string> string len = 6000 106 ns 106 ns 6609299 BM_format_to_iterator/<std::vector> string len = 6000 106 ns 106 ns 6613867 BM_format_to_iterator/<std::deque> string len = 6000 367 ns 366 ns 1912818 BM_format/string_view len = 6000 910 ns 907 ns 771491 BM_format_to_back_inserter<std::string>/string_view len = 6000 911 ns 909 ns 770065 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6000 878 ns 876 ns 794976 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6000 15031 ns 14994 ns 46651 BM_format_to_back_inserter<std::list<char>>/string_view len = 6000 114510 ns 114219 ns 6130 BM_format_to_iterator/<std::array> string_view len = 6000 121 ns 120 ns 5814249 BM_format_to_iterator/<std::string> string_view len = 6000 116 ns 115 ns 6072315 BM_format_to_iterator/<std::vector> string_view len = 6000 115 ns 115 ns 6095762 BM_format_to_iterator/<std::deque> string_view len = 6000 351 ns 350 ns 2002175 After --------------------------------------------------------------------------------------------------------------- Benchmark Time CPU Iterations --------------------------------------------------------------------------------------------------------------- BM_sprintf/C string len = 6 4.83 ns 4.83 ns 145502957 BM_format/C string len = 6 55.1 ns 55.1 ns 12687656 BM_format_to_back_inserter<std::string>/C string len = 6 55.1 ns 55.1 ns 12691642 BM_format_to_back_inserter<std::vector<char>>/C string len = 6 71.2 ns 71.3 ns 9819560 BM_format_to_back_inserter<std::deque<char>>/C string len = 6 154 ns 154 ns 4548709 BM_format_to_back_inserter<std::list<char>>/C string len = 6 131 ns 131 ns 5338318 BM_format_to_iterator/<std::array> C string len = 6 45.0 ns 45.0 ns 15569429 BM_format_to_iterator/<std::string> C string len = 6 45.9 ns 45.9 ns 15240594 BM_format_to_iterator/<std::vector> C string len = 6 44.4 ns 44.4 ns 15768343 BM_format_to_iterator/<std::deque> C string len = 6 50.1 ns 50.1 ns 13995837 BM_format/string len = 6 54.8 ns 54.8 ns 12738209 BM_format_to_back_inserter<std::string>/string len = 6 55.4 ns 55.4 ns 12634483 BM_format_to_back_inserter<std::vector<char>>/string len = 6 70.4 ns 70.4 ns 9948288 BM_format_to_back_inserter<std::deque<char>>/string len = 6 154 ns 154 ns 4531741 BM_format_to_back_inserter<std::list<char>>/string len = 6 132 ns 132 ns 5289798 BM_format_to_iterator/<std::array> string len = 6 44.5 ns 44.5 ns 15743437 BM_format_to_iterator/<std::string> string len = 6 44.9 ns 44.9 ns 15591961 BM_format_to_iterator/<std::vector> string len = 6 45.0 ns 45.0 ns 15541308 BM_format_to_iterator/<std::deque> string len = 6 50.5 ns 50.5 ns 13837884 BM_format/string_view len = 6 54.5 ns 54.5 ns 12833591 BM_format_to_back_inserter<std::string>/string_view len = 6 54.6 ns 54.6 ns 12818233 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6 69.9 ns 69.9 ns 10018025 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6 154 ns 154 ns 4534215 BM_format_to_back_inserter<std::list<char>>/string_view len = 6 131 ns 131 ns 5337938 BM_format_to_iterator/<std::array> string_view len = 6 44.2 ns 44.2 ns 15854695 BM_format_to_iterator/<std::string> string_view len = 6 45.0 ns 45.0 ns 15551054 BM_format_to_iterator/<std::vector> string_view len = 6 45.0 ns 45.0 ns 15567905 BM_format_to_iterator/<std::deque> string_view len = 6 50.5 ns 50.5 ns 13858261 BM_sprintf/C string len = 60 4.16 ns 4.16 ns 168066307 BM_format/C string len = 60 73.8 ns 73.8 ns 9487364 BM_format_to_back_inserter<std::string>/C string len = 60 73.7 ns 73.7 ns 9492371 BM_format_to_back_inserter<std::vector<char>>/C string len = 60 83.1 ns 83.1 ns 8399017 BM_format_to_back_inserter<std::deque<char>>/C string len = 60 284 ns 284 ns 2466510 BM_format_to_back_inserter<std::list<char>>/C string len = 60 1177 ns 1177 ns 592514 BM_format_to_iterator/<std::array> C string len = 60 44.9 ns 44.9 ns 15558172 BM_format_to_iterator/<std::string> C string len = 60 45.8 ns 45.8 ns 15283103 BM_format_to_iterator/<std::vector> C string len = 60 44.6 ns 44.6 ns 15678967 BM_format_to_iterator/<std::deque> C string len = 60 50.5 ns 50.5 ns 13839524 BM_format/string len = 60 72.2 ns 72.2 ns 9687634 BM_format_to_back_inserter<std::string>/string len = 60 72.0 ns 72.1 ns 9695746 BM_format_to_back_inserter<std::vector<char>>/string len = 60 82.3 ns 82.3 ns 8509528 BM_format_to_back_inserter<std::deque<char>>/string len = 60 279 ns 279 ns 2506108 BM_format_to_back_inserter<std::list<char>>/string len = 60 1180 ns 1180 ns 592963 BM_format_to_iterator/<std::array> string len = 60 44.7 ns 44.7 ns 15657865 BM_format_to_iterator/<std::string> string len = 60 45.0 ns 45.0 ns 15569049 BM_format_to_iterator/<std::vector> string len = 60 44.9 ns 44.9 ns 15576187 BM_format_to_iterator/<std::deque> string len = 60 50.7 ns 50.7 ns 13803188 BM_format/string_view len = 60 72.4 ns 72.4 ns 9663061 BM_format_to_back_inserter<std::string>/string_view len = 60 72.8 ns 72.8 ns 9638941 BM_format_to_back_inserter<std::vector<char>>/string_view len = 60 81.9 ns 81.9 ns 8529931 BM_format_to_back_inserter<std::deque<char>>/string_view len = 60 283 ns 283 ns 2471522 BM_format_to_back_inserter<std::list<char>>/string_view len = 60 1177 ns 1177 ns 594752 BM_format_to_iterator/<std::array> string_view len = 60 44.2 ns 44.2 ns 15841413 BM_format_to_iterator/<std::string> string_view len = 60 45.1 ns 45.1 ns 15546279 BM_format_to_iterator/<std::vector> string_view len = 60 45.0 ns 45.0 ns 15555756 BM_format_to_iterator/<std::deque> string_view len = 60 50.1 ns 50.1 ns 10000000 BM_sprintf/C string len = 6000 344 ns 344 ns 2037753 BM_format/C string len = 6000 980 ns 980 ns 713341 BM_format_to_back_inserter<std::string>/C string len = 6000 979 ns 979 ns 709571 BM_format_to_back_inserter<std::vector<char>>/C string len = 6000 944 ns 944 ns 744518 BM_format_to_back_inserter<std::deque<char>>/C string len = 6000 14916 ns 14915 ns 46875 BM_format_to_back_inserter<std::list<char>>/C string len = 6000 114686 ns 114688 ns 6110 BM_format_to_iterator/<std::array> C string len = 6000 159 ns 159 ns 4394506 BM_format_to_iterator/<std::string> C string len = 6000 159 ns 159 ns 4384577 BM_format_to_iterator/<std::vector> C string len = 6000 159 ns 159 ns 4393225 BM_format_to_iterator/<std::deque> C string len = 6000 437 ns 437 ns 1601253 BM_format/string len = 6000 929 ns 929 ns 751889 BM_format_to_back_inserter<std::string>/string len = 6000 933 ns 933 ns 752042 BM_format_to_back_inserter<std::vector<char>>/string len = 6000 892 ns 892 ns 785064 BM_format_to_back_inserter<std::deque<char>>/string len = 6000 14840 ns 14839 ns 47177 BM_format_to_back_inserter<std::list<char>>/string len = 6000 114940 ns 114942 ns 6095 BM_format_to_iterator/<std::array> string len = 6000 144 ns 144 ns 4859849 BM_format_to_iterator/<std::string> string len = 6000 106 ns 106 ns 6565564 BM_format_to_iterator/<std::vector> string len = 6000 107 ns 107 ns 6584152 BM_format_to_iterator/<std::deque> string len = 6000 368 ns 368 ns 1904727 BM_format/string_view len = 6000 919 ns 919 ns 760401 BM_format_to_back_inserter<std::string>/string_view len = 6000 917 ns 917 ns 760934 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6000 880 ns 880 ns 796244 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6000 14854 ns 14853 ns 47101 BM_format_to_back_inserter<std::list<char>>/string_view len = 6000 114963 ns 114967 ns 6086 BM_format_to_iterator/<std::array> string_view len = 6000 117 ns 117 ns 5974080 BM_format_to_iterator/<std::string> string_view len = 6000 116 ns 116 ns 6016080 BM_format_to_iterator/<std::vector> string_view len = 6000 116 ns 116 ns 6053780 BM_format_to_iterator/<std::deque> string_view len = 6000 351 ns 351 ns 1993879 Comparing libcxx/benchmarks/1/write_string_comparison.bench.out to libcxx/benchmarks/2/write_string_comparison.bench.out Benchmark Time CPU Time Old Time New CPU Old CPU New ------------------------------------------------------------------------------------------------------------------------------------------------------------------- BM_sprintf/C string len = 6 +0.0034 +0.0058 5 5 5 5 BM_format/C string len = 6 +0.0484 +0.0508 53 55 52 55 BM_format_to_back_inserter<std::string>/C string len = 6 +0.0395 +0.0424 53 55 53 55 BM_format_to_back_inserter<std::vector<char>>/C string len = 6 +0.0220 +0.0244 70 71 70 71 BM_format_to_back_inserter<std::deque<char>>/C string len = 6 +0.0399 +0.0424 148 154 148 154 BM_format_to_back_inserter<std::list<char>>/C string len = 6 +0.0339 +0.0365 127 131 126 131 BM_format_to_iterator/<std::array> C string len = 6 +0.0494 +0.0520 43 45 43 45 BM_format_to_iterator/<std::string> C string len = 6 +0.0539 +0.0568 44 46 43 46 BM_format_to_iterator/<std::vector> C string len = 6 +0.0359 +0.0384 43 44 43 44 BM_format_to_iterator/<std::deque> C string len = 6 +0.0488 +0.0513 48 50 48 50 BM_format/string len = 6 -0.0105 -0.0081 55 55 55 55 BM_format_to_back_inserter<std::string>/string len = 6 +0.0008 +0.0036 55 55 55 55 BM_format_to_back_inserter<std::vector<char>>/string len = 6 -0.0046 -0.0021 71 70 71 70 BM_format_to_back_inserter<std::deque<char>>/string len = 6 +0.0066 +0.0091 153 154 153 154 BM_format_to_back_inserter<std::list<char>>/string len = 6 +0.0291 +0.0316 128 132 128 132 BM_format_to_iterator/<std::array> string len = 6 -0.0030 -0.0006 45 44 44 44 BM_format_to_iterator/<std::string> string len = 6 +0.0045 +0.0069 45 45 45 45 BM_format_to_iterator/<std::vector> string len = 6 +0.0150 +0.0177 44 45 44 45 BM_format_to_iterator/<std::deque> string len = 6 +0.0059 +0.0084 50 51 50 51 BM_format/string_view len = 6 +0.0050 +0.0075 54 55 54 55 BM_format_to_back_inserter<std::string>/string_view len = 6 +0.0052 +0.0081 54 55 54 55 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6 -0.0017 +0.0008 70 70 70 70 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6 +0.0113 +0.0137 153 154 152 154 BM_format_to_back_inserter<std::list<char>>/string_view len = 6 +0.0260 +0.0286 128 131 128 131 BM_format_to_iterator/<std::array> string_view len = 6 -0.0006 +0.0021 44 44 44 44 BM_format_to_iterator/<std::string> string_view len = 6 +0.0059 +0.0084 45 45 45 45 BM_format_to_iterator/<std::vector> string_view len = 6 +0.0083 +0.0108 45 45 45 45 BM_format_to_iterator/<std::deque> string_view len = 6 +0.0048 +0.0073 50 51 50 51 BM_sprintf/C string len = 60 +0.0002 +0.0029 4 4 4 4 BM_format/C string len = 60 -0.5640 -0.5629 169 74 169 74 BM_format_to_back_inserter<std::string>/C string len = 60 -0.5592 -0.5582 167 74 167 74 BM_format_to_back_inserter<std::vector<char>>/C string len = 60 -0.5294 -0.5282 177 83 176 83 BM_format_to_back_inserter<std::deque<char>>/C string len = 60 -0.2591 -0.2570 383 284 382 284 BM_format_to_back_inserter<std::list<char>>/C string len = 60 -0.0730 -0.0707 1270 1177 1267 1177 BM_format_to_iterator/<std::array> C string len = 60 -0.6804 -0.6797 141 45 140 45 BM_format_to_iterator/<std::string> C string len = 60 -0.6759 -0.6750 141 46 141 46 BM_format_to_iterator/<std::vector> C string len = 60 -0.6849 -0.6841 141 45 141 45 BM_format_to_iterator/<std::deque> C string len = 60 -0.6481 -0.6471 144 51 143 51 BM_format/string len = 60 -0.0167 -0.0142 73 72 73 72 BM_format_to_back_inserter<std::string>/string len = 60 -0.0151 -0.0127 73 72 73 72 BM_format_to_back_inserter<std::vector<char>>/string len = 60 +0.0093 +0.0118 82 82 81 82 BM_format_to_back_inserter<std::deque<char>>/string len = 60 -0.0003 +0.0023 279 279 279 279 BM_format_to_back_inserter<std::list<char>>/string len = 60 +0.0025 +0.0050 1177 1180 1174 1180 BM_format_to_iterator/<std::array> string len = 60 +0.0046 +0.0070 45 45 44 45 BM_format_to_iterator/<std::string> string len = 60 +0.0050 +0.0075 45 45 45 45 BM_format_to_iterator/<std::vector> string len = 60 +0.0025 +0.0051 45 45 45 45 BM_format_to_iterator/<std::deque> string len = 60 +0.0031 +0.0056 51 51 50 51 BM_format/string_view len = 60 -0.0054 -0.0030 73 72 73 72 BM_format_to_back_inserter<std::string>/string_view len = 60 +0.0001 +0.0026 73 73 73 73 BM_format_to_back_inserter<std::vector<char>>/string_view len = 60 -0.0090 -0.0066 83 82 82 82 BM_format_to_back_inserter<std::deque<char>>/string_view len = 60 +0.0097 +0.0126 280 283 280 283 BM_format_to_back_inserter<std::list<char>>/string_view len = 60 +0.0011 +0.0036 1176 1177 1173 1177 BM_format_to_iterator/<std::array> string_view len = 60 +0.0001 +0.0026 44 44 44 44 BM_format_to_iterator/<std::string> string_view len = 60 +0.0083 +0.0107 45 45 45 45 BM_format_to_iterator/<std::vector> string_view len = 60 +0.0068 +0.0093 45 45 45 45 BM_format_to_iterator/<std::deque> string_view len = 60 -0.0038 -0.0014 50 50 50 50 BM_sprintf/C string len = 6000 +2.0230 +2.0305 114 344 114 344 BM_format/C string len = 6000 -0.9169 -0.9167 11792 980 11763 980 BM_format_to_back_inserter<std::string>/C string len = 6000 -0.9169 -0.9166 11778 979 11746 979 BM_format_to_back_inserter<std::vector<char>>/C string len = 6000 -0.9194 -0.9192 11715 944 11686 944 BM_format_to_back_inserter<std::deque<char>>/C string len = 6000 -0.4143 -0.4129 25464 14916 25403 14915 BM_format_to_back_inserter<std::list<char>>/C string len = 6000 -0.0901 -0.0878 126044 114686 125726 114688 BM_format_to_iterator/<std::array> C string len = 6000 -0.9852 -0.9852 10792 159 10766 159 BM_format_to_iterator/<std::string> C string len = 6000 -0.9852 -0.9852 10791 159 10761 159 BM_format_to_iterator/<std::vector> C string len = 6000 -0.9852 -0.9852 10775 159 10750 159 BM_format_to_iterator/<std::deque> C string len = 6000 -0.9611 -0.9610 11242 437 11215 437 BM_format/string len = 6000 +0.0108 +0.0133 919 929 917 929 BM_format_to_back_inserter<std::string>/string len = 6000 +0.0138 +0.0167 920 933 917 933 BM_format_to_back_inserter<std::vector<char>>/string len = 6000 +0.0041 +0.0064 888 892 886 892 BM_format_to_back_inserter<std::deque<char>>/string len = 6000 -0.0107 -0.0082 14999 14840 14963 14839 BM_format_to_back_inserter<std::list<char>>/string len = 6000 +0.0038 +0.0064 114504 114940 114213 114942 BM_format_to_iterator/<std::array> string len = 6000 +0.2011 +0.2040 120 144 120 144 BM_format_to_iterator/<std::string> string len = 6000 +0.0032 +0.0057 106 106 106 106 BM_format_to_iterator/<std::vector> string len = 6000 +0.0057 +0.0085 106 107 106 107 BM_format_to_iterator/<std::deque> string len = 6000 +0.0011 +0.0036 367 368 366 368 BM_format/string_view len = 6000 +0.0105 +0.0130 910 919 907 919 BM_format_to_back_inserter<std::string>/string_view len = 6000 +0.0057 +0.0081 911 917 909 917 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6000 +0.0023 +0.0050 878 880 876 880 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6000 -0.0118 -0.0094 15031 14854 14994 14853 BM_format_to_back_inserter<std::list<char>>/string_view len = 6000 +0.0040 +0.0065 114510 114963 114219 114967 BM_format_to_iterator/<std::array> string_view len = 6000 -0.0299 -0.0275 121 117 120 117 BM_format_to_iterator/<std::string> string_view len = 6000 +0.0062 +0.0086 116 116 115 116 BM_format_to_iterator/<std::vector> string_view len = 6000 +0.0034 +0.0062 115 116 115 116 BM_format_to_iterator/<std::deque> string_view len = 6000 +0.0011 +0.0035 351 351 350 351 OVERALL_GEOMEAN -0.2959 -0.2941 0 0 0 0
llvmbot
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libc++
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@llvm/pr-subscribers-libcxx Author: Mark de Wever (mordante) ChangesThis changes the __output_buffer to a new structure. Since the other formatting fucntions std::format_to, std::format_to_n, and std::formatted_size still use the old codepaths the class is in a transition state. At the end of the series the class should be in its final state. write_double_comparison: BeforeBenchmark Time CPU IterationsBM_sprintf 197 ns 196 ns 3550000 AfterBenchmark Time CPU IterationsBM_sprintf 197 ns 197 ns 3550000 Comparison
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| /// The original design (as shipped up to LLVM-19) uses the following design: | ||
| /// - There is an external object that connects the buffer to the output. | ||
| /// - The class constructor stores a function pointer to a grow function and a | ||
| /// type-erased pointer to the object that does the grow. | ||
| /// - When writing data to the buffer would exceed the external buffer's | ||
| /// capacity it requests the external buffer to flush its contents. |
There was a problem hiding this comment.
