Pass entire mask to components (#801)

crates/prover/src/constraint_framework/component.rs

@@ -1,11 +1,13 @@
 use std::borrow::Cow;
+use std::iter::zip;
+use std::ops::Deref;
 
 use itertools::Itertools;
 use tracing::{span, Level};
 
 use super::{EvalAtRow, InfoEvaluator, PointEvaluator, SimdDomainEvaluator};
 use crate::core::air::accumulation::{DomainEvaluationAccumulator, PointEvaluationAccumulator};
-use crate::core::air::{Component, ComponentProver, ComponentTrace};
+use crate::core::air::{Component, ComponentProver, Trace};
 use crate::core::backend::simd::column::VeryPackedSecureColumnByCoords;
 use crate::core::backend::simd::m31::LOG_N_LANES;
 use crate::core::backend::simd::very_packed_m31::{VeryPackedBaseField, LOG_N_VERY_PACKED_ELEMS};
@@ -15,36 +17,87 @@ use crate::core::constraints::coset_vanishing;
 use crate::core::fields::m31::BaseField;
 use crate::core::fields::qm31::SecureField;
 use crate::core::fields::FieldExpOps;
-use crate::core::pcs::TreeVec;
+use crate::core::pcs::{TreeSubspan, TreeVec};
 use crate::core::poly::circle::{CanonicCoset, CircleEvaluation, PolyOps};
 use crate::core::poly::BitReversedOrder;
 use crate::core::{utils, ColumnVec, InteractionElements, LookupValues};
 
+// TODO(andrew): Docs.
+// TODO(andrew): Consider better location for this.
+#[derive(Debug, Default)]
+pub struct TraceLocationAllocator {
+    /// Mapping of tree index to next available column offset.
+    next_tree_offsets: TreeVec<usize>,
+}
+
+impl TraceLocationAllocator {
+    fn next_for_structure<T>(&mut self, structure: &TreeVec<ColumnVec<T>>) -> TreeVec<TreeSubspan> {
+        if structure.len() > self.next_tree_offsets.len() {
+            self.next_tree_offsets.resize(structure.len(), 0);
+        }
+
+        TreeVec::new(
+            zip(&mut *self.next_tree_offsets, &**structure)
+                .enumerate()
+                .map(|(tree_index, (offset, cols))| {
+                    let col_start = *offset;
+                    let col_end = col_start + cols.len();
+                    *offset = col_end;
+                    TreeSubspan {
+                        tree_index,
+                        col_start,
+                        col_end,
+                    }
+                })
+                .collect(),
+        )
+    }
+}
+
 /// A component defined solely in means of the constraints framework.
-/// Implementing this trait introduces implementations for [Component] and [ComponentProver] for the
-/// SIMD backend.
+/// Implementing this trait introduces implementations for [`Component`] and [`ComponentProver`] for
+/// the SIMD backend.
 /// Note that the constraint framework only support components with columns of the same size.
-pub trait FrameworkComponent {
+pub trait FrameworkEval {
     fn log_size(&self) -> u32;
+
     fn max_constraint_log_degree_bound(&self) -> u32;
+
     fn evaluate<E: EvalAtRow>(&self, eval: E) -> E;
 }
 
-impl<C: FrameworkComponent> Component for C {
+pub struct FrameworkComponent<C: FrameworkEval> {
+    eval: C,
+    trace_locations: TreeVec<TreeSubspan>,
+}
+
+impl<E: FrameworkEval> FrameworkComponent<E> {
+    pub fn new(provider: &mut TraceLocationAllocator, eval: E) -> Self {
+        let eval_tree_structure = eval.evaluate(InfoEvaluator::default()).mask_offsets;
+        let trace_locations = provider.next_for_structure(&eval_tree_structure);
+        Self {
+            eval,
+            trace_locations,
+        }
+    }
+}
+
+impl<E: FrameworkEval> Component for FrameworkComponent<E> {
     fn n_constraints(&self) -> usize {
-        self.evaluate(InfoEvaluator::default()).n_constraints
+        self.eval.evaluate(InfoEvaluator::default()).n_constraints
     }
 
     fn max_constraint_log_degree_bound(&self) -> u32 {
-        FrameworkComponent::max_constraint_log_degree_bound(self)
+        self.eval.max_constraint_log_degree_bound()
     }
 
