Rename mix_nonce -> mix_u64 (#828)

crates/prover/src/core/backend/cpu/grind.rs

@@ -8,7 +8,7 @@ impl<C: Channel> GrindOps<C> for CpuBackend {
         let mut nonce = 0;
         loop {
             let mut channel = channel.clone();
-            channel.mix_nonce(nonce);
+            channel.mix_u64(nonce);
             if channel.trailing_zeros() >= pow_bits {
                 return nonce;
             }

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

@@ -69,7 +69,7 @@ impl GrindOps<Poseidon252Channel> for SimdBackend {
         let mut nonce = 0;
         loop {
             let mut channel = channel.clone();
-            channel.mix_nonce(nonce);
+            channel.mix_u64(nonce);
             if channel.trailing_zeros() >= pow_bits {
                 return nonce;
             }

crates/prover/src/core/channel/blake2s.rs

@@ -67,7 +67,7 @@ impl Channel for Blake2sChannel {
         self.update_digest(hasher.finalize());
     }
 
-    fn mix_nonce(&mut self, nonce: u64) {
+    fn mix_u64(&mut self, nonce: u64) {
         let digest: [u32; 8] = unsafe { std::mem::transmute(self.digest) };
         let mut msg = [0; 16];
         msg[0] = nonce as u32;

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

@@ -35,7 +35,7 @@ pub trait Channel: Default + Clone {
 
     // Mix functions.
     fn mix_felts(&mut self, felts: &[SecureField]);
-    fn mix_nonce(&mut self, nonce: u64);
+    fn mix_u64(&mut self, value: u64);
 
     // Draw functions.
     fn draw_felt(&mut self) -> SecureField;

crates/prover/src/core/channel/poseidon252.rs

@@ -81,7 +81,7 @@ impl Channel for Poseidon252Channel {
         self.update_digest(poseidon_hash_many(&res));
     }
 
-    fn mix_nonce(&mut self, nonce: u64) {
+    fn mix_u64(&mut self, nonce: u64) {
         self.update_digest(poseidon_hash(self.digest, nonce.into()));
     }
 

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

@@ -123,7 +123,7 @@ impl<'a, B: BackendForChannel<MC>, MC: MerkleChannel> CommitmentSchemeProver<'a,
         let span1 = span!(Level::INFO, "Grind").entered();
         let proof_of_work = B::grind(channel, self.config.pow_bits);
         span1.exit();
-        channel.mix_nonce(proof_of_work);
+        channel.mix_u64(proof_of_work);
 
         // FRI decommitment phase.
         let (fri_proof, fri_query_domains) = fri_prover.decommit(channel);

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

@@ -82,7 +82,7 @@ impl<MC: MerkleChannel> CommitmentSchemeVerifier<MC> {
             FriVerifier::<MC>::commit(channel, self.config.fri_config, proof.fri_proof, bounds)?;
 
         // Verify proof of work.
-        channel.mix_nonce(proof.proof_of_work);
+        channel.mix_u64(proof.proof_of_work);
         if channel.trailing_zeros() < self.config.pow_bits {
             return Err(VerificationError::ProofOfWork);
         }

crates/prover/src/examples/blake/air.rs

@@ -55,8 +55,7 @@ impl BlakeStatement0 {
         TreeVec::concat_cols(sizes.into_iter())
     }
     fn mix_into(&self, channel: &mut impl Channel) {
-        // TODO(spapini): Do this better.
-        channel.mix_nonce(self.log_size as u64);
+        channel.mix_u64(self.log_size as u64);
     }
 }