From 7d9ed98019cb3995aacbc49dbae8e17127b17057 Mon Sep 17 00:00:00 2001
From: Qian Bin <cola.tin.com@gmail.com>
Date: Wed, 11 May 2022 17:00:29 +0800
Subject: [PATCH] core/vm: optimize Memory.Set32 (#24847)

* core/vm: remove unnecessary memset for Memory.Set32

* core/vm: optimize Memory.Set32
---
 core/vm/memory.go | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/core/vm/memory.go b/core/vm/memory.go
index 7db2308187bf..35b729996075 100644
--- a/core/vm/memory.go
+++ b/core/vm/memory.go
@@ -53,10 +53,9 @@ func (m *Memory) Set32(offset uint64, val *uint256.Int) {
 	if offset+32 > uint64(len(m.store)) {
 		panic("invalid memory: store empty")
 	}
-	// Zero the memory area
-	copy(m.store[offset:offset+32], []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})
 	// Fill in relevant bits
-	val.WriteToSlice(m.store[offset:])
+	b32 := val.Bytes32()
+	copy(m.store[offset:], b32[:])
 }
 
 // Resize resizes the memory to size