     fn trace_log_degree_bounds(&self) -> TreeVec<ColumnVec<u32>> {
         TreeVec::new(
-            self.evaluate(InfoEvaluator::default())
+            self.eval
+                .evaluate(InfoEvaluator::default())
                 .mask_offsets
                 .iter()
-                .map(|tree_masks| vec![self.log_size(); tree_masks.len()])
+                .map(|tree_masks| vec![self.eval.log_size(); tree_masks.len()])
                 .collect(),
         )
     }
@@ -53,8 +106,8 @@ impl<C: FrameworkComponent> Component for C {
         &self,
         point: CirclePoint<SecureField>,
     ) -> TreeVec<ColumnVec<Vec<CirclePoint<SecureField>>>> {
-        let info = self.evaluate(InfoEvaluator::default());
-        let trace_step = CanonicCoset::new(self.log_size()).step();
+        let info = self.eval.evaluate(InfoEvaluator::default());
+        let trace_step = CanonicCoset::new(self.eval.log_size()).step();
         info.mask_offsets.map_cols(|col_mask| {
             col_mask
                 .iter()
@@ -71,30 +124,32 @@ impl<C: FrameworkComponent> Component for C {
         _interaction_elements: &InteractionElements,
         _lookup_values: &LookupValues,
     ) {
-        self.evaluate(PointEvaluator::new(
-            mask.as_ref(),
+        self.eval.evaluate(PointEvaluator::new(
+            mask.sub_tree(&self.trace_locations),
             evaluation_accumulator,
-            coset_vanishing(CanonicCoset::new(self.log_size()).coset, point).inverse(),
+            coset_vanishing(CanonicCoset::new(self.eval.log_size()).coset, point).inverse(),
         ));
     }
 }
 
-impl<C: FrameworkComponent> ComponentProver<SimdBackend> for C {
+impl<E: FrameworkEval> ComponentProver<SimdBackend> for FrameworkComponent<E> {
     fn evaluate_constraint_quotients_on_domain(
         &self,
-        trace: &ComponentTrace<'_, SimdBackend>,
+        trace: &Trace<'_, SimdBackend>,
         evaluation_accumulator: &mut DomainEvaluationAccumulator<SimdBackend>,
         _interaction_elements: &InteractionElements,
         _lookup_values: &LookupValues,
     ) {
         let eval_domain = CanonicCoset::new(self.max_constraint_log_degree_bound()).circle_domain();
-        let trace_domain = CanonicCoset::new(self.log_size());
+        let trace_domain = CanonicCoset::new(self.eval.log_size());
+
+        let component_polys = trace.polys.sub_tree(&self.trace_locations);
+        let component_evals = trace.evals.sub_tree(&self.trace_locations);
 
         // Extend trace if necessary.
         // TODO(spapini): Don't extend when eval_size < committed_size. Instead, pick a good
         // subdomain.
-        let need_to_extend = trace
-            .evals
+        let need_to_extend = component_evals
             .iter()
             .flatten()
             .any(|c| c.domain != eval_domain);
@@ -103,12 +158,11 @@ impl<C: FrameworkComponent> ComponentProver<SimdBackend> for C {
         > = if need_to_extend {
             let _span = span!(Level::INFO, "Extension").entered();
             let twiddles = SimdBackend::precompute_twiddles(eval_domain.half_coset);
-            trace
-                .polys
+            component_polys
                 .as_cols_ref()
                 .map_cols(|col| Cow::Owned(col.evaluate_with_twiddles(eval_domain, &twiddles)))
         } else {
-            trace.evals.as_cols_ref().map_cols(|c| Cow::Borrowed(*c))
+            component_evals.clone().map_cols(|c| Cow::Borrowed(*c))
         };
 
         // Denom inverses.
@@ -137,7 +191,7 @@ impl<C: FrameworkComponent> ComponentProver<SimdBackend> for C {
                 trace_domain.log_size(),
                 eval_domain.log_size(),
             );
-            let row_res = self.evaluate(eval).row_res;
+            let row_res = self.eval.evaluate(eval).row_res;
 
             // Finalize row.
             unsafe {
@@ -150,7 +204,15 @@ impl<C: FrameworkComponent> ComponentProver<SimdBackend> for C {
         }
     }
 
