Important default behaviour

As in library benchmarks, the environment variables are cleared before running a binary benchmark. Have a look at the Configuration section if you want to change this behavior. Iai-Callgrind sometimes deviates from the valgrind defaults which are:

As show in the table above, the benchmarks run with cache simulation switched on. This adds run time for each benchmark. If you don't need the cache metrics and estimation of cycles, you can easily switch cache simulation off for example with

#![allow(unused)]
fn main() {
extern crate iai_callgrind;
use iai_callgrind::BinaryBenchmarkConfig;

BinaryBenchmarkConfig::default().callgrind_args(["--cache-sim=no"]);
}

To switch off cache simulation for all benchmarks in the same file:

extern crate iai_callgrind;
macro_rules! env { ($m:tt) => {{ "/some/path" }} }
use iai_callgrind::{
    binary_benchmark, binary_benchmark_group, main, BinaryBenchmarkConfig
};

#[binary_benchmark]
fn bench_binary() -> iai_callgrind::Command {
    iai_callgrind::Command::new(env!("CARGO_BIN_EXE_my-foo"))
}

binary_benchmark_group!(name = my_group; benchmarks = bench_binary);
fn main() {
main!(
    config = BinaryBenchmarkConfig::default().callgrind_args(["--cache-sim=no"]);
    binary_benchmark_groups = my_group
);
}