New random access gadget

This commit is contained in:
wborgeaud 2021-10-18 15:45:52 +02:00
parent 104fd08e72
commit a35cd98b03
3 changed files with 33 additions and 27 deletions

View File

@ -6,8 +6,32 @@ use crate::iop::target::Target;
use crate::plonk::circuit_builder::CircuitBuilder;
impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
/// Checks that a `Target` matches a vector at a non-deterministic index.
/// Note: `index` is not range-checked.
/// Checks that an `ExtensionTarget` matches a vector at a non-deterministic index.
/// Note: `access_index` is not range-checked.
pub fn random_access(&mut self, access_index: Target, claimed_element: Target, v: Vec<Target>) {
debug_assert!(!v.is_empty());
if v.len() == 1 {
return self.connect(claimed_element, v[0]);
}
let gate = RandomAccessGate::new(1, v.len());
let gate_index = self.add_gate(gate.clone(), vec![]);
let copy = 0;
v.iter().enumerate().for_each(|(i, &val)| {
self.connect(val, Target::wire(gate_index, gate.wire_list_item(i, copy)));
});
self.connect(
access_index,
Target::wire(gate_index, gate.wire_access_index(copy)),
);
self.connect(
claimed_element,
Target::wire(gate_index, gate.wire_claimed_element(copy)),
);
}
/// Checks that an `ExtensionTarget` matches a vector at a non-deterministic index.
/// Note: `access_index` is not range-checked.
pub fn random_access_extension(
&mut self,
access_index: Target,

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@ -106,7 +106,6 @@ impl<F: RichField + Extendable<D>, const D: usize> Gate<F, D> for RandomAccessGa
let index_matches = vars.local_wires[self.wire_index_matches_for_index(i, copy)];
// The two index equality constraints.
dbg!(difference, equality_dummy, index_matches);
constraints.push(difference * equality_dummy - (F::Extension::ONE - index_matches));
constraints.push(index_matches * difference);
// Value equality constraint.
@ -382,7 +381,6 @@ mod tests {
.zip(&access_indices)
.map(|(l, &i)| l[i])
.collect();
dbg!(&lists, &access_indices, &good_claimed_elements);
let good_vars = EvaluationVars {
local_constants: &[],
local_wires: &get_wires(lists.clone(), access_indices.clone(), good_claimed_elements),
@ -395,7 +393,6 @@ mod tests {
public_inputs_hash: &HashOut::rand(),
};
dbg!(gate.eval_unfiltered(good_vars));
assert!(
gate.eval_unfiltered(good_vars).iter().all(|x| x.is_zero()),
"Gate constraints are not satisfied."

View File

@ -75,17 +75,6 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
}
let index = self.le_sum(leaf_index_bits[proof.siblings.len()..].to_vec().into_iter());
let state_ext = state.elements[..].try_into().expect("requires D = 4");
let state_ext = ExtensionTarget(state_ext);
let cap_ext = merkle_cap
.0
.iter()
.map(|h| {
let tmp = h.elements[..].try_into().expect("requires D = 4");
ExtensionTarget(tmp)
})
.collect();
self.random_access_extension(index, state_ext, cap_ext);
}
/// Same a `verify_merkle_proof` but with the final "cap index" as extra parameter.
@ -112,17 +101,13 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
};
}
let state_ext = state.elements[..].try_into().expect("requires D = 4");
let state_ext = ExtensionTarget(state_ext);
let cap_ext = merkle_cap
.0
.iter()
.map(|h| {
let tmp = h.elements[..].try_into().expect("requires D = 4");
ExtensionTarget(tmp)
})
.collect();
self.random_access_extension(cap_index, state_ext, cap_ext);
for i in 0..4 {
self.random_access(
cap_index,
state.elements[i],
merkle_cap.0.iter().map(|h| h.elements[i]).collect(),
);
}
}
pub fn assert_hashes_equal(&mut self, x: HashOutTarget, y: HashOutTarget) {