Note the last patch in the series will remove this comment.
The implementation itself is in a transition state too, this also will be cleaned in the final patch of the series.
This changes the __output_buffer to a new structure. Since the other formatting fucntions std::format_to, std::format_to_n, and std::formatted_size still use the old codepaths the class is in a transition state. At the end of the series the class should be in its final state. write_double_comparison: Before ---------------------------------------------------------------------------------------- Benchmark Time CPU Iterations ---------------------------------------------------------------------------------------- BM_sprintf 197 ns 196 ns 3550000 BM_to_string 218 ns 218 ns 3214000 BM_to_chars 42.4 ns 42.3 ns 16575000 BM_to_chars_as_string 48.2 ns 48.1 ns 14542000 BM_format 175 ns 175 ns 4000000 BM_format_to_back_inserter<std::string> 175 ns 175 ns 3995000 BM_format_to_back_inserter<std::vector<char>> 207 ns 206 ns 3393000 BM_format_to_back_inserter<std::list<char>> 752 ns 750 ns 931000 BM_format_to_iterator/<std::array> 161 ns 161 ns 4345000 BM_format_to_iterator/<std::string> 161 ns 161 ns 4344000 BM_format_to_iterator/<std::vector> 162 ns 161 ns 4344000 After ---------------------------------------------------------------------------------------- Benchmark Time CPU Iterations ---------------------------------------------------------------------------------------- BM_sprintf 197 ns 197 ns 3550000 BM_to_string 219 ns 219 ns 3199000 BM_to_chars 42.4 ns 42.4 ns 16554000 BM_to_chars_as_string 48.1 ns 48.1 ns 14569000 BM_format 167 ns 167 ns 4203000 BM_format_to_back_inserter<std::string> 179 ns 179 ns 3920000 BM_format_to_back_inserter<std::vector<char>> 214 ns 214 ns 3274000 BM_format_to_back_inserter<std::list<char>> 751 ns 751 ns 930000 BM_format_to_iterator/<std::array> 164 ns 164 ns 4258000 BM_format_to_iterator/<std::string> 165 ns 164 ns 4247000 BM_format_to_iterator/<std::vector> 165 ns 165 ns 4248000 Comparison Benchmark Time CPU Time Old Time New CPU Old CPU New -------------------------------------------------------------------------------------------------------------------------------------------- BM_sprintf +0.0013 +0.0028 197 197 196 197 BM_to_string +0.0023 +0.0038 218 219 218 219 BM_to_chars +0.0014 +0.0030 42 42 42 42 BM_to_chars_as_string -0.0025 -0.0010 48 48 48 48 BM_format -0.0476 -0.0462 175 167 175 167 BM_format_to_back_inserter<std::string> +0.0190 +0.0205 175 179 175 179 BM_format_to_back_inserter<std::vector<char>> +0.0348 +0.0363 207 214 206 214 BM_format_to_back_inserter<std::list<char>> -0.0013 +0.0005 752 751 750 751 BM_format_to_iterator/<std::array> +0.0188 +0.0203 161 164 161 164 BM_format_to_iterator/<std::string> +0.0207 +0.0226 161 165 161 164 BM_format_to_iterator/<std::vector> +0.0197 +0.0212 162 165 161 165 OVERALL_GEOMEAN +0.0058 +0.0074 0 0 0 0 write_int_comparison: Before ---------------------------------------------------------------------------------------- Benchmark Time CPU Iterations ---------------------------------------------------------------------------------------- BM_sprintf 79.6 ns 79.5 ns 8739000 BM_to_string 14.9 ns 14.9 ns 46713000 BM_to_chars 5.68 ns 5.67 ns 120614000 BM_to_chars_as_string 14.2 ns 14.1 ns 49513000 BM_format 69.3 ns 69.2 ns 10105000 BM_format_to_back_inserter<std::string> 69.2 ns 69.1 ns 10138000 BM_format_to_back_inserter<std::vector<char>> 90.6 ns 90.5 ns 7728000 BM_format_to_back_inserter<std::list<char>> 234 ns 234 ns 2986000 BM_format_to_iterator/<std::array> 59.3 ns 59.3 ns 11805000 BM_format_to_iterator/<std::string> 58.7 ns 58.6 ns 11943000 BM_format_to_iterator/<std::vector> 60.1 ns 60.1 ns 11670000 After ---------------------------------------------------------------------------------------- Benchmark Time CPU Iterations ---------------------------------------------------------------------------------------- BM_sprintf 80.2 ns 80.2 ns 8670000 BM_to_string 15.0 ns 15.0 ns 46559000 BM_to_chars 4.93 ns 4.93 ns 138016000 BM_to_chars_as_string 15.4 ns 15.4 ns 45415000 BM_format 62.1 ns 62.0 ns 11316000 BM_format_to_back_inserter<std::string> 70.2 ns 70.2 ns 9962000 BM_format_to_back_inserter<std::vector<char>> 92.8 ns 92.8 ns 7544000 BM_format_to_back_inserter<std::list<char>> 240 ns 240 ns 2917000 BM_format_to_iterator/<std::array> 60.5 ns 60.5 ns 11572000 BM_format_to_iterator/<std::string> 60.2 ns 60.2 ns 11653000 BM_format_to_iterator/<std::vector> 60.1 ns 60.1 ns 11659000 Comparison Benchmark Time CPU Time Old Time New CPU Old CPU New -------------------------------------------------------------------------------------------------------------------------------------------- BM_sprintf +0.0072 +0.0081 80 80 80 80 BM_to_string +0.0043 +0.0053 15 15 15 15 BM_to_chars -0.1324 -0.1316 6 5 6 5 BM_to_chars_as_string +0.0895 +0.0906 14 15 14 15 BM_format -0.1047 -0.1040 69 62 69 62 BM_format_to_back_inserter<std::string> +0.0148 +0.0157 69 70 69 70 BM_format_to_back_inserter<std::vector<char>> +0.0241 +0.0251 91 93 90 93 BM_format_to_back_inserter<std::list<char>> +0.0222 +0.0232 234 240 234 240 BM_format_to_iterator/<std::array> +0.0196 +0.0205 59 60 59 60 BM_format_to_iterator/<std::string> +0.0266 +0.0275 59 60 59 60 BM_format_to_iterator/<std::vector> -0.0004 +0.0005 60 60 60 60 OVERALL_GEOMEAN -0.0045 -0.0036 0 0 0 0 write_string_comparison: Before --------------------------------------------------------------------------------------------------------------- Benchmark Time CPU Iterations --------------------------------------------------------------------------------------------------------------- BM_sprintf/C string len = 6 4.82 ns 4.82 ns 145548481 BM_format/C string len = 6 55.1 ns 55.1 ns 12713693 BM_format_to_back_inserter<std::string>/C string len = 6 55.1 ns 55.1 ns 12690821 BM_format_to_back_inserter<std::vector<char>>/C string len = 6 71.5 ns 71.5 ns 9805550 BM_format_to_back_inserter<std::deque<char>>/C string len = 6 154 ns 154 ns 4536256 BM_format_to_back_inserter<std::list<char>>/C string len = 6 130 ns 130 ns 5348845 BM_format_to_iterator/<std::array> C string len = 6 44.9 ns 44.9 ns 15556175 BM_format_to_iterator/<std::string> C string len = 6 45.8 ns 45.8 ns 15290662 BM_format_to_iterator/<std::vector> C string len = 6 44.4 ns 44.4 ns 15807704 BM_format_to_iterator/<std::deque> C string len = 6 50.0 ns 50.0 ns 13973893 BM_format/string len = 6 54.7 ns 54.7 ns 12793406 BM_format_to_back_inserter<std::string>/string len = 6 55.5 ns 55.5 ns 12620370 BM_format_to_back_inserter<std::vector<char>>/string len = 6 70.4 ns 70.4 ns 9936490 BM_format_to_back_inserter<std::deque<char>>/string len = 6 155 ns 155 ns 4521357 BM_format_to_back_inserter<std::list<char>>/string len = 6 135 ns 135 ns 5201519 BM_format_to_iterator/<std::array> string len = 6 44.6 ns 44.6 ns 15703872 BM_format_to_iterator/<std::string> string len = 6 45.0 ns 45.0 ns 15545182 BM_format_to_iterator/<std::vector> string len = 6 45.0 ns 45.0 ns 15539130 BM_format_to_iterator/<std::deque> string len = 6 50.5 ns 50.5 ns 13846916 BM_format/string_view len = 6 54.6 ns 54.6 ns 12821301 BM_format_to_back_inserter<std::string>/string_view len = 6 54.6 ns 54.6 ns 12827673 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6 69.9 ns 69.9 ns 9958365 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6 157 ns 157 ns 4462445 BM_format_to_back_inserter<std::list<char>>/string_view len = 6 134 ns 134 ns 5232155 BM_format_to_iterator/<std::array> string_view len = 6 44.2 ns 44.2 ns 15871362 BM_format_to_iterator/<std::string> string_view len = 6 45.0 ns 45.0 ns 15582582 BM_format_to_iterator/<std::vector> string_view len = 6 45.1 ns 45.1 ns 15539906 BM_format_to_iterator/<std::deque> string_view len = 6 50.5 ns 50.5 ns 13896524 BM_sprintf/C string len = 60 4.15 ns 4.15 ns 168165776 BM_format/C string len = 60 73.8 ns 73.8 ns 9498291 BM_format_to_back_inserter<std::string>/C string len = 60 73.6 ns 73.6 ns 9535890 BM_format_to_back_inserter<std::vector<char>>/C string len = 60 83.1 ns 83.1 ns 8428154 BM_format_to_back_inserter<std::deque<char>>/C string len = 60 281 ns 281 ns 2490093 BM_format_to_back_inserter<std::list<char>>/C string len = 60 1157 ns 1157 ns 605227 BM_format_to_iterator/<std::array> C string len = 60 44.9 ns 44.9 ns 15604442 BM_format_to_iterator/<std::string> C string len = 60 45.8 ns 45.8 ns 15272196 BM_format_to_iterator/<std::vector> C string len = 60 44.6 ns 44.7 ns 15683193 BM_format_to_iterator/<std::deque> C string len = 60 50.6 ns 50.6 ns 13698382 BM_format/string len = 60 72.3 ns 72.3 ns 9648955 BM_format_to_back_inserter<std::string>/string len = 60 72.0 ns 72.0 ns 9738373 BM_format_to_back_inserter<std::vector<char>>/string len = 60 82.3 ns 82.3 ns 8517896 BM_format_to_back_inserter<std::deque<char>>/string len = 60 280 ns 280 ns 2496054 BM_format_to_back_inserter<std::list<char>>/string len = 60 1162 ns 1162 ns 602383 BM_format_to_iterator/<std::array> string len = 60 44.5 ns 44.5 ns 15727799 BM_format_to_iterator/<std::string> string len = 60 49.6 ns 49.6 ns 14096012 BM_format_to_iterator/<std::vector> string len = 60 49.8 ns 49.8 ns 14053734 BM_format_to_iterator/<std::deque> string len = 60 50.8 ns 50.8 ns 13801448 BM_format/string_view len = 60 72.5 ns 72.5 ns 9653638 BM_format_to_back_inserter<std::string>/string_view len = 60 72.7 ns 72.7 ns 9598203 BM_format_to_back_inserter<std::vector<char>>/string_view len = 60 81.9 ns 81.9 ns 8522306 BM_format_to_back_inserter<std::deque<char>>/string_view len = 60 283 ns 283 ns 2475014 BM_format_to_back_inserter<std::list<char>>/string_view len = 60 1162 ns 1162 ns 600924 BM_format_to_iterator/<std::array> string_view len = 60 44.1 ns 44.1 ns 15858951 BM_format_to_iterator/<std::string> string_view len = 60 44.9 ns 44.9 ns 15579340 BM_format_to_iterator/<std::vector> string_view len = 60 44.9 ns 44.9 ns 15586711 BM_format_to_iterator/<std::deque> string_view len = 60 50.0 ns 50.0 ns 13980804 BM_sprintf/C string len = 6000 116 ns 116 ns 6051541 BM_format/C string len = 6000 1000 ns 1000 ns 698647 BM_format_to_back_inserter<std::string>/C string len = 6000 1002 ns 1002 ns 701440 BM_format_to_back_inserter<std::vector<char>>/C string len = 6000 956 ns 956 ns 727585 BM_format_to_back_inserter<std::deque<char>>/C string len = 6000 14898 ns 14898 ns 46994 BM_format_to_back_inserter<std::list<char>>/C string len = 6000 114860 ns 114859 ns 6106 BM_format_to_iterator/<std::array> C string len = 6000 158 ns 158 ns 4425133 BM_format_to_iterator/<std::string> C string len = 6000 161 ns 161 ns 4335471 BM_format_to_iterator/<std::vector> C string len = 6000 157 ns 157 ns 4444174 BM_format_to_iterator/<std::deque> C string len = 6000 445 ns 445 ns 1574120 BM_format/string len = 6000 929 ns 929 ns 753630 BM_format_to_back_inserter<std::string>/string len = 6000 930 ns 930 ns 752888 BM_format_to_back_inserter<std::vector<char>>/string len = 6000 910 ns 910 ns 771111 BM_format_to_back_inserter<std::deque<char>>/string len = 6000 14875 ns 14876 ns 47221 BM_format_to_back_inserter<std::list<char>>/string len = 6000 114937 ns 114936 ns 6092 BM_format_to_iterator/<std::array> string len = 6000 118 ns 118 ns 5963643 BM_format_to_iterator/<std::string> string len = 6000 106 ns 106 ns 6584711 BM_format_to_iterator/<std::vector> string len = 6000 106 ns 106 ns 6583118 BM_format_to_iterator/<std::deque> string len = 6000 391 ns 391 ns 1790538 BM_format/string_view len = 6000 935 ns 935 ns 744348 BM_format_to_back_inserter<std::string>/string_view len = 6000 934 ns 934 ns 742039 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6000 895 ns 895 ns 783527 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6000 14864 ns 14865 