Initialize logups automatically when first used.

crates/prover/src/constraint_framework/assert.rs

@@ -1,7 +1,7 @@
 use num_traits::{One, Zero};
 
-use super::logup::LogupAtRow;
-use super::EvalAtRow;
+use super::logup::{LogupAtRow, LogupSums};
+use super::{EvalAtRow, INTERACTION_TRACE_IDX};
 use crate::core::backend::{Backend, Column};
 use crate::core::fields::m31::BaseField;
 use crate::core::fields::qm31::SecureField;
@@ -19,12 +19,17 @@ pub struct AssertEvaluator<'a> {
     pub logup: LogupAtRow<Self>,
 }
 impl<'a> AssertEvaluator<'a> {
-    pub fn new(trace: &'a TreeVec<Vec<Vec<BaseField>>>, row: usize) -> Self {
+    pub fn new(
+        trace: &'a TreeVec<Vec<Vec<BaseField>>>,
+        row: usize,
+        log_size: u32,
+        logup_sums: LogupSums,
+    ) -> Self {
         Self {
             trace,
             col_index: TreeVec::new(vec![0; trace.len()]),
             row,
-            logup: LogupAtRow::dummy(),
+            logup: LogupAtRow::new(INTERACTION_TRACE_IDX, logup_sums.0, logup_sums.1, log_size),
         }
     }
 }
@@ -69,6 +74,7 @@ pub fn assert_constraints<B: Backend>(
     trace_polys: &TreeVec<Vec<CirclePoly<B>>>,
     trace_domain: CanonicCoset,
     assert_func: impl Fn(AssertEvaluator<'_>),
+    logup_sums: LogupSums,
 ) {
     let traces = trace_polys.as_ref().map(|tree| {
         tree.iter()
@@ -84,7 +90,8 @@ pub fn assert_constraints<B: Backend>(
             .collect()
     });
     for row in 0..trace_domain.size() {
-        let eval = AssertEvaluator::new(&traces, row);
+        let eval = AssertEvaluator::new(&traces, row, trace_domain.log_size(), logup_sums);
+
         assert_func(eval);
     }
 }

crates/prover/src/constraint_framework/component.rs

@@ -10,6 +10,7 @@ use rayon::prelude::*;
 use tracing::{span, Level};
 
 use super::cpu_domain::CpuDomainEvaluator;
+use super::logup::LogupSums;
 use super::preprocessed_columns::PreprocessedColumn;
 use super::{
     EvalAtRow, InfoEvaluator, PointEvaluator, SimdDomainEvaluator, PREPROCESSED_TRACE_IDX,
@@ -113,11 +114,16 @@ pub struct FrameworkComponent<C: FrameworkEval> {
     trace_locations: TreeVec<TreeSubspan>,
     info: InfoEvaluator,
     preprocessed_column_indices: Vec<usize>,
+    logup_sums: LogupSums,
 }
 
 impl<E: FrameworkEval> FrameworkComponent<E> {
-    pub fn new(location_allocator: &mut TraceLocationAllocator, eval: E) -> Self {
-        let info = eval.evaluate(InfoEvaluator::default());
+    pub fn new(
+        location_allocator: &mut TraceLocationAllocator,
+        eval: E,
+        logup_sums: LogupSums,
+    ) -> Self {
+        let info = eval.evaluate(InfoEvaluator::new(eval.log_size(), vec![], logup_sums));
         let trace_locations = location_allocator.next_for_structure(&info.mask_offsets);
 
         let preprocessed_column_indices = info
@@ -148,6 +154,7 @@ impl<E: FrameworkEval> FrameworkComponent<E> {
             trace_locations,
             info,
             preprocessed_column_indices,
+            logup_sums,
         }
     }
 
@@ -217,6 +224,8 @@ impl<E: FrameworkEval> Component for FrameworkComponent<E> {
             mask_points,
             evaluation_accumulator,
             coset_vanishing(CanonicCoset::new(self.eval.log_size()).coset, point).inverse(),
+            self.eval.log_size(),
+            self.logup_sums,
         ));
     }
 }
@@ -296,6 +305,8 @@ impl<E: FrameworkEval + Sync> ComponentProver<SimdBackend> for FrameworkComponen
                     &accum.random_coeff_powers,
                     trace_domain.log_size(),
                     eval_domain.log_size(),
+                    self.eval.log_size(),
+                    self.logup_sums,
                 );
                 let row_res = self.eval.evaluate(eval).row_res;
 
@@ -333,6 +344,8 @@ impl<E: FrameworkEval + Sync> ComponentProver<SimdBackend> for FrameworkComponen
                     &accum.random_coeff_powers,
                     trace_domain.log_size(),
                     eval_domain.log_size(),
+                    self.eval.log_size(),
+                    self.logup_sums,
                 );
                 let row_res = self.eval.evaluate(eval).row_res;
 

crates/prover/src/constraint_framework/cpu_domain.rs

@@ -2,8 +2,8 @@ use std::ops::Mul;
 
 use num_traits::Zero;
 
