Calling a function that returns more than two registers corrupts the registers of the caller

[sirasistant]

Aim

Running this:

global VALUE_NOTE_LEN: Field = 4;

struct ValueNote {
    value: Field,
    x: Field,
    y: Field,
    is_real: bool,
}

impl ValueNote {
    fn deserialise(preimage: [Field; VALUE_NOTE_LEN]) -> Self {
        ValueNote {
            value: preimage[0],
            x: preimage[1],
            y: preimage[2],
            is_real: preimage[3] as bool,
        }
    }
}

unconstrained fn main(fields: [Field; VALUE_NOTE_LEN]) -> pub ValueNote {
    ValueNote::deserialise(fields)
}

Expected Behavior

With this prover.toml :

fields = [0x0000000000000000000000000000000000000000000000000000000000000001, 0x0000000000000000000000000000000000000000000000000000000000000002, 0x0000000000000000000000000000000000000000000000000000000000000003, 0x0000000000000000000000000000000000000000000000000000000000000001]

the verifier.toml should be

[return]
is_real = true
value = "0x0000000000000000000000000000000000000000000000000000000000000001"
x = "0x0000000000000000000000000000000000000000000000000000000000000002"
y = "0x0000000000000000000000000000000000000000000000000000000000000003"

Bug

actual returned value:

[return]
is_real = false
value = "0x0000000000000000000000000000000000000000000000000000000000000001"
x = "0x0000000000000000000000000000000000000000000000000000000000000002"
y = "0x0000000000000000000000000000000000000000000000000000000000000001"

To Reproduce

Installation Method

None

Nargo Version

No response

Additional Context

No response

Would you like to submit a PR for this Issue?

Yes

Support Needs

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