ns 47122 BM_format_to_back_inserter<std::list<char>>/string_view len = 6000 115042 ns 115044 ns 6091 BM_format_to_iterator/<std::array> string_view len = 6000 115 ns 115 ns 6070197 BM_format_to_iterator/<std::string> string_view len = 6000 116 ns 116 ns 6035109 BM_format_to_iterator/<std::vector> string_view len = 6000 115 ns 115 ns 6067683 BM_format_to_iterator/<std::deque> string_view len = 6000 387 ns 387 ns 1803466 After --------------------------------------------------------------------------------------------------------------- Benchmark Time CPU Iterations --------------------------------------------------------------------------------------------------------------- BM_sprintf/C string len = 6 3.56 ns 3.56 ns 196337806 BM_format/C string len = 6 49.1 ns 49.1 ns 14241174 BM_format_to_back_inserter<std::string>/C string len = 6 56.8 ns 56.8 ns 12341483 BM_format_to_back_inserter<std::vector<char>>/C string len = 6 72.9 ns 72.9 ns 9610864 BM_format_to_back_inserter<std::deque<char>>/C string len = 6 155 ns 155 ns 4528719 BM_format_to_back_inserter<std::list<char>>/C string len = 6 137 ns 137 ns 5103340 BM_format_to_iterator/<std::array> C string len = 6 46.4 ns 46.4 ns 15081626 BM_format_to_iterator/<std::string> C string len = 6 47.0 ns 47.0 ns 14893458 BM_format_to_iterator/<std::vector> C string len = 6 45.9 ns 45.9 ns 15243762 BM_format_to_iterator/<std::deque> C string len = 6 52.6 ns 52.6 ns 13323560 BM_format/string len = 6 49.3 ns 49.3 ns 14181485 BM_format_to_back_inserter<std::string>/string len = 6 55.4 ns 55.4 ns 12644078 BM_format_to_back_inserter<std::vector<char>>/string len = 6 72.7 ns 72.7 ns 9618696 BM_format_to_back_inserter<std::deque<char>>/string len = 6 154 ns 154 ns 4540873 BM_format_to_back_inserter<std::list<char>>/string len = 6 134 ns 134 ns 5220153 BM_format_to_iterator/<std::array> string len = 6 46.5 ns 46.5 ns 15064445 BM_format_to_iterator/<std::string> string len = 6 47.3 ns 47.3 ns 14786851 BM_format_to_iterator/<std::vector> string len = 6 46.5 ns 46.5 ns 15069381 BM_format_to_iterator/<std::deque> string len = 6 52.9 ns 52.9 ns 13207437 BM_format/string_view len = 6 47.6 ns 47.6 ns 14688449 BM_format_to_back_inserter<std::string>/string_view len = 6 56.1 ns 56.1 ns 12514239 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6 72.0 ns 72.0 ns 9705591 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6 152 ns 152 ns 4607470 BM_format_to_back_inserter<std::list<char>>/string_view len = 6 134 ns 134 ns 5233005 BM_format_to_iterator/<std::array> string_view len = 6 46.0 ns 46.0 ns 15205542 BM_format_to_iterator/<std::string> string_view len = 6 46.5 ns 46.5 ns 15067775 BM_format_to_iterator/<std::vector> string_view len = 6 46.5 ns 46.5 ns 15057288 BM_format_to_iterator/<std::deque> string_view len = 6 51.8 ns 51.8 ns 13564649 BM_sprintf/C string len = 60 4.83 ns 4.83 ns 145020116 BM_format/C string len = 60 72.3 ns 72.3 ns 9665555 BM_format_to_back_inserter<std::string>/C string len = 60 85.0 ns 85.0 ns 8249050 BM_format_to_back_inserter<std::vector<char>>/C string len = 60 94.7 ns 94.7 ns 7398143 BM_format_to_back_inserter<std::deque<char>>/C string len = 60 286 ns 286 ns 2452225 BM_format_to_back_inserter<std::list<char>>/C string len = 60 1179 ns 1179 ns 595011 BM_format_to_iterator/<std::array> C string len = 60 46.1 ns 46.1 ns 15157525 BM_format_to_iterator/<std::string> C string len = 60 47.0 ns 47.0 ns 14899863 BM_format_to_iterator/<std::vector> C string len = 60 45.8 ns 45.8 ns 15272542 BM_format_to_iterator/<std::deque> C string len = 60 58.7 ns 58.7 ns 11958910 BM_format/string len = 60 61.7 ns 61.7 ns 11308865 BM_format_to_back_inserter<std::string>/string len = 60 74.2 ns 74.2 ns 9401855 BM_format_to_back_inserter<std::vector<char>>/string len = 60 86.6 ns 86.6 ns 8079197 BM_format_to_back_inserter<std::deque<char>>/string len = 60 278 ns 278 ns 2519254 BM_format_to_back_inserter<std::list<char>>/string len = 60 1169 ns 1170 ns 597703 BM_format_to_iterator/<std::array> string len = 60 46.4 ns 46.4 ns 15074759 BM_format_to_iterator/<std::string> string len = 60 47.3 ns 47.3 ns 14801107 BM_format_to_iterator/<std::vector> string len = 60 46.3 ns 46.4 ns 15085548 BM_format_to_iterator/<std::deque> string len = 60 52.2 ns 52.2 ns 13331015 BM_format/string_view len = 60 65.0 ns 65.0 ns 10756847 BM_format_to_back_inserter<std::string>/string_view len = 60 78.5 ns 78.5 ns 9051370 BM_format_to_back_inserter<std::vector<char>>/string_view len = 60 87.9 ns 87.9 ns 7946825 BM_format_to_back_inserter<std::deque<char>>/string_view len = 60 280 ns 280 ns 2505999 BM_format_to_back_inserter<std::list<char>>/string_view len = 60 1174 ns 1174 ns 594829 BM_format_to_iterator/<std::array> string_view len = 60 46.3 ns 46.3 ns 15149785 BM_format_to_iterator/<std::string> string_view len = 60 46.7 ns 46.7 ns 15002678 BM_format_to_iterator/<std::vector> string_view len = 60 46.7 ns 46.7 ns 14996445 BM_format_to_iterator/<std::deque> string_view len = 60 52.6 ns 52.6 ns 13255470 BM_sprintf/C string len = 6000 77.1 ns 77.1 ns 9099121 BM_format/C string len = 6000 350 ns 350 ns 2013049 BM_format_to_back_inserter<std::string>/C string len = 6000 992 ns 992 ns 709093 BM_format_to_back_inserter<std::vector<char>>/C string len = 6000 1016 ns 1016 ns 694784 BM_format_to_back_inserter<std::deque<char>>/C string len = 6000 15158 ns 15159 ns 46125 BM_format_to_back_inserter<std::list<char>>/C string len = 6000 115703 ns 115705 ns 6055 BM_format_to_iterator/<std::array> C string len = 6000 166 ns 166 ns 4224749 BM_format_to_iterator/<std::string> C string len = 6000 153 ns 153 ns 4573034 BM_format_to_iterator/<std::vector> C string len = 6000 150 ns 150 ns 4678898 BM_format_to_iterator/<std::deque> C string len = 6000 465 ns 465 ns 1506323 BM_format/string len = 6000 281 ns 281 ns 2462572 BM_format_to_back_inserter<std::string>/string len = 6000 935 ns 935 ns 745376 BM_format_to_back_inserter<std::vector<char>>/string len = 6000 939 ns 939 ns 747498 BM_format_to_back_inserter<std::deque<char>>/string len = 6000 15069 ns 15069 ns 46429 BM_format_to_back_inserter<std::list<char>>/string len = 6000 115537 ns 115539 ns 6063 BM_format_to_iterator/<std::array> string len = 6000 120 ns 120 ns 5849159 BM_format_to_iterator/<std::string> string len = 6000 108 ns 108 ns 6482306 BM_format_to_iterator/<std::vector> string len = 6000 107 ns 107 ns 6547915 BM_format_to_iterator/<std::deque> string len = 6000 397 ns 397 ns 1763729 BM_format/string_view len = 6000 282 ns 282 ns 2490133 BM_format_to_back_inserter<std::string>/string_view len = 6000 927 ns 927 ns 750931 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6000 946 ns 946 ns 735544 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6000 15028 ns 15029 ns 46612 BM_format_to_back_inserter<std::list<char>>/string_view len = 6000 115153 ns 115153 ns 6057 BM_format_to_iterator/<std::array> string_view len = 6000 122 ns 122 ns 5753940 BM_format_to_iterator/<std::string> string_view len = 6000 108 ns 108 ns 6507555 BM_format_to_iterator/<std::vector> string_view len = 6000 107 ns 107 ns 6510450 BM_format_to_iterator/<std::deque> string_view len = 6000 398 ns 398 ns 1762517 Comparison Benchmark Time CPU Time Old Time New CPU Old CPU New ------------------------------------------------------------------------------------------------------------------------------------------------------------------- BM_sprintf/C string len = 6 -0.2599 -0.2599 5 4 5 4 BM_format/C string len = 6 -0.1094 -0.1095 55 49 55 49 BM_format_to_back_inserter<std::string>/C string len = 6 +0.0316 +0.0316 55 57 55 57 BM_format_to_back_inserter<std::vector<char>>/C string len = 6 +0.0204 +0.0204 71 73 71 73 BM_format_to_back_inserter<std::deque<char>>/C string len = 6 +0.0023 +0.0023 154 155 154 155 BM_format_to_back_inserter<std::list<char>>/C string len = 6 +0.0521 +0.0520 130 137 130 137 BM_format_to_iterator/<std::array> C string len = 6 +0.0317 +0.0317 45 46 45 46 BM_format_to_iterator/<std::string> C string len = 6 +0.0265 +0.0265 46 47 46 47 BM_format_to_iterator/<std::vector> C string len = 6 +0.0345 +0.0345 44 46 44 46 BM_format_to_iterator/<std::deque> C string len = 6 +0.0511 +0.0511 50 53 50 53 BM_format/string len = 6 -0.0981 -0.0981 55 49 55 49 BM_format_to_back_inserter<std::string>/string len = 6 -0.0028 -0.0028 56 55 56 55 BM_format_to_back_inserter<std::vector<char>>/string len = 6 +0.0331 +0.0331 70 73 70 73 BM_format_to_back_inserter<std::deque<char>>/string len = 6 -0.0040 -0.0040 155 154 155 154 BM_format_to_back_inserter<std::list<char>>/string len = 6 -0.0019 -0.0019 135 134 135 134 BM_format_to_iterator/<std::array> string len = 6 +0.0427 +0.0427 45 46 45 46 BM_format_to_iterator/<std::string> string len = 6 +0.0515 +0.0515 45 47 45 47 BM_format_to_iterator/<std::vector> string len = 6 +0.0316 +0.0316 45 46 45 46 BM_format_to_iterator/<std::deque> string len = 6 +0.0475 +0.0475 51 53 51 53 BM_format/string_view len = 6 -0.1267 -0.1267 55 48 55 48 BM_format_to_back_inserter<std::string>/string_view len = 6 +0.0283 +0.0283 55 56 55 56 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6 +0.0291 +0.0291 70 72 70 72 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6 -0.0305 -0.0306 157 152 157 152 BM_format_to_back_inserter<std::list<char>>/string_view len = 6 -0.0012 -0.0012 134 134 134 134 BM_format_to_iterator/<std::array> string_view len = 6 +0.0426 +0.0426 44 46 44 46 BM_format_to_iterator/<std::string> string_view len = 6 +0.0322 +0.0322 45 46 45 46 BM_format_to_iterator/<std::vector> string_view len = 6 +0.0309 +0.0309 45 46 45 46 BM_format_to_iterator/<std::deque> string_view len = 6 +0.0248 +0.0248 51 52 51 52 BM_sprintf/C string len = 60 +0.1633 +0.1633 4 5 4 5 BM_format/C string len = 60 -0.0203 -0.0203 74 72 74 72 BM_format_to_back_inserter<std::string>/C string len = 60 +0.1548 +0.1548 74 85 74 85 BM_format_to_back_inserter<std::vector<char>>/C string len = 60 +0.1395 +0.1395 83 95 83 95 BM_format_to_back_inserter<std::deque<char>>/C string len = 60 +0.0157 +0.0157 281 286 281 286 BM_format_to_back_inserter<std::list<char>>/C string len = 60 +0.0191 +0.0191 1157 1179 1157 1179 BM_format_to_iterator/<std::array> C string len = 60 +0.0283 +0.0283 45 46 45 46 BM_format_to_iterator/<std::string> C string len = 60 +0.0251 +0.0252 46 47 46 47 BM_format_to_iterator/<std::vector> C string len = 60 +0.0263 +0.0263 45 46 45 46 BM_format_to_iterator/<std::deque> C string len = 60 +0.1592 +0.1591 51 59 51 59 BM_format/string len = 60 -0.1466 -0.1466 72 62 72 62 BM_format_to_back_inserter<std::string>/string len = 60 +0.0299 +0.0299 72 74 72 74 BM_format_to_back_inserter<std::vector<char>>/string len = 60 +0.0522 +0.0522 82 87 82 87 BM_format_to_back_inserter<std::deque<char>>/string len = 60 -0.0099 -0.0099 280 278 280 278 BM_format_to_back_inserter<std::list<char>>/string len = 60 +0.0062 +0.0062 1162 1169 1162 1170 BM_format_to_iterator/<std::array> string len = 60 +0.0430 +0.0430 45 46 45 46 BM_format_to_iterator/<std::string> string len = 60 -0.0466 -0.0466 50 47 50 47 BM_format_to_iterator/<std::vector> string len = 60 -0.0693 -0.0693 50 46 50 46 BM_format_to_iterator/<std::deque> string len = 60 +0.0275 +0.0275 51 52 51 52 BM_format/string_view len = 60 -0.1034 -0.1034 73 65 73 65 BM_format_to_back_inserter<std::string>/string_view len = 60 +0.0790 +0.0790 73 78 73 78 BM_format_to_back_inserter<std::vector<char>>/string_view len = 60 +0.0735 +0.0735 82 88 82 88 BM_format_to_back_inserter<std::deque<char>>/string_view len = 60 -0.0103 -0.0104 283 280 283 280 BM_format_to_back_inserter<std::list<char>>/string_view len = 60 +0.0101 +0.0101 1162 1174 1162 1174 BM_format_to_iterator/<std::array> string_view len = 60 +0.0484 +0.0484 44 46 44 46 BM_format_to_iterator/<std::string> string_view len = 60 +0.0387 +0.0387 45 47 45 47 BM_format_to_iterator/<std::vector> string_view len = 60 +0.0402 +0.0402 45 47 45 47 BM_format_to_iterator/<std::deque> string_view len = 60 +0.0508 +0.0508 50 53 50 53 BM_sprintf/C string len = 6000 -0.3337 -0.3337 116 77 116 77 BM_format/C string len = 6000 -0.6500 -0.6500 1000 350 1000 350 BM_format_to_back_inserter<std::string>/C string len = 6000 -0.0104 -0.0105 1002 992 1002 992 BM_format_to_back_inserter<std::vector<char>>/C string len = 6000 +0.0630 +0.0630 956 1016 956 1016 BM_format_to_back_inserter<std::deque<char>>/C string len = 6000 +0.0175 +0.0175 14898 15158 14898 15159 BM_format_to_back_inserter<std::list<char>>/C string len = 6000 +0.0073 +0.0074 114860 115703 114859 115705 BM_format_to_iterator/<std::array> C string len = 6000 +0.0504 +0.0504 158 166 158 166 BM_format_to_iterator/<std::string> C string len = 6000 -0.0486 -0.0486 161 153 161 153 BM_format_to_iterator/<std::vector> C string len = 6000 -0.0483 -0.0483 157 150 157 150 BM_format_to_iterator/<std::deque> C string len = 6000 +0.0459 +0.0459 445 465 445 465 BM_format/string len = 6000 -0.6975 -0.6975 929 281 929 281 BM_format_to_back_inserter<std::string>/string len = 6000 +0.0050 +0.0050 930 935 930 935 BM_format_to_back_inserter<std::vector<char>>/string len = 6000 +0.0321 +0.0322 910 939 910 939 BM_format_to_back_inserter<std::deque<char>>/string len = 6000 +0.0130 +0.0130 14875 15069 14876 15069 BM_format_to_back_inserter<std::list<char>>/string len = 6000 +0.0052 +0.0052 114937 115537 114936 115539 BM_format_to_iterator/<std::array> string len = 6000 +0.0211 +0.0211 118 120 118 120 BM_format_to_iterator/<std::string> string len = 6000 +0.0146 +0.0146 106 108 106 108 BM_format_to_iterator/<std::vector> string len = 6000 +0.0048 +0.0048 106 107 106 107 BM_format_to_iterator/<std::deque> string len = 6000 +0.0150 +0.0150 391 397 391 397 BM_format/string_view len = 6000 -0.6989 -0.6989 935 282 935 282 BM_format_to_back_inserter<std::string>/string_view len = 6000 -0.0083 -0.0083 934 927 934 927 BM_format_to_back_inserter<std::vector<char>>/string_view len = 6000 +0.0566 +0.0566 895 946 895 946 BM_format_to_back_inserter<std::deque<char>>/string_view len = 6000 +0.0111 +0.0110 14864 15028 14865 15029 BM_format_to_back_inserter<std::list<char>>/string_view len = 6000 +0.0010 +0.0009 115042 115153 115044 115153 BM_format_to_iterator/<std::array> string_view len = 6000 +0.0560 +0.0560 115 122 115 122 BM_format_to_iterator/<std::string> string_view len = 6000 -0.0693 -0.0693 116 108 116 108 BM_format_to_iterator/<std::vector> string_view len = 6000 -0.0703 -0.0703 115 107 115 107 BM_format_to_iterator/<std::deque> string_view len = 6000 +0.0271 +0.0271 387 398 387 398 OVERALL_GEOMEAN -0.0350 -0.0350 0 0 0 0 format: Before -------------------------------------------------------------------------------------------- Benchmark Time CPU Iterations UserCounters... -------------------------------------------------------------------------------------------- BM_format_string<char>/1 55.5 ns 55.5 ns 12463288 bytes_per_second=17.187Mi/s BM_format_string<char>/2 27.6 ns 27.6 ns 25421994 bytes_per_second=69.1874Mi/s BM_format_string<char>/4 14.0 ns 14.0 ns 49785656 bytes_per_second=271.524Mi/s BM_format_string<char>/8 7.07 ns 7.07 ns 99247048 bytes_per_second=1.05444Gi/s BM_format_string<char>/16 3.53 ns 3.53 ns 198072224 bytes_per_second=4.21726Gi/s BM_format_string<char>/32 2.31 ns 2.31 ns 302771136 bytes_per_second=12.9138Gi/s BM_format_string<char>/64 1.15 ns 1.15 ns 606646976 bytes_per_second=51.7527Gi/s BM_format_string<char>/128 0.597 ns 0.597 ns 1172263936 bytes_per_second=199.688Gi/s BM_format_string<char>/256 0.327 ns 0.327 ns 2148927744 bytes_per_second=728.678Gi/s BM_format_string<char>/512 0.248 ns 0.248 ns 2821635584 bytes_per_second=1.8779Ti/s BM_format_string<char>/1024 0.203 ns 0.203 ns 3433579520 bytes_per_second=4.57798Ti/s BM_format_string<char>/2048 0.164 ns 0.164 ns 4277524480 bytes_per_second=11.3793Ti/s BM_format_string<char>/4096 0.137 ns 0.137 ns 5122269184 bytes_per_second=27.2589Ti/s BM_format_string<char>/8192 0.126 ns 0.126 ns 5564243968 bytes_per_second=59.2812Ti/s BM_format_string<char>/16384 0.136 ns 0.136 ns 5153013760 bytes_per_second=109.492Ti/s BM_format_string<char>/32768 0.135 ns 0.135 ns 5165088768 bytes_per_second=219.985Ti/s BM_format_string<char>/65536 0.243 ns 0.242 ns 2930180096 bytes_per_second=246.57Ti/s BM_format_string<char>/131072 0.490 ns 0.489 ns 1437990912 bytes_per_second=243.75Ti/s BM_format_string<char>/262144 0.593 ns 0.592 ns 1183055872 bytes_per_second=402.931Ti/s BM_format_string<char>/524288 0.643 ns 0.641 ns 1092616192 bytes_per_second=743.445Ti/s BM_format_string<char>/1048576 0.669 ns 0.668 ns 1045430272 bytes_per_second=1.39478Pi/s BM_format_string<wchar_t>/1 56.0 ns 55.9 ns 12511543 bytes_per_second=68.2628Mi/s BM_format_string<wchar_t>/2 28.0 ns 27.9 ns 25062366 bytes_per_second=273.519Mi/s BM_format_string<wchar_t>/4 14.0 ns 14.0 ns 50257068 bytes_per_second=1.06742Gi/s BM_format_string<wchar_t>/8 9.24 ns 9.21 ns 76118616 bytes_per_second=3.23473Gi/s BM_format_string<wchar_t>/16 4.66 ns 4.65 ns 151420352 bytes_per_second=12.8261Gi/s BM_format_string<wchar_t>/32 2.35 ns 2.35 ns 298417600 bytes_per_second=50.7972Gi/s BM_format_string<wchar_t>/64 1.35 ns 1.34 ns 521608704 bytes_per_second=177.502Gi/s BM_format_string<wchar_t>/128 1.03 ns 1.03 ns 680946304 bytes_per_second=463.91Gi/s BM_format_string<wchar_t>/256 0.849 ns 0.847 ns 825871104 bytes_per_second=1.09901Ti/s BM_format_string<wchar_t>/512 0.681 ns 0.679 ns 1033245696 bytes_per_second=2.74383Ti/s BM_format_string<wchar_t>/1024 0.576 ns 0.575 ns 1219777536 bytes_per_second=6.48343Ti/s BM_format_string<wchar_t>/2048 0.515 ns 0.514 ns 1361629184 bytes_per_second=14.4881Ti/s BM_format_string<wchar_t>/4096 0.546 ns 0.545 ns 1285427200 bytes_per_second=27.3342Ti/s BM_format_string<wchar_t>/8192 0.550 ns 0.548 ns 1277042688 bytes_per_second=54.3343Ti/s BM_format_string<wchar_t>/16384 0.583 ns 0.581 ns 1203879936 bytes_per_second=102.544Ti/s BM_format_string<wchar_t>/32768 0.640 ns 0.638 ns 1095139328 bytes_per_second=186.82Ti/s BM_format_string<wchar_t>/65536 0.642 ns 0.640 ns 1093337088 bytes_per_second=372.283Ti/s BM_format_string<wchar_t>/131072 0.655 ns 0.654 ns 1070596096 bytes_per_second=729.428Ti/s BM_format_string<wchar_t>/262144 2.68 ns 2.67 ns 262406144 bytes_per_second=357.446Ti/s BM_format_string<wchar_t>/524288 2.13 ns 2.13 ns 330301440 bytes_per_second=897.574Ti/s BM_format_string<wchar_t>/1048576 2.44 ns 2.43 ns 288358400 bytes_per_second=1.53149Pi/s After -------------------------------------------------------------------------------------------- Benchmark Time CPU Iterations UserCounters... -------------------------------------------------------------------------------------------- BM_format_string<char>/1 49.3 ns 49.1 ns 14230742 bytes_per_second=19.4054Mi/s BM_format_string<char>/2 24.8 ns 24.8 ns 28253114 bytes_per_second=77.0465Mi/s BM_format_string<char>/4 12.4 ns 12.4 ns 56381440 bytes_per_second=307.462Mi/s BM_format_string<char>/8 6.23 ns 6.21 ns 112951232 bytes_per_second=1.19924Gi/s BM_format_string<char>/16 3.10 ns 3.09 ns 225822496 bytes_per_second=4.81566Gi/s BM_format_string<char>/32 1.98 ns 1.98 ns 354208192 bytes_per_second=15.0825Gi/s BM_format_string<char>/64 0.990 ns 0.987 ns 714296384 bytes_per_second=60.3689Gi/s BM_format_string<char>/128 0.504 ns 0.503 ns 1399988480 bytes_per_second=237.144Gi/s BM_format_string<char>/256 0.335 ns 0.334 ns 2084828928 bytes_per_second=712.859Gi/s BM_format_string<char>/512 0.187 ns 0.186 ns 3760082432 bytes_per_second=2.50102Ti/s BM_format_string<char>/1024 0.109 ns 0.108 ns 6455339008 bytes_per_second=8.59552Ti/s BM_format_string<char>/2048 0.080 ns 0.080 ns 8754006016 bytes_per_second=23.2731Ti/s BM_format_string<char>/4096 0.051 ns 0.051 ns 13786701824 bytes_per_second=73.4088Ti/s BM_format_string<char>/8192 0.042 ns 0.042 ns 16851435520 bytes_per_second=178.737Ti/s BM_format_string<char>/16384 0.122 ns 0.122 ns 5746589696 bytes_per_second=122.029Ti/s BM_format_string<char>/32768 0.107 ns 0.106 ns 6571687936 bytes_per_second=280.122Ti/s BM_format_string<char>/65536 0.102 ns 0.102 ns 6876626944 bytes_per_second=584.381Ti/s BM_format_string<char>/131072 0.106 ns 0.105 ns 6643122176 bytes_per_second=1.10413Pi/s BM_format_string<char>/262144 0.589 ns 0.587 ns 1189609472 bytes_per_second=406.438Ti/s BM_format_string<char>/524288 0.644 ns 0.642 ns 1088946176 bytes_per_second=743.064Ti/s BM_format_string<char>/1048576 0.672 ns 0.670 ns 1039138816 bytes_per_second=1.38968Pi/s BM_format_string<wchar_t>/1 48.7 ns 48.6 ns 14423178 bytes_per_second=78.5263Mi/s BM_format_string<wchar_t>/2 24.4 ns 24.3 ns 28831748 bytes_per_second=313.869Mi/s BM_format_string<wchar_t>/4 12.2 ns 12.2 ns 57661220 bytes_per_second=1.2253Gi/s BM_format_string<wchar_t>/8 7.81 ns 7.79 ns 89887592 bytes_per_second=3.82675Gi/s BM_format_string<wchar_t>/16 3.88 ns 3.87 ns 180450176 bytes_per_second=15.418Gi/s BM_format_string<wchar_t>/32 1.98 ns 1.98 ns 354046112 bytes_per_second=60.3262Gi/s BM_format_string<wchar_t>/64 1.02 ns 1.01 ns 689511680 bytes_per_second=234.906Gi/s BM_format_string<wchar_t>/128 0.577 ns 0.576 ns 1215361408 bytes_per_second=828.297Gi/s BM_format_string<wchar_t>/256 0.804 ns 0.802 ns 872249088 bytes_per_second=1.16111Ti/s BM_format_string<wchar_t>/512 0.642 ns 0.641 ns 1093858304 bytes_per_second=2.90766Ti/s BM_format_string<wchar_t>/1024 0.517 ns 0.516 ns 1354798080 bytes_per_second=7.21845Ti/s BM_format_string<wchar_t>/2048 0.469 ns 0.467 ns 1491910656 bytes_per_second=15.9386Ti/s BM_format_string<wchar_t>/4096 0.794 ns 0.792 ns 883822592 bytes_per_second=18.8156Ti/s BM_format_string<wchar_t>/8192 0.722 ns 0.720 ns 971718656 bytes_per_second=41.3996Ti/s BM_format_string<wchar_t>/16384 0.703 ns 0.701 ns 998031360 bytes_per_second=85.0369Ti/s BM_format_string<wchar_t>/32768 0.724 ns 0.720 ns 971538432 bytes_per_second=165.467Ti/s BM_format_string<wchar_t>/65536 0.745 ns 0.744 ns 941228032 bytes_per_second=320.665Ti/s BM_format_string<wchar_t>/131072 0.742 ns 0.740 ns 945422336 bytes_per_second=644.032Ti/s BM_format_string<wchar_t>/262144 2.99 ns 2.98 ns 234881024 bytes_per_second=319.75Ti/s BM_format_string<wchar_t>/524288 3.31 ns 3.30 ns 212860928 bytes_per_second=578.085Ti/s BM_format_string<wchar_t>/1048576 2.69 ns 2.68 ns 260046848 bytes_per_second=1.39081Pi/s Comparison Benchmark Time CPU Time Old Time New CPU Old CPU New -------------------------------------------------------------------------------------------------------------------------------- BM_format_string<char>/1 -0.1122 -0.1143 55 49 55 49 BM_format_string<char>/2 -0.0999 -0.1020 28 25 28 25 BM_format_string<char>/4 -0.1148 -0.1169 14 12 14 12 BM_format_string<char>/8 -0.1186 -0.1207 7 6 7 6 BM_format_string<char>/16 -0.1222 -0.1243 4 3 4 3 BM_format_string<char>/32 -0.1417 -0.1438 2 2 2 2 BM_format_string<char>/64 -0.1407 -0.1427 1 1 1 1 BM_format_string<char>/128 -0.1559 -0.1579 1 1 1 1 BM_format_string<char>/256 +0.0249 +0.0222 0 0 0 0 BM_format_string<char>/512 -0.2473 -0.2491 0 0 0 0 BM_format_string<char>/1024 -0.4661 -0.4674 0 0 0 0 BM_format_string<char>/2048 -0.5096 -0.5111 0 0 0 0 BM_format_string<char>/4096 -0.6278 -0.6287 0 0 0 0 BM_format_string<char>/8192 -0.6674 -0.6683 0 0 0 0 BM_format_string<char>/16384 -0.1005 -0.1027 0 0 0 0 BM_format_string<char>/32768 -0.2127 -0.2147 0 0 0 0 BM_format_string<char>/65536 -0.5796 -0.5781 0 0 0 0 BM_format_string<char>/131072 -0.7844 -0.7844 0 0 0 0 BM_format_string<char>/262144 -0.0073 -0.0086 1 1 1 1 BM_format_string<char>/524288 +0.0017 +0.0005 1 1 1 1 BM_format_string<char>/1048576 +0.0039 +0.0037 1 1 1 1 BM_format_string<wchar_t>/1 -0.1304 -0.1307 56 49 56 49 BM_format_string<wchar_t>/2 -0.1285 -0.1286 28 24 28 24 BM_format_string<wchar_t>/4 -0.1288 -0.1288 14 12 14 12 BM_format_string<wchar_t>/8 -0.1547 -0.1547 9 8 9 8 BM_format_string<wchar_t>/16 -0.1681 -0.1681 5 4 5 4 BM_format_string<wchar_t>/32 -0.1579 -0.1580 2 2 2 2 BM_format_string<wchar_t>/64 -0.2443 -0.2444 1 1 1 1 BM_format_string<wchar_t>/128 -0.4400 -0.4399 1 1 1 1 BM_format_string<wchar_t>/256 -0.0535 -0.0535 1 1 1 1 BM_format_string<wchar_t>/512 -0.0563 -0.0563 1 1 1 1 BM_format_string<wchar_t>/1024 -0.1018 -0.1018 1 1 1 1 BM_format_string<wchar_t>/2048 -0.0910 -0.0910 1 0 1 0 BM_format_string<wchar_t>/4096 +0.4528 +0.4527 1 1 1 1 BM_format_string<wchar_t>/8192 +0.3121 +0.3124 1 1 1 1 BM_format_string<wchar_t>/16384 +0.2059 +0.2059 1 1 1 1 BM_format_string<wchar_t>/32768 +0.1316 +0.1290 1 1 1 1 BM_format_string<wchar_t>/65536 +0.1604 +0.1610 1 1 1 1 BM_format_string<wchar_t>/131072 +0.1326 +0.1326 1 1 1 1 BM_format_string<wchar_t>/262144 +0.1181 +0.1179 3 3 3 3 BM_format_string<wchar_t>/524288 +0.5515 +0.5527 2 3 2 3 BM_format_string<wchar_t>/1048576 +0.1007 +0.1011 2 3 2 3 OVERALL_GEOMEAN -0.1685 -0.1693 0 0 0 0
