mirror of
https://github.com/logos-storage/plonky2.git
synced 2026-01-13 03:03:05 +00:00
ce786c7a9c
* Add comments about number of columns used. * Split modular operations across two rows. * Fix test setup. * Use constraint_transition() in common code. * Ensure all inputs/outputs are on the first row. * Fix constraint for single-row ops. * Tidy up loop; make MODULAR_AUX_INPUT length reflect reality.
108 lines
4.1 KiB
Rust
108 lines
4.1 KiB
Rust
use std::marker::PhantomData;
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use std::ops::Add;
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use itertools::Itertools;
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use plonky2::field::extension::{Extendable, FieldExtension};
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use plonky2::field::packed::PackedField;
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use plonky2::hash::hash_types::RichField;
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use crate::arithmetic::{add, columns, compare, modular, mul, sub};
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use crate::constraint_consumer::{ConstraintConsumer, RecursiveConstraintConsumer};
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use crate::stark::Stark;
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use crate::vars::{StarkEvaluationTargets, StarkEvaluationVars};
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#[derive(Copy, Clone)]
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pub struct ArithmeticStark<F, const D: usize> {
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pub f: PhantomData<F>,
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}
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impl<F: RichField, const D: usize> ArithmeticStark<F, D> {
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pub fn generate(
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&self,
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local_values: &mut [F; columns::NUM_ARITH_COLUMNS],
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next_values: &mut [F; columns::NUM_ARITH_COLUMNS],
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) {
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// Check that at most one operation column is "one" and that the
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// rest are "zero".
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assert_eq!(
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columns::ALL_OPERATIONS
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.iter()
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.map(|&c| {
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if local_values[c] == F::ONE {
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Ok(1u64)
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} else if local_values[c] == F::ZERO {
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Ok(0u64)
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} else {
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Err("column was not 0 nor 1")
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}
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})
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.fold_ok(0u64, Add::add),
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Ok(1)
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);
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if local_values[columns::IS_ADD].is_one() {
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add::generate(local_values);
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} else if local_values[columns::IS_SUB].is_one() {
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sub::generate(local_values);
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} else if local_values[columns::IS_MUL].is_one() {
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mul::generate(local_values);
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} else if local_values[columns::IS_LT].is_one() {
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compare::generate(local_values, columns::IS_LT);
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} else if local_values[columns::IS_GT].is_one() {
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compare::generate(local_values, columns::IS_GT);
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} else if local_values[columns::IS_ADDMOD].is_one() {
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modular::generate(local_values, next_values, columns::IS_ADDMOD);
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} else if local_values[columns::IS_SUBMOD].is_one() {
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modular::generate(local_values, next_values, columns::IS_SUBMOD);
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} else if local_values[columns::IS_MULMOD].is_one() {
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modular::generate(local_values, next_values, columns::IS_MULMOD);
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} else if local_values[columns::IS_MOD].is_one() {
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modular::generate(local_values, next_values, columns::IS_MOD);
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} else if local_values[columns::IS_DIV].is_one() {
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modular::generate(local_values, next_values, columns::IS_DIV);
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} else {
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panic!("the requested operation should not be handled by the arithmetic table");
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}
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}
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}
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impl<F: RichField + Extendable<D>, const D: usize> Stark<F, D> for ArithmeticStark<F, D> {
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const COLUMNS: usize = columns::NUM_ARITH_COLUMNS;
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fn eval_packed_generic<FE, P, const D2: usize>(
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&self,
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vars: StarkEvaluationVars<FE, P, { Self::COLUMNS }>,
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yield_constr: &mut ConstraintConsumer<P>,
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) where
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FE: FieldExtension<D2, BaseField = F>,
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P: PackedField<Scalar = FE>,
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{
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let lv = vars.local_values;
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let nv = vars.next_values;
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add::eval_packed_generic(lv, yield_constr);
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sub::eval_packed_generic(lv, yield_constr);
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mul::eval_packed_generic(lv, yield_constr);
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compare::eval_packed_generic(lv, yield_constr);
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modular::eval_packed_generic(lv, nv, yield_constr);
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}
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fn eval_ext_circuit(
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&self,
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builder: &mut plonky2::plonk::circuit_builder::CircuitBuilder<F, D>,
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vars: StarkEvaluationTargets<D, { Self::COLUMNS }>,
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yield_constr: &mut RecursiveConstraintConsumer<F, D>,
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) {
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let lv = vars.local_values;
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let nv = vars.next_values;
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add::eval_ext_circuit(builder, lv, yield_constr);
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sub::eval_ext_circuit(builder, lv, yield_constr);
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mul::eval_ext_circuit(builder, lv, yield_constr);
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compare::eval_ext_circuit(builder, lv, yield_constr);
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modular::eval_ext_circuit(builder, lv, nv, yield_constr);
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}
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fn constraint_degree(&self) -> usize {
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3
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}
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}
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