-use super::logup::LogupAtRow;
-use super::EvalAtRow;
+use super::logup::{LogupAtRow, LogupSums};
+use super::{EvalAtRow, INTERACTION_TRACE_IDX};
 use crate::core::backend::CpuBackend;
 use crate::core::fields::m31::BaseField;
 use crate::core::fields::qm31::SecureField;
@@ -35,6 +35,8 @@ impl<'a> CpuDomainEvaluator<'a> {
         random_coeff_powers: &'a [SecureField],
         domain_log_size: u32,
         eval_log_size: u32,
+        log_size: u32,
+        logup_sums: LogupSums,
     ) -> Self {
         Self {
             trace_eval,
@@ -45,7 +47,7 @@ impl<'a> CpuDomainEvaluator<'a> {
             constraint_index: 0,
             domain_log_size,
             eval_domain_log_size: eval_log_size,
-            logup: LogupAtRow::dummy(),
+            logup: LogupAtRow::new(INTERACTION_TRACE_IDX, logup_sums.0, logup_sums.1, log_size),
         }
     }
 }

crates/prover/src/constraint_framework/expr.rs

@@ -2,8 +2,8 @@ use std::ops::{Add, AddAssign, Mul, MulAssign, Neg, Sub};
 
 use num_traits::{One, Zero};
 
-use super::logup::LogupAtRow;
-use super::EvalAtRow;
+use super::logup::{LogupAtRow, LogupSums};
+use super::{EvalAtRow, INTERACTION_TRACE_IDX};
 use crate::core::fields::m31::BaseField;
 use crate::core::fields::qm31::SecureField;
 use crate::core::fields::FieldExpOps;
@@ -156,6 +156,16 @@ struct ExprEvaluator {
     pub logup: LogupAtRow<Self>,
 }
 
+impl ExprEvaluator {
+    pub fn _new(log_size: u32, logup_sums: LogupSums) -> Self {
+        Self {
+            cur_var_index: Default::default(),
+            constraints: Default::default(),
+            logup: LogupAtRow::new(INTERACTION_TRACE_IDX, logup_sums.0, logup_sums.1, log_size),
+        }
+    }
+}
+
 impl EvalAtRow for ExprEvaluator {
     // TODO(alont): Should there be a version of this that disallows Secure fields for F?
     type F = Expr;

crates/prover/src/constraint_framework/info.rs

@@ -2,9 +2,9 @@ use std::ops::Mul;
 
 use num_traits::One;
 
-use super::logup::LogupAtRow;
+use super::logup::{LogupAtRow, LogupSums};
 use super::preprocessed_columns::PreprocessedColumn;
-use super::EvalAtRow;
+use super::{EvalAtRow, INTERACTION_TRACE_IDX};
 use crate::constraint_framework::PREPROCESSED_TRACE_IDX;
 use crate::core::fields::m31::BaseField;
 use crate::core::fields::qm31::SecureField;
@@ -21,8 +21,23 @@ pub struct InfoEvaluator {
     pub logup: LogupAtRow<Self>,
 }
 impl InfoEvaluator {
-    pub fn new() -> Self {
-        Self::default()
+    pub fn new(
+        log_size: u32,
+        preprocessed_columns: Vec<PreprocessedColumn>,
+        logup_sums: LogupSums,
+    ) -> Self {
+        Self {
+            mask_offsets: Default::default(),
+            n_constraints: Default::default(),
+            preprocessed_columns,
+            logup: LogupAtRow::new(INTERACTION_TRACE_IDX, logup_sums.0, logup_sums.1, log_size),
+        }
+    }
+
+    /// Create an empty `InfoEvaluator`, to measure components before their size and logup sums are
+    /// available.
+    pub fn empty() -> Self {
+        Self::new(16, vec![], (SecureField::default(), None))
     }
 }
 impl EvalAtRow for InfoEvaluator {

crates/prover/src/constraint_framework/logup.rs

@@ -24,6 +24,8 @@ use crate::core::ColumnVec;
 /// Represents the value of the prefix sum column at some index.
 /// Should be used to eliminate padded rows for the logup sum.
 pub type ClaimedPrefixSum = (SecureField, usize);
+// (total_sum, claimed_sum)
+pub type LogupSums = (SecureField, Option<ClaimedPrefixSum>);
 
