From e28e02ecd40dadf70caae78e18bc2ca9adba2169 Mon Sep 17 00:00:00 2001
From: John Tromp <john.tromp@gmail.com>
Date: Mon, 8 Jun 2020 23:04:06 +0200
Subject: [PATCH] simplify by avoiding unnecessary conversions (#3343)

---
 core/src/pow/cuckaroo.rs  | 10 ++++------
 core/src/pow/cuckarood.rs | 12 +++++-------
 core/src/pow/cuckaroom.rs | 20 +++++++++-----------
 core/src/pow/cuckarooz.rs | 10 ++++------
 4 files changed, 22 insertions(+), 30 deletions(-)

diff --git a/core/src/pow/cuckaroo.rs b/core/src/pow/cuckaroo.rs
index 88311dfaff..2f4f62fc7b 100644
--- a/core/src/pow/cuckaroo.rs
+++ b/core/src/pow/cuckaroo.rs
@@ -76,6 +76,7 @@ where
 		let mut uvs = vec![0u64; 2 * proof.proof_size()];
 		let mut xor0: u64 = 0;
 		let mut xor1: u64 = 0;
+		let node_mask: u64 = to_u64!(self.params.edge_mask);
 
 		for n in 0..proof.proof_size() {
 			if nonces[n] > to_u64!(self.params.edge_mask) {
@@ -85,13 +86,10 @@ where
 				return Err(ErrorKind::Verification("edges not ascending".to_owned()).into());
 			}
 			// 21 is standard siphash rotation constant
-			let edge = to_edge!(
-				T,
-				siphash_block(&self.params.siphash_keys, nonces[n], 21, false)
-			);
-			uvs[2 * n] = to_u64!(edge & self.params.edge_mask);
-			uvs[2 * n + 1] = to_u64!((edge >> 32) & self.params.edge_mask);
+			let edge: u64 = siphash_block(&self.params.siphash_keys, nonces[n], 21, false);
+			uvs[2 * n] = edge & node_mask;
 			xor0 ^= uvs[2 * n];
+			uvs[2 * n + 1] = (edge >> 32) & node_mask;
 			xor1 ^= uvs[2 * n + 1];
 		}
 		if xor0 | xor1 != 0 {
diff --git a/core/src/pow/cuckarood.rs b/core/src/pow/cuckarood.rs
index c5fb8c9246..a4e1e00dc3 100644
--- a/core/src/pow/cuckarood.rs
+++ b/core/src/pow/cuckarood.rs
@@ -76,7 +76,7 @@ where
 		let mut ndir = vec![0usize; 2];
 		let mut xor0: u64 = 0;
 		let mut xor1: u64 = 0;
-		let nodemask = self.params.edge_mask >> 1;
+		let node_mask: u64 = to_u64!(self.params.edge_mask) >> 1;
 
 		for n in 0..proof.proof_size() {
 			let dir = (nonces[n] & 1) as usize;
@@ -89,14 +89,12 @@ where
 			if n > 0 && nonces[n] <= nonces[n - 1] {
 				return Err(ErrorKind::Verification("edges not ascending".to_owned()).into());
 			}
-			let edge = to_edge!(
-				T,
-				siphash_block(&self.params.siphash_keys, nonces[n], 25, false)
-			);
+			// cuckarood uses a non-standard siphash rotation constant 25 as anti-ASIC tweak
+			let edge: u64 = siphash_block(&self.params.siphash_keys, nonces[n], 25, false);
 			let idx = 4 * ndir[dir] + 2 * dir;
-			uvs[idx] = to_u64!(edge & nodemask);
-			uvs[idx + 1] = to_u64!((edge >> 32) & nodemask);
+			uvs[idx] = edge & node_mask;
 			xor0 ^= uvs[idx];
+			uvs[idx + 1] = (edge >> 32) & node_mask;
 			xor1 ^= uvs[idx + 1];
 			ndir[dir] += 1;
 		}
diff --git a/core/src/pow/cuckaroom.rs b/core/src/pow/cuckaroom.rs
index 7600250931..82f9f36bb7 100644
--- a/core/src/pow/cuckaroom.rs
+++ b/core/src/pow/cuckaroom.rs
@@ -72,11 +72,11 @@ where
 			return Err(ErrorKind::Verification("wrong cycle length".to_owned()).into());
 		}
 		let nonces = &proof.nonces;
-		let mut from = vec![0u32; proofsize];
-		let mut to = vec![0u32; proofsize];
-		let mut xor_from: u32 = 0;
-		let mut xor_to: u32 = 0;
-		let nodemask = self.params.edge_mask >> 1;
+		let mut from = vec![0u64; proofsize];
+		let mut to = vec![0u64; proofsize];
+		let mut xor_from: u64 = 0;
+		let mut xor_to: u64 = 0;
+		let node_mask: u64 = to_u64!(self.params.edge_mask) >> 1;
 
 		for n in 0..proofsize {
 			if nonces[n] > to_u64!(self.params.edge_mask) {
@@ -85,13 +85,11 @@ where
 			if n > 0 && nonces[n] <= nonces[n - 1] {
 				return Err(ErrorKind::Verification("edges not ascending".to_owned()).into());
 			}
-			let edge = to_edge!(
-				T,
-				siphash_block(&self.params.siphash_keys, nonces[n], 21, true)
-			);
-			from[n] = to_u32!(edge & nodemask);
+			// 21 is standard siphash rotation constant
+			let edge: u64 = siphash_block(&self.params.siphash_keys, nonces[n], 21, true);
+			from[n] = edge & node_mask;
 			xor_from ^= from[n];
-			to[n] = to_u32!((edge >> 32) & nodemask);
+			to[n] = (edge >> 32) & node_mask;
 			xor_to ^= to[n];
 		}
 		if xor_from != xor_to {
diff --git a/core/src/pow/cuckarooz.rs b/core/src/pow/cuckarooz.rs
index 6781be8a2a..74d73e0c15 100644
--- a/core/src/pow/cuckarooz.rs
+++ b/core/src/pow/cuckarooz.rs
@@ -74,6 +74,7 @@ where
 		let nonces = &proof.nonces;
 		let mut uvs = vec![0u64; 2 * proof.proof_size()];
 		let mut xoruv: u64 = 0;
+		let node_mask: u64 = to_u64!(self.params.edge_mask) << 1 | 1;
 
 		for n in 0..proof.proof_size() {
 			if nonces[n] > to_u64!(self.params.edge_mask) {
@@ -83,12 +84,9 @@ where
 				return Err(ErrorKind::Verification("edges not ascending".to_owned()).into());
 			}
 			// 21 is standard siphash rotation constant
-			let edge = to_edge!(
-				T,
-				siphash_block(&self.params.siphash_keys, nonces[n], 21, true)
-			);
-			uvs[2 * n] = to_u64!(edge & self.params.edge_mask);
-			uvs[2 * n + 1] = to_u64!((edge >> 32) & self.params.edge_mask);
+			let edge: u64 = siphash_block(&self.params.siphash_keys, nonces[n], 21, true);
+			uvs[2 * n] = edge & node_mask;
+			uvs[2 * n + 1] = (edge >> 32) & node_mask;
 			xoruv ^= uvs[2 * n] ^ uvs[2 * n + 1];
 		}
 		if xoruv != 0 {