From f5fa48311f457276a6d156f1e40cd262f08dd073 Mon Sep 17 00:00:00 2001
From: xtaci <imap@live.com>
Date: Wed, 15 May 2019 16:14:14 +0800
Subject: [PATCH] save 1-loc

---
 alloc.go      |  7 +++----
 alloc_test.go | 11 ++++++++++-
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/alloc.go b/alloc.go
index 831f66d..3b02cb0 100644
--- a/alloc.go
+++ b/alloc.go
@@ -55,11 +55,10 @@ func (alloc *Allocator) Put(buf []byte) error {
 // msb return the pos of most significiant bit
 func msb(size int) uint16 {
 	var pos uint16
-	for {
+	size >>= 1
+	for size > 0 {
 		size >>= 1
-		if size == 0 {
-			return pos
-		}
 		pos++
 	}
+	return pos
 }
diff --git a/alloc_test.go b/alloc_test.go
index 3e1a2b3..e8b27e5 100644
--- a/alloc_test.go
+++ b/alloc_test.go
@@ -1,6 +1,9 @@
 package smux
 
-import "testing"
+import (
+	"math/rand"
+	"testing"
+)
 
 func TestAllocGet(t *testing.T) {
 	alloc := NewAllocator()
@@ -70,3 +73,9 @@ func TestAllocPutThenGet(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkMSB(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		msb(rand.Int())
+	}
+}