parallel sha256

crates/prover/Cargo.toml

@@ -4,6 +4,7 @@ version.workspace = true
 edition.workspace = true
 
 [features]
+default = ["parallel"]
 parallel = ["rayon"]
 small_blowup = []
 tiny_blowup = []

crates/prover/src/core/backend/simd/sha256.rs

@@ -1,4 +1,6 @@
 use itertools::Itertools;
+#[cfg(feature = "parallel")]
+use rayon::prelude::*;
 
 use crate::core::backend::simd::column::BaseColumn;
 use crate::core::backend::simd::SimdBackend;
@@ -22,13 +24,18 @@ impl MerkleOps<BWSSha256MerkleHasher> for SimdBackend {
         prev_layer: Option<&Vec<BWSSha256Hash>>,
         columns: &[&BaseColumn],
     ) -> Vec<BWSSha256Hash> {
-        return (0..1 << log_size)
-            .map(|i| {
-                BWSSha256MerkleHasher::hash_node(
-                    prev_layer.map(|prev_layer| (prev_layer[2 * i], prev_layer[2 * i + 1])),
-                    &columns.iter().map(|column| column.at(i)).collect_vec(),
-                )
-            })
-            .collect();
+        #[cfg(not(feature = "parallel"))]
+        let iter = 0..1 << log_size;
+
+        #[cfg(feature = "parallel")]
+        let iter = (0..1 << log_size).into_par_iter();
+
+        iter.map(|i| {
+            BWSSha256MerkleHasher::hash_node(
+                prev_layer.map(|prev_layer| (prev_layer[2 * i], prev_layer[2 * i + 1])),
+                &columns.iter().map(|column| column.at(i)).collect_vec(),
+            )
+        })
+        .collect()
     }
 }

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

@@ -23,7 +23,9 @@ use crate::core::vcs::ops::MerkleOps;
 use crate::core::vcs::verifier::MerkleVerificationError;
 
 #[cfg(all(feature = "tiny_blowup", feature = "small_blowup"))]
-compile_error!("feature \"tiny_blowup\" and feature \"small_blowup\" cannot be enabled at the same time");
+compile_error!(
+    "feature \"tiny_blowup\" and feature \"small_blowup\" cannot be enabled at the same time"
+);
 
 #[cfg(not(any(feature = "small_blowup", feature = "tiny_blowup")))]
 pub const LOG_BLOWUP_FACTOR: u32 = 10;