[libc++][format][2/7] Optimizes c-string arguments. #101805
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@llvm/pr-subscribers-libcxx Author: Mark de Wever (mordante) ChangesThe 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>. BeforeBenchmark Time CPU IterationsBM_sprintf/C string len = 6 4.81 ns 4.80 ns 145890280 AfterBenchmark Time CPU IterationsBM_sprintf/C string len = 6 4.83 ns 4.83 ns 145502957 Comparing libcxx/benchmarks/1/write_string_comparison.bench.out to libcxx/benchmarks/2/write_string_comparison.bench.out
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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
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/186/builds/2983 Here is the relevant piece of the build log for the reference |
* commit 'FETCH_HEAD': [X86] getIntImmCostInst - pull out repeated Imm.getBitWidth() calls. NFC. [X86] Add test coverage for llvm#111323 [Driver] Use empty multilib file in another test (llvm#111352) [clang][OpenMP][test] Use x86_64-linux-gnu triple for test referencing avx512f feature (llvm#111337) [doc] Fix Kaleidoscope tutorial chapter 3 code snippet and full listing discrepancies (llvm#111289) [Flang][OpenMP] Improve entry block argument creation and binding (llvm#110267) [x86] combineMul - handle 0/-1 KnownBits cases before MUL_IMM logic (REAPPLIED) [llvm-dis] Fix non-deterministic disassembly across multiple inputs (llvm#110988) [lldb][test] TestDataFormatterLibcxxOptionalSimulator.py: change order of ifdefs [lldb][test] Add libcxx-simulators test for std::optional (llvm#111133) [x86] combineMul - use computeKnownBits directly to find MUL_IMM constant splat. (REAPPLIED) Reland "[lldb][test] TestDataFormatterLibcxxStringSimulator.py: add new padding layout" (llvm#111123) Revert "[x86] combineMul - use computeKnownBits directly to find MUL_IMM constant splat." update_test_checks: fix a simple regression (llvm#111347) [LegalizeVectorTypes] Always widen fabs (llvm#111298) [lsan] Make ReportUnsuspendedThreads return bool also for Fuchsia [mlir][vector] Add more tests for ConvertVectorToLLVM (6/n) (llvm#111121) [bazel] port 9144fed [SystemZ] Remove inlining threshold multiplier. (llvm#106058) [LegalizeVectorTypes] When widening don't check for libcalls if promoted (llvm#111297) [clang][Driver] Improve multilib custom error reporting (llvm#110804) [clang][Driver] Rename "FatalError" key to "Error" in multilib.yaml (llvm#110804) [LLVM][Maintainers] Update release managers (llvm#111164) [Clang][Driver] Add option to provide path for multilib's YAML config file (llvm#109640) [LoopVectorize] Remove redundant code in emitSCEVChecks (llvm#111132) [AMDGPU] Only emit SCOPE_SYS global_wb (llvm#110636) [ELF] Change Ctx::target to unique_ptr (llvm#111260) [ELF] Pass Ctx & to some free functions [RISCV] Only disassemble fcvtmod.w.d if the rounding mode is rtz. (llvm#111308) [Clang] Remove the special-casing for RequiresExprBodyDecl in BuildResolvedCallExpr() after fd87d76 (llvm#111277) [ELF] Pass Ctx & to InputFile [clang-format] Add AlignFunctionDeclarations to AlignConsecutiveDeclarations (llvm#108241) [AMDGPU] Support preloading hidden kernel arguments (llvm#98861) [ELF] Move static nextGroupId isInGroup to LinkerDriver [clangd] Add ArgumentLists config option under Completion (llvm#111322) [ELF] Pass Ctx & to SyntheticSections [ELF] Pass Ctx & to Symbols [ELF] Pass Ctx & to Symbols [ELF] getRelocTargetVA: pass Ctx and Relocation. NFC [clang-tidy] Avoid capturing a local variable in a static lambda in UseRangesCheck (llvm#111282) [VPlan] Use pointer to member 0 as VPInterleaveRecipe's pointer arg. (llvm#106431) [clangd] Simplify ternary expressions with std::optional::value_or (NFC) (llvm#111309) [libc++][format][2/3] Optimizes c-string arguments. (llvm#101805) [RISCV] Combine RVBUnary and RVKUnary into classes that are more similar to ALU(W)_r(r/i). NFC (llvm#111279) [ELF] Pass Ctx & to InputFiles [libc] GPU RPC interface: add return value to `rpc_host_call` (llvm#111288) Signed-off-by: kyvangka1610 <[email protected]>
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, convert 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>.