I have a very simple Google Benchmark program that benchmarks a function taking two integer arguments, I'm trying to use the benchmark to see how exactly does the time the function takes increase as the second argument's value increases from 1
to 100
, so with the first argument staying with the same value of 999999
.
The way to achieve this that looked the most logical to me was to use Google Benchmark's Ranges()
function like this:
// registering function 'largestDivisorOdd' as a benchmark
BENCHMARK(largestDivisorOdd) ->Ranges( { {999999, 999999}, {1,100} } );
The resulting output was this:
-----------------------------------------------------------------------
Benchmark Time CPU Iterations
-----------------------------------------------------------------------
largestDivisorOdd/999999/1 116 ns 116 ns 6018141
largestDivisorOdd/999999/8 205 ns 205 ns 3485489
largestDivisorOdd/999999/64 2715 ns 2715 ns 260611
largestDivisorOdd/999999/100 2710 ns 2710 ns 256160
My problem is that it seems Google Benchmark has made the range from only values of an exponential increase from 1
to 100
, resulting in only 4 benchmarks of 4 different values for the second parameter, instead of 100 benchmarks of 100 values from 1
to 100
as I expected and wanted.
CodePudding user response:
One of the following should work:
BENCHMARK(largestDivisorOdd)
->ArgsProduct({
benchmark::CreateRange(999999, 999999, /*multi=*/2), // This is probably not what you want
benchmark::CreateDenseRange(1, 100, /*step=*/1) // This creates a DenseRange from 1 to 100
})
Or create your own custom arguments:
static void CustomArguments(benchmark::internal::Benchmark* b) {
for (int i = 999999; i <= 999999; i)
for (int j = 1; j <= 100; j )
b->Args({i, j});
}
BENCHMARK(BM_SetInsert)->Apply(CustomArguments);
Both examples are taken from the User Guide