machine-friendly output format

[dweiller]

Having some common machine-readable format(s) would be helpful for analyzing results. There should be a format that is easy for plotting packages like gnuplot and matplotlib to consume - I expect CSV (which is a subset of the gnuplot text data format) is the right starting point for this.

There might be other formats of interest, maybe JSON that looks something like:

{
    "name": "Benchmark name",
    "optimize": "ReleaseFast",
    "target": "x86-64-linux-gnu",
    "summary": {
        "mean_wall_time": {
            "value": 123438432,
            "stddev": 1234,
            "min": 12314566,
            "max": 2431248383,
        },
        "other_summary_statistic": {
            "value": 12345,
            "stddev": 123432
            "min": 23432,
            "max": 12382132
        }
    },
    "samples": [
        { "wall_time": 123455677, "peak_rss": 1234, "cpu_cycles": 123, "instructions": 1232, "cache_references": 12321, "cache_misses": 234232, "branch_misses": 128234 },
        { "wall_time": 123455677, "peak_rss": 1234, "cpu_cycles": 123, "instructions": 1232, "cache_references": 12321, "cache_misses": 234232, "branch_misses": 128234 },
    ]
}

JSON is pretty verbose for using as a storage format, but it would compress well.

[candrewlee14]

Machine-friendly output could also lead to potential plotting options as well.