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As discussed, I think we should behave more like std::vector and not assume that elements between [size(), capacity()) are already initialized. IMO this is a simpler mental model that is consistent with std::vector and I don't think we leave anything on the table by doing that.
| /// - The class constructor stores a function pointer to a grow function and a | ||
| /// type-erased pointer to the object that does the grow. |
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| /// - The class constructor stores a function pointer to a grow function and a | |
| /// type-erased pointer to the object that does the grow. | |
| /// - The class constructor stores a function pointer to a "grow" function and a | |
| /// type-erased pointer to the object that should be grown. |
| /// - Contains the number of code units that are requested to be written. | ||
| /// This number is returned to the user of format_to_n. |
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| /// - Contains the number of code units that are requested to be written. | |
| /// This number is returned to the user of format_to_n. | |
| /// - Contains the number of code units that were actually written. | |
| /// This number is returned to the user of format_to_n. |
| /// - The write functions call objects __request_write member function. | ||
| /// This function: |
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| /// - The write functions call objects __request_write member function. | |
| /// This function: | |
| /// - The write functions call the object's __request_write member function. | |
| /// This function: |
| /// - __ptr_ the start of the buffer. | ||
| /// - __capacity_ the number of code units that can be written. | ||
| /// This means [__ptr_, __ptr_ + __capacity_) is a valid range to write to. | ||
| /// - __size_ the number of code units written in the buffer. The next code | ||
| /// unit will be written at __ptr_ + __size_. This __size_ may NOT contain | ||
| /// the total number of code units written by the __output_buffer. Whether or | ||
| /// not it does depends on the sub-class used. Typically the total number of | ||
| /// code units written is not interesting. It is interesting for format_to_n | ||
| /// which has its own way to track this number. |
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| /// - __ptr_ the start of the buffer. | |
| /// - __capacity_ the number of code units that can be written. | |
| /// This means [__ptr_, __ptr_ + __capacity_) is a valid range to write to. | |
| /// - __size_ the number of code units written in the buffer. The next code | |
| /// unit will be written at __ptr_ + __size_. This __size_ may NOT contain | |
| /// the total number of code units written by the __output_buffer. Whether or | |
| /// not it does depends on the sub-class used. Typically the total number of | |
| /// code units written is not interesting. It is interesting for format_to_n | |
| /// which has its own way to track this number. | |
| /// - __ptr_ | |
| /// The start of the buffer. | |
| /// - __capacity_ | |
| /// The number of code units that can be written. | |
| /// This means [__ptr_, __ptr_ + __capacity_) is a valid range to write to. | |
| /// - __size_ | |
| /// The number of code units written in the buffer. The next code | |
| /// unit will be written at __ptr_ + __size_. This __size_ may NOT contain | |
| /// the total number of code units written by the __output_buffer. Whether or | |
| /// not it does depends on the sub-class used. Typically the total number of | |
| /// code units written is not interesting. It is interesting for format_to_n | |
| /// which has its own way to track this number. |
Breaking the line makes it easier to see that the first word is the name of the member.
| /// __output_buffer<_CharT>& __buffer, size_t __code_units); | ||
| /// | ||
| /// This function is called when a write function writes more code units than | ||
| /// the buffer' available space. When an __max_output_size object is provided |
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| /// the buffer' available space. When an __max_output_size object is provided | |
| /// the buffer's available space. When an __max_output_size object is provided |
| } | ||
|
|
||
| // New LLVM-20 function. | ||
| _LIBCPP_HIDE_FROM_ABI void __buffer_flused() { __size_ = 0; } |
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| _LIBCPP_HIDE_FROM_ABI void __buffer_flused() { __size_ = 0; } | |
| _LIBCPP_HIDE_FROM_ABI void __buffer_flushed() { __size_ = 0; } |
| auto __guard = std::__make_exception_guard([&] { | ||
| allocator_traits<_Alloc>::deallocate(__alloc_, __result.ptr, __result.count); | ||
| }); | ||
| // This shouldn't throw, but just to be safe. Note that at -O1 this | ||
| // guard is optimized away so there is no runtime overhead. | ||
| new (__result.ptr) _CharT[__result.count]; | ||
| std::copy_n(__ptr_, this->__size(), __result.ptr); | ||
| __guard.__complete(); | ||
| if (__ptr_ != __buffer_) { | ||
| ranges::destroy_n(__ptr_, this->__capacity()); | ||
| allocator_traits<_Alloc>::deallocate(__alloc_, __ptr_, this->__capacity()); | ||
| } |
There was a problem hiding this comment.
| auto __guard = std::__make_exception_guard([&] { | |
| allocator_traits<_Alloc>::deallocate(__alloc_, __result.ptr, __result.count); | |
| }); | |
| // This shouldn't throw, but just to be safe. Note that at -O1 this | |
| // guard is optimized away so there is no runtime overhead. | |
| new (__result.ptr) _CharT[__result.count]; | |
| std::copy_n(__ptr_, this->__size(), __result.ptr); | |
| __guard.__complete(); | |
| if (__ptr_ != __buffer_) { | |
| ranges::destroy_n(__ptr_, this->__capacity()); | |
| allocator_traits<_Alloc>::deallocate(__alloc_, __ptr_, this->__capacity()); | |
| } | |
| auto __guard = std::__make_exception_guard([&] { | |
| allocator_traits<_Alloc>::deallocate(__alloc_, __result.ptr, __result.count); | |
| }); | |
| // This shouldn't throw, but just to be safe. Note that at -O1 this | |
| // guard is optimized away so there is no runtime overhead. | |
| std::__uninitialized_allocator_relocate(__alloc_, __ptr_, __ptr_ + this->__size(), __result.ptr); | |
| __guard.__complete(); | |
| if (__ptr_ != __buffer_) { | |
| allocator_traits<_Alloc>::deallocate(__alloc_, __ptr_, this->__capacity()); | |
| } |
| // At the moment the allocator is hard-code. There might be reasons to have | ||
| // an allocator trait in the future. This ensures forward compatibility. | ||
| using _Alloc = allocator<_CharT>; | ||
| _LIBCPP_NO_UNIQUE_ADDRESS _Alloc __alloc_; |
There was a problem hiding this comment.
If we hardcode the allocator, I would simply not use one. This would simplify business with construct_at & friends too.
|
|
||
| _LIBCPP_HIDE_FROM_ABI auto __make_output_iterator() { return std::back_insert_iterator{*this}; } | ||
|
|
||
| // Used in std::back_insert_iterator. |
There was a problem hiding this comment.
Here I think it should be
_LIBCPP_HIDE_FROM_ABI void push_back(_CharT __c) {
std::__construct_at(__ptr_ + __size_, __c);
++__size_;
// Profiling showed flushing after adding is more efficient than flushing
// when entering the function.
if (__size_ == __capacity_)
__flush(0);
}| std::vformat_to(std::back_inserter(__res), __fmt, __args); | ||
| return __res; | ||
| __format::__allocating_buffer<char> __buffer; | ||
| std::vformat_to(__buffer.__make_output_iterator(), __fmt, __args); |
There was a problem hiding this comment.
Can we remove an include since you don't mention back_inserter directly anymore?
| // Since allocating is expensive the class has a small internal buffer. When | ||
| // its capacity is exceeded a dynamic buffer will be allocated. | ||
| static constexpr size_t __buffer_size_ = 256; | ||
| _CharT __buffer_[__buffer_size_]; |
There was a problem hiding this comment.
| _CharT __buffer_[__buffer_size_]; | |
| std::byte __buffer_[__buffer_size_ * sizeof(_CharT)]; |
There was a problem hiding this comment.
After looking at the patches later in the series, I am not certain these comments about implementing this as vector (i.e. elements beyond size() not having their lifetime started yet) is the best approach. I think your current approach may be better.
However, I think that the usage of back_insert_iterator<__output_buffer> + __output_buffer::push_back is misleading -- that's what caused me to think this should behave as a vector when in reality this is a different beast. If instead we had a method called __push_back (or __insert_back) and we used our own small iterator type to output to the buffer, it would make the design of this class clearer. It would also put __push_back/__insert_back on the same level as the other "insertion" functions like __fill and others. So IMO the current design might be fine lifetime-wise, but I think it would be nice to avoid using back_insert_iterator<__output_buffer> since __output_buffer is fundamentally not a container.
I understand that using back_inserter greatly simplifies the boilerplate needed, but IMO that's still the right design.
| string __res; | ||
| std::vformat_to(std::back_inserter(__res), __fmt, __args); | ||
| return __res; | ||
| __format::__allocating_buffer<char> __buffer; |
There was a problem hiding this comment.
It would actually be really nice if vformat_to(std::back_inserter(string), ...) were just as performant as using the allocating buffer. It seems to me that if using the __allocating_buffer directly is faster, there may be a problem with next patch's buffer_selector which would basically be picking a less efficient approach for the case of std::back_inserter<std::string>.
| /// | ||
| /// The latter option allows formatted_size to use the output buffer without | ||
| /// ever writing anything to the buffer. | ||
| template <__fmt_char_type _CharT> |
There was a problem hiding this comment.
| template <__fmt_char_type _CharT> | |
| template <contiguous_iterator _BufferIterator, __fmt_char_type _CharT> |
This would allow the derived classes to pass down their actual iterator types, which would make it possible to e.g. retain bounds information when we have some in the iterator.
|
|
||
| // New LLVM-20 function. | ||
| [[nodiscard]] | ||
| _LIBCPP_HIDE_FROM_ABI explicit __output_buffer(_CharT* __ptr, size_t __capacity, __prepare_write_type __prepare_write) |
There was a problem hiding this comment.