-    fn lookup_values(&self, _trace: &ComponentTrace<'_, SimdBackend>) -> LookupValues {
+    fn lookup_values(&self, _trace: &Trace<'_, SimdBackend>) -> LookupValues {
         LookupValues::default()
     }
 }
+
+impl<E: FrameworkEval> Deref for FrameworkComponent<E> {
+    type Target = E;
+
+    fn deref(&self) -> &E {
+        &self.eval
+    }
+}

crates/prover/src/constraint_framework/mod.rs

@@ -12,7 +12,7 @@ use std::fmt::Debug;
 use std::ops::{Add, AddAssign, Mul, Neg, Sub};
 
 pub use assert::{assert_constraints, AssertEvaluator};
-pub use component::FrameworkComponent;
+pub use component::{FrameworkComponent, FrameworkEval, TraceLocationAllocator};
 pub use info::InfoEvaluator;
 use num_traits::{One, Zero};
 pub use point::PointEvaluator;

crates/prover/src/constraint_framework/point.rs

@@ -9,14 +9,14 @@ use crate::core::ColumnVec;
 
 /// Evaluates expressions at a point out of domain.
 pub struct PointEvaluator<'a> {
-    pub mask: TreeVec<&'a ColumnVec<Vec<SecureField>>>,
+    pub mask: TreeVec<ColumnVec<&'a Vec<SecureField>>>,
     pub evaluation_accumulator: &'a mut PointEvaluationAccumulator,
     pub col_index: Vec<usize>,
     pub denom_inverse: SecureField,
 }
 impl<'a> PointEvaluator<'a> {
     pub fn new(
-        mask: TreeVec<&'a ColumnVec<Vec<SecureField>>>,
+        mask: TreeVec<ColumnVec<&'a Vec<SecureField>>>,
         evaluation_accumulator: &'a mut PointEvaluationAccumulator,
         denom_inverse: SecureField,
     ) -> Self {

crates/prover/src/core/air/components.rs

@@ -1,12 +1,11 @@
-use itertools::{zip_eq, Itertools};
+use itertools::Itertools;
 
 use super::accumulation::{DomainEvaluationAccumulator, PointEvaluationAccumulator};
-use super::{Component, ComponentProver, ComponentTrace};
-use crate::core::backend::{Backend, BackendForChannel};
-use crate::core::channel::MerkleChannel;
+use super::{Component, ComponentProver, Trace};
+use crate::core::backend::Backend;
 use crate::core::circle::CirclePoint;
 use crate::core::fields::qm31::SecureField;
-use crate::core::pcs::{CommitmentTreeProver, TreeVec};
+use crate::core::pcs::TreeVec;
 use crate::core::poly::circle::SecureCirclePoly;
 use crate::core::{ColumnVec, InteractionElements, LookupValues};
 
@@ -31,21 +30,21 @@ impl<'a> Components<'a> {
     pub fn eval_composition_polynomial_at_point(
         &self,
         point: CirclePoint<SecureField>,
-        mask_values: &Vec<TreeVec<Vec<Vec<SecureField>>>>,
+        mask_values: &TreeVec<Vec<Vec<SecureField>>>,
         random_coeff: SecureField,
         interaction_elements: &InteractionElements,
         lookup_values: &LookupValues,
     ) -> SecureField {
         let mut evaluation_accumulator = PointEvaluationAccumulator::new(random_coeff);
-        zip_eq(&self.0, mask_values).for_each(|(component, mask)| {
+        for component in &self.0 {
             component.evaluate_constraint_quotients_at_point(
                 point,
-                mask,
+                mask_values,
                 &mut evaluation_accumulator,
                 interaction_elements,
                 lookup_values,
             )
-        });
+        }
         evaluation_accumulator.finalize()
     }
 
@@ -67,7 +66,7 @@ impl<'a, B: Backend> ComponentProvers<'a, B> {
     pub fn compute_composition_polynomial(
         &self,
         random_coeff: SecureField,
-        component_traces: &[ComponentTrace<'_, B>],
+        trace: &Trace<'_, B>,
         interaction_elements: &InteractionElements,
         lookup_values: &LookupValues,
     ) -> SecureCirclePoly<B> {
@@ -77,63 +76,22 @@ impl<'a, B: Backend> ComponentProvers<'a, B> {
             self.components().composition_log_degree_bound(),
             total_constraints,
         );
-        zip_eq(&self.0, component_traces).for_each(|(component, trace)| {
+        for component in &self.0 {
             component.evaluate_constraint_quotients_on_domain(
                 trace,
                 &mut accumulator,
                 interaction_elements,
                 lookup_values,
             )
-        });
+        }
         accumulator.finalize()
     }
 
