C++17 drop-in replacement for std::allocator, using mi_malloc for a back-end.
Below the results for pushing a random number of values into a std::vector that is already filled with a random number of values (the total size after the operation is at most 4, 64, 1024 etc.), comparing the std::allocator and sax::mi_allocator. Binary compiled with vc-16.2.4, AVX2, /LTCG.
sax::mi_allocator is 60% faster for allocations up to size 4, up till 325% faster for (consecutive) allocations up till 4'194'304. After that (at some point) on my machine, disk-swapping starts to kick in.
09/08/19 10:40:55
Running Y:\REPOS\mi_allocator\x64\Release\mi_allocator.exe
Run on (4 X 1995 MHz CPU s)
CPU Caches:
L1 Data 32K (x2)
L1 Instruction 32K (x2)
L2 Unified 262K (x2)
L3 Unified 3145K (x1)
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Benchmark Time CPU Iterations
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bm_emplace_back_random<std::vector<value_type>>/4/4194304/repeats:4_mean 654 ns 652 ns 4
bm_emplace_back_random<std::vector<value_type>>/4/4194304/repeats:4_median 652 ns 656 ns 4
bm_emplace_back_random<std::vector<value_type>>/4/4194304/repeats:4_stddev 13.4 ns 34.6 ns 4
bm_emplace_back_random<std::vector<value_type>>/64/4194304/repeats:4_mean 948 ns 994 ns 4
bm_emplace_back_random<std::vector<value_type>>/64/4194304/repeats:4_median 954 ns 994 ns 4
bm_emplace_back_random<std::vector<value_type>>/64/4194304/repeats:4_stddev 15.7 ns 65.1 ns 4
bm_emplace_back_random<std::vector<value_type>>/1024/4194304/repeats:4_mean 3626 ns 3632 ns 4
bm_emplace_back_random<std::vector<value_type>>/1024/4194304/repeats:4_median 3524 ns 3498 ns 4
bm_emplace_back_random<std::vector<value_type>>/1024/4194304/repeats:4_stddev 354 ns 354 ns 4
bm_emplace_back_random<std::vector<value_type>>/16384/4194304/repeats:4_mean 25006 ns 23228 ns 4
bm_emplace_back_random<std::vector<value_type>>/16384/4194304/repeats:4_median 25019 ns 22600 ns 4
bm_emplace_back_random<std::vector<value_type>>/16384/4194304/repeats:4_stddev 386 ns 2234 ns 4
bm_emplace_back_random<std::vector<value_type>>/262144/4194304/repeats:4_mean 1742890 ns 1811594 ns 4
bm_emplace_back_random<std::vector<value_type>>/262144/4194304/repeats:4_median 1745266 ns 1788949 ns 4
bm_emplace_back_random<std::vector<value_type>>/262144/4194304/repeats:4_stddev 10217 ns 97837 ns 4
bm_emplace_back_random<std::vector<value_type>>/4194304/4194304/repeats:4_mean 34633198 ns 34268466 ns 4
bm_emplace_back_random<std::vector<value_type>>/4194304/4194304/repeats:4_median 34621030 ns 33735795 ns 4
bm_emplace_back_random<std::vector<value_type>>/4194304/4194304/repeats:4_stddev 562463 ns 1867866 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/4/4194304/repeats:4_mean 409 ns 398 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/4/4194304/repeats:4_median 409 ns 401 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/4/4194304/repeats:4_stddev 2.78 ns 10.3 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/64/4194304/repeats:4_mean 533 ns 499 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/64/4194304/repeats:4_median 532 ns 467 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/64/4194304/repeats:4_stddev 2.28 ns 77.6 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/1024/4194304/repeats:4_mean 1802 ns 1750 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/1024/4194304/repeats:4_median 1803 ns 1742 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/1024/4194304/repeats:4_stddev 4.89 ns 159 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/16384/4194304/repeats:4_mean 36056 ns 35871 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/16384/4194304/repeats:4_median 36080 ns 35679 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/16384/4194304/repeats:4_stddev 165 ns 735 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/262144/4194304/repeats:4_mean 525654 ns 498744 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/262144/4194304/repeats:4_median 526444 ns 481306 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/262144/4194304/repeats:4_stddev 10658 ns 50139 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/4194304/4194304/repeats:4_mean 10638554 ns 10463170 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/4194304/4194304/repeats:4_median 10649298 ns 10742188 ns 4
bm_emplace_back_random<std::vector<value_type, sax::mi_allocator<value_type>>>/4194304/4194304/repeats:4_stddev 74735 ns 867502 ns 4