Then this would become
| _LIBCPP_HIDE_FROM_ABI explicit __output_buffer(_CharT* __ptr, size_t __capacity, __prepare_write_type __prepare_write) | |
| _LIBCPP_HIDE_FROM_ABI explicit __output_buffer(_BufferIterator __ptr, size_t __capacity, __prepare_write_type __prepare_write) |
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|
Abandoned, done in a different patch. |
This changes the __output_buffer to a new structure. Since the other formatting functions std::format_to, std::format_to_n, and std::formatted_size still use the old codepaths the class is in a transition state. At the end of the patch series the class should be in its final state.
write_double_comparison:
Before
Benchmark Time CPU Iterations
BM_sprintf 197 ns 196 ns 3550000
BM_to_string 218 ns 218 ns 3214000
BM_to_chars 42.4 ns 42.3 ns 16575000
BM_to_chars_as_string 48.2 ns 48.1 ns 14542000
BM_format 175 ns 175 ns 4000000
BM_format_to_back_inserterstd::string 175 ns 175 ns 3995000
BM_format_to_back_inserter<std::vector> 207 ns 206 ns 3393000
BM_format_to_back_inserter<std::list> 752 ns 750 ns 931000
BM_format_to_iterator/std::array 161 ns 161 ns 4345000
BM_format_to_iterator/std::string 161 ns 161 ns 4344000
BM_format_to_iterator/std::vector 162 ns 161 ns 4344000
After
Benchmark Time CPU Iterations
BM_sprintf 197 ns 197 ns 3550000
BM_to_string 219 ns 219 ns 3199000
BM_to_chars 42.4 ns 42.4 ns 16554000
BM_to_chars_as_string 48.1 ns 48.1 ns 14569000
BM_format 167 ns 167 ns 4203000
BM_format_to_back_inserterstd::string 179 ns 179 ns 3920000
BM_format_to_back_inserter<std::vector> 214 ns 214 ns 3274000
BM_format_to_back_inserter<std::list> 751 ns 751 ns 930000
BM_format_to_iterator/std::array 164 ns 164 ns 4258000
BM_format_to_iterator/std::string 165 ns 164 ns 4247000
BM_format_to_iterator/std::vector 165 ns 165 ns 4248000
Comparison
Benchmark Time CPU Time Old Time New CPU Old CPU New
BM_sprintf +0.0013 +0.0028 197 197 196 197
BM_to_string +0.0023 +0.0038 218 219 218 219
BM_to_chars +0.0014 +0.0030 42 42 42 42
BM_to_chars_as_string -0.0025 -0.0010 48 48 48 48
BM_format -0.0476 -0.0462 175 167 175 167
BM_format_to_back_inserterstd::string +0.0190 +0.0205 175 179 175 179
BM_format_to_back_inserter<std::vector> +0.0348 +0.0363 207 214 206 214
BM_format_to_back_inserter<std::list> -0.0013 +0.0005 752 751 750 751
BM_format_to_iterator/std::array +0.0188 +0.0203 161 164 161 164
BM_format_to_iterator/std::string +0.0207 +0.0226 161 165 161 164
BM_format_to_iterator/std::vector +0.0197 +0.0212 162 165 161 165
OVERALL_GEOMEAN +0.0058 +0.0074 0 0 0 0
write_int_comparison:
Before
Benchmark Time CPU Iterations
BM_sprintf 79.6 ns 79.5 ns 8739000
BM_to_string 14.9 ns 14.9 ns 46713000
BM_to_chars 5.68 ns 5.67 ns 120614000
BM_to_chars_as_string 14.2 ns 14.1 ns 49513000
BM_format 69.3 ns 69.2 ns 10105000
BM_format_to_back_inserterstd::string 69.2 ns 69.1 ns 10138000
BM_format_to_back_inserter<std::vector> 90.6 ns 90.5 ns 7728000
BM_format_to_back_inserter<std::list> 234 ns 234 ns 2986000
BM_format_to_iterator/std::array 59.3 ns 59.3 ns 11805000
BM_format_to_iterator/std::string 58.7 ns 58.6 ns 11943000
BM_format_to_iterator/std::vector 60.1 ns 60.1 ns 11670000
After
Benchmark Time CPU Iterations
BM_sprintf 80.2 ns 80.2 ns 8670000
BM_to_string 15.0 ns 15.0 ns 46559000
BM_to_chars 4.93 ns 4.93 ns 138016000
BM_to_chars_as_string 15.4 ns 15.4 ns 45415000
BM_format 62.1 ns 62.0 ns 11316000
BM_format_to_back_inserterstd::string 70.2 ns 70.2 ns 9962000
BM_format_to_back_inserter<std::vector> 92.8 ns 92.8 ns 7544000
BM_format_to_back_inserter<std::list> 240 ns 240 ns 2917000
BM_format_to_iterator/std::array 60.5 ns 60.5 ns 11572000
BM_format_to_iterator/std::string 60.2 ns 60.2 ns 11653000
BM_format_to_iterator/std::vector 60.1 ns 60.1 ns 11659000
Comparison
Benchmark Time CPU Time Old Time New CPU Old CPU New
BM_sprintf +0.0072 +0.0081 80 80 80 80
BM_to_string +0.0043 +0.0053 15 15 15 15
BM_to_chars -0.1324 -0.1316 6 5 6 5
BM_to_chars_as_string +0.0895 +0.0906 14 15 14 15
BM_format -0.1047 -0.1040 69 62 69 62
BM_format_to_back_inserterstd::string +0.0148 +0.0157 69 70 69 70
BM_format_to_back_inserter<std::vector> +0.0241 +0.0251 91 93 90 93
BM_format_to_back_inserter<std::list> +0.0222 +0.0232 234 240 234 240
BM_format_to_iterator/std::array +0.0196 +0.0205 59 60 59 60
BM_format_to_iterator/std::string +0.0266 +0.0275 59 60 59 60
BM_format_to_iterator/std::vector -0.0004 +0.0005 60 60 60 60
OVERALL_GEOMEAN -0.0045 -0.0036 0 0 0 0
write_string_comparison:
Before
Benchmark Time CPU Iterations
BM_sprintf/C string len = 6 4.82 ns 4.82 ns 145548481
BM_format/C string len = 6 55.1 ns 55.1 ns 12713693
BM_format_to_back_inserterstd::string/C string len = 6 55.1 ns 55.1 ns 12690821
BM_format_to_back_inserter<std::vector>/C string len = 6 71.5 ns 71.5 ns 9805550
BM_format_to_back_inserter<std::deque>/C string len = 6 154 ns 154 ns 4536256
BM_format_to_back_inserter<std::list>/C string len = 6 130 ns 130 ns 5348845
BM_format_to_iterator/std::array C string len = 6 44.9 ns 44.9 ns 15556175
BM_format_to_iterator/std::string C string len = 6 45.8 ns 45.8 ns 15290662
BM_format_to_iterator/std::vector C string len = 6 44.4 ns 44.4 ns 15807704
BM_format_to_iterator/std::deque C string len = 6 50.0 ns 50.0 ns 13973893
BM_format/string len = 6 54.7 ns 54.7 ns 12793406
BM_format_to_back_inserterstd::string/string len = 6 55.5 ns 55.5 ns 12620370
BM_format_to_back_inserter<std::vector>/string len = 6 70.4 ns 70.4 ns 9936490
BM_format_to_back_inserter<std::deque>/string len = 6 155 ns 155 ns 4521357
BM_format_to_back_inserter<std::list>/string len = 6 135 ns 135 ns 5201519
BM_format_to_iterator/std::array string len = 6 44.6 ns 44.6 ns 15703872
BM_format_to_iterator/std::string string len = 6 45.0 ns 45.0 ns 15545182
BM_format_to_iterator/std::vector string len = 6 45.0 ns 45.0 ns 15539130
BM_format_to_iterator/std::deque string len = 6 50.5 ns 50.5 ns 13846916
BM_format/string_view len = 6 54.6 ns 54.6 ns 12821301
BM_format_to_back_inserterstd::string/string_view len = 6 54.6 ns 54.6 ns 12827673
BM_format_to_back_inserter<std::vector>/string_view len = 6 69.9 ns 69.9 ns 9958365
BM_format_to_back_inserter<std::deque>/string_view len = 6 157 ns 157 ns 4462445
BM_format_to_back_inserter<std::list>/string_view len = 6 134 ns 134 ns 5232155
BM_format_to_iterator/std::array string_view len = 6 44.2 ns 44.2 ns 15871362
BM_format_to_iterator/std::string string_view len = 6 45.0 ns 45.0 ns 15582582
BM_format_to_iterator/std::vector string_view len = 6 45.1 ns 45.1 ns 15539906
BM_format_to_iterator/std::deque string_view len = 6 50.5 ns 50.5 ns 13896524
BM_sprintf/C string len = 60 4.15 ns 4.15 ns 168165776
BM_format/C string len = 60 73.8 ns 73.8 ns 9498291
BM_format_to_back_inserterstd::string/C string len = 60 73.6 ns 73.6 ns 9535890
BM_format_to_back_inserter<std::vector>/C string len = 60 83.1 ns 83.1 ns 8428154
BM_format_to_back_inserter<std::deque>/C string len = 60 281 ns 281 ns 2490093
BM_format_to_back_inserter<std::list>/C string len = 60 1157 ns 1157 ns 605227
BM_format_to_iterator/std::array C string len = 60 44.9 ns 44.9 ns 15604442
BM_format_to_iterator/std::string C string len = 60 45.8 ns 45.8 ns 15272196
BM_format_to_iterator/std::vector C string len = 60 44.6 ns 44.7 ns 15683193
BM_format_to_iterator/std::deque C string len = 60 50.6 ns 50.6 ns 13698382
BM_format/string len = 60 72.3 ns 72.3 ns 9648955
BM_format_to_back_inserterstd::string/string len = 60 72.0 ns 72.0 ns 9738373
BM_format_to_back_inserter<std::vector>/string len = 60 82.3 ns 82.3 ns 8517896
BM_format_to_back_inserter<std::deque>/string len = 60 280 ns 280 ns 2496054
BM_format_to_back_inserter<std::list>/string len = 60 1162 ns 1162 ns 602383
BM_format_to_iterator/std::array string len = 60 44.5 ns 44.5 ns 15727799
BM_format_to_iterator/std::string string len = 60 49.6 ns 49.6 ns 14096012
BM_format_to_iterator/std::vector string len = 60 49.8 ns 49.8 ns 14053734
BM_format_to_iterator/std::deque string len = 60 50.8 ns 50.8 ns 13801448
BM_format/string_view len = 60 72.5 ns 72.5 ns 9653638
BM_format_to_back_inserterstd::string/string_view len = 60 72.7 ns 72.7 ns 9598203
BM_format_to_back_inserter<std::vector>/string_view len = 60 81.9 ns 81.9 ns 8522306
BM_format_to_back_inserter<std::deque>/string_view len = 60 283 ns 283 ns 2475014
BM_format_to_back_inserter<std::list>/string_view len = 60 1162 ns 1162 ns 600924
BM_format_to_iterator/std::array string_view len = 60 44.1 ns 44.1 ns 15858951
BM_format_to_iterator/std::string string_view len = 60 44.9 ns 44.9 ns 15579340
BM_format_to_iterator/std::vector string_view len = 60 44.9 ns 44.9 ns 15586711
BM_format_to_iterator/std::deque string_view len = 60 50.0 ns 50.0 ns 13980804
BM_sprintf/C string len = 6000 116 ns 116 ns 6051541
BM_format/C string len = 6000 1000 ns 1000 ns 698647
BM_format_to_back_inserterstd::string/C string len = 6000 1002 ns 1002 ns 701440
BM_format_to_back_inserter<std::vector>/C string len = 6000 956 ns 956 ns 727585
BM_format_to_back_inserter<std::deque>/C string len = 6000 14898 ns 14898 ns 46994
BM_format_to_back_inserter<std::list>/C string len = 6000 114860 ns 114859 ns 6106
BM_format_to_iterator/std::array C string len = 6000 158 ns 158 ns 4425133
BM_format_to_iterator/std::string C string len = 6000 161 ns 161 ns 4335471
BM_format_to_iterator/std::vector C string len = 6000 157 ns 157 ns 4444174
BM_format_to_iterator/std::deque C string len = 6000 445 ns 445 ns 1574120
BM_format/string len = 6000 929 ns 929 ns 753630
BM_format_to_back_inserterstd::string/string len = 6000 930 ns 930 ns 752888
BM_format_to_back_inserter<std::vector>/string len = 6000 910 ns 910 ns 771111
BM_format_to_back_inserter<std::deque>/string len = 6000 14875 ns 14876 ns 47221
BM_format_to_back_inserter<std::list>/string len = 6000 114937 ns 114936 ns 6092
BM_format_to_iterator/std::array string len = 6000 118 ns 118 ns 5963643
BM_format_to_iterator/std::string string len = 6000 106 ns 106 ns 6584711
BM_format_to_iterator/std::vector string len = 6000 106 ns 106 ns 6583118
BM_format_to_iterator/std::deque string len = 6000 391 ns 391 ns 1790538
BM_format/string_view len = 6000 935 ns 935 ns 744348
BM_format_to_back_inserterstd::string/string_view len = 6000 934 ns 934 ns 742039
BM_format_to_back_inserter<std::vector>/string_view len = 6000 895 ns 895 ns 783527
BM_format_to_back_inserter<std::deque>/string_view len = 6000 14864 ns 14865 ns 47122
BM_format_to_back_inserter<std::list>/string_view len = 6000 115042 ns 115044 ns 6091
BM_format_to_iterator/std::array string_view len = 6000 115 ns 115 ns 6070197
BM_format_to_iterator/std::string string_view len = 6000 116 ns 116 ns 6035109
BM_format_to_iterator/std::vector string_view len = 6000 115 ns 115 ns 6067683
BM_format_to_iterator/std::deque string_view len = 6000 387 ns 387 ns 1803466
After
Benchmark Time CPU Iterations
BM_sprintf/C string len = 6 3.56 ns 3.56 ns 196337806
BM_format/C string len = 6 49.1 ns 49.1 ns 14241174
BM_format_to_back_inserterstd::string/C string len = 6 56.8 ns 56.8 ns 12341483
BM_format_to_back_inserter<std::vector>/C string len = 6 72.9 ns 72.9 ns 9610864
BM_format_to_back_inserter<std::deque>/C string len = 6 155 ns 155 ns 4528719
BM_format_to_back_inserter<std::list>/C string len = 6 137 ns 137 ns 5103340
BM_format_to_iterator/std::array C string len = 6 46.4 ns 46.4 ns 15081626
BM_format_to_iterator/std::string C string len = 6 47.0 ns 47.0 ns 14893458
BM_format_to_iterator/std::vector C string len = 6 45.9 ns 45.9 ns 15243762
BM_format_to_iterator/std::deque C string len = 6 52.6 ns 52.6 ns 13323560
BM_format/string len = 6 49.3 ns 49.3 ns 14181485
BM_format_to_back_inserterstd::string/string len = 6 55.4 ns 55.4 ns 12644078
BM_format_to_back_inserter<std::vector>/string len = 6 72.7 ns 72.7 ns 9618696
BM_format_to_back_inserter<std::deque>/string len = 6 154 ns 154 ns 4540873
BM_format_to_back_inserter<std::list>/string len = 6 134 ns 134 ns 5220153
BM_format_to_iterator/std::array string len = 6 46.5 ns 46.5 ns 15064445
BM_format_to_iterator/std::string string len = 6 47.3 ns 47.3 ns 14786851
