[PGO] collect cycle data

[qwang98]

WIP. Read and write data are currently hardcoded to 0 because I still need to figure out their length, which depends on a runtime constant. However the idea should remain the same.

How this works

• Depends on OVM branch (also tagged cycle-data): [PGO] collect cycle data openvm#48
• Collects data in the follow format from pure execution in OVM via PGO data collection.

Cycle -> {
    pc
    reads: Vec<(addr space, addr, value)>
    writes: Vec<(addr space, addr, value)>
}

• Prints something like the following when you run RUST_LOG=trace cargo test --release --package powdr-openvm --lib -- tests::guest_execution_data --exact --show-output.

Execution data: [
    Cycle {
        pc: 2100976,
        reads: [],
        writes: [
            (
                1,
                12,
                0,
            ),
        ],
    },
    Cycle {
        pc: 2100980,
        reads: [
            (
                1,
                12,
                0,
            ),
        ],
        writes: [
            (
                1,
                12,
                0,
            ),
        ],
    },
    ...
]

[qwang98]

Happy to make this a part of our CLI if we run these frequently.

[qwang98]

TODO: Top part mostly same as execution_profile_from_guest. Make it a helper.

[qwang98]

TODO: Make it a JSON like the following as per @georgwiese.

{
    "runtime_values": [
        {
            "pc": 1024,
            "reads": [
                {
                    "address_space": 1,
                    "address": 40,
                    "value": 16
                },
                {
                    "address_space": 1,
                    "address": 44,
                    "value": 32
                }
            ],
            "writes": [
                {
                    "address_space": 1,
                    "address": 40,
                    "value": 17
                }
            ]
        },
        {
            "pc": 1024,
            "reads": [
                {
                    "address_space": 1,
                    "address": 40,
                    "value": 16
                },
                {
                    "address_space": 1,
                    "address": 44,
                    "value": 17
                }
            ],
            "writes": [
                {
                    "address_space": 1,
                    "address": 40,
                    "value": 17
                }
            ]
        }
    ]
}

[georgwiese]

Nice! 🤩

Pushed a few commits to update the JSON format and integrate with my notebook (which I pushed too).

E.g., you can run:
mkdir -f keccak100 && cargo run --bin powdr_openvm -r --features metrics prove guest-keccak --input 100 --autoprecompiles 12 --apc-candidates-dir keccak100

Then, the notebook looks at the 9th instruction (1-indexed) of this block.

It works end-to-end, but I think there is currently a bug, because the value is always zero. I haven't looked into this yet, but noting that it is already the case in the example in the PR description.