Code example for this blog post (insert link here later)
$ bazel build -c opt --copt=-O3 :bm_loop
$ ./bazel-bin/bm_loop
---------------------------------------------------------------------
Benchmark Time CPU Iterations
---------------------------------------------------------------------
BM_LoopNo1/16 131 ns 108 ns 8960000
BM_LoopNo1/64 1965 ns 1726 ns 407273
BM_LoopNo1/512 129987 ns 97656 ns 5600
BM_LoopNo1/4096 9786057 ns 8789062 ns 112
BM_LoopNo1/8192 39223035 ns 21354167 ns 30
BM_LoopNo2/16 128 ns 73.4 ns 10000000
BM_LoopNo2/64 1975 ns 1420 ns 407273
BM_LoopNo2/512 784854 ns 619071 ns 1792
BM_LoopNo2/4096 139502128 ns 111111111 ns 9
BM_LoopNo2/8192 794375658 ns 656250000 ns 1
BM_LoopNo1WithBigElem/16 101 ns 83.7 ns 8960000
BM_LoopNo1WithBigElem/64 3625 ns 3139 ns 224000
BM_LoopNo1WithBigElem/512 1043527 ns 731485 ns 1303
BM_LoopNo1WithBigElem/2048 27770281 ns 15988372 ns 43
BM_LoopNo2WithBigElem/16 139 ns 116 ns 10000000
BM_LoopNo2WithBigElem/64 11965 ns 7500 ns 100000
BM_LoopNo2WithBigElem/512 2746846 ns 1726423 ns 896
BM_LoopNo2WithBigElem/2048 51166731 ns 30330882 ns 17To investigate performance issue, you can use below commands:
perf record ... # Need to get a Linux box