BM_format_to_iterator/std::vector string len = 6 46.5 ns 46.5 ns 15069381
BM_format_to_iterator/std::deque string len = 6 52.9 ns 52.9 ns 13207437
BM_format/string_view len = 6 47.6 ns 47.6 ns 14688449
BM_format_to_back_inserterstd::string/string_view len = 6 56.1 ns 56.1 ns 12514239
BM_format_to_back_inserter<std::vector>/string_view len = 6 72.0 ns 72.0 ns 9705591
BM_format_to_back_inserter<std::deque>/string_view len = 6 152 ns 152 ns 4607470
BM_format_to_back_inserter<std::list>/string_view len = 6 134 ns 134 ns 5233005
BM_format_to_iterator/std::array string_view len = 6 46.0 ns 46.0 ns 15205542
BM_format_to_iterator/std::string string_view len = 6 46.5 ns 46.5 ns 15067775
BM_format_to_iterator/std::vector string_view len = 6 46.5 ns 46.5 ns 15057288
BM_format_to_iterator/std::deque string_view len = 6 51.8 ns 51.8 ns 13564649
BM_sprintf/C string len = 60 4.83 ns 4.83 ns 145020116
BM_format/C string len = 60 72.3 ns 72.3 ns 9665555
BM_format_to_back_inserterstd::string/C string len = 60 85.0 ns 85.0 ns 8249050
BM_format_to_back_inserter<std::vector>/C string len = 60 94.7 ns 94.7 ns 7398143
BM_format_to_back_inserter<std::deque>/C string len = 60 286 ns 286 ns 2452225
BM_format_to_back_inserter<std::list>/C string len = 60 1179 ns 1179 ns 595011
BM_format_to_iterator/std::array C string len = 60 46.1 ns 46.1 ns 15157525
BM_format_to_iterator/std::string C string len = 60 47.0 ns 47.0 ns 14899863
BM_format_to_iterator/std::vector C string len = 60 45.8 ns 45.8 ns 15272542
BM_format_to_iterator/std::deque C string len = 60 58.7 ns 58.7 ns 11958910
BM_format/string len = 60 61.7 ns 61.7 ns 11308865
BM_format_to_back_inserterstd::string/string len = 60 74.2 ns 74.2 ns 9401855
BM_format_to_back_inserter<std::vector>/string len = 60 86.6 ns 86.6 ns 8079197
BM_format_to_back_inserter<std::deque>/string len = 60 278 ns 278 ns 2519254
BM_format_to_back_inserter<std::list>/string len = 60 1169 ns 1170 ns 597703
BM_format_to_iterator/std::array string len = 60 46.4 ns 46.4 ns 15074759
BM_format_to_iterator/std::string string len = 60 47.3 ns 47.3 ns 14801107
BM_format_to_iterator/std::vector string len = 60 46.3 ns 46.4 ns 15085548
BM_format_to_iterator/std::deque string len = 60 52.2 ns 52.2 ns 13331015
BM_format/string_view len = 60 65.0 ns 65.0 ns 10756847
BM_format_to_back_inserterstd::string/string_view len = 60 78.5 ns 78.5 ns 9051370
BM_format_to_back_inserter<std::vector>/string_view len = 60 87.9 ns 87.9 ns 7946825
BM_format_to_back_inserter<std::deque>/string_view len = 60 280 ns 280 ns 2505999
BM_format_to_back_inserter<std::list>/string_view len = 60 1174 ns 1174 ns 594829
BM_format_to_iterator/std::array string_view len = 60 46.3 ns 46.3 ns 15149785
BM_format_to_iterator/std::string string_view len = 60 46.7 ns 46.7 ns 15002678
BM_format_to_iterator/std::vector string_view len = 60 46.7 ns 46.7 ns 14996445
BM_format_to_iterator/std::deque string_view len = 60 52.6 ns 52.6 ns 13255470
BM_sprintf/C string len = 6000 77.1 ns 77.1 ns 9099121
BM_format/C string len = 6000 350 ns 350 ns 2013049
BM_format_to_back_inserterstd::string/C string len = 6000 992 ns 992 ns 709093
BM_format_to_back_inserter<std::vector>/C string len = 6000 1016 ns 1016 ns 694784
BM_format_to_back_inserter<std::deque>/C string len = 6000 15158 ns 15159 ns 46125
BM_format_to_back_inserter<std::list>/C string len = 6000 115703 ns 115705 ns 6055
BM_format_to_iterator/std::array C string len = 6000 166 ns 166 ns 4224749
BM_format_to_iterator/std::string C string len = 6000 153 ns 153 ns 4573034
BM_format_to_iterator/std::vector C string len = 6000 150 ns 150 ns 4678898
BM_format_to_iterator/std::deque C string len = 6000 465 ns 465 ns 1506323
BM_format/string len = 6000 281 ns 281 ns 2462572
BM_format_to_back_inserterstd::string/string len = 6000 935 ns 935 ns 745376
BM_format_to_back_inserter<std::vector>/string len = 6000 939 ns 939 ns 747498
BM_format_to_back_inserter<std::deque>/string len = 6000 15069 ns 15069 ns 46429
BM_format_to_back_inserter<std::list>/string len = 6000 115537 ns 115539 ns 6063
BM_format_to_iterator/std::array string len = 6000 120 ns 120 ns 5849159
BM_format_to_iterator/std::string string len = 6000 108 ns 108 ns 6482306
BM_format_to_iterator/std::vector string len = 6000 107 ns 107 ns 6547915
BM_format_to_iterator/std::deque string len = 6000 397 ns 397 ns 1763729
BM_format/string_view len = 6000 282 ns 282 ns 2490133
BM_format_to_back_inserterstd::string/string_view len = 6000 927 ns 927 ns 750931
BM_format_to_back_inserter<std::vector>/string_view len = 6000 946 ns 946 ns 735544
BM_format_to_back_inserter<std::deque>/string_view len = 6000 15028 ns 15029 ns 46612
BM_format_to_back_inserter<std::list>/string_view len = 6000 115153 ns 115153 ns 6057
BM_format_to_iterator/std::array string_view len = 6000 122 ns 122 ns 5753940
BM_format_to_iterator/std::string string_view len = 6000 108 ns 108 ns 6507555
BM_format_to_iterator/std::vector string_view len = 6000 107 ns 107 ns 6510450
BM_format_to_iterator/std::deque string_view len = 6000 398 ns 398 ns 1762517
Comparison
Benchmark Time CPU Time Old Time New CPU Old CPU New
BM_sprintf/C string len = 6 -0.2599 -0.2599 5 4 5 4
BM_format/C string len = 6 -0.1094 -0.1095 55 49 55 49
BM_format_to_back_inserterstd::string/C string len = 6 +0.0316 +0.0316 55 57 55 57
BM_format_to_back_inserter<std::vector>/C string len = 6 +0.0204 +0.0204 71 73 71 73
BM_format_to_back_inserter<std::deque>/C string len = 6 +0.0023 +0.0023 154 155 154 155
BM_format_to_back_inserter<std::list>/C string len = 6 +0.0521 +0.0520 130 137 130 137
BM_format_to_iterator/std::array C string len = 6 +0.0317 +0.0317 45 46 45 46
BM_format_to_iterator/std::string C string len = 6 +0.0265 +0.0265 46 47 46 47
BM_format_to_iterator/std::vector C string len = 6 +0.0345 +0.0345 44 46 44 46
BM_format_to_iterator/std::deque C string len = 6 +0.0511 +0.0511 50 53 50 53
BM_format/string len = 6 -0.0981 -0.0981 55 49 55 49
BM_format_to_back_inserterstd::string/string len = 6 -0.0028 -0.0028 56 55 56 55
BM_format_to_back_inserter<std::vector>/string len = 6 +0.0331 +0.0331 70 73 70 73
BM_format_to_back_inserter<std::deque>/string len = 6 -0.0040 -0.0040 155 154 155 154
BM_format_to_back_inserter<std::list>/string len = 6 -0.0019 -0.0019 135 134 135 134
BM_format_to_iterator/std::array string len = 6 +0.0427 +0.0427 45 46 45 46
BM_format_to_iterator/std::string string len = 6 +0.0515 +0.0515 45 47 45 47
BM_format_to_iterator/std::vector string len = 6 +0.0316 +0.0316 45 46 45 46
BM_format_to_iterator/std::deque string len = 6 +0.0475 +0.0475 51 53 51 53
BM_format/string_view len = 6 -0.1267 -0.1267 55 48 55 48
BM_format_to_back_inserterstd::string/string_view len = 6 +0.0283 +0.0283 55 56 55 56
BM_format_to_back_inserter<std::vector>/string_view len = 6 +0.0291 +0.0291 70 72 70 72
BM_format_to_back_inserter<std::deque>/string_view len = 6 -0.0305 -0.0306 157 152 157 152
BM_format_to_back_inserter<std::list>/string_view len = 6 -0.0012 -0.0012 134 134 134 134
BM_format_to_iterator/std::array string_view len = 6 +0.0426 +0.0426 44 46 44 46
BM_format_to_iterator/std::string string_view len = 6 +0.0322 +0.0322 45 46 45 46
BM_format_to_iterator/std::vector string_view len = 6 +0.0309 +0.0309 45 46 45 46
BM_format_to_iterator/std::deque string_view len = 6 +0.0248 +0.0248 51 52 51 52
BM_sprintf/C string len = 60 +0.1633 +0.1633 4 5 4 5
BM_format/C string len = 60 -0.0203 -0.0203 74 72 74 72
BM_format_to_back_inserterstd::string/C string len = 60 +0.1548 +0.1548 74 85 74 85
BM_format_to_back_inserter<std::vector>/C string len = 60 +0.1395 +0.1395 83 95 83 95
BM_format_to_back_inserter<std::deque>/C string len = 60 +0.0157 +0.0157 281 286 281 286
BM_format_to_back_inserter<std::list>/C string len = 60 +0.0191 +0.0191 1157 1179 1157 1179
BM_format_to_iterator/std::array C string len = 60 +0.0283 +0.0283 45 46 45 46
BM_format_to_iterator/std::string C string len = 60 +0.0251 +0.0252 46 47 46 47
BM_format_to_iterator/std::vector C string len = 60 +0.0263 +0.0263 45 46 45 46
BM_format_to_iterator/std::deque C string len = 60 +0.1592 +0.1591 51 59 51 59
BM_format/string len = 60 -0.1466 -0.1466 72 62 72 62
BM_format_to_back_inserterstd::string/string len = 60 +0.0299 +0.0299 72 74 72 74
BM_format_to_back_inserter<std::vector>/string len = 60 +0.0522 +0.0522 82 87 82 87
BM_format_to_back_inserter<std::deque>/string len = 60 -0.0099 -0.0099 280 278 280 278
BM_format_to_back_inserter<std::list>/string len = 60 +0.0062 +0.0062 1162 1169 1162 1170
BM_format_to_iterator/std::array string len = 60 +0.0430 +0.0430 45 46 45 46
BM_format_to_iterator/std::string string len = 60 -0.0466 -0.0466 50 47 50 47
BM_format_to_iterator/std::vector string len = 60 -0.0693 -0.0693 50 46 50 46
BM_format_to_iterator/std::deque string len = 60 +0.0275 +0.0275 51 52 51 52
BM_format/string_view len = 60 -0.1034 -0.1034 73 65 73 65
BM_format_to_back_inserterstd::string/string_view len = 60 +0.0790 +0.0790 73 78 73 78
BM_format_to_back_inserter<std::vector>/string_view len = 60 +0.0735 +0.0735 82 88 82 88
BM_format_to_back_inserter<std::deque>/string_view len = 60 -0.0103 -0.0104 283 280 283 280
BM_format_to_back_inserter<std::list>/string_view len = 60 +0.0101 +0.0101 1162 1174 1162 1174
BM_format_to_iterator/std::array string_view len = 60 +0.0484 +0.0484 44 46 44 46
BM_format_to_iterator/std::string string_view len = 60 +0.0387 +0.0387 45 47 45 47
BM_format_to_iterator/std::vector string_view len = 60 +0.0402 +0.0402 45 47 45 47
BM_format_to_iterator/std::deque string_view len = 60 +0.0508 +0.0508 50 53 50 53
BM_sprintf/C string len = 6000 -0.3337 -0.3337 116 77 116 77
BM_format/C string len = 6000 -0.6500 -0.6500 1000 350 1000 350
BM_format_to_back_inserterstd::string/C string len = 6000 -0.0104 -0.0105 1002 992 1002 992
BM_format_to_back_inserter<std::vector>/C string len = 6000 +0.0630 +0.0630 956 1016 956 1016
BM_format_to_back_inserter<std::deque>/C string len = 6000 +0.0175 +0.0175 14898 15158 14898 15159
BM_format_to_back_inserter<std::list>/C string len = 6000 +0.0073 +0.0074 114860 115703 114859 115705
BM_format_to_iterator/std::array C string len = 6000 +0.0504 +0.0504 158 166 158 166
BM_format_to_iterator/std::string C string len = 6000 -0.0486 -0.0486 161 153 161 153
BM_format_to_iterator/std::vector C string len = 6000 -0.0483 -0.0483 157 150 157 150
BM_format_to_iterator/std::deque C string len = 6000 +0.0459 +0.0459 445 465 445 465
BM_format/string len = 6000 -0.6975 -0.6975 929 281 929 281
BM_format_to_back_inserterstd::string/string len = 6000 +0.0050 +0.0050 930 935 930 935
BM_format_to_back_inserter<std::vector>/string len = 6000 +0.0321 +0.0322 910 939 910 939
BM_format_to_back_inserter<std::deque>/string len = 6000 +0.0130 +0.0130 14875 15069 14876 15069
BM_format_to_back_inserter<std::list>/string len = 6000 +0.0052 +0.0052 114937 115537 114936 115539
BM_format_to_iterator/std::array string len = 6000 +0.0211 +0.0211 118 120 118 120
BM_format_to_iterator/std::string string len = 6000 +0.0146 +0.0146 106 108 106 108
BM_format_to_iterator/std::vector string len = 6000 +0.0048 +0.0048 106 107 106 107
BM_format_to_iterator/std::deque string len = 6000 +0.0150 +0.0150 391 397 391 397
BM_format/string_view len = 6000 -0.6989 -0.6989 935 282 935 282
BM_format_to_back_inserterstd::string/string_view len = 6000 -0.0083 -0.0083 934 927 934 927
BM_format_to_back_inserter<std::vector>/string_view len = 6000 +0.0566 +0.0566 895 946 895 946
BM_format_to_back_inserter<std::deque>/string_view len = 6000 +0.0111 +0.0110 14864 15028 14865 15029
BM_format_to_back_inserter<std::list>/string_view len = 6000 +0.0010 +0.0009 115042 115153 115044 115153
BM_format_to_iterator/std::array string_view len = 6000 +0.0560 +0.0560 115 122 115 122
BM_format_to_iterator/std::string string_view len = 6000 -0.0693 -0.0693 116 108 116 108
BM_format_to_iterator/std::vector string_view len = 6000 -0.0703 -0.0703 115 107 115 107
BM_format_to_iterator/std::deque string_view len = 6000 +0.0271 +0.0271 387 398 387 398
OVERALL_GEOMEAN -0.0350 -0.0350 0 0 0 0
format:
Before
Benchmark Time CPU Iterations UserCounters...
