From 225d0095b3c19376fe3999f0ffa528225c1c8c76 Mon Sep 17 00:00:00 2001
From: cuiweixie <cuiweixie@gmail.com>
Date: Sun, 12 Oct 2025 20:00:44 +0800
Subject: [PATCH 1/2] p2p/enode: opt LogDist

---
 p2p/enode/node.go      | 15 ++++++++++-----
 p2p/enode/node_test.go | 22 ++++++++++++++++++++++
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/p2p/enode/node.go b/p2p/enode/node.go
index d6f2ac7ff562..5ea8d288ecc3 100644
--- a/p2p/enode/node.go
+++ b/p2p/enode/node.go
@@ -19,6 +19,7 @@ package enode
 import (
 	"crypto/ecdsa"
 	"encoding/base64"
+	"encoding/binary"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -372,15 +373,19 @@ func DistCmp(target, a, b ID) int {
 
 // LogDist returns the logarithmic distance between a and b, log2(a ^ b).
 func LogDist(a, b ID) int {
+	lenA := len(a)
+	totalBits := lenA * 8
 	lz := 0
-	for i := range a {
-		x := a[i] ^ b[i]
+	for i := 0; i < lenA; i += 8 {
+		ai := binary.BigEndian.Uint64(a[i : i+8])
+		bi := binary.BigEndian.Uint64(b[i : i+8])
+		x := ai ^ bi
 		if x == 0 {
-			lz += 8
+			lz += 64
 		} else {
-			lz += bits.LeadingZeros8(x)
+			lz += bits.LeadingZeros64(x)
 			break
 		}
 	}
-	return len(a)*8 - lz
+	return totalBits - lz
 }
diff --git a/p2p/enode/node_test.go b/p2p/enode/node_test.go
index e9fe631f3459..f276af663883 100644
--- a/p2p/enode/node_test.go
+++ b/p2p/enode/node_test.go
@@ -378,6 +378,28 @@ func TestID_logdist(t *testing.T) {
 	}
 }
 
+func makeIDs() (ID, ID) {
+	var a, b ID
+	size := len(a)
+	// last byte differs
+	for i := 0; i < size-1; i++ {
+		a[i] = 0xAA
+		b[i] = 0xAA
+	}
+	a[size-1] = 0xAA
+	b[size-1] = 0xAB
+	return a, b
+}
+
+// Benchmark LogDist
+func BenchmarkLogDist(b *testing.B) {
+	aID, bID := makeIDs() // 256-bit ID
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = LogDist(aID, bID)
+	}
+}
+
 // The random tests is likely to miss the case where a and b are equal,
 // this test checks it explicitly.
 func TestID_logdistEqual(t *testing.T) {

From 250ad041e5eacc5d1c9709fff2e596ae67ebb87b Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Mon, 13 Oct 2025 13:09:12 +0200
Subject: [PATCH 2/2] Revert variable addition

---
 p2p/enode/node.go | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/p2p/enode/node.go b/p2p/enode/node.go
index 5ea8d288ecc3..8198050353bd 100644
--- a/p2p/enode/node.go
+++ b/p2p/enode/node.go
@@ -373,10 +373,8 @@ func DistCmp(target, a, b ID) int {
 
 // LogDist returns the logarithmic distance between a and b, log2(a ^ b).
 func LogDist(a, b ID) int {
-	lenA := len(a)
-	totalBits := lenA * 8
 	lz := 0
-	for i := 0; i < lenA; i += 8 {
+	for i := 0; i < len(a); i += 8 {
 		ai := binary.BigEndian.Uint64(a[i : i+8])
 		bi := binary.BigEndian.Uint64(b[i : i+8])
 		x := ai ^ bi
@@ -387,5 +385,5 @@ func LogDist(a, b ID) int {
 			break
 		}
 	}
-	return totalBits - lz
+	return len(a)*8 - lz
 }