-    pub fn component_traces<'b, MC: MerkleChannel>(
-        &'b self,
-        trees: &'b [CommitmentTreeProver<B, MC>],
-    ) -> Vec<ComponentTrace<'b, B>>
-    where
-        B: BackendForChannel<MC>,
-    {
-        let mut poly_iters = trees
-            .iter()
-            .map(|tree| tree.polynomials.iter())
-            .collect_vec();
-        let mut eval_iters = trees
-            .iter()
-            .map(|tree| tree.evaluations.iter())
-            .collect_vec();
-
-        self.0
-            .iter()
-            .map(|component| {
-                let col_sizes_per_tree = component
-                    .trace_log_degree_bounds()
-                    .iter()
-                    .map(|col_sizes| col_sizes.len())
-                    .collect_vec();
-                let polys = col_sizes_per_tree
-                    .iter()
-                    .zip(poly_iters.iter_mut())
-                    .map(|(n_columns, iter)| iter.take(*n_columns).collect_vec())
-                    .collect_vec();
-                let evals = col_sizes_per_tree
-                    .iter()
-                    .zip(eval_iters.iter_mut())
-                    .map(|(n_columns, iter)| iter.take(*n_columns).collect_vec())
-                    .collect_vec();
-                ComponentTrace {
-                    polys: TreeVec::new(polys),
-                    evals: TreeVec::new(evals),
-                }
-            })
-            .collect_vec()
-    }
-
-    pub fn lookup_values(&self, component_traces: &[ComponentTrace<'_, B>]) -> LookupValues {
+    pub fn lookup_values(&self, trace: &Trace<'_, B>) -> LookupValues {
         let mut values = LookupValues::default();
-        zip_eq(&self.0, component_traces)
-            .for_each(|(component, trace)| values.extend(component.lookup_values(trace)));
+        for component in &self.0 {
+            values.extend(component.lookup_values(trace))
+        }
         values
     }
 }

crates/prover/src/core/air/mod.rs

@@ -62,30 +62,22 @@ pub trait ComponentProver<B: Backend>: Component {
     /// Accumulates quotients in `evaluation_accumulator`.
     fn evaluate_constraint_quotients_on_domain(
         &self,
-        trace: &ComponentTrace<'_, B>,
+        trace: &Trace<'_, B>,
         evaluation_accumulator: &mut DomainEvaluationAccumulator<B>,
         interaction_elements: &InteractionElements,
         lookup_values: &LookupValues,
     );
 
     /// Returns the values needed to evaluate the components lookup boundary constraints.
-    fn lookup_values(&self, _trace: &ComponentTrace<'_, B>) -> LookupValues;
+    fn lookup_values(&self, _trace: &Trace<'_, B>) -> LookupValues;
 }
 
-/// A component trace is a set of polynomials for each column on that component.
+/// The set of polynomials that make up the trace.
+///
 /// Each polynomial is stored both in a coefficients, and evaluations form (for efficiency)
-pub struct ComponentTrace<'a, B: Backend> {
+pub struct Trace<'a, B: Backend> {
     /// Polynomials for each column.
     pub polys: TreeVec<ColumnVec<&'a CirclePoly<B>>>,
-    /// Evaluations for each column (evaluated on the commitment domains).
+    /// Evaluations for each column (evaluated on their commitment domains).
     pub evals: TreeVec<ColumnVec<&'a CircleEvaluation<B, BaseField, BitReversedOrder>>>,
 }
-
-impl<'a, B: Backend> ComponentTrace<'a, B> {
-    pub fn new(
-        polys: TreeVec<ColumnVec<&'a CirclePoly<B>>>,
-        evals: TreeVec<ColumnVec<&'a CircleEvaluation<B, BaseField, BitReversedOrder>>>,
-    ) -> Self {
-        Self { polys, evals }
-    }
-}

crates/prover/src/core/pcs/mod.rs

@@ -19,7 +19,7 @@ pub use self::verifier::CommitmentSchemeVerifier;
 use super::fri::FriConfig;
 
 #[derive(Copy, Debug, Clone, PartialEq, Eq)]
-pub struct TreeColumnSpan {
+pub struct TreeSubspan {
     pub tree_index: usize,
     pub col_start: usize,
     pub col_end: usize,