BM_format_string/1 55.5 ns 55.5 ns 12463288 bytes_per_second=17.187Mi/s
BM_format_string/2 27.6 ns 27.6 ns 25421994 bytes_per_second=69.1874Mi/s
BM_format_string/4 14.0 ns 14.0 ns 49785656 bytes_per_second=271.524Mi/s
BM_format_string/8 7.07 ns 7.07 ns 99247048 bytes_per_second=1.05444Gi/s
BM_format_string/16 3.53 ns 3.53 ns 198072224 bytes_per_second=4.21726Gi/s
BM_format_string/32 2.31 ns 2.31 ns 302771136 bytes_per_second=12.9138Gi/s
BM_format_string/64 1.15 ns 1.15 ns 606646976 bytes_per_second=51.7527Gi/s
BM_format_string/128 0.597 ns 0.597 ns 1172263936 bytes_per_second=199.688Gi/s
BM_format_string/256 0.327 ns 0.327 ns 2148927744 bytes_per_second=728.678Gi/s
BM_format_string/512 0.248 ns 0.248 ns 2821635584 bytes_per_second=1.8779Ti/s
BM_format_string/1024 0.203 ns 0.203 ns 3433579520 bytes_per_second=4.57798Ti/s
BM_format_string/2048 0.164 ns 0.164 ns 4277524480 bytes_per_second=11.3793Ti/s
BM_format_string/4096 0.137 ns 0.137 ns 5122269184 bytes_per_second=27.2589Ti/s
BM_format_string/8192 0.126 ns 0.126 ns 5564243968 bytes_per_second=59.2812Ti/s
BM_format_string/16384 0.136 ns 0.136 ns 5153013760 bytes_per_second=109.492Ti/s
BM_format_string/32768 0.135 ns 0.135 ns 5165088768 bytes_per_second=219.985Ti/s
BM_format_string/65536 0.243 ns 0.242 ns 2930180096 bytes_per_second=246.57Ti/s
BM_format_string/131072 0.490 ns 0.489 ns 1437990912 bytes_per_second=243.75Ti/s
BM_format_string/262144 0.593 ns 0.592 ns 1183055872 bytes_per_second=402.931Ti/s
BM_format_string/524288 0.643 ns 0.641 ns 1092616192 bytes_per_second=743.445Ti/s
BM_format_string/1048576 0.669 ns 0.668 ns 1045430272 bytes_per_second=1.39478Pi/s
BM_format_string<wchar_t>/1 56.0 ns 55.9 ns 12511543 bytes_per_second=68.2628Mi/s
BM_format_string<wchar_t>/2 28.0 ns 27.9 ns 25062366 bytes_per_second=273.519Mi/s
BM_format_string<wchar_t>/4 14.0 ns 14.0 ns 50257068 bytes_per_second=1.06742Gi/s
BM_format_string<wchar_t>/8 9.24 ns 9.21 ns 76118616 bytes_per_second=3.23473Gi/s
BM_format_string<wchar_t>/16 4.66 ns 4.65 ns 151420352 bytes_per_second=12.8261Gi/s
BM_format_string<wchar_t>/32 2.35 ns 2.35 ns 298417600 bytes_per_second=50.7972Gi/s
BM_format_string<wchar_t>/64 1.35 ns 1.34 ns 521608704 bytes_per_second=177.502Gi/s
BM_format_string<wchar_t>/128 1.03 ns 1.03 ns 680946304 bytes_per_second=463.91Gi/s
BM_format_string<wchar_t>/256 0.849 ns 0.847 ns 825871104 bytes_per_second=1.09901Ti/s
BM_format_string<wchar_t>/512 0.681 ns 0.679 ns 1033245696 bytes_per_second=2.74383Ti/s
BM_format_string<wchar_t>/1024 0.576 ns 0.575 ns 1219777536 bytes_per_second=6.48343Ti/s
BM_format_string<wchar_t>/2048 0.515 ns 0.514 ns 1361629184 bytes_per_second=14.4881Ti/s
BM_format_string<wchar_t>/4096 0.546 ns 0.545 ns 1285427200 bytes_per_second=27.3342Ti/s
BM_format_string<wchar_t>/8192 0.550 ns 0.548 ns 1277042688 bytes_per_second=54.3343Ti/s
BM_format_string<wchar_t>/16384 0.583 ns 0.581 ns 1203879936 bytes_per_second=102.544Ti/s
BM_format_string<wchar_t>/32768 0.640 ns 0.638 ns 1095139328 bytes_per_second=186.82Ti/s
BM_format_string<wchar_t>/65536 0.642 ns 0.640 ns 1093337088 bytes_per_second=372.283Ti/s
BM_format_string<wchar_t>/131072 0.655 ns 0.654 ns 1070596096 bytes_per_second=729.428Ti/s
BM_format_string<wchar_t>/262144 2.68 ns 2.67 ns 262406144 bytes_per_second=357.446Ti/s
BM_format_string<wchar_t>/524288 2.13 ns 2.13 ns 330301440 bytes_per_second=897.574Ti/s
BM_format_string<wchar_t>/1048576 2.44 ns 2.43 ns 288358400 bytes_per_second=1.53149Pi/s
After
Benchmark Time CPU Iterations UserCounters...
BM_format_string/1 49.3 ns 49.1 ns 14230742 bytes_per_second=19.4054Mi/s
BM_format_string/2 24.8 ns 24.8 ns 28253114 bytes_per_second=77.0465Mi/s
BM_format_string/4 12.4 ns 12.4 ns 56381440 bytes_per_second=307.462Mi/s
BM_format_string/8 6.23 ns 6.21 ns 112951232 bytes_per_second=1.19924Gi/s
BM_format_string/16 3.10 ns 3.09 ns 225822496 bytes_per_second=4.81566Gi/s
BM_format_string/32 1.98 ns 1.98 ns 354208192 bytes_per_second=15.0825Gi/s
BM_format_string/64 0.990 ns 0.987 ns 714296384 bytes_per_second=60.3689Gi/s
BM_format_string/128 0.504 ns 0.503 ns 1399988480 bytes_per_second=237.144Gi/s
BM_format_string/256 0.335 ns 0.334 ns 2084828928 bytes_per_second=712.859Gi/s
BM_format_string/512 0.187 ns 0.186 ns 3760082432 bytes_per_second=2.50102Ti/s
BM_format_string/1024 0.109 ns 0.108 ns 6455339008 bytes_per_second=8.59552Ti/s
BM_format_string/2048 0.080 ns 0.080 ns 8754006016 bytes_per_second=23.2731Ti/s
BM_format_string/4096 0.051 ns 0.051 ns 13786701824 bytes_per_second=73.4088Ti/s
BM_format_string/8192 0.042 ns 0.042 ns 16851435520 bytes_per_second=178.737Ti/s
BM_format_string/16384 0.122 ns 0.122 ns 5746589696 bytes_per_second=122.029Ti/s
BM_format_string/32768 0.107 ns 0.106 ns 6571687936 bytes_per_second=280.122Ti/s
BM_format_string/65536 0.102 ns 0.102 ns 6876626944 bytes_per_second=584.381Ti/s
BM_format_string/131072 0.106 ns 0.105 ns 6643122176 bytes_per_second=1.10413Pi/s
BM_format_string/262144 0.589 ns 0.587 ns 1189609472 bytes_per_second=406.438Ti/s
BM_format_string/524288 0.644 ns 0.642 ns 1088946176 bytes_per_second=743.064Ti/s
BM_format_string/1048576 0.672 ns 0.670 ns 1039138816 bytes_per_second=1.38968Pi/s
BM_format_string<wchar_t>/1 48.7 ns 48.6 ns 14423178 bytes_per_second=78.5263Mi/s
BM_format_string<wchar_t>/2 24.4 ns 24.3 ns 28831748 bytes_per_second=313.869Mi/s
BM_format_string<wchar_t>/4 12.2 ns 12.2 ns 57661220 bytes_per_second=1.2253Gi/s
BM_format_string<wchar_t>/8 7.81 ns 7.79 ns 89887592 bytes_per_second=3.82675Gi/s
BM_format_string<wchar_t>/16 3.88 ns 3.87 ns 180450176 bytes_per_second=15.418Gi/s
BM_format_string<wchar_t>/32 1.98 ns 1.98 ns 354046112 bytes_per_second=60.3262Gi/s
BM_format_string<wchar_t>/64 1.02 ns 1.01 ns 689511680 bytes_per_second=234.906Gi/s
BM_format_string<wchar_t>/128 0.577 ns 0.576 ns 1215361408 bytes_per_second=828.297Gi/s
BM_format_string<wchar_t>/256 0.804 ns 0.802 ns 872249088 bytes_per_second=1.16111Ti/s
BM_format_string<wchar_t>/512 0.642 ns 0.641 ns 1093858304 bytes_per_second=2.90766Ti/s
BM_format_string<wchar_t>/1024 0.517 ns 0.516 ns 1354798080 bytes_per_second=7.21845Ti/s
BM_format_string<wchar_t>/2048 0.469 ns 0.467 ns 1491910656 bytes_per_second=15.9386Ti/s
BM_format_string<wchar_t>/4096 0.794 ns 0.792 ns 883822592 bytes_per_second=18.8156Ti/s
BM_format_string<wchar_t>/8192 0.722 ns 0.720 ns 971718656 bytes_per_second=41.3996Ti/s
BM_format_string<wchar_t>/16384 0.703 ns 0.701 ns 998031360 bytes_per_second=85.0369Ti/s
BM_format_string<wchar_t>/32768 0.724 ns 0.720 ns 971538432 bytes_per_second=165.467Ti/s
BM_format_string<wchar_t>/65536 0.745 ns 0.744 ns 941228032 bytes_per_second=320.665Ti/s
BM_format_string<wchar_t>/131072 0.742 ns 0.740 ns 945422336 bytes_per_second=644.032Ti/s
BM_format_string<wchar_t>/262144 2.99 ns 2.98 ns 234881024 bytes_per_second=319.75Ti/s
BM_format_string<wchar_t>/524288 3.31 ns 3.30 ns 212860928 bytes_per_second=578.085Ti/s
BM_format_string<wchar_t>/1048576 2.69 ns 2.68 ns 260046848 bytes_per_second=1.39081Pi/s
Comparison
Benchmark Time CPU Time Old Time New CPU Old CPU New
BM_format_string/1 -0.1122 -0.1143 55 49 55 49
BM_format_string/2 -0.0999 -0.1020 28 25 28 25
BM_format_string/4 -0.1148 -0.1169 14 12 14 12
BM_format_string/8 -0.1186 -0.1207 7 6 7 6
BM_format_string/16 -0.1222 -0.1243 4 3 4 3
BM_format_string/32 -0.1417 -0.1438 2 2 2 2
BM_format_string/64 -0.1407 -0.1427 1 1 1 1
BM_format_string/128 -0.1559 -0.1579 1 1 1 1
BM_format_string/256 +0.0249 +0.0222 0 0 0 0
BM_format_string/512 -0.2473 -0.2491 0 0 0 0
BM_format_string/1024 -0.4661 -0.4674 0 0 0 0
BM_format_string/2048 -0.5096 -0.5111 0 0 0 0
BM_format_string/4096 -0.6278 -0.6287 0 0 0 0
BM_format_string/8192 -0.6674 -0.6683 0 0 0 0
BM_format_string/16384 -0.1005 -0.1027 0 0 0 0
BM_format_string/32768 -0.2127 -0.2147 0 0 0 0
BM_format_string/65536 -0.5796 -0.5781 0 0 0 0
BM_format_string/131072 -0.7844 -0.7844 0 0 0 0
BM_format_string/262144 -0.0073 -0.0086 1 1 1 1
BM_format_string/524288 +0.0017 +0.0005 1 1 1 1
BM_format_string/1048576 +0.0039 +0.0037 1 1 1 1
BM_format_string<wchar_t>/1 -0.1304 -0.1307 56 49 56 49
BM_format_string<wchar_t>/2 -0.1285 -0.1286 28 24 28 24
BM_format_string<wchar_t>/4 -0.1288 -0.1288 14 12 14 12
BM_format_string<wchar_t>/8 -0.1547 -0.1547 9 8 9 8
BM_format_string<wchar_t>/16 -0.1681 -0.1681 5 4 5 4
BM_format_string<wchar_t>/32 -0.1579 -0.1580 2 2 2 2
BM_format_string<wchar_t>/64 -0.2443 -0.2444 1 1 1 1
BM_format_string<wchar_t>/128 -0.4400 -0.4399 1 1 1 1
BM_format_string<wchar_t>/256 -0.0535 -0.0535 1 1 1 1
BM_format_string<wchar_t>/512 -0.0563 -0.0563 1 1 1 1
BM_format_string<wchar_t>/1024 -0.1018 -0.1018 1 1 1 1
BM_format_string<wchar_t>/2048 -0.0910 -0.0910 1 0 1 0
BM_format_string<wchar_t>/4096 +0.4528 +0.4527 1 1 1 1
BM_format_string<wchar_t>/8192 +0.3121 +0.3124 1 1 1 1
BM_format_string<wchar_t>/16384 +0.2059 +0.2059 1 1 1 1
BM_format_string<wchar_t>/32768 +0.1316 +0.1290 1 1 1 1
BM_format_string<wchar_t>/65536 +0.1604 +0.1610 1 1 1 1
BM_format_string<wchar_t>/131072 +0.1326 +0.1326 1 1 1 1
BM_format_string<wchar_t>/262144 +0.1181 +0.1179 3 3 3 3
BM_format_string<wchar_t>/524288 +0.5515 +0.5527 2 3 2 3
BM_format_string<wchar_t>/1048576 +0.1007 +0.1011 2 3 2 3
OVERALL_GEOMEAN -0.1685 -0.1693 0 0 0 0