 /// Evaluates constraints for batched logups.
 /// These constraint enforce the sum of multiplicity_i / (z + sum_j alpha^j * x_j) = claimed_sum.
@@ -38,11 +40,12 @@ pub struct LogupAtRow<E: EvalAtRow> {
     pub claimed_sum: Option<ClaimedPrefixSum>,
     /// The evaluation of the last cumulative sum column.
     pub prev_col_cumsum: E::EF,
-    cur_frac: Option<Fraction<E::EF, E::EF>>,
-    is_finalized: bool,
+    pub cur_frac: Option<Fraction<E::EF, E::EF>>,
+    pub is_finalized: bool,
     /// The value of the `is_first` constant column at current row.
     /// See [`super::preprocessed_columns::gen_is_first()`].
     pub is_first: E::F,
+    pub log_size: u32,
 }
 
 impl<E: EvalAtRow> Default for LogupAtRow<E> {
@@ -55,16 +58,17 @@ impl<E: EvalAtRow> LogupAtRow<E> {
         interaction: usize,
         total_sum: SecureField,
         claimed_sum: Option<ClaimedPrefixSum>,
-        is_first: E::F,
+        log_size: u32,
     ) -> Self {
         Self {
             interaction,
             total_sum,
             claimed_sum,
             prev_col_cumsum: E::EF::zero(),
             cur_frac: None,
-            is_finalized: false,
-            is_first,
+            is_finalized: true,
+            is_first: E::F::zero(),
+            log_size,
         }
     }
 
@@ -78,53 +82,9 @@ impl<E: EvalAtRow> LogupAtRow<E> {
             cur_frac: None,
             is_finalized: true,
             is_first: E::F::zero(),
+            log_size: 10,
         }
     }
-
-    pub fn write_frac(&mut self, eval: &mut E, fraction: Fraction<E::EF, E::EF>) {
-        // Add a constraint that num / denom = diff.
-        if let Some(cur_frac) = self.cur_frac.clone() {
-            let [cur_cumsum] = eval.next_extension_interaction_mask(self.interaction, [0]);
-            let diff = cur_cumsum.clone() - self.prev_col_cumsum.clone();
-            self.prev_col_cumsum = cur_cumsum;
-            eval.add_constraint(diff * cur_frac.denominator - cur_frac.numerator);
-        }
-        self.cur_frac = Some(fraction);
-    }
-
-    pub fn finalize(&mut self, eval: &mut E) {
-        assert!(!self.is_finalized, "LogupAtRow was already finalized");
-
-        let frac = self.cur_frac.clone().unwrap();
-
-        // TODO(ShaharS): remove `claimed_row_index` interaction value and get the shifted offset
-        // from the is_first column when constant columns are supported.
-        let (cur_cumsum, prev_row_cumsum) = match self.claimed_sum {
-            Some((claimed_sum, claimed_row_index)) => {
-                let [cur_cumsum, prev_row_cumsum, claimed_cumsum] = eval
-                    .next_extension_interaction_mask(
-                        self.interaction,
-                        [0, -1, claimed_row_index as isize],
-                    );
-
-                // Constrain that the claimed_sum in case that it is not equal to the total_sum.
-                eval.add_constraint((claimed_cumsum - claimed_sum) * self.is_first.clone());
-                (cur_cumsum, prev_row_cumsum)
-            }
-            None => {
-                let [cur_cumsum, prev_row_cumsum] =
-                    eval.next_extension_interaction_mask(self.interaction, [0, -1]);
-                (cur_cumsum, prev_row_cumsum)
-            }
-        };
-        // Fix `prev_row_cumsum` by subtracting `total_sum` if this is the first row.
-        let fixed_prev_row_cumsum = prev_row_cumsum - self.is_first.clone() * self.total_sum;
-        let diff = cur_cumsum - fixed_prev_row_cumsum - self.prev_col_cumsum.clone();
-
-        eval.add_constraint(diff * frac.denominator - frac.numerator);
-
-        self.is_finalized = true;
-    }
 }
 
 /// Ensures that the LogupAtRow is finalized.
@@ -314,30 +274,11 @@ impl<'a> LogupColGenerator<'a> {
 
 #[cfg(test)]
 mod tests {
-    use num_traits::One;
-
-    use super::{LogupAtRow, LookupElements};
-    use crate::constraint_framework::{InfoEvaluator, INTERACTION_TRACE_IDX};
+    use super::LookupElements;
     use crate::core::channel::Blake2sChannel;
     use crate::core::fields::m31::BaseField;
     use crate::core::fields::qm31::SecureField;
     use crate::core::fields::FieldExpOps;
-    use crate::core::lookups::utils::Fraction;
-
-    #[test]
-    #[should_panic]
-    fn test_logup_not_finalized_panic() {
-        let mut logup = LogupAtRow::<InfoEvaluator>::new(
-            INTERACTION_TRACE_IDX,
-            SecureField::one(),
-            None,
-            BaseField::one(),
-        );
-        logup.write_frac(
-            &mut InfoEvaluator::default(),
-            Fraction::new(SecureField::one(), SecureField::one()),
-        );
-    }
 
     #[test]
     fn test_lookup_elements_combine() {