chore: use a constant for log2(num_limbs)

Author: jonathanpwang

Cargo.lock

@@ -30,6 +30,7 @@ num-bigint.workspace = true
 num-integer.workspace = true
 serde = { workspace = true, features = ["derive", "std"] }
 serde-big-array.workspace = true
+static_assertions.workspace = true
 
 [dev-dependencies]
 openvm-stark-sdk = { workspace = true }

extensions/rv32im/circuit/Cargo.toml

@@ -36,12 +36,12 @@ use openvm_stark_backend::{
     p3_air::{Air, AirBuilder, BaseAir},
     p3_field::{Field, FieldAlgebra, PrimeField32},
     p3_matrix::{dense::RowMajorMatrix, Matrix},
-    p3_util::log2_strict_usize,
     prover::types::AirProofInput,
     rap::{AnyRap, BaseAirWithPublicValues, PartitionedBaseAir},
     Chip, ChipUsageGetter,
 };
 use serde::{Deserialize, Serialize};
+use static_assertions::const_assert_eq;
 
 use crate::adapters::{compose, decompose};
 
@@ -89,6 +89,9 @@ impl<F: Field> BaseAir<F> for Rv32HintStoreAir {
 impl<F: Field> BaseAirWithPublicValues<F> for Rv32HintStoreAir {}
 impl<F: Field> PartitionedBaseAir<F> for Rv32HintStoreAir {}
 
+const LOG2_RV32_REGISTER_NUM_LIMBS: usize = 2;
+const_assert_eq!(1 << LOG2_RV32_REGISTER_NUM_LIMBS, RV32_REGISTER_NUM_LIMBS);
+
 impl<AB: InteractionBuilder> Air<AB> for Rv32HintStoreAir {
     fn eval(&self, builder: &mut AB) {
         let main = builder.main();
@@ -235,7 +238,7 @@ impl<AB: InteractionBuilder> Air<AB> for Rv32HintStoreAir {
             .range_check::<AB::Expr>(
                 local_cols.mem_ptr_limbs[0]
                     * AB::F::from_canonical_usize(RV32_REGISTER_NUM_LIMBS).inverse(),
-                RV32_CELL_BITS - log2_strict_usize(RV32_REGISTER_NUM_LIMBS),
+                RV32_CELL_BITS - LOG2_RV32_REGISTER_NUM_LIMBS,
             )
             .eval(builder, is_start.clone());
         // We only check this on `is_start` since it is implied on non-start rows by the next_mem_ptr = mem_ptr + 4 constraint below
@@ -482,8 +485,8 @@ impl<F: PrimeField32> Rv32HintStoreChip<F> {
             rem_words_msl << (RV32_REGISTER_NUM_LIMBS * RV32_CELL_BITS - pointer_max_bits),
         );
         memory.range_checker().add_count(
-            (mem_ptr & ((1 << RV32_CELL_BITS) - 1)) >> 2,
-            RV32_CELL_BITS - 2,
+            (mem_ptr & ((1 << RV32_CELL_BITS) - 1)) >> LOG2_RV32_REGISTER_NUM_LIMBS,
+            RV32_CELL_BITS - LOG2_RV32_REGISTER_NUM_LIMBS,
         );
         for (i, &(data, write)) in record.hints.iter().enumerate() {
             for half in 0..(RV32_REGISTER_NUM_